Measured my roller cam endplay...need 2 cents

bluegate

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Joined
Oct 8, 2016
Measured with a dab of JB weld between cover and button, thin gasket from Weber. Cut the extra around the edge after it hardend, measured at .020.

I plan to add the only .09 shim i have left and call it good.

But, Ill take your 2 cents, as to my method or if .011 clearance is too much. before proceeding. Thanks guys.
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your asking so ill give you miy opinion Leave it loose 20 thousands is good number (whats it going to hurt) IMHO.I had mine at 5 and ate sensor gears. I loosened it up and did the oiling mod and all is good now.Ready for the shit storm come get me!
 
.010 would be about the min for me. I shoot for just a little more like .015

one of these little Sterret gizmos works well:

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Keep in mind, when the oil pump loads the cam against the back of the block so it doesn't have any forces to push it forward against the timing cover. Also, the thermal expansion rate of aluminum is right at double that of cast iron. When the engine warms up the cover will move away from the cam a little.

That being said, I don't know how much your gasket is going to give after a few days or weeks when it takes a set.


About your measuring method, that's kinda ingenious .. Except I think it might be flawed. Unless you had the cam pulled against the block you might have a false reading that showing less gap than actual.

The easiest way to measure end play to me if the cam plug is installed in the rear(giggidy) is to lay a dial indicator down in the valley with the tip touching the timing gear. Reach into a lifter bore and move the cam back and forth. As long as you don't bump the indicator you can do about 5 readings in two seconds. IF they all match, that's it.
 
Keep in mind, when the oil pump loads the cam against the back of the block so it doesn't have any forces to push it forward against the timing cover. Also, the thermal expansion rate of aluminum is right at double that of cast iron. When the engine warms up the cover will move away from the cam a little.

That being said, I don't know how much your gasket is going to give after a few days or weeks when it takes a set.


About your measuring method, that's kinda ingenious .. Except I think it might be flawed. Unless you had the cam pulled against the block you might have a false reading that showing less gap than actual.

The easiest way to measure end play to me if the cam plug is installed in the rear(giggidy) is to lay a dial indicator down in the valley with the tip touching the timing gear. Reach into a lifter bore and move the cam back and forth. As long as you don't bump the indicator you can do about 5 readings in two seconds. IF they all match, that's it.
Thanks Earl.
Higher expansion of aluminum is what i was concerned about, and initially thought maybe it would be better to have it tighter. Im being lazy and didnt want make yet another online order for a dang .05 shim, because id probably end up buying something else like a 12 stage, triple nozzle, alky, Nos injection kit.

I did tap the little cup for the button roller into the cam pretty good before setting the cover, and could easily tell it was all the way back. Plus i used the putty type jb weld thinking it had some preasure in itself.

I thought about getting a dial just to compare my method to it. I let the jb weld sit for about 20 minutes, it seta in 5. I wonder how much it expands or contracts...

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You'll need a dial indicator when you degree you cam....


...won't even be that much money when you compare it to the price of the 12 stage, triple nozzle, alky, Nos injection kit. :D


Or you could just the a spring loaded roller bearing like the flat cams use and let it fly.
 
Are you serious? I thought the spring loaded button was only for cam buttons without the bearing in it.

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You'll need a dial indicator when you degree you cam....


...won't even be that much money when you compare it to the price of the 12 stage, triple nozzle, alky, Nos injection kit. :D


Or you could just the a spring loaded roller bearing like the flat cams use and let it fly.
Is that what usually comes with Cam kits? Sorry I'm a noob but have an up coming build in which I will install the cam lol
 
Is that what usually comes with Cam kits? Sorry I'm a noob but have an up coming build in which I will install the cam lol
Could be wrong, but I don't think they come with either

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A spring loaded button is usually used for flat tappet cams, but some builders use them for cast roller cams. Flat tappet cam lobes are ground so that the lifters spin and cause a very slight movement of the cam toward the block. Roller cams don't have that feature ground in. The lifters can't spin. Most builders use shimmed roller buttons on roller cams. The problem with the spring loaded button on a roller cam is if the spring breaks, the cam can move forward and a roller could possibly hit a lobe that it should not. It's very unlikely that a spring will break, although I had a roller button spring break on a flat tappet cam, with no consequences. Very unusual. It's a pain to set up the shimmed roller button, but I like it better on a roller cam.
 
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i've NEVER heard of a spring breaking They aren't exactly brittle since they're made out of spring steel.


Yes, flat cams are ground with a taper. 1/2 of them thrust forward and 1/2 of them thrust towards the rear so they end up cancelling... EXCEPT for the Buick V6. Since the #3 exhaust is damn near centered and has VERY little spin, the good cam grinders grind that lobe 'wrong' to minimize the odds of wiping that compromised lifter bore location....



....but like I said earlier, the oil pump load pushes the cam towards the block no matter what direction the tappets spin... or if you have roller tappets that don't spin at all.
 
i've NEVER heard of a spring breaking They aren't exactly brittle since they're made out of spring steel.


Yes, flat cams are ground with a taper. 1/2 of them thrust forward and 1/2 of them thrust towards the rear so they end up cancelling... EXCEPT for the Buick V6. Since the #3 exhaust is damn near centered and has VERY little spin, the good cam grinders grind that lobe 'wrong' to minimize the odds of wiping that compromised lifter bore location....



....but like I said earlier, the oil pump load pushes the cam towards the block no matter what direction the tappets spin... or if you have roller tappets that don't spin at all.
What's the best method for keeping the roller cam in place, the button with spring or?
 
What's the best method for keeping the roller cam in place, the button with spring or?
I would say the best way to retain the cam is the cam retainer plate . U drill and tap 3 hose in the block . This plate retains the cam so u don't need Any cam buttons .
 
I would say the best way to retain the cam is the cam retainer plate . U drill and tap 3 hose in the block . This plate retains the cam so u don't need Any cam buttons .
I have my block at the machine shop right now, is there a kit I should consider? Is this more fool proof?
 
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