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Cam button use

So, while we were taking a break, I made a call to Keith Black Racing and talked to the Head of Operations.
Asked if he'd ever built a Mopar Big Block. Oh Boy! Yes, he said. About 1500 or so! O.K., so have I got a
question for you! He said that NO Big Block they have ever built had a cam button because they don't need
one. We had a lengthy conversation about the problem of misinformation, and he said he did not know how
this started. I'm not trying to bust anyone's Balls, but just trying to clear up the B.S. If any of you still don't
believe this is a true statement, please get someone of great importance to back your claim up so we can all
learn something. I've been wrong in the past, and I'm done yet!
I asked this of you before and I cannot find the post again.....yet. Please once more, how many big block MOPAR roller cams have you installed and run? Still searching for the post where you answered the above question.
 
Zero! Back in 1973 Rollers were from outer space. They were like Nitrous, few and far between.
Let's see some pic's of buggerd up timing covers, shattered auxiliary shafts, bent fuel push rods
and cams that have suffered this fate.
 
Zero! Back in 1973 Rollers were from outer space. They were like Nitrous, few and far between.
Let's see some pic's of buggerd up timing covers, shattered auxiliary shafts, bent fuel push rods
and cams that have suffered this fate.

There is a buggered timing cover in the "engine damage what to do" thread.... We've all presented legitimate reasons for using a cam button... All you've presented is "Don't use one"... Why not? What harm could using one do? An un-needed expense?
 
I present this with all due respect...
zyzzyx has a theory. Thinking about it logically, it does make sense.
IQ52 has the experience.
Compared to them I haven't much of either to offer at the moment...but me being me, I love to test things out for myself:



A hydraulic cam with the lifters removed was used for this demonstration to simulate a roller cam.
The cam fell right out of the block when I allowed it to, I felt almost no resistance while spinning it rapidly.
The gear mesh did nothing to thrust it to the rear while it was turning.
 
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Well in theory you should not need a button on a big block Mopar. But theoretically bumble bees should not be able to fly either! As stated, the gear should hold the cam in place. The only way the cam could possibly move is if you rotated it backwards. Then it would basically "screw out". In normal operation, regardless of RPM, that cam should not move forward - at all - ever! Now if that bronze gear wears, all bets are off.

As for talking to the guys at KB, how many BB Mopars have they built that aren't running a fuel pump driven off the cam? There's your "button".

Anyhow, despite my thoughts and opinions on this, I run a cam button. Hell, for a couple of bucks, why not ?!?!
 
My use of a button was also based on the "misinformation" provided by my observation of a few of my timing covers. Even with the button there can be enough movement(oscillation) to leave a very slight mark after some use. This is with static clearance between the button and the timing cover.
I never ran a mechanical fuel pump, so no pump push rod.
The gear on the distributor does wear slightly with use. Especially the bronze gears and high pressure valve springs, 500#'s or more.
But to each their own.
 
I found that the intermediate shaft gear must be held still to keep the camshaft in place.
The cam floats around and wants to slide off the shaft gear when spun in either direction.

BTW...I don't know about you guys but to play my video I had to click on "watch on YouTube".
For some reason it never would play by clicking the 'play' button from here...wtf.
 
BTW...I don't know about you guys but to play my video I had to click on "watch on YouTube".
For some reason it never would play by clicking the 'play' button from here...wtf.

Dunno.... worked fine "from here"
 
Well hopefully you guys get this thread worked out by the time I get back to check my mail.... in about 2 weeks! :thumbsup::D:D
 
I found that the intermediate shaft gear must be held still to keep the camshaft in place.
The cam floats around and wants to slide off the shaft gear when spun in either direction.

BTW...I don't know about you guys but to play my video I had to click on "watch on YouTube".
For some reason it never would play by clicking the 'play' button from here...wtf.
It ( video) worked for me Bean and thank you for the demonstration. Ill take pics of the timing cover when I get to the shop this weekend...as embarrassing as it is to me.
In a side note , can you post dyno numbers on that index finger? Is it a street or strip?
Thanks again
One other thing I failed to mention that as the contact was made with the cover by the bolt head, it actually broke the bolts loose and they started unscrewing due to the directionof rotation. I had a locking tab installed but with the small 12pt heads was kind of useless ...live and learn I guess, lessons are expensive with any hobby .
Thanks to all!
 
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It ( video) worked for me Bean and thank you for the demonstration. Ill take pics of the timing cover when I get to the shop this weekend...as embarrassing as it is to me.
In a side note , can you post dump numbers on that index finger? Is it a street or strip?
Thanks again
Strictly low-rpm cruiser since we went away from rotary telephones hahaha
And I got the video thing figured out...well, my kid did....sure made me feel like an old techtard!
 
Zero! Back in 1973 Rollers were from outer space. They were like Nitrous, few and far between.
Let's see some pic's of buggerd up timing covers, shattered auxiliary shafts, bent fuel push rods
and cams that have suffered this fate.
I've spent tens of thousands of dollars testing my own stuff. You've spent zero on roller cams. Build one with no cam button and post the results. Time to step up before you ruin some other person's engine.
 
Sorry, not trying to ruin anyone's engine! Just trying to get to the bottom of this. Using one sure can't hurt,
but it seems to me to be in the Billet Dipstick Tube category. I'll do more research and check back.
 
Sorry, not trying to ruin anyone's engine! Just trying to get to the bottom of this. Using one sure can't hurt,
but it seems to me to be in the Billet Dipstick Tube category. I'll do more research and check back.
A billet dipstick won’t ruin an engine like a non existent cam button. Well unless u don’t add oil. Kim
 
Sorry, not trying to ruin anyone's engine! Just trying to get to the bottom of this. Using one sure can't hurt,
but it seems to me to be in the Billet Dipstick Tube category. I'll do more research and check back.
One thing I will not do..........is tell you to do something that I have not put my own *** on the line trying first.
 
Well in theory you should not need a button on a big block Mopar. But theoretically bumble bees should not be able to fly either! As stated, the gear should hold the cam in place. The only way the cam could possibly move is if you rotated it backwards. Then it would basically "screw out". In normal operation, regardless of RPM, that cam should not move forward - at all - ever! Now if that bronze gear wears, all bets are off.

As for talking to the guys at KB, how many BB Mopars have they built that aren't running a fuel pump driven off the cam? There's your "button".

Anyhow, despite my thoughts and opinions on this, I run a cam button. Hell, for a couple of bucks, why not ?!?!

Stanton, I agree that "in normal operation" the cam should push into the block if anything, however the loads imposed by high rate valve springs & roller cams cause oscillation or harmonics that differ from a static condition. One of my oil pump/distributor drives(with bronze gear) developed a bow tie shape to the drive slot in the shaft & slight wear in the bronze gear. These sorts of things happen. The button is a bit of cheap insurance, IMHO.
 
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