Cam Shaft ID help - Forums - Official C3 Vette Registry

SPONSOR AD

Support our Vendors! | Advertise Here

Topic: Cam Shaft ID help

in Forum: C3 Engines

Already a Member?
Login
Not yet a Member?
Register for Free!

Back to top of thread

Cam Shaft ID help (5/15)
9/6/09 12:37pm

sulm68
Former Member
Send Private Message

Jacksonville, FL - USA

Vette(s):
1968 convertable 327 300hp All numbers matching, rally red with black interior. A/C, power windows, power brakes. Tremic 5speed

Joined: 8/28/2007
Posts: 44

Thanks for the reply. It was a big help. What do you think about roller tip rockers?

Quote

Cam Shaft ID help (6/15)
9/6/09 2:46pm

aceinthehole

Lifetime Member
Send Private Message

Manteca, CA - USA

Vette(s):
1978,two tone,Metalic Rootbeer & gold 1975 L48 4 speed

Joined: 11/20/2005
Posts: 3623

I'm not an expert on this and I have gotten advice from Nosal1 on the subject before. Roller rockers are great and will free up a few more horses (less friction and heat on the valve train) I'm a fan, but not without issues. If you have large hi-perf valve springs, some rockers will not clear them. You'll want to decide whether to go with self aligning rockers or regular style and add pushrod guides (and consequently hardened push rods) and hopefully the additional thickness of the guides won't change the geometry of the roller on the valve enough to warrant pushrod length recalibration. The safe and sane way to go would be a set of Comp's roller tip rockers. If you stick with the stock type lock nut and not the poly lock 2 pc. style, I believe they may still fit under the stock valve covers, other wise you have to get tall covers. aceinthehole2009-09-06 11:49:39

______________

Jimmy B.
Just can't wait to get on the road again.

Click to see larger views!

Quote

Cam Shaft ID help (7/15)
9/6/09 7:08pm

nosal1
Former Member
Send Private Message

Dunedin, FL - USA

Vette(s):
1980 Corvette Torch Red with Gold metallic 370HP/350 CU.IN.Turbo 350 w/shift kit.Originally CA.Car with 305 CU.IN.

Joined: 3/21/2006
Posts: 262

sulm68,

           Aceinthehole is quite right on his summations as to some of the drawbacks of the roller rockers,albeit they are the greatest thing since bubble gum,and I have changed many things to use them,however in your case it will not be necessary.If you have the valve covers off and can read the casting numbers on the heads, and they are the original heads then you will have casting # 461 or 462 (last three digits),and if not, if you tell me what casting # they are, I can tell you what you have.
         With the original heads and valve springs that came stock in the heads you can use any of the cam # I had sent you.
          As far as roller tip rockers,you can get the "Stamped Steel" roller lifters (1.5 ratio)which I have in stock for an engine I'm building for a guy who wants to use his stock valve covers, along with the expensive spread, like recommended by aceinthehole (which I have in stock for future builds) along with Cranes roller,Scorpion,and a host of others that the price starts really increases..
            Another trick I use is buy thicker valve cover gaskets from Fel Pro ..They make a thicker cork gasket than the stock gasket.The number escapes me at this time,however then you can use aluminum roller rockers with the poly lock nuts and allen head lockers..
             Like I said send me the casting numbers for the heads and we can go from there..

          Take care and good luck,

                 Sal C   nosal1

Quote

Cam Shaft ID help (8/15)
9/6/09 8:58pm

aceinthehole

Lifetime Member
Send Private Message

Manteca, CA - USA

Vette(s):
1978,two tone,Metalic Rootbeer & gold 1975 L48 4 speed

Joined: 11/20/2005
Posts: 3623

You da man Sal . It's great to know we have people around us with your expertise.

______________

Jimmy B.
Just can't wait to get on the road again.

Click to see larger views!

Quote

Cam Shaft ID help (9/15)
9/8/09 7:58am

Jimmy

           Thank you for the kind words..I hope all is well with you and better..
           Take care of you and "keep on keep'en on" my friend..

         Sal C        nosal1

Quote

Cam Shaft ID help (10/15)
9/8/09 1:36pm

Sal and others,

My heads are part no 3917291 which is not what you thought. Or maybe it was, in anycase does that change the cam recommendations or anything else.

Quote

Cam Shaft ID help (11/15)
9/8/09 5:28pm

3917291....67-68...302/327/350..Camel hump,no accessory holes,64cc chamber

Good Afternoon Sulm68,

       The aforementioned heads (461/462)are the brothers to the 291's. You have great flow characteristics as needed to produced the horses and torque and a step better than the 461/462,which I still have in stock just for a nostalgic build, because of their flow stats. You have a little better set of the 291 series because of the casting date code which, in the event you have not decoded, were cast on Jan,22,1967 and were used on early 302/327 engines and early Camaro 350's not many of these old boy's around. They are as rare and sought after as the 186 that used predominately on Vettes and Camaro Z 28 engines..Please note the intake runners,how nice and rectangular and defined they are which makes them flow excellent....The data above is for your heads.
          Sorry I get a bit long winded....To the main question of these heads for what you want to do, and the answer is a very positive yes.
          Better than the 461/462 ..

          Someone must have done a valve job or at least changed springs and removed the rotators on the exhaust valves which would indicate they changed the springs to VS 739R springs used also on Z28 and Corvette for performance engines. I can not tell by the photo,however if you look through the spring you should see a flat spiral spring.
             Spring diameter should be 1.2456..
             All information tells me you have the "makin's to keep you shakin' in your Vette
          I hope this is a help and I have been some assistance and feel free to ask any question I may be of help...
           Take care and good luck....
       Sal C           nosal1

Quote

Cam Shaft ID help (12/15)
9/8/09 6:41pm

Sal,

I can't thank you enough. Tongue

You obviously are extremely knowledgeable and are what make C3 REGISTRY such a great website. Thanks you too, Adam.

Scott Ulm

sulm68

Quote

Cam Shaft ID help (13/15)
9/8/09 6:58pm

Scott,
     You are very welcome and thank you for your kind comments.
     I just noticed that you must have a manual trans(I noticed the clutch ball bracket) and can run at a lower curb idle 650-750 rpm with the higher lift cam.
       I wish you luck and again if there are any questions please let me know..
             Sal C    nosal1

Quote

Cam Shaft ID help (14/15)
9/9/09 5:23pm

I'm planning on going with with the 229-1990 cam and comp cam roller tipped rockers. The springs do have some type of inner spring so I'm assuming they are all right. We will probably vacuum test them the valves to confirm their seal. I hope all this turns out all right. I'm a little nervous.

Quote

Cam Shaft ID help (15/15)
9/9/09 7:03pm

sulm68 Scott,

             Good choice on the cam and roller rockers.. You will be OK on the springs.
             I assume you are going to get new lifters as well. You should replace timing chain and cam sprocket unless they are new,which is unlikely..
              In any event you should not have any problems with the cam rocker combination.

              As I mentioned before,if you have any questions please let me know.

             Take care

                 Sal C     nosal1

Quote

Our Sponsors help support C3VR