Oil pump shaft question

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gtmopar

gtmopar

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So I've got some really good responses on someone else's thread, but I'm just running it by several of you guys to get your opinion. I'm almost done rebuilding my LA factory roller motor when a couple of knowledgable guys suggested that I order a hardened pump shaft due to the billet roller cam that I just installed. The pump shaft that came in the motor looked heat treated but looks aren't always what they seem. Do I need to spend 300 bucks on a shaft from hughes or is the factory shaft from that roller motor strong enough? This isn't a full race motor or anything. It's my first roller motor and I don't want it to take a chit fast. Let me know what you guys have experienced and what I absolutely need to do. Thanks
 
I'd think it depends on how you plan to run the engine and the oil pump you're using. Road racing, high volume/high pressure oil pump, high viscosity lubricant all argue for a more durable oil pump shaft. Just my 2¢ worth.
 
If it's a steel billet cam core, you have to use a bronze geared pump drive, which I'm sure are hardened, anyway. Nonetheless, it is possible to have a pump drive failure, so why scrimp there with an OEM style? Not cheap, but Milodon has them at a reasonable price - part # 21535.

http://www.summitracing.com/parts/mil-21535
 
Thanks for the responses guys I value each and everyone's opinion......almost everyone. Lol
 
if you have a high volume oil pump you should get a harden intermediate shaft....if you have a regular oil pump you dont need one....unless the stock one hex is getting rounded

secondly....since you have billet roller cam...unless it has a cast cam gear installed on it....you need a bronze gear or a coated gear

if it has a cast distributor gear on the cam...then you do not need a bronze gear or coated gear.....

so you kind of need to know what you have.........
 
post a picture of the gear on the camshaft....

the oil pump....if it is a melling with be mh-72hv for high volume....or mh-72 for regular...
 
Damn I already buttoned the pan up. It came with my summit rebuild kit I'm 90% sure its a high volume pump. I posted a pic on another thread, ill post it on here shortly. Thanks guys.
 
I just ordered the hardened one from summit. Do it right and be safe or don't do it at all. Thanks for all the input guys.
 
I just put the cam in and it seems like its going back too far towards the back of the motor, its not staying flush with the front of the block. Does the pump drive gear keep it forward when it meshes? I put new cam bearings in but they are where they are sopposed to be as far as lining up with the oil holes.
 
gtmopar said:
I just put the cam in and it seems like its going back too far towards the back of the motor, its not staying flush with the front of the block. Does the pump drive gear keep it forward when it meshes? I put new cam bearings in but they are where they are sopposed to be as far as lining up with the oil holes.
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The gear will position the cam and the thrust plate keeps it there.
If you are running roller lifters , cam end play is pretty important. They don't like a bunch of it. Check it and if you have more than .020 , I'd be looking to control it with a thrust bearing / plate combo.
 
tubtar said:
The gear will position the cam and the thrust plate keeps it there.
If you are running roller lifters , cam end play is pretty important. They don't like a bunch of it. Check it and if you have more than .020 , I'd be looking to control it with a thrust bearing / plate combo.
Click to expand...

Awesome thanks bud. Yea I'm waiting on the hardened shaft to get to me and when I slid the cam in it seemed like it was going back to far. Yea I know end play is critical on a roller setup. Thanks again
 
The gear doesn't position the cam. It turns it. when the gear is in you will be able to move the cam the same distance front and back. the drive gear will just turn. The cam plate is there to hold the cam from moving rearward with tappet lifters. the timing gear rides on the cam plate. If you want to control cam movement you shim the cam behind the plate. which is usually never needed. unless you have a wear issue. Or a cheap Cam.

A billet cam always needs a bronze drive gear. A standard hardened shaft with gear will destroy the gear on the cam. Billet cams have soft gears and won't hold up against a cast gear. Get a bronze drive gear on a hardened shaft. also make sure you size the bushing in the block before assembling the engine. You don't want the filings floating around in your engine.

Also re-drill and chamfer all oil feed hole and cam bearings after the bearings are installed. then wash the block. this will insure your bearings are not partially covering the oil feed holes.
 
I was always under the impression that roller cams wanted to push toward the front of the block, hence the need for a cam thrust button in engines not equipped with a cam thrust plate. If somebody knows something different, I'm all ears.
 
I just got the miloden hardened shaft with bronze gear about 10 min ago from ups. Just dropped it in and I'm getting ready to put the thrust plate on. I've already put the cam bearings in and made sure the holes were all aligned. So far so good.
 
A thrust button is used on GM motors or any block that doesn't have a cam retaining plate. On GM motors there is nothing holding the cam from moving front except for the lifters on a tappet motor.
If you take the lifters and the dist. out you can take the cam out with the gear on it. When installing a roller cam a button is installed to keep the cam from moving front. The gear stops it from moving back.

On a chrysler the cam is held by a retaining plate. This is good except it prevents proper chain oiling from the front cam bearing over flow.. This plate which the timing gear rides against prevents the cam from being pulled rearward by lifter rotation. It is also used to hold roller cams in place on later motors. These plates and or tentioners have a oil grove cut in them unlike the early plates.. These should also be used when installing a roler cam. The clearance is designed into the step on the cam behind the plate. You should have at least .003 -.006 no less To much and you may need to shim.

The buttons on GM's are used in conjunction with a aluminum timing cover. If you don't see a aluminum cover in a SBC and they say its a roller motor. They don't know what they are doing and it won't last. The flex of the tin cover will cause roller failure . I have a billet mopar cover and want to use it for a cam button for better chain oiling.

Note the oiling goove in the later cam plate for roller cams
 

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What holds the cam in on a big block?
 
We use a 3 bolt cam with a button if you want to know. A special cover is used also if you want to control cam movement. I thought we were talking small block here. Wonder what holds the cam rearward with out the button on a tappet motor. Must be lifter rotation as I said earlier. Also big blocks never came with a roller from the factory as the small blocks did. Nor did the Hemi's.
 
Yea I'm familiar with the GM cam buttons I've built 10 gm's to every mopar and its been over 10 years since I've built a small block mopar. Forgot how much it costs to build one of these little bastards! Lol. Thanks for the input I needed a little refresher.
 
gtmopar said:
Yea I'm familiar with the GM cam buttons I've built 10 gm's to every mopar and its been over 10 years since I've built a small block mopar. Forgot how much it costs to build one of these little bastards! Lol. Thanks for the input I needed a little refresher.
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Unless you want to rip your motor apart again, don't use that bronze gear. The bronze gears are designed for race motors that constantly being ripped apart and cleaned.
 
If you have a billet cam...you either use the bronze gear or a coat gear if the camshaft is new....you have no other choice....

bronze gear has nothing to do with race...it has to do with the material the camshaft is made out of....
 
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