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Anybody tried .904 lifters in a SBC ??? I talked to Lunati , they said no problem cutting a cam to optimize the bigger diameter lifter.

What pushrod works for this ??

I'm seriously thinking about going with a hydraulic cam with as much lift practical instead of a roller this time.
 

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Ol' Earl Wade did a lot of this for the limited circle track guys. I believe he actually had better luck with the Ford diameter lifters.:yes: The .904's were just a little too big and had a problem "Catching neighboring lobes" as he said.

There's also the old mushroom lifter option available as well but they are all solid flat tappets I believe.:yes:

Give Harold a call. He can fill you in on all of the details!!:yes:
 

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We used to do this for Claimer motors and some street motors. It allows for a much faster ramp profile. Ultradyne had several profiles for this. Make sure the machine shop has the proper tooling to blueprint the lifter bore angles and locations. It helps the cam and lifters last if the lifters have been bored to oil the cam directly. Many factors affect pushrod length. I've found it best to assemble the motor then measure to determine ideal length.
 

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well..... ya cant use Mopar lifters, they are solid.. no oil hole to pump oil up the push rods..... I think ya need to use a AMC lifter(same .904" I believe) they have push rod oiling.:D
 

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I would say that unless you are racing under "flat tappet only" rules and allow .904" lifters, you'll get better results with less hassle (and money) using a roller cam.
 

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Ol' Earl Wade did a lot of this for the limited circle track guys. I believe he actually had better luck with the Ford diameter lifters.:yes: The .904's were just a little too big and had a problem "Catching neighboring lobes" as he said.

There's also the old mushroom lifter option available as well but they are all solid flat tappets I believe.:yes:

Give Harold a call. He can fill you in on all of the details!!:yes:

We probably machine more .904 lifter bore then .875 for smoe of the circle track guys and to get the cams to live we also machine the cam tunnels to BBC

When the lobes are cut for side clearance it tends to make a stress riser if there is not enough radius and will cause the cams to break near the last lobe on the cam.

If guys do use the STD cam tunnel the COMP lobe lock core is a good choice.
 

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Oversize lifters solid or roller have been common for years the oversize is .903

The common use s to allow a re-bore for perfect alignment to the camshaft.

Now because of the weight difference, Larger being more weight. Most are boring & installing bronze sleeves. or like NASCAR blocks, the lifter bores are not even cut in the factory supplied block. They do this work them selves.

The RO7 engine actuality uses a very small bore lifter. Again! WEIGHT!

In a street engine or even a engine where rules for max performance related to CI limits is a minuscule improvement for the investment.


Unless your repairing a block from lifter damage, I would not spend the money.

As I am sure even CNC BLOCKS will attest. this is not a cheep process.
 

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Actually Al, the more common purpose of the process it to be able to utilize a larger lifter face. With the larger lifter, the lobes can get quite a bit more aggressive.:yes:

Worth it? Only to those limited by class rules.

Costly...ABSOLUTELY!!!:yes:
 

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We charge 250 dollars for machining lifter bores to .875 with no bushings.

Whats amazing is guys will correct there lifter bores in an 010 block and do nothing about the cam tunnel as we have found them all over the place as the worst one we have seen has been .016 off from blue print.
 

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All the machining expense on a typical 010 block makes the aftermarket blocks seem like a bargain.
 

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All the machining expense on a typical 010 block makes the aftermarket blocks seem like a bargain.

that is the truth!

I have some major machine work in 010 block.

been better off to start with a GM Sportsman Bowtie block. Less than a grand.

Al
 

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Al has a inside deal...... forget aboudit... If he say less than a G for him... then it's less than a G... ok maybe 999.99 99/100.:D. but less than a G
 

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Al has a inside deal...... forget aboudit... If he say less than a G for him... then it's less than a G... ok maybe 999.99 99/100.:D. but less than a G

yea, I kinda let the dog out on that one.

But I still have few connections! :D:rolleyes::cool:

but anyone can get a new block for 800.00 range
Part# 10066034 4 bolt std block.
or a 1 piece rear main seal 10105123 in the 850.00 range.

Al
 

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Oversize lifters solid or roller have been common for years the oversize is .903

The common use s to allow a re-bore for perfect alignment to the camshaft.

Now because of the weight difference, Larger being more weight. Most are boring & installing bronze sleeves. or like NASCAR blocks, the lifter bores are not even cut in the factory supplied block. They do this work them selves.

The RO7 engine actuality uses a very small bore lifter. Again! WEIGHT!


.
The Cup guys are using .875 lifters with their flat tappet cams as that the biggest lifter NASCAR allows.
 

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Discussion Starter #19
sooo

hmm ,,, looks like there is more to this than meets the eye ,,, ::: glancing over at the 2 rollers left over from the last engine ::: might have to pull one of them out of retirement ,,,

i'm looking for low maintenance , durability , but not leave anything on the table if its not too expensive.

comp cams still lists a mushroom lifter in their catalog ,,, never tried that before ,, I hear the machining process isn't that complicated ,,,
 
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