BBM solid or hydraulic roller cams on the street questi

Posted By: Moparmatty

BBM solid or hydraulic roller cams on the street questi - 12/03/12 04:23 AM

I've been getting some information lately that running roller cams on the street in our beloved Mopars is bad news. Ive been hearing stories of the distributor gears burning up rather quickly.

I want to run a hydraulic roller in a 500" motor. I also want to be able to drive it 2000 miles at a time if I choose to do so.

Is the burning up of distributor gears an actual problem that exists? If so, what's the fix?

GM and Ford small blocks have been running rollers for years from the factory with out issue.

Posted By: 71yelladustr

Re: BBM solid or hydraulic roller cams on the street questi - 12/03/12 05:29 AM

FWIW, I built a 496 stroker with a solid roller cam w/ MP bronze oil pump drive gear for my buddies 70 challenger. He has put quite a few miles on it on the street over the last 5 years. I too have heard stories about them not lasting so, I pulled the oil pump drive gear to inspect it recently. It had little to no wear on it. Looked good enough to me, so I stuck it back in. The timing has stayed put and no bronze has been found in the oil filters.
I wouldn't worry about it if I were you.

Posted By: Cab_Burge

Re: BBM solid or hydraulic roller cams on the street questi - 12/03/12 08:50 AM

I heard the same urban myth years ago. I called Crane Cams to order two piece BB Mopar roller cam, stock front distributor drive welded onto a steel core, and they ask me why I wanted one, I siad for the street. The rep siad that they had a employee that had a Roadrunner with a big inch Indy motor in it that had been on the Hot Rod tour multiple yeas as well as the One Lap Around America, I assumed it was a advertisement for the company, and it had around 77,000 mile ssn the original bronze distributor drive with no porblems at that time. My 518 C.I. pump gas Duster has going on five years of street(under 2000 miles total) and strip use on its gear and still looks new

The other alternative is a composite gear

Posted By: jbc426

Re: BBM solid or hydraulic roller cams on the street questi - 12/03/12 01:52 PM

I'm running a locking collar on the distributor shaft to keep the bronze gear from climbing up the cam gear. It stabilized the contact interface and decreased the wear on it. It helped stabilize my timing too.

About 1500 miles on the motor and it still looks good. If I have to change it again, I will have the next one cryogenically treated too.

Posted By: Von

Re: BBM solid or hydraulic roller cams on the street questi - 12/03/12 11:23 PM

Quote:

I'm running a locking collar on the distributor shaft to keep the bronze gear from climbing up the cam gear.

How does the locking collar (I use two on my dist drive) help the oil pump/dist grive gear from climbing cam gear when the dist drive is fully seated against the oil pump/dist drive gear?

Posted By: jbc426

Re: BBM solid or hydraulic roller cams on the street questi - 12/04/12 12:45 AM

Quote:

Quote:

I'm running a locking collar on the distributor shaft to keep the bronze gear from climbing up the cam gear.

How does the locking collar (I use two on my dist drive) help the oil pump/dist grive gear from climbing cam gear when the dist drive is fully seated against the oil pump/dist drive gear?

The first few hours I ran my motor without the collars on the distributor shaft.

I could clearly see that the wear marks on the gear were bigger on the gear teeth than they should be with the gear all the way seated on the bushing. The only way the cam gear could make such long wear patterns on the gear, was if the gear was moving up off the bushing while the motor was running, causing the longer contact marks.

Once I installed the collars(I run two as well), there was no more free play. The bronze gear stayed down on the bushing in the block, and the wear pattern of the gear became smaller/shorter.

Posted By: VincentVega

Re: BBM solid or hydraulic roller cams on the street questi - 12/04/12 02:32 AM

Does anyone want to explain WHY this happens? What's different about a roller cam setup that causes this interaction?

Posted By: jbc426

Re: BBM solid or hydraulic roller cams on the street questi - 12/04/12 05:08 AM

Quote:

Does anyone want to explain WHY this happens? What's different about a roller cam setup that causes this interaction?

I think they all do it to some degree, and that's part of the reason the timing jumps around without the collars on. The gear floats up and down as it spins within the up & down freeplay. That changes timing slightly.

Once you tighten it up using the collars on the distributor shaft, the free play is reduced and the gear has to spin within the reduced freeplay. It has less up and down motion because the collars restrict that motion.

The steel gears just handle abuse and wear better.

I wonder if anyone has tried cryogenically treating the bronze gears and seen what the results are.

Posted By: Skeptic

Re: BBM solid or hydraulic roller cams on the street questi - 12/04/12 02:49 PM

Crane cams has developed a gear that is compatible with a roller that isn't bronze. I don't remember exact material right now, it's a little early yet.

Posted By: Dodgem

Re: BBM solid or hydraulic roller cams on the street questi - 12/04/12 03:02 PM

hughes sells a coated gear going by the PN may be crane.
http://www.hughesengines.com/Index/produ...mp;partid=26734

Posted By: Darryls-Demon

Re: BBM solid or hydraulic roller cams on the street questi - 12/05/12 02:50 AM

I have a solid roller cam in my 440 and the timing does not jump around and I do not use a collar, motor has appox 2500 miles on it.

Posted By: BIGSTROKER

Re: BBM solid or hydraulic roller cams on the street questi - 12/05/12 03:46 AM

i have a solid roller in my 500 inch motor
12000 street miles no problems at all
bronze gear with the collar
crane ultra pro rollers $800

Posted By: ahy

Re: BBM solid or hydraulic roller cams on the street questi - 12/05/12 03:55 AM

I went the solid FT route. I've got about 10k miles on an aggressive MM lobe cam without difficulty. I like the benefits of roller but don't care for the bronze gear wear. I understand the collar helps, a standard volume oil pump helps (hope you don't need high volume for hot idle OP on the street), running light oil helps. Still its a wear item while the steel gear is reliably good for the life of the engine and isn't bothered by a high volume pump. Plus roller is expensive.