Rather than call this a tech page, lets call this a useful "tid-bits" page.  
We do not see any reason to talk about Hondas timelines and changes they made unless its useful.
We do not see any reason to copy and paste a bunch of tech articles about theories that do not pertain to the Honda cb750 engine.

 

 

 

Honda SOHC High Performance Camshaft Details
 
Camshafts always raise a lot of questions: What kind of performance do you expect? What kind of top end power do you expect?
What kind of riding do you do? What kind of valve relief do your pistons have?
Below are some camshaft profiles you will enjoy without the headaches that monster cams can produce without background and experience behind you.

(Click pics above for an expanded view)

Here is the problem...

With 11 Cycle X Honda CB750 camshafts and more to come, camshaft installation knowledge would be helpful to your machine shop and to the customer knowing what to buy. 

For example: Unless a "drop-in" camshaft is being installed. The machine shop or cylinder head assembler will need to know which camshaft is being used. Some of the most common heartbreak stories we hear from the public is that a customer had their head ported with oversize valves and all the latest, greatest parts and the valves collided because the the camshaft was chosen lastly. With most "big boy" camshafts, valve to valve clearance and also valve guide seal to top spring retainer clearances are very important but are taken for granted occasionally and a catastrophic situation occurs. The Cycle X high-lift valve guides prevent the top spring retainer from hitting and the valve guide seal from falling inside the keeper groove area of the valve stem and cause potential oil usage. We don't want to get long winded about the well documented procedures with cam clearances and installation procedures. So, here is what we are doing...

  • All of our camshafts will now have valve to valve clearances with stock size valves.
  • All valve to valve clearances with oversize valves with all the cams and how far to sink the valves.
  • All camshafts that will require "high-lift" valve guides.
  • Installed heights and spring pressures for those heights.
  • This knowledge will allow you to change camshafts for performance desires without possibly doing all the mathematics again.
  • This knowledge will allow you to keep the sinking of the valves to a minimum and losing precious flow numbers.

 


 

 

 

We will be referring to this measurement when preparing a cylinder head for sunken valves.
"Valve stem protrusion"
Note:
Valve stem protrusion on a stock cylinder head with stock valves is about 1.700ish.

This measurement is mainly referring to spring pressures.
"Installed height"
Note:
"Installed height" measurements specs will be seen on most valve spring packages. For reference, stock cylinder head, valves and spring installed height is 1.455ish.

This photo simply shows valve to valve measuring location when big camshafts, oversize valves or both are being considered.
"Valve to valve"
You will need a minimum of .040 valve to valve clearance.
 

Honda CB750 SOHC High Performance Valve Springs & Details

This section will provide some basic guidelines, spring pressure comparisons and recommendations for some of the larger camshafts listed below.
Installed heights and such are a good start. But, installed height seat lbs is what we are going to focus on right now.
Generally speaking, the goal is to have 75-90 lbs of seat pressure with most performance camshafts.

A small comparison:
Stock K model valve spring installed height (1.455ish) seat pressure lbs (no shims)
50 lbs
Stock 77-78 F model valve spring installed height (1.455ish) seat pressure lbs (no shims)
60 lbs

Valve weight will also be a factor in making spring pressure decisions.
These valve weights are for Cycle X valves:
F2 intake: 47.5 grams.
F2 exhaust: 47 grams.
K intake: 45.5 grams.
K exhaust: 41 grams.
K oversize 33.5 intake: 49 grams.
5mm Kibblewhite 34mm intake: 38 grams
5mm Kibblewhite std exhaust: 29 grams
 
Note:
Do not use OEM stock upper valve spring retainers with higher pressure springs and performance camshafts on 77-78 "F" super sport models.


 

 


 

High Performance Valve Springs
(K & F models)


These Kibblewhite valve springs are the most common valve springs used by Honda CB750 SOHC (69-78) owners for years and years.

Stock valve spring installed height (1.455ish) spring pressures with these Kibblewhite ENV-008 springs are:
65lbs (no shims)
80lbs (.060 copper shims)
180lbs @ 375 lift (no shims)
200lbs @ 375 lift (.060 copper shims)

Kit includes:
(8) .060 shims
(16) .015 shims


ENV-008     $69.95

 

 

 


 

Precision Valve Train Springs, Titanium Retainers and Matching Keepers.
Kit #1

These kits are the ultimate in precision and weight reduction.

Race proven and a must for higher RPM situations.
Check spring specs for your application below (ENV-009)
 

Kit includes:
Titanium top spring retainers.
Precision matching keepers.
High lift Cycle X / Kibblewhite spring set. (ENV-009)


ENV-KIT1     $290.00


 

 

 

 


 

Precision Valve Train Springs, Titanium Retainers and Matching Keepers.
Kit #2

Same as above at a reduced price.
Check spring specs for your application below (ENV-008) 


Kit includes:
Titanium top spring retainers.
Precision matching keepers.
High lift Cycle X / Kibblewhite spring set. (ENV-008)



ENV-KIT2    $250.00


 

 

 

 


 

Precision Valve Train Springs, Titanium Retainers, Titanium Adjustor Jam Nuts and Matching Keepers.
Kit #3

This kit is upgraded with hard welded rocker arms.

Race proven by people who actually race!

Kit includes:
Hard welded rocker arms.
High lift valve springs.
Titanium top retainers.
Matching valve spring keepers.
Titanium adjustor jam nuts.

Retail - $899.00


ENV-KIT3     $799.00

Call for availability.

 

 

 


 

Precision Valve Train Springs, Titanium Retainers, Titanium Adjustor Jam Nuts and Matching Keepers.
Kit #4

This kit is upgraded with hard welded rocker arms.

Same as above at a reduced price.

Kit includes:
Hard welded rocker arms.
High lift valve springs.
Titanium top retainers.
Matching valve spring keepers.
Titanium adjustor jam nuts.

Retail - $859.00


ENV-KIT4     $759.00

Call for availability.

 

 

 

 


 

High Performance Valve Springs for Large Camshafts (K & F models)

 These Cycle X, Kibblewhite valve springs are the favorite around here and with many pros worldwide. They are used exclusively when high-lift cams require valve sinking for valve to valve clearances. The reason these springs are used is they will not require piles of spring shims to get desired pressures.

So, stock valve spring installed height (1.455ish) spring pressures with Cycle X, Kibblewhite ENV-009 springs are:
85lbs (no shims)
90lbs (.015 shim)
105lbs (.060 shim)
75lbs with .030 sunken valves (K & F models)

Kit includes:
(8) .060 shims
(16) .015 shims

ENV-009     $109.00

 

 

 

 

The Highest Level Bee-Hive Valve Springs

These bee hive spring sets are manufactured by Kibblewhite for Cycle X years ago and are installed in some of the fastest Hondas worldwide. Combined with titanium rocker arm adjustor jam nuts and lightened rocker arms. You will have the best current valve train combination available.
Well, combine the 5mm valve kit to have the ultimate combination.
Installed height: 1.370 - 1.380.
Seat pressure: 90-95lbs.
Open pressure at 0.460 lift: 220lbs
Max lift: 0.460.
Specify "K" or "F" model.


ENV-010K for "K" models     $239.00


ENV-010F for 77-78 "F" models     $239.00


ENV-010-5MM for Kibblewhite 5mm kits     $239.00

 

 

 

 

 

 

 

 

(77-78) Honda CB750 F2, F3 Valve Spring and Retainer Combo

These Cycle X, Kibblewhite valve springs are the favorite around here and with many pros worldwide. They are used exclusively when high-lift cams require valve sinking for valve to valve clearances. The reason these springs are used is they will not require piles of spring shims to get desired pressures. So, stock valve spring installed height (1.455ish) spring pressures with Cycle X, Kibblewhite ENV-009 springs are:
85lbs (no shims)
90lbs (.015 shim)
105lbs (.060 shim)
75lbs with .030 sunken valves (K & F models)

Caution:
Honda CB750 77-78 K's and especially F2's have the potential of the keepers pulling through the top spring retainers and dropping the valve into the motor. Many people have felt this heartbreak for the past 30+ years. Honda's later model spring retainers are stamped steel, combined with a steep keeper angle, has only been addressed by complete spring kits costing hundreds of dollars, until now.

 We have been working with Kibblewhite and have developed these top retainers to cure this problem once and for all at a reduced cost. Heat is a problem in the F2 valve tranes, these new lightweight top spring retainers feature 8 holes on the top of the retainer. The purpose for these holes is to allow oil to drip down the springs to help with heat dispersion. Keep in mind, oil lubricates, picks up heat and carries it away to coolers and such. People in NASCAR use the same technique and it helps keep the valves well lubricated for longer life. These retainers are made from heat treated carbon steel for durability and strength. 11.25 grams per retainer!

ENV-011     Combo - $210.00

 

ENV-F2R     Retainers only - $119.00

 

 

 

Budget High Performance F2, F3 Spring and Top Retainer Combo

This high performance combo kit is similar to above, but a budget version. This kit includes ENV-008 and ENV-011.

Kit includes:
(8) .060 shims
(16) .015 shims

ENV-013     $178.00

 

 

 

 

 

Under construction. More tech info coming soon.

For Advice Please Call (715) 356-7346

 

Camshafts

Disclaimer:
The values, specifications, spring pressures and clearances listed above and below are a good start to your Honda CB750 go-fast project. Results may vary.

 

Drop-in Camshaft

No valve to valve or valve to piston checking needed.

These 975, 990 and 1000 camshafts are all drop-in camshafts with ever-so-slight differences in characteristics that many people never notice. Check out the specifications or call for further advice.
By the way, these drop-in camshafts might be the easiest install and best bang-for-the buck when it comes to performance upgrades.
Very similar to the CX-1.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (77-78); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.328

0.325

DURATION @ .0.050":

227

228

LOBE CENTER:

112.5

103

 

INTAKE OPENS     1     BEFORE TDC

EXHAUST OPENS     37     BEFORE BDC

INTAKE CLOSES     46     AFTER BDC

EXHAUST CLOSES     11     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

NOTE: This camshaft is considered a drop-in or a bolt-in grind.
Valve to valve, Valve to piston, Valve drop at TDC and all the other performance checks and procedures are generally not needed.
 
"Generally" not needed?
 
Well, if someone has milled the head or cylinder, used bigger intake and exhaust valves, used stock pistons, used thinner gaskets and such, checking will be needed.
 

CX1-R-975     $265.00

Drop-in Camshaft

No valve to valve or valve to piston checking needed.

These 975, 990 and 1000 camshafts are all drop-in camshafts with ever-so-slight differences in characteristics that many people never notice. Check out the specifications or call for further advice.
By the way, these drop-in camshafts might be the easiest install and best bang-for-the buck when it comes to performance upgrades.
Very similar to the CX-1.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (77-78); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.328

0.328

DURATION @ .0.050":

228.5

229

LOBE CENTER:

109.25

105.5

 

INTAKE OPENS     15     BEFORE TDC

EXHAUST OPENS     40     BEFORE BDC

INTAKE CLOSES     43.5     AFTER BDC

EXHAUST CLOSES     9     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

NOTE: This camshaft is considered a drop-in or a bolt-in grind.
Valve to valve, Valve to piston, Valve drop at TDC and all the other performance checks and procedures are generally not needed.
 
"Generally" not needed?
 
Well, if someone has milled the head or cylinder, used bigger intake and exhaust valves, used stock pistons, used thinner gaskets and such, checking will be needed.

 

CX1-R-990     $265.00

 

Drop-in Camshaft

No valve to valve or valve to piston checking needed.

These 975, 990 and 1000 camshafts are all drop-in camshafts with ever-so-slight differences in characteristics that many people never notice. Check out the specifications or call for further advice.
By the way, these drop-in camshafts might be the easiest install and best bang-for-the buck when it comes to performance upgrades.
Very similar to the CX-1.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (77-78); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.328

0.328

DURATION @ .0.050":

228

228

LOBE CENTER:

107

107

 

INTAKE OPENS     7     BEFORE TDC

EXHAUST OPENS     41     BEFORE BDC

INTAKE CLOSES     41     AFTER BDC

EXHAUST CLOSES     7     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

NOTE: This camshaft is considered a drop-in or a bolt-in grind.
Valve to valve, Valve to piston, Valve drop at TDC and all the other performance checks and procedures are generally not needed.
 
"Generally" not needed?
 
Well, if someone has milled the head or cylinder, used bigger intake and exhaust valves, used stock pistons, used thinner gaskets and such, checking will be needed.

 

CX1-R-1000     $265.00

 





 

Drop-in Camshaft

No valve to valve or valve to piston checking needed.

Kenny Harman "D" grind. OK with stock pistons. Use HD springs. Mid-range and some top-end.
Longer exhaust duration allows for cooler combustion chambers.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (75-76); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.345

0.327

DURATION @ .0.050":

277

294

LOBE CENTER:

106.5

110

 

INTAKE OPENS     32     BEFORE TDC

EXHAUST OPENS     77     BEFORE BDC

INTAKE CLOSES     65     AFTER BDC

EXHAUST CLOSES     37     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

NOTE: This camshaft is considered a drop-in or a bolt-in grind.
Valve to valve, Valve to piston, Valve drop at TDC and all the other performance checks and procedures are generally not needed.
 
"Generally" not needed?
 
Well, if someone has milled the head or cylinder, used bigger intake and exhaust valves, used stock pistons, used thinner gaskets and such, checking will be needed.
 

KHD CX-1     $299.00

Drop-in Camshaft

No valve to valve or valve to piston checking needed.

Broad power range. This cam will bolt right in stock engines. You will notice good power increase with this one. This camshaft profile was used on tight road-race tracks. You will like it. Made For Cycle X by Web Cam. Equivalent to their 41 Cam.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F (75-76); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.340

0.340

DURATION @ .0.050":

229

229

LOBE CENTER:

103

103

 

INTAKE OPENS     11.5     BEFORE TDC

EXHAUST OPENS     37.5     BEFORE BDC

INTAKE CLOSES     37.5     AFTER BDC

EXHAUST CLOSES     11.5     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

NOTE: This camshaft is considered a drop-in or a bolt-in grind.

Valve to valve, Valve to piston, Valve drop at TDC and all the other performance checks and procedures are generally not needed.

"Generally" not needed?

Well, if someone has milled the head or cylinder, used bigger intake and exhaust valves, used stock pistons, used thinner gaskets and such, checking will be needed.

 

CX-1     $299.00

 

 

Drop-in Camshaft

No valve to valve or valve to piston checking needed.

Need a little more power? We have used this camshaft profile in stock displacement motors but check carefully. Works well with 836cc kits. Made for Cycle X by Web Cam. Equivalent to a 41A.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F (75-76); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.345

0.345

DURATION @ .0.050":

235

235

LOBE CENTER:

95.5

99.5*

* = 97.5 overall

 

INTAKE OPENS     22     BEFORE TDC

EXHAUST OPENS     37     BEFORE BDC

INTAKE CLOSES     33     AFTER BDC

EXHAUST CLOSES     18     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

NOTE: This camshaft is considered a drop-in or a bolt-in grind.

Valve to valve, Valve to piston, Valve drop at TDC and all the other performance checks and procedures are generally not needed.

"Generally" not needed?

Well, if someone has milled the head or cylinder, used bigger intake and exhaust valves, used stock pistons, used thinner gaskets and such, checking will be needed.

 

CX-2     $299.00

Call for availability.

 

 

Here is a great cam for your 836cc hot street motor. Springs, big bore kit will be needed to utilize this cams potential. Made for Cycle X by Web Cam. Equivalent to a 63A.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F (75-76); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.355

0.355

DURATION @ .0.050":

251

250

LOBE CENTER:

98

99*

* = 98.5 overall

 

INTAKE OPENS     27.5     BEFORE TDC

EXHAUST OPENS     44     BEFORE BDC

INTAKE CLOSES     43.5     AFTER BDC

EXHAUST CLOSES     26     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.
 

MAKE  
MODEL  
YEAR  
CAMSHAFT  
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

 

MAKE  
MODEL  
YEAR  
CAMSHAFT  
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

 

MAKE  
MODEL  
YEAR  
CAMSHAFT  
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

Additional tech info coming soon.

CX-3     $299.00

 

 

 

Strong mid and top end power for street-strip. Use with big bore, headers, and valve springs. Made for Cycle X by Web Cam.
Equivalent to a 63B.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F (75-76); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.345

0.345

ADVERTISED DURATION: 296 296

DURATION @ .0.050":

257

260

LOBE CENTER:

98

98

 

INTAKE OPENS     30.5     BEFORE TDC

EXHAUST OPENS     48     BEFORE BDC

INTAKE CLOSES     46.5     AFTER BDC

EXHAUST CLOSES     32     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.
 

MAKE  
MODEL  
YEAR  
CAMSHAFT  
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

 

MAKE  
MODEL  
YEAR  
CAMSHAFT  
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

 

MAKE  
MODEL  
YEAR  
CAMSHAFT  
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

Additional tech info coming soon.

CX-4     $299.00

Call for availability.

 

 

Upper midrange and top end camshaft. Use with big-bore, exhaust system and 12 plus compression ratio pistons.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (75-76); CB750 K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.350

0.350

DURATION @ .0.050":

273

273

LOBE CENTER:

99

99

 

INTAKE OPENS     37.5     BEFORE TDC

EXHAUST OPENS     55.5     BEFORE BDC

INTAKE CLOSES     55.5     AFTER BDC

EXHAUST CLOSES     37.5     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

MAKE Honda CB750 SOHC
MODEL 69-78 K model
YEAR 69-78 with the preferred 69-76 valve keepers and valves.
CAMSHAFT CX-5
INTAKE VALVE SIZE 32mm standard.
EXHAUST VALVE SIZE 28mm standard.
LASH 0 lash
INTAKE SINK .020
EXHAUST SINK .020
VALVE TO VALVE CLEARANCE Averages .048 with 0 lash
SPRINGS ENV-008, ENV-009 and Bee-hives spring sets will work great.
   
VALVE STEM PROTRUSION 1.720
VALVE GUIDES High lift guides are needed
NOTES:
This is a high RPM camshaft.
Any time we use these high RPM camshafts with sunken valves 020 or more, we like ENV-009 or bee-hive spring sets.

 

MAKE Honda cb750 sohc
MODEL 69-78 K model.
YEAR 69-78 with preferred 69-76 valve keepers and valves.
CAMSHAFT CX-5
INTAKE VALVE SIZE 33.5 oversize intake valves.
EXHAUST VALVE SIZE 28mm standard exhaust valves.
LASH 0 lash
INTAKE SINK .030
EXHAUST SINK .030
VALVE TO VALVE CLEARANCE .030. ( .040 minimum is needed)  Check notes below.
SPRINGS ENV-009 or bee-hives
   
VALVE STEM PROTRUSION 1.730
VALVE GUIDES High lift
NOTES:
With this CX-5 high RPM long duration camshaft and 33.5 oversize intake valves, close attention to set-up is a must.
You will notice that the valve to valve clearance is in the danger zone. Sinking the valves a bit more and setting the running valve lash will help, but many builders do not want to sink more than .030.
One of the preferred methods to gain more valve to valve clearance without sinking more is reducing the outside diameter of the intake and maybe the exhaust valve on the lathe up to the lapping line on the valve face.
Recommend ENV-009 or bee-hive spring sets.

 

MAKE  
MODEL  
YEAR  
CAMSHAFT  
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

Additional tech info coming soon.

CX-5     $299.00

 

 

 

 

Specialty Camshafts

This camshaft is for drag race applications.
This is the biggest, baddest camshaft for Honda cb750 ever made.
Extensive head work will be needed and all clearances be checked.
Designed by Kenny Harman and used by some of the fastest Hondas in the olden days.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F (75-76); CB750 K (69-78) SOHC 8v - Special Base Circle

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.006" - .008"

.008" - .010"

VALVE LIFT (INCH):

0.457

0.457

DURATION:

287

291

LOBE CENTER:

108.5

107.5

 

INTAKE OPENS     35     BEFORE TDC

EXHAUST OPENS     73     BEFORE BDC

INTAKE CLOSES     72     AFTER BDC

EXHAUST CLOSES     38     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

NOTES:
We will not be able to give any opinions or data for installing this XXX-4 in a Honda CB750 SOHC head. The camshaft is so big, a special head will need to be built especially for this camshaft.

Additional tech info coming soon.

VERY LIMITED STOCK. One left available!

XXX-4     $299.00

Call for availability.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This camshaft is one of our favorites for 890cc and bigger Honda CB750 race bikes. (12+ comp ratio or more)
This camshaft is perfect for road race or drag race applications.
Very similar to the Mega-cycle 125-X12, but with a 112 lobe center.

This camshaft is bigger than billets will allow us to go. Therefore, they are only offered in hardweld only.

In stock.

INSTALLATION INFORMATION

ENGINE:  Honda CB750F2 (75-78); CB750K (69-78) SOHC 8v

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.420

0.430

DURATION:

258.5

261

LOBE CENTER:

109.75

115.5

 

INTAKE OPENS     19.5     BEFORE TDC

EXHAUST OPENS     66     BEFORE BDC

INTAKE CLOSES     59     AFTER BDC

EXHAUST CLOSES     15     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT CX-10
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH 0 lash for checking.
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT Check above.
VALVE STEM PROTRUSION  
VALVE GUIDES High lift guides are needed with the CX-10
NOTES:

 
MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT CX-10
INTAKE VALVE SIZE 32mm standard.
EXHAUST VALVE SIZE 28mm standard.
LASH 0 lash for checking.
INTAKE SINK No sink. 1.700 valve stem protrusion.
EXHAUST SINK No sink. 1.700 valve st6em protrusion.
VALVE TO VALVE CLEARANCE .051 Average
SPRINGS ENV-008. 65lbs 1.455 installed height. no shims.
80lbs with 1.395 installed height (.060 shims)
ENV-009. 85lbs 1. 455 installed height. no shims. Add shims if needed.
Bee-hive ENV-010K 1.380 installed height. 90-95lbs. Add shims if needed.
INSTALLED HEIGHT Check above.
VALVE STEM PROTRUSION 1.700. Intake and exhaust.
VALVE GUIDES High lift guides are needed with the CX-10
NOTES:

 

MAKE Honda CB750 SOHC
MODEL F2/ F3 Supersport models
YEAR 77-78
CAMSHAFT CX-10
INTAKE VALVE SIZE 34mm standard
EXHAUST VALVE SIZE 31mm standard.
LASH 0 lash for checking.
INTAKE SINK .030
EXHAUST SINK .030
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION 1.730. Intake and exhaust. (sunk .030)
VALVE GUIDES High lift guides are required.
NOTES:
More specs coming soon.
Cam tower clearancing will be needed.

Additional tech info coming soon.

VERY LIMITED STOCK. One left available!

CX-10     $299.00

Call for availability.

This camshaft profile is one of the hardest hitting mid-range and excellent top-end camshafts designed for Honda CB750's.
Works great with 65mm bores and larger.
Higher compression ratios are recommended.
You vintage road racing people should try this cam!
 

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (75-76); CB750 K (69-78) SOHC 8v

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.385

0.330

DURATION @ 0.050:

256

265

LOBE CENTER:

109

110

 

INTAKE OPENS     19     BEFORE TDC

EXHAUST OPENS     62.5     BEFORE BDC

INTAKE CLOSES     57     AFTER BDC

EXHAUST CLOSES     22.5     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT CX-11
INTAKE VALVE SIZE 32mm standard.
EXHAUST VALVE SIZE 28mm standard.
LASH 0 lash for checking.
INTAKE SINK No sink. 1.700 valve stem protrusion.
EXHAUST SINK No sink. 1.700 valve stem protrusion.
VALVE TO VALVE CLEARANCE .060 Average
SPRINGS ENV-008. 65lbs 1.455 installed height. no shims.
80lbs with 1.395 installed height (.060 shims)
ENV-009. 85lbs 1. 455 installed height. no shims. Add shims if needed.
Bee-hive ENV-010K 1.380 installed height. 90-95lbs. Add shims if needed.
INSTALLED HEIGHT Check above.
VALVE STEM PROTRUSION 1.700. Intake and exhaust.
VALVE GUIDES High lift guides are needed with the CX-11
NOTES:

 

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT CX-11
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES High lift guides are needed with the CX-11
NOTES:

 

MAKE Honda CB750 SOHC
MODEL F2/F3 Supersport models
YEAR 77-78
CAMSHAFT CX-11
INTAKE VALVE SIZE 34mm standard.
EXHAUST VALVE SIZE 31mm standard.
LASH 0 lash for checking.
INTAKE SINK .015 sink
EXHAUST SINK .015 sink
VALVE TO VALVE CLEARANCE . Averages .050 with o lash
SPRINGS All above springs will work. Check pressures and specs for your needs.
   
VALVE STEM PROTRUSION 1.715
VALVE GUIDES Standard or High-lift guides are okay.
NOTES:
More specs coming soon.
Cam tower clearancing will be needed.

Additional tech info coming soon.

CX-11     $299.00

Call for availability.

 

Similar to the Mega Cycle 125-75 but with 3 more degrees of duration. We found this cam to work well with 915cc kits and above.

INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (75-78); Honda CB750K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.395

0.366

DURATION @ .0.050":

258

252

LOBE CENTER:

104.5

106

 

INTAKE OPENS     24.5     BEFORE TDC

EXHAUST OPENS     52     BEFORE BDC

INTAKE CLOSES     53.5     AFTER BDC

EXHAUST CLOSES     20     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

 

 

MAKE Honda CB750 SOHC
MODEL F2/F3 Supersport
YEAR 77-78
CAMSHAFT CX-7
INTAKE VALVE SIZE 34mm
EXHAUST VALVE SIZE 31mm
LASH 0 lash for checking
INTAKE SINK .015
EXHAUST SINK .015
VALVE TO VALVE CLEARANCE Averages .050 with 0 lash
SPRINGS Check above specs and pressures and favor 85 to 90lbs or more with this camshaft.
   
VALVE STEM PROTRUSION 1.715
VALVE GUIDES Standard or high lift
NOTES:
The intake and exhaust "ballpark" valve sink is .015 on our test head and valves. Sometimes you can achieve this small amount of sink by a basic valve job and adjusting your valve lash. Our 0 valve lash for testing is because some tuners will adjust running valve lash's to their own liking.
Cam tower clearances must be checked.
 


 

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves
CAMSHAFT CX-7
INTAKE VALVE SIZE 33.5mm oversize valves
EXHAUST VALVE SIZE 28mm standard exhaust
LASH 0 lash
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
   
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:


 

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT CX-7
INTAKE VALVE SIZE 32mm standard
EXHAUST VALVE SIZE 28mm standard
LASH 0 lash
INTAKE SINK No sink 
EXHAUST SINK No sink
VALVE TO VALVE CLEARANCE .060
SPRINGS Check spring pressures and specs above. ENV-008, ENV-009 and Bee-hives will work great.
   
VALVE STEM PROTRUSION 1.700 average
VALVE GUIDES High lift guides are needed.
NOTES:
As you can see .... There is plenty of valve to valve clearances with standard valve sizes and the CX-7 camshaft. Valve to piston and such will be next on your check list. 
 

Additional tech info coming soon.

CX-7     $299.00
Cycle X Race Team Approved

This "Hellcat" camshaft is the latest addition to our specialty performance camshaft options.
Made with a nice combination of old Honda CB750 camshaft thoughts and modern camshaft technology
thoughts and theory.
Big bore and higher compression recommended.


INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (75-78) SOHC 8V; Honda CB750K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.400

0.400

DURATION @ .0.050":

263

263

LOBE CENTER:

110

117

 

INTAKE OPENS     21.5     BEFORE TDC

EXHAUST OPENS     68.5     BEFORE BDC

INTAKE CLOSES     61.5     AFTER BDC

EXHAUST CLOSES     14.5     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT Hellcat
INTAKE VALVE SIZE 33.5mm oversize.
EXHAUST VALVE SIZE 28mm standard.
LASH 0 lash for checking.
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

 

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT Hellcat
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:


 

MAKE Honda CB750 SOHC
MODEL F2/F3 Supersport
YEAR 77-78
CAMSHAFT Hellcat
INTAKE VALVE SIZE 34mm
EXHAUST VALVE SIZE 31mm
LASH 0 lash for checking
INTAKE SINK .025
EXHAUST SINK .025
VALVE TO VALVE CLEARANCE Averages .055 with 0 lash
SPRINGS Check above specs and pressures and favor 85 to 90lbs or more with this camshaft.
   
VALVE STEM PROTRUSION 1.725
VALVE GUIDES Standard or high lift

Additional tech info coming soon.

CX-HELLCAT     $299.00
Cycle X Race Team Approved

 

 

 

 

 

This "Hellcat 2" camshaft is the latest addition to our specialty performance camshaft options.
Check out the specifications on this camshaft to keep you go-fast people ahead of the competition.
 
INSTALLATION INFORMATION

ENGINE:  Honda CB750 F2 (75-78) SOHC 8V; Honda CB750K (69-78) SOHC 8V

 

INTAKE

EXHAUST

VALVE LASH (INCH):

.004"

.005"

VALVE LIFT (INCH):

0.396

0.400

DURATION @ .0.050":

276

277

LOBE CENTER:

110.5

106.5

 

INTAKE OPENS     27.5     BEFORE TDC

EXHAUST OPENS     65     BEFORE BDC

INTAKE CLOSES     68.5     AFTER BDC

EXHAUST CLOSES     32     AFTER TDC

VALVE TIMING IS CHECKED WITH ZERO VALVE LASH @ 0.050 INCHES OF VALVE LIFT.

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT Hellcat 2
INTAKE VALVE SIZE 33.5mm oversize.
EXHAUST VALVE SIZE 28mm standard.
LASH 0 lash for checking.
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:

 

MAKE Honda CB750 SOHC
MODEL K model
YEAR 69-78 (69-76 K model valves)
CAMSHAFT Hellcat 2
INTAKE VALVE SIZE  
EXHAUST VALVE SIZE  
LASH  
INTAKE SINK  
EXHAUST SINK  
VALVE TO VALVE CLEARANCE  
SPRINGS  
INSTALLED HEIGHT  
VALVE STEM PROTRUSION  
VALVE GUIDES  
NOTES:


 

MAKE Honda CB750 SOHC
MODEL F2/F3 Supersport
YEAR 77-78
CAMSHAFT Hellcat 2
INTAKE VALVE SIZE 34mm
EXHAUST VALVE SIZE 31mm
LASH 0 lash for checking
INTAKE SINK .025
EXHAUST SINK .025
VALVE TO VALVE CLEARANCE Averages .055 with 0 lash
SPRINGS Check above specs and pressures and favor 85 to 90lbs or more with this camshaft.
   
VALVE STEM PROTRUSION 1.725
VALVE GUIDES Standard or high lift

Additional tech info coming soon.

CX-HELLCAT2     $299.00
Cycle X Race Team Approved

Call for availability.

 

 

 

 

 

 

 

 

CLICK HERE:  FOR INFO ON DEGREEING AND CAM INSTALLATION

 

 

Hardwelded Honda CB750 SOHC Rocker Arms

Hardwelded and precision ground from original equipment cores. These durable and long lasting rocker arms are important with high performance and even stock motor configurations. Many conversations are had with folks trying to make the flat tappet designs survive nowadays. Zinc and other and oil additives are being blended to help make these flat tappet motors live. On the other hand, hardwelded rocker arms are the best option. Recommended for use with all cam profiles, both billet and hardweld.

No core required. Outright sale.

For ALL year model CB750 SOHC 1969-78

ROCKER-ARMS     $492.00 (Set of 8)

Call for availability.

 

 

 

 



Titanium Rocker Arm Jam Nut Set

These Titanium rocker arm jam nuts were used on our Vintage heavyweight Super Bike. They are now available for your go-fast Honda CB750 SOHC project. (69-78) 1.2 grams per nut.

ENV-321            $49.95

 

 

 

Under heavy construction.
More to come

 

Camshafts
 

Advancing and Retarding the Camshaft

Begins Intake Event Sooner - Advancing

Delays Intake Closing Event - Retarding

Open Intake Valve Sooner

Keeps Intake Valve Open Later

Builds More Low-End Torque

Builds More High-RPM Power

Decrease Piston-Intake Valve Clearance

Increase Piston-Intake Valve Clearance

Increase Piston-Exhaust Valve Clearance

Decrease Piston-Exhaust Valve Clearance


Changing the Lobe Center

Begins Intake Event Sooner - Tightening lobe center

Delays Intake Closing Event - Spreading lobe center

Open Intake Valve Sooner

Keeps Intake Valve Open Later

Builds More Low-End Torque

Builds More High-RPM Power

Decrease Piston-Intake Valve Clearance

Increase Piston-Intake Valve Clearance

Increase Piston-Exhaust Valve Clearance

Decrease Piston-Exhaust Valve Clearance


A Good Start
At max lift, top retainer to valve guide seal should .030 minimum.
At max lift, minimum of .015 between three coils for a total clearance of .045 of clearance. (Springs)
With both valves open, minimum of .040 clearance is needed.
Piston to cylinder head clearance (with head gasket) should be .030. (Steel rods)
Piston to intake and exhaust valve clearance should be .050 intake and .080 exhaust. (Checked at various degrees)


Why do cam manufactures say "must be used with 12.1 or more compression pistons"?
When looking at the power output of a engine, the mass or volume of the trapped charge is the important thing.
With a static (not running) look, flow dynamics are not present. But once the engine starts turning or running, everything changes.
At low RPM or cranking speed with a later closing intake valve with performance camshafts the cylinder fill is reduced.
When the engine starts its combustion cycle, RPM and exhaust pulses are introduced to the game, things greatly change.
Closing the intake valve later with performance cam shafts at higher RPM will allow more flow inertia resulting in more cylinder fill.
Because a later closing intake valve with performance camshafts and the cylinder fill reduced at lower RPM the term corrected compression ratios is often mentioned.

 

 Hence: The statement use 12 or more compression pistons are needed.
We have our favorite ways to increase or correct compression ratios on Honda CB750 engines. A look at the piston section might be advised.  


But, in the mean time, Here is a "quick reference" of some off-the-shelf piston and recommended camshaft choices.



Stock domed and those inexpensive eBay 836cc similar domed pistons will be limited to our CX-1 or KHD CX-1 camshaft because of the valve pockets.

 

 



10.25 to 1 compression ratio pistons like Wiseco and others have the compression ratios and valve pockets to use CX-1, CX-2, KHD CX-1 or CX-3 camshafts.

 

 



12.5 to 1 compression ratio pistons like Wiseco and others have the compression ratios and valve pockets to use CX-3, CX-4 and CX-7 camshafts.
 

 





Camshaft Stuff from the 70's Era

Interesting? Maybe!
Note: You will notice some of the manufactures do not state where these numbers were measured from.

 

 

SIG ERSON

Honda CB750 4 Cylinder SOHC/Proferal Billet 1.1 to 1 Ratio

Grind Number

Cam Part Number

Timing

Valve Clearance

Valve Lift

Duration

General Characteristics

RB282

1000

I.O. 37   I.C. 65

E.O. 65   E.C. 37

.004"

.004"

.375"

.375"

282

282

The ultimate street and touring cam for the 750. Provides increased performance from idle through top R.P.M. Easy starting and smooth idle. Clears stock pistons, no machine work required for installation.

*SS288

1001

I.O. 40   I.C. 68

E.O. 68   E.C. 40

.004"

.004"

.395"

.395"

288

288

Street, touring, drag strip, cafe racer. Increased performance from 3500 R.P.M. up. Slightly higher idle speed, but smooth. Valve to piston clearance must be checked.

*SS298

1002

I.O. 45   I.C. 73

E.O. 73   E.C. 45

.004"

.004"

.420"

.420"

298

298

Strong mid range and top end cam for the hot street and strip machine. Big power increase from 5000 R.P.M. up. Must have added valve to piston clearance.

*SS310

1003

I.O. 51   I.C. 79

E.O. 79   E.C. 51

.004"

.004"

.400"

.400"

310

310

Upper mid range and top end cam. Drag strip, road racing, all out road burner. Needs improved exhaust and proper gearing for best results. Great in bored and stroked engines. Runs hard!

*DS324

1004

I.O. 54   I.C. 90

E.O. 90   E.C. 54

.004"

.004"

.425"

.425"

324

324

Drag strip, time trails, road racing, etc. Top end power cam, pulls hard from 7500 R.P.M. up. Well suited to large displacement engines. Needs good exhaust system.

H750 valve spring kit is recommended with all cams for best results.

Titanium retainers are only recommended for all out racing applications where high R.P.M will be maintained.

 

*These cams must be carefully checked for valve to piston clearance. Most high performance pistons have adequate clearance but must be checked during assembly. Factory pistons may be machined for added clearance. Valve to valve interference should be checked with cams over 310 duration.

None of the listed cams will work in the 1977 750 F2 model Honda as valve to valve interference will occur due to the larger diameter valve fitted. For the 1977 750 F2 engine, only one cam will work. Grind number RB278SPC, Part #1005.

 

 

POWROLL

 

High Performance Billet Cams

 

These totally new cams, precision-machined from billet steel, eliminate the need for an "exchange" with your present stock cam. High-lift lobes are of the required contour without hardwelding or regrinding. Choose from two different profiles engineered specifically for Honda 750s.

 

FOR STOCK OR BIG BORE displacements, this grind aids performance throughout the power range. Although compatible with stock springs, we recommend the use of our special valve springs.

12661

Valve Opens

Valve Closes

Valve Lifts

Running Clearance

Intake

19 BTDC

46 ABDC

.333 in.

.004 in.

Exhaust

48 BBDC

19 ATDC

.325 in.

.004 in.

Note: All timing specs are standardized at .040 in. valve lift and zero clearance.

Powroll Order No. 12661

 

 

FOR HIGH-DISPLACEMENT ENGINES only, this cam is inappropriate for the stock 750. Provides maximum engine-breathing capability for displacement over 900cc. Compatible with stock springs, but operated more effectively with Powroll's special valve springs.

12662

Valve Opens

Valve Closes

Valve Lifts

Running Clearance

Intake

23 BTDC

53 ABDC

.373 in.

.004 in.

Exhaust

50 BBDC

19 ATDC

.350 in.

.004 in.

Powroll Order No. 12662

 

 

ANDREWS PRODUCTS

Grind Number

Timing

Valve Lift*

Duration**

General Characteristics

A

STREET / STRIP

20/40

40/20

.350"

.345"

240

240

Mild street cam for bolting into stock 750 motors. No modifications or head work required. Stock springs OK. More power thru RPM range; slightly higher idle speed; smoothness unaffected.

D

DAYTONA +

19/45

45/19

.365"

.365"

244

244

Daytona; For modified and hotter engines 750/850cc; much more power especially middle and higher RPM ranges. Requires springs, spacing, and head work. Very streetable but slight lope @ idle.

K

SUPER STREET

35/63

63/35

.375"

.365"

278

278

Super Street grind. Best for big inch 750s (over 860 ccs) Strong pull from 5000/9500 RPM. Springs, spacing, and head work required.

4

DRAGS

32/68

70/30

.400"

.400"

280

280

Hottest Competition Cam made for 750 engines! On a big inch dragster #4 cam yields more HP and lower ETS than anything else available! Springs and head work required for installation.

*Maximum valve lift @ 0 Lash.

**Durations measured @ .050 valve lift; cam @ 0 Lash.

 

 

 

 

 

R.C ENGINEERING PERFORMANCE PRODUCTS

RACING CAMS: HONDA, 1969-78 CB750

RC240 Torque Cam - The only R.C. Honda cam that can be bolted into a stock motor without piston valve pocket machining. No head disassembly necessary. For smaller bore, low compression motors. Good for road racing. (Sold as a regrind only - send us your cam)

RC240 Timing:

Total Duration

Lobe Centers

Lift

Lash

296

118

.327" in.; .330" ex.

.004" in.; .004" ex.

 

 

RC295 Racer Cam - Smooth, good idle and torque with lots of the top end. Quiet operation. Exceptional for smaller motor. Ideal for 900cc motors.

RC295 Timing:

Total Duration

Lobe Centers

Lift

Lash

306 in./296 ex.

105

.390" in.; .360" ex.

.004" in.; .006" ex.

 

 

RC315 Hot Racer Cam - Strong torque curve from the ground up. Comes on low and never quits. This one makes lots of horsepower. Very good for heavy street and altered race bikes. Our favorite in the Street Class. Has flowed us to many national records. Very tractable. Fair idle - quiet. Ideal for 900cc and larger motors.

RC315 Timing:

Total Duration

Lobe Centers

Lift

Lash

310

104

.365" in.; .365" ex.

.012" in.; .012" ex.

 

 

RC327 Full Competition Cam - Similar to #315, but with more lift and overlap. Designed with more duration for maximum revs and BHP on all big motors. The best choice for use in 1000cc motors.

RC327 Timing:

Total Duration

Lobe Centers

Lift

Lash

325

104

.368" in.; .368" ex.

.012" in.; .012" ex.

 

 

 

 

 

ACTION FOURS

We use new, cast billets exclusively. Regrinds are cheaper, but there is not enough material to obtain an efficient profile and adequate base circle dimensions.

Stock pistons cannot be used with any cams we sell. You would not get your money's worth. A proper profile that would give safe valve-to-piston clearance would not increase performance significantly. A cam that would give clearance and increased performance could not have a safe profile. Notching stock pistons is not of much value either, since a hot cammed, low compression motor is a very poor performer.

 

Lift and duration figures are real. The drawing below shows how "extra" lift and duration may be added to no advantage. Buying the "biggest number" without regard to proven results is a fool's game.

 

 

THE "NUMBERS GAME"

Are the cams above the same? They are by the "numbers"!

 

Cams A, B, and C above all have the same lift (shown at "L") and duration (shown at "D"). Yet, there are obviously very different. If cam B is correct in design, then cam A would give good "low end" but less H.P and float the valves more easily. Cam C would have plenty of "top end", but would exhibit a narrow power band and open the valves too rapidly for good reliability.

No degreeing-in is required if stock components (tensioner, cam chain, etc.) in good condition are used. All our cams are indexed from the sprocket mounting rather than the drive slot. This insures far greater accuracy for "drop in" installation.

 

Most cams are located for grinding from the keyway as shown at "Y". The same arrangement is used on Kawasaki cam but is removed after grinding. All our cams are located from the mounting bolt holes, as shown at "X". Since the bolt holes determine the cam location, "spot on" results. The keyways becomes your "which tooth" indicator only. Of course, this applies to standard components in good condition only. Milling the head or cylinder, or using non-standard or badly worn parts will affect actual timing.

 

Is 11 good enough for you?

 

Big valves cannot be used in most cases. As overlap increases, valves come closer together. In our experience, an unrestricted profile will do more for performance than oversize valves. More latitude for cam timing variations are possible with stock valve sizes, too.

 

Carefully designed and tested profiles prevent excess stress and premature float. Extreme, power-robbing valve spring pressure is not required.

 

To test for adequate valve to piston clearance with any cam, rotate the nearest cylinder slowly to the overlap (exhaust closing, intake opening) position. Rotate the motor slowly, stopping every few degrees, from 35 BTDC to TDC (top dead center). Each time you stop, depress the exhaust valve follower (a padded screwdriver works well) until the valve contacts the piston. The point at which the valve moves the least is your minimum clearance and it may now be measured. In no case should it be less than 1mm (.040"). Reverse the procedure (TDC to 35 ATDC) to check intake valve clearance. Advancing the cam (forward in relation to motor rotation) will increase exhaust and reduce intake clearance. Retarding the cam has the opposite effect.

 

 

CB750 'SS' SERIES CAMSHAFTS

 

'SS-1' GRIND

High 11, low 12 second 1/4 mile times (used with 811cc Bore Kits) yet as smooth and tractable as a stock machine! This is definitely the cam for those riders who are worried about their "hot" cams.

May be used with stock valve springs for economic applications. Of course, we recommend a complete racing valve spring set for an even wider margin of over-rev protection.

Camshaft Only PART # 19-101
Cam & Racing Valve Spring Set (Except F2) PART # 20-101
Cam & Racing Valve Spring Set (F2 Models) PART # 20-201

Note: The SS-1 may be safely used in F2 (large valve head) models, without valve modification.

 

 

'SS-2A' GRIND

For maximum acceleration. Preferred by those who are serious about drag racing, yet need a certain degree of tractability. Best power from 6,500 up. Racing valve spring set is recommended.

 

Camshaft Only PART # 19-102
Cam & Racing Valve Spring Set (Except F2) PART # 20-102
Cam & Racing Valve Spring Set (F2 Models) PART # 20-202

For the best performance and reliability use them cams with Action Fours high compression big bore kits.

 

 

CB750 K-H CAMSHAFTS

 

Kenny Harmon's 35 years of cam design and grinding experience are manifest in these excellent profiles. 750 Honda cams from K-H have become an industry standard for quality and performance. All cams are precisely indexed for "spot-on" timing.

 

'D' GRIND

A famous grind. Excellent for riders who desire a major H.P increase, but insist on a wide range of us. Well balanced with reasonable idle and "low end" and a major increase in acceleration. Long exhaust duration allows for sustained high speed cruising without excess combustion chamber temperature.

 

May be used with stock springs if desired. For greatest reliability our racing valve spring set is recommended.
 

Camshaft Only PART # 19-103
Cam & Racing Valve Spring Set (Except F2) PART # 20-103
Cam & Racing Valve Spring Set (F2 Models) PART # 20-203

 

 

'F' GRIND

For the greatest H.P possible, consistent with sustained use. Extra long exhaust duration and substantial intake area provide record setting H.P, as well as efficient temperature control.

The best choice for road racing and other "top end" applications. Best power 7-11,000 RPM.

May be used on the street or for drag racing with very low gearing. Should be used only with racing valve spring set.
 

Camshaft Only PART # 19-104
Cam & Racing Valve Spring Set (Except F2) PART # 20-104
Cam & Racing Valve Spring Set (F2 Models) PART # 20-204

 

 

SUPER 'F' GRIND

The ultimate DRAG RACING ONLY cam. ABSOLUTELY NOT FOR STREET USE.

Extreme valve lift is combined with over 300 intake and "short" exhaust timing to get off the line hard and accelerate to high RPM.

No compromises in profile design whatever. This cam is not suitable for for any sustained use. Should only be used with complete racing valve spring set.

 

Camshaft Only PART # 19-105
Cam & Racing Valve Spring Set (Except F2) PART # 20-105
Cam & Racing Valve Spring Set (F2 Models) PART # 20-205

For the best performance and reliability use them cams with Action Fours high compression big bore kits.

 

 

 

 

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