Ductile roller cam install findings

[Russ Merritt]

Building my girdled 109 engine in the kitchen today (cause I can ma, it's MY kitchen! ) I notice the lifters run awful close to adjacent lobes on #1 and 3 cylinders. I was thinkin bout just using the roller cam button that Comp says will work but now that I see how close some run, I'm running the solid button. I have bout .020 clearance between the lifter and the "other" lobe. Gonna try to run it with .005 end play, no more. Still will be close but should work. Wonder why they make the lobes so wide on the ductile iron cams?

 

[BigChinooks]

Russ,

I have run these cams both ways with out any problems.
To run the solid button with shims,you will have to have the nose machined for it.

I am currently running the ductile roller with a needle bearing cam button with no problems at all.

Mike.

 

[Russ Merritt]

This button pressed in. Got it from PTE. Gotta wait now for the new timing cover to come in so I can adjust it. Comp makes the same press in button now.

 

[BigChinooks]

I would use some loc tight on the part that you pressed into the cam unless you already did so.

Mike.

 

[Russ Merritt]

Yea I did.

 

[TURBO 6]

Russ, Can you explain how to measure for push rod length? I am debating on getting the 218/212 ductile roller. (I've emailed you in the past) I know I have to check, but I don't know how. Thanks

 

[Russ Merritt]

With adjustable rockers you can figure it out with an old one and a tape measure. With non adjustable rockers you need to know what your doing. You'll need a push rod length finder. Never used one myself as I've always had roller rockers.

 

[TURBO 6]

Thanks Russ. I know someone with a push rod length finder.

 

[Nick Micale]

Originally posted by Russ Merritt
.....I notice the lifters run awful close to adjacent lobes on #1 and 3 cylinders. I was thinkin bout just using the roller cam button that Comp says will work but now that I see how close some run, I'm running the solid button. I have bout .020 clearance between the lifter and the "other" lobe. Gonna try to run it with .005 end play, no more. Still will be close but should work. Wonder why they make the lobes so wide on the ductile iron cams?

I talked with Comp about the wide lobes since we did an engine that had this issue with a ductile cam. They will change this in the future.

If the front surface where the cam rides is worn enough so the cam will be further in the block, it could cause a lifter to touch the "other" lobe.

 

[Russ Merritt]

In my engines case, riding back another .010 would be great. I'm not worried but narrower lobes will definately be better.

 

[TurboBob]

This has probably been asked before, but. Are these issues present in the Comp Billet Rollers?


The reason I ask is that I have a very mild 206 billet roller that has valvetrain noise. I have tried every preload, new lifters, stock rockers, new stock rockers on BILLET shafts, and now T&D's The noise comes and goes, but the motor makes excellent power, so it's hopefully something simple.

Perhaps it's in the heads, since we changed those at the same time.

Bob

 

[Russ Merritt]

The engine that is in my car now has the same issue. It's ATR's billet 212/206 (Crane) so it can happen to any manufacturer. Something you gotta live with I guess. When it's all warmed up, it sounds great. Still a noisy valve train but sounds good. What valve springs are you running?

 

[TurboBob]

I got the springs from PTE, I think they might be Kmotion.

They are 125lbs on the seat, and 'whatever' open.

Bob

 

[Russ Merritt]

Degreed this 218/212 today and it came up to 109 centerline instead of 112. Gonne leave it as it should retard a bit once the engine runs.

 

[bruce]

Originally posted by TurboBob
I got the springs from PTE, I think they might be Kmotion.

They are 125lbs on the seat, and 'whatever' open.

Bob

Might try adding a little GM EOS.
Or less low LV8 timing to keep the oil temp a little lower.

Maybe even a different brand of oily stuff.

 

[Russ Merritt]

Originally posted by Russ Merritt
Degreed this 218/212 today and it came up to 109 centerline instead of 112. Gonne leave it as it should retard a bit once the engine runs.

No I'm not! Gonna ditch the Comp timing chain for a Rollmaster. Should be able to get it pretty close now.

 

[Russ Merritt]

Instead of a 120$ Rollmaster, I learned today how to bush the cam gear 2 degrees. Got a 111.5 centerline now. Close enough. Thanks to Reids Automotive for the help!