spring loaded roller cam button

[turbofabricator]

How many folks use the spring loaded roller thrust button with a roller cam? I have used it before, with success, but am a little nervous. I usually use the positive thrust bumper. Anyone else use the springy deal and how may miles have you logged with-out issues? Has anyone even had an issue. Setting the cam thrust is such a pain. I've done LOTS of them and it still takes valuable time.

The only time I've had an issue with cam thrust is one time I had a guy bring his GN over after he had a buddy build it. It smoked out the breather something terrible and had a pop to it when it came up on boost/RPM. (Random popping) At tear down I found std. rings in a .030" overbore, which explained the breather smoke, and the cam had a lobe that was cast wrong. It was cast in the wrong location about .050" too far forward, and when the RPM came up, it would hit the adjacent lifter, popping the vavle open at the wrong time, causing the popping. Cam thrust in that case was the issue, I suppose. I replaced the cam, no more popping, (oh ya, and the rings, too.)

 

[Ed Valvo]

Ken, I'm using a spring loaded type on mine. 3-4K on the motor since the cam swap. So far so good.

 

[MSDGN]

I'm using one...ATR billet roller...have about 3K miles and around 200 mid to low 10 second runs on the motor...still going strong...at least the motor is...trans is another story...:frown:

 

[turboclam]

I think Nick Micale is using the spring cam button in his roller cammed motors. I think there is a thread on this somewhere. I'm using one and my engine has about 8000 miles on it without problems.

 

[pmoore4321]

Comp 206/206 roller with spring button and about 2k.

 

[turbofabricator]

I figure that with zero taper ground on the lobes of a roller cam, there should be minimal, if any, thrust at all. I just feel better using a positive thrust stop, though. Has anyone ever had an issue using the spring style?, anyone....anyone........Bueler......

 

[SPOOLFOOL2]

No issues here.
3500 miles, and over 400 ten second passes or dyno pulls.

Mike Barnard

 

[TurboBob]

I have probably 20 - 30K on mine.

There is thrust created by the oil pump drive, but I believe it pushes the cam into the block(?).

I put in the spring/roller bumper in 2005? The cam is a custom ground austemper roller.

I have had no issues. The car is my daily driver in the summer.

Bob

 

[Mike Licht]

The only time I ever tried it the cam moved forward and broke two lifters. I know lots of guys who do this with success but the cost of broken parts is far more than a postive stop button
Mike

 

[turbofabricator]

The only time I ever tried it the cam moved forward and broke two lifters. I know lots of guys who do this with success but the cost of broken parts is far more than a postive stop button
Mike

That's kinda how I feel about it, too. I've thought about machining an adjuster into the timing cover (under the water pump) to more accurately set the thrust, but just using the shims that come with the FT roller kit is easy enough to not justify the R&D time.

 

[TurboBob]

I will admit that I used the spring doodad because I was installing the cam in the car and I was in a hurry.

If the engine was out of the car, I would have used the shimmed thrust bumper.

Bob