Learn from my mistake

Ray R · #1 (**permalink**) 06-04-2003, 09:56 PM

We recently finished building my 351W, now actually 408, and decided to use a MSD distributor, part 8458 with vacume advance. My engine builder believes that vacume advance is a good idea for street driven cars since it allows them to run cooler and get better fuel economy. I agree.

The cam we used is a Comp Cam part 35-452-8 nodular iron unit. The distributor came with an iron gear as well. So, we figured iron gear to iron gear would be just like stock...no problem. Unfortunately, the iron gear on the cam was hardened along with the rest of the cam, and wore all of the teeth off the distributor gear in a matter of 15 minutes run time!

So, we immediately called the distributor company, and they said use a bronze gear on the distributor. We also called the cam company, and they said use a steel gear. So now what?

After much research, we determined that a steel gear is the right answer. But there was a better answer! Comp Cams makes a composite gear, part number 35100, that works with ANY cam metal type (billit, cast, nodular, steel, whatever)! It's on the way here.

The really good thing about all of this is that I decided to break the engine in on a dyno. It's a whole lot easier to find out you have a problem when the engine is on a dyno than when it's in a car! And the dyno is the perfect solution for engine break-in!

When most guys get a new engine installed, they fire it up for the first time and walk around the car with it idling, admiring their handiwork and that great sound at idle, checking for leaks, etc. Nothing could be harder on a new engine, except maybe forgetting to put oil in it!

Anyway, the dyno has a super oil filtering system so you can check for particulate content, etc, and it caught all of the debris that didn't fall to the bottom of the oil pan, so the engine is fine. Just a few red faces!

peterd · #2 (**permalink**) 06-04-2003, 10:30 PM

I just came in from the garage having buttoned up the last few wires on my rebuild. I have built a 408 with a comp cam 35-000-8 and a MSD 85805 distributor. I was browsing the web site and saw your posting. I ran back to the garage and pulled the distributor and sure enough it was starting to wear after 10 minutes of run time. Thank you saved my very expensive stroker from sure death. I will call comp cams tomorrow and order the 35100 drive gear.

Rick Parker · #3 (**permalink**) 06-04-2003, 11:08 PM

Just a word of caution here guys. Last fall I was in contact with a gentleman by the name of Frank Mills with "Performance Plastics" the maker of the above recommended gear. We through several Emails discussed the intended and current applications for the product. At the time the gear had only proven viable in a dry sump application, due to the additional load imposed by the oil pump in a wet sump motor. At the time they had ongoing tests that were still being conducted to determine what would be needed to deliver it it wet sump engine builders. It was developed for NASCAR and specifically for Winston/Busch with the dry sump motors. One of the main benefits eluded to was "weight savings" (??) Suggest you contact WWW.performanceplastics.com to be sure before you bet the bank on this one.

Just a heads up

Rick

Excaliber · #4 (**permalink**) 06-05-2003, 12:11 AM

I always woory about composite "stuff",,,,,might be a good thing. Dam I hate being "cutting edge". One thing is for sure, THAT gear needs to be carefully thought out, measured and worried over. Steel, brass, composite or whatever. More than a few motors have been it's "victim" before!

Ernie

auto10x · #5 (**permalink**) 06-05-2003, 05:53 AM

Sometimes these types of problems are caused / agrevated by the used of a high volume oil pump, perhaps even trying to pump 20W-50 oil. Argueably, neither of which are needed, IMHO.
auto10x
Bill

peterd · #6 (**permalink**) 06-05-2003, 01:25 PM

I contacted MSD and have ordered part #85834, this is a steel drive gear.

Ray R · #7 (**permalink**) 06-05-2003, 03:39 PM

The other thing that's kind of funky on the MSD distributors is that the gear is pressed fit, so when you replace it, you have to press the new one on and drill a new hole for the pin. MSD recommends a max of two holes per distributor shaft.

BTW...you can get the MSD steel gear from summitracing.com for @$60...part number 85834.

Jack21 · #8 (**permalink**) 06-06-2003, 05:22 PM

There is a Ford SVO steel gear, available from any Ford dealer, or speed shop for about half that. These were OEM on 351W '94&'95 roller motors.

Ray R · #9 (**permalink**) 06-06-2003, 10:03 PM

So I call MSDs tech line again today, just to make sure I'm getting the right gear for my application. They guy at MSD insists that I should use a cast distributor gear, and the ones that come with their distributors are hardened to a "rosswell hardness" of between 50 and 57, with most of them being around 56. When I tell him about what happened to the gear originally, he said my cast cam was too hard, probably hardened to over 60+. So I called Comp Cams tech line, and the guy there said he couldn't tell me what the roswell hardness of the cam was, and I should use a steel gear. When I told him the guy I talked to previously at comp cams sold me a composite gear, saying "it would work with any metal type", he said the composite gear would probably be too hard for my cam. I guess my real frustration is not being able to get any sound advice from the sources! It seems the real story is that you should use like hardness metals for the cam and distributor gears. But what about bronze distributor gears with billit steel cams? Those can't be like hardnesses.

Does anyone know anybody that has the "real story"? Each time I call the tech lines for the manufacturers, I get a different story. It's like the engine builder said, "It's really hard to find good aftermarket performance parts anymore. They've all gone 'production', and don't pay enough attention to quality." Geeze, isn't that the truth!

I've got a steel gear on the way, and will be using it for the next dyno run....probably June 14th. I'll keep you posted.

Now my wife has jinxed this whole project (Superformance 1649 to be delivered this month, Ford 408 Windsor in progress, TKOII waiting in my garage). She says she's got a bad feeling in her gut about all of this!

The good news is that the tuner and builder searched through the engine and found zero damage. The filter system did it's job, and the oil pan caught the rest. This thing ought to be rock solid bullet proof once we get the whole distributor gear thing figured out. I just pray the engine gods don't decide to mess with me and prove my wife right!

peterd · #10 (**permalink**) 06-07-2003, 08:50 AM

I just got my replacement gear, when I talked with MSD they told me I should use a steel gear with a roller cam. My part arrived and I put it on last night this requires you drilling a second hole in the distributor shaft. One thing I didn't check in the original was that the distance from the distibutor ring which mounts flush with the block and the bottom of the gear is 4.00 inches +/- .005. The gear I took off was soft, I could file it easly and did not appear to be hardend at all. I will let you know how it goes, if the rain stops I will be firing it up today. The guy at Comp Cams also said steel gear. He also told me that a roller cam is ostempford (not sure on the spelling), it is a cast cam which is specially treated and is very hard. BTW make sure you put cam lub on the gear it will come in the box with the gear.

ENTDOC · #11 (**permalink**) 06-07-2003, 09:38 AM

I see no way the distributor gear you lost could have disentegrated in such a short time unless other factors contributed.A bronze gear is standard with retro roller conversions and of course much softer than steel(that is the idea,wear the bronze gear not he cam gear)There must have been an alignment problem or otherfactor.Look up Butcher's build page,he has a wealth of info on the subject.I also do not see the composite gear as likely to wear out the cam gear,they are not made of ceramic. chuck

zipzip · #12 (**permalink**) 06-08-2003, 06:43 AM

Just to clarify things:

"Rosswell" hardeness is really Rockwell hardness. This is simply a common methodology to measure hardness of a material. It deals with the depth that a diamond point will penetrate under a fixed load. A Rockwell "C" hardness of 60 to 62 is indicative of a carburized material and is "file hard" meaning a file is about the same hardness.

"Ostempford" is really austempered - a heat treat condition generally used for cast ductile iron. If you're really inquisitive, and want to be totally bored, go here: www.appliedprocess.com/html/what_is.html

With a cast iron gearing, one member must be a different material than the other. This is because of the metallurgy of cast iron. Two cast gears together are basically like rubbing two pieces of sandpaper together. A bronze, steel, or composite gear should work - I would heed Rick's advise though on the composite. If designed correctly, the composite should be the least sensitive to any oil problems - it could almost run dry. For proven performance, go with the steel or bronze.

Todd

Back in Black · #13 (**permalink**) 06-08-2003, 10:00 AM

By Ford performance...

is 15/50 So, since I cannot find that viscosity, I am using 20/50 Valvoline racing (street) oil, and I am glad I am, since my motor is still running hot in traffic/cruise conditions. Break-in and all that

peterd · #14 (**permalink**) 06-08-2003, 04:40 PM

I fired up the motor today and ran it for 20 minutes, removed the distributor and checked the gear, no sign of wear. I will check it again after more running. Looks like steel gear was the right choice, good luck on the Dyno. Now onto tuning the ECU with my laptop (so many variables so little time).

Ray R · #15 (**permalink**) 07-03-2003, 10:54 PM

Yep! Steel gear is the right one. Ran the engine for quite a while and the gears show no signs of wear.

I picked up the car last week and am beginning to work on the installation. It's a bit more work than I originally thought, but alot of fun!

Mestizo · #16 (**permalink**) 07-12-2003, 01:14 PM

Hey guys, I am still confused about this. Isn't the steel gear on the distriburtor shaft what got damaged in the first place? Did you determine a particular hardness or supplier? What says it won't happen again? Did anyone try the composite gear? I would prefer steel as well but that's what was on there when the problem came up, right? Is it just alignment and lube then? Or do you have to know and match cam gear hardness to distributor gear hardness?
Any advice would be very much appreciated. Thanks.

peterd · #17 (**permalink**) 07-13-2003, 10:53 AM

In my case the problem was with a cast gear, the steel gear solved the problem.

Ray R · #18 (**permalink**) 07-14-2003, 12:28 PM

Ya..the original gear on the distributor was a hardened cast iron. The cam gear was also a hardened cast iron, just hardened much more than the distributor gear. A steel distributor gear matched with the really hard cast iron cam gear seems to be working fine.

Mestizo · #19 (**permalink**) 07-18-2003, 07:19 AM

Thanks for the clarification guys. I will make sure the steel gear is on my MSD shaft.

fxbill · #20 (**permalink**) 07-25-2003, 02:09 AM

I lost an engine for the very same reason.....stupidity on my part....and it only took 10 miles with an iron gear against a new roller cam! After an expensive rebuild I installed the only other gear available for the MSD 351 distributor...the bronze gear. After less than 500 miles it was almost gone too. It was only then that I listened to my engine shop when it suggested that I trash the high volume oil pump and install a standard. I'd been running almost 80 lbs of pressure and the standard dropped it to around 60 or so running.....It also stopped all the gear wear.. That was almost a year ago..
I was at the local speed shop the other day and discovered that MSD has recently come out with a hardened steel gear for the 351 distributor. It is also .001" larger on the shaft bore so that you needn't heat it to install it or drive or press it on....makes it much nicer to use...especially when trying to set the end play.