Bronze Oil Pump Drive Gear

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T56MaxTorq

T56MaxTorq

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Hey all, have a LA360 in a rebuild and have a comp roller cam that needs a bronze gear for the oil pump drive. Deciding what driveshaft to go with is giving me a headache. The motor and cam has been ran about 3000 miles before the heads burned enough oil and well..I'm rebuilding everything a second time :banghead: The old bronze gear came as just a gear that I press onto the stock driveshaft. Well upon inspection the gear is worn way too much for comfort. It seems the shaft bottomed out and was slightly pressing the bronze upward onto the cam gear, causing irregular wear. So with a few choices in bronze gears with hardened shafts (milodon, MP, Comp cams, etc) Are they all interchangeable? I did a quick search on fabo and are there really 3 different sizes? I think I have a stock melling replacement oil pump but it may be high volume. Thank you.
 
Do yourself a favor, ditch both the cam and cam gear. That bronze gear is designed for racers that are constantly going into/rebuilding their motors. Instead go find yourself a new cam that has a cast iron intergrated gear on it and buy a hardened shaft (I have this setup in my 340 with a hyd roller cam). This way you won't have to by constantly ripping into the motor. I know that crane has the cast iron gear on it because that's where I got my cam from.
 
is your comp cam a hydraulic roller or a solid? As far as i know the comp hydraulic rollers are cast cores and compatible with the original oil pump drive.

Michael
 
360duster said:
is your comp cam a hydraulic roller or a solid? As far as i know the comp hydraulic rollers are cast cores and compatible with the original oil pump drive.

Michael
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You might have to ask/tell them that you want a cast iron gear on it. When i went searching (sept of 2010 for 4 hours) crane was the only one that had a cast iron gear on it. Everybody elses was a billit cam requiring a bronze gear (that mistake cost me 200 bucks on restocking fees and was only found out just before it went into the motor).
 
If it's a solid roller, it will need the bronze gear. I use the MP ones, and I'd inspect it every 5K miles or once a year, which ever comes first. I know Crane hydraulic roller cams come with the iron gear, but I don't know for sure about others. The bronze is there as the wear surface... So it should be considered a wear item and inspected. I've seem some that have gone for tens of thousands with no problem, and I've seen some that were trashed after one summer of less than 2500 miles.
 
FWIW, the bronze gear in my motor (solid roller cam) looks good as new after 3 years of constant abuse at the track, and quite a few street miles as well.
 
It's a hydraulic roller cam. I called comp and asked if I absolutely needed a bronze gear and yes I do.

Here is a link: http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=646&sb=0

I'd honestly like a smaller cam, this engine is going into a ramcharger. Motor specs are LA 360 .030 over, kb step dish pistons, stock rods/crank, 308 heads w/ 2.02 valves, roller rockers, 1 5/8 tube headers, 9-9.3:1 compression, gasket matched eddy performer intake, prolly start with a 600cfm carb, truck lives at 6500' altitude. I may look into a smaller cam with a cast gear for normal people. I'd like to keep my stock torque converter.

I don't understand what the point of a bronze gear is. I know it's cause of the billet cam core but why not just use a cast cam gear and be done with it? A bronze gear with a hardened shaft is around $200 and a roller cam is about $300 if you're lucky.

Last time I'm ever using a roller cam haha

Thanks for the quick replies guys!
 
Quote{It seems the shaft bottomed out and was slightly pressing the bronze upward onto the cam gear, causing irregular wear}. This is your problem, The bronze gear will wear out quick.You have to set it up.The shaft can not bottom out and there is a tolerance at the staft and oil pump.Most aftermarket shafts come a little longer so you can fit it to your block.The bronze gear should ride in the bushing and the shaft should be shortend about .060. into the bottom of the oil pump.This is from milodon.
3. Length of distributor drive shaft should always be checked to be sure that shaft is not
bottoming out in gear causing this gear to dig into and ruin the pump cover. A minimum of​
.060" shaft end clearance is required. Shaft should be shortened if neccessary.In a A small block it will ruin the gear and or the oil pump shaft and the oil pump.Hope this helps. Mark
 
Thanks dartcuda, I will take pics of the worn gear when I get home. I'm assuming this is how my gear became so worn down but I do not know for sure. I had to actually take a stock shaft and press on a new bronze gear, so I wouldn't be shocked if I messed that up haha

So basically, the gear should ride on the bushing in the block freely and the tip of the shaft should float in the oil pump and not bottom out on the pump.
 
I just ordered a new comp cam for my 360 magnum pn 20-746-9. It's an hydraulic roller. There's no warning that I need to use a bronze gear. Do I need one?
 
The reasons for using a billet vs. using a pressed on iron gear is economy and strength. Mostly in that order. It's easier to use one part and grind it all on it, and technically stronger in terms of twist of the cam which is a problem on larger roller profiles and a cam-driven oil system. But the billet material is a bit harder than cast, so instead of having steel particles running around the engine, it's made of softer bronze as the sacrificial link in the chain. The thought in years past was that a roller cam engine was not getting the high mileage and the drive would be fine for seasons of racing.
 
All this talk is not making me feel good about my billet cam in my engine build.........
 
It's not a big deal. Every 2nd or so oil change, pull the drive and inspect it. If it's worn, replace it. If you inspect it twice and there's no major wear, forget about it.
 
Crane Cams has a steel gear for the intermediate shaft that is designed to be used on the billet roller cams. The part number for the big block is 66970-1 and the small block is 69970-1. You can use these to replace the soft bronze gear and they are compatible with the hardened roller cams.
 
from Hughes website on the crane 69970-1...Read Last Sentence....

We now offer fully machined, specially coated and processed steel distributor gears for both small block & big block engines. These gears are designed to be used on steel roller tappet camshafts that previously required a bronze gear on the intermediate shaft. The problem with the bronze gear is that it wears very rapidly, especially on the street and therfore requires frequent replacement. These specially coated gears live with O.E.M. style lifespans. But wait, that's not all! They can also be used with stock or aftermarket cams as well! Hey, these babies work on everything. Only one caution, Do not install them on a used cam.

$98.00 dollars
 
T56MaxTorq said:
It's a hydraulic roller cam. I called comp and asked if I absolutely needed a bronze gear and yes I do.

Here is a link: http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=646&sb=0

I'd honestly like a smaller cam, this engine is going into a ramcharger. Motor specs are LA 360 .030 over, kb step dish pistons, stock rods/crank, 308 heads w/ 2.02 valves, roller rockers, 1 5/8 tube headers, 9-9.3:1 compression, gasket matched eddy performer intake, prolly start with a 600cfm carb, truck lives at 6500' altitude. I may look into a smaller cam with a cast gear for normal people. I'd like to keep my stock torque converter.

I don't understand what the point of a bronze gear is. I know it's cause of the billet cam core but why not just use a cast cam gear and be done with it? A bronze gear with a hardened shaft is around $200 and a roller cam is about $300 if you're lucky.

Last time I'm ever using a roller cam haha

Thanks for the quick replies guys!
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Hey T56, i had the same question to the comp tech after i bought my xr286hr from them. First tech said bronze gear drive is necessary, second said no, not necessary.....after checking here with some pros i found out that it´s not necessary with these cams. Look at your cam, the shaft is cast, not billet.

If i were you i´d go with the standard gear, hardened shaft if you have a hv pump (don´t like this pump, but that´s another story...:))

Michael
 
Lame..there doesn't seem to be any cheaper alternative, my cam has been used before. I don't mind inspecting a bronze gear a couple times a year. I just don't want to replace a $215 shaft and gear after a year ya know? I'm on the boarderline of what to do, buy a bronze gear and shaft or buy a cam. anyone have any cam recomendations for use in a truck? I have 3.23 gears, stock converter, 31" tires. I honestly think a smaller cam would work better for my application but changing a cam mid build is a tough decision when I already have the correct springs.

I'm going to take some measurements and post some pics before I decide anything.
 
360duster, you bring up a good point. I think the cam gear looks cast if I remember right. Will check on this tonight! Is a billet cam gear shiny or dull? Mine is a dullish black
 
i took a look at mine during preload setup five minutes ago, it´s definitely cast - you´ll see it. Another thing to mention: did ma mopar make a difference between the intermediate shaft for LA or Magnum? No, because the magnums hydraulic roller cam is a cast one, just like yours.

Michael
 
So i guess they are making melonized gears for us too. thats a good thing. but why not on a used cam???
 
Yes you got it.I was one of the first guys in my area to run a rollor cam.It was a custom grind racer brown som where in the 640 lift range.I had the same problem and found I had to adjust the shaft.Once that was done I had no problem in that area again.It was nice helping Mark
T56MaxTorq said:
Thanks dartcuda, I will take pics of the worn gear when I get home. I'm assuming this is how my gear became so worn down but I do not know for sure. I had to actually take a stock shaft and press on a new bronze gear, so I wouldn't be shocked if I messed that up haha

So basically, the gear should ride on the bushing in the block freely and the tip of the shaft should float in the oil pump and not bottom out on the pump.
Click to expand...
 
Here's what I'm dealing with:
 

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Ok I THINK I have this straight. My previous machinist was an idiot in giving me this hunk of bronze and the tech at comp cams was incorrect, and I was simply ignorant by installing it in the first place. I do not need a bronze gear for the intermediate shaft. Bronze gears are only for solid roller cams, not hydraulic. I looked up several hydraulic roller cams on comp cams website and they all list no special instructions or cautions for a hyd roller. When you browse their solid rollers, they require you to buy their bronze gears.

DartFred, you do NOT need a bronze gear for the intermediate shaft. But please double check my work. If it is a billet gear it will be shiny like the lobes, not a dull black like every other gear.
 
Oh, mine is looking very different. Don´t want to worry you, but mine is definitively a cast surface between the lobes, not machined as yours. Are you sure it´s a XR274HR cam? is there any number on the cam where you can verify? Did you buy it new or did you get it used?

Michael
 
It was a new cam. I believe a custom grind but the specs are the same as a XR274HR. I have the grind # and so ID on the cam itself.
 
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