Cam lobe to Lifter misalignment

[ssgtgoodwrench]

I have a 1985 Hot Air that i am doing a IC conversion. I am refreshing the IC motor. Broke it down to just a short block. Cleaned it all up and now i am putting everything back together. I bought a edelbrock cam from gbody parts. I just wanted something new that had great street manners. Got the cam in and the timing gears on. Everything went on fine. I put the lifters in and it looks like only half the lifter is sitting on the cam lobe. I know the cam i fully seated. The timing chain was nice and striaght. Has anyone seen this before? Do you think they ground the cam off? Any ideas would help. Thanks guys.

 

[Turbo6inKY]

Spin the cam around with the lifters in, no pushrods.

Then pull the lifters and remove the cam and check to see if the wipe pattern is centered on all the lobes. Looking through those holes isn't going to tell you if you're lined up very well. The angle is too goofy. Just spin it and check the pattern.

 

[Nick Micale]

I would not install that cam.

In 1999-2001 there was an issue with manny cam blanks which had that issue. Some were worse than what you have.

I wonder how long that cam has been on the shelf?

Just be sure you degree the cam when it is installed, or have it checked with a Cam Doctor. If no shop has on near you, TA Performance has a machine to check it out.

Every now and then we find a cam out of spec.

 

[challengermike]

as far as I remember they should be like that. they are offset so the lifter rotates when running.

 

[raregn]

as far as I remember they should be like that. they are offset so the lifter rotates when running.

Exactly, only roller lifters will be centered on the cam lobe.
As stated above it is like the so the lifters and push rods spin while they are moving up and down.

 

[ssgtgoodwrench]

Awesome. This is my first flat tappet cam install. Thanks for clearing that up for me. I love this forum.

 

[androboost4]

Exactly, only roller lifters will be centered on the cam lobe.
As stated above it is like the so the lifters and push rods spin while they are moving up and down.

This may over simplified ,but if you were to drop a roller lifter into that same hole won’t it be offset too ? So really nothing changes the location of lifter . Don’t see the problem going away with rollers.


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[Chuck Leeper]

This may over simplified ,but if you were to drop a roller lifter into that same hole won’t it be offset too ? So really nothing changes the location of lifter . Don’t see the problem going away with rollers.


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The lobes on the roller are in a different location.

 

[androboost4]

The lobes on the roller are in a different location.

This is good info , I would be willing to learn the locational differences between the two . Can you point me to that info so for future reference.


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[Turbo6inKY]

This is good info , I would be willing to learn the locational differences between the two . Can you point me to that info so for future reference.


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Your best bet would be to call Comp Cams' tech line and ask them. Unless somebody on here is willing to snap a photo of a flat tappet cam next to a roller.

 

[Chuck Leeper]

Additionally, the v sicks is known to have poor lifter bore registry.
Lifter Tru boring tool is the way to find the errors. Not cheap. Off location? Bush and bore to correct location.

 

[androboost4]

Thanks , you know that is correct, I read that in a old post years ago about our 6'es. The off set does not need to be a lot to assist the followers to rotate as required with the conical ends of the ground follower plus the tapered ground lobe .

 

[Turbo6inKY]

Additionally, the v sicks is known to have poor lifter bore resistry.
Lifter Tru boring tool is the way to find the errors. Not cheap. Off location? Bush and bore to correct location.

Thanks , you know that is correct, I read that in a old post years ago about our 6'es. The off set does not need to be a lot to assist the followers to rotate as required with the conical ends of the ground follower plus the tapered ground lobe .

I really want to blame people posting from phones, so no fault assigned. But damn, those are not sentences.

 

[A2000RICH]

Additionally, the v sicks is known to have poor lifter bore resistry.
Lifter Tru boring tool is the way to find the errors. Not cheap. Off location? Bush and bore to correct location.

lifter bore alignment on the Buick v6 is not very consistent throughout the block, this is one of the reasons that this engine was used in one of the API cam and lifter wear test sequences throughout the 90's and into the early 2000's, a few of the lifters even rotate in the opposite direction from the rest, as far as this block/cam combo is concerned the only thing to check is if any of the lobes come too close to adjacent lobes, I have had that problem on a few rare occasions, the only fix for this is to grind the side of the lobes to clear or return the cam for replacement, another thing to check is if the thrust surface of your block is worn excessively, this can cause the cam to sit in the wrong position in the block

 

[750H.P.V6]

The lobes are ground with a taper and the lifter faces are convex. if the lifter wasn't offset from the centerline of the lobe it wouldn't spin. This is a large contributor to the lifter failure rate of the #3 exhaust lifter. Typically it has the least amount of offset and the lobe taper is reversed.

Neal

 

[ATL_87GN]

Here is a wiped #3 exhaust lobe and lifter. It had a total of 0.134” lift. The car it came out of would not gain any more mph from the 1/8 to the 1/4 no matter what we did. We were stock at 78mph at the 1/8 and 98mph at the 1/4. After it was fixed and Alky was added, we picked up 12mph and knocked off 1.2 seconds in the 1/4 within ~1psi of the previous boost setting.

 

[earlbrown]

Awesome. This is my first flat tappet cam install. .

Fill your engine up with magnets. One on each drain hole per head, one or two stuck on the outside of the oil filter, and a magnetic drain plug is a good start.



You can check on the top magnets after 20 miles or so when you pull the valve cover to see if 3E is still intact.

 

[STGMAN]

lifter bore alignment on the Buick v6 is not very consistent throughout the block, this is one of the reasons that this engine was used in one of the API cam and lifter wear test sequences throughout the 90's and into the early 2000's, a few of the lifters even rotate in the opposite direction from the rest, as far as this block/cam combo is concerned the only thing to check is if any of the lobes come too close to adjacent lobes, I have had that problem on a few rare occasions, the only fix for this is to grind the side of the lobes to clear or return the cam for replacement, another thing to check is if the thrust surface of your block is worn excessively, this can cause the cam to sit in the wrong position in the block

Richard will comment on this later ronight

 

[STGMAN]

.

Richard Clark will post more on this subject tonight

 

[TTipe]

I worked in the V6 base engine group at the BOC V6 center of expertise at what was 902 E.Hamilton Ave, Flint Mich 48550 with the turbo group as a test /applications engineer. I have never seen an as released Turbo V6 valve geometry which looked so sick. The allowable tolerances which I reviewed as compared to the pictures do not make sense. The factory 36 ( engine plant ) checking gage / fixture would not allow a cam to be off the push rod/ lifter c/L so badly as to not be detected. These pictures look like possibly the wrong cam, or the cam thrust face (block bulkhead) was milled significantly (for whatever reason), or the cam collar was turned down. I can only imagine what the front cover looked like with "0.070" thrust clearance even with the old plastic thrust button. I was fortunate to have needle bearings laying around which I could use for cam thrust in the "80's". Sorry to sound disgusted but the product was better than that. Have a great day.