Msd distributor concern/question

[Jimmy P]

For those using the MSD Distributor like myself can yous chime in and tell me if you've heard that one MUST, WITHOUT FAIL, use the brass gear found on the distributor when being used on a SBF motor? I'm being advised by a very reliable source that the brass gear found on the distributor must be used, checked and replaced about every 2-3K without fail because its actually made to disintegrate into the motor requiring more frequent oil changes. If not checked at intervals it will tear up the cam and eventually the motor. I find this hard to fathom but if true I will of course place into my periodic maintenance schedule. As always, thanks.

[Kirby Schrader]

Originally Posted by tractorboy

For those using the MSD Distributor like myself can yous chime in and tell me if you've heard that one MUST, WITHOUT FAIL, use the brass gear found on the distributor when being used on a SBF motor? I'm being advised by a very reliable source that the brass gear found on the distributor must be used, checked and replaced about every 2-3K without fail because its actually made to disintegrate into the motor requiring more frequent oil changes. If not checked at intervals it will tear up the cam and eventually the motor. I find this hard to fathom but if true I will of course place into my periodic maintenance schedule. As always, thanks.

Jimmy,

This subject is a messy one.... There are steel gears, composite gears, brass gears... and lots of opinions.

The key is to check with the cam manufacturer. You need the correct distributor gear for the cam you are using.

Based on my personal experience, if you have the gear mounted on the distributor shaft correctly so it is meshing with the cam gear correctly, then you'll get a lot more than 2-3K miles out of it. And circumstantial evidence that I can't truly prove (which has also been said by others 'who know') is that the second brass gear will last longer than the first one.

Also, it depends on the load the oil pump is putting on the shaft/gear.

Find the details on the camshaft you are using and check with them.

FWIW,
Kirby

[Ron Earp]

Roller cam, steel gear. Get it installed at the correct depth on the shaft. As Kirby says, check with the cam maker. If you match the correct gear / cam and have it properly installed on the dizzy shaft it'll last forever.

[Pat Buckley]

Also consider what oil pump (HD?) and oil (50W?) viscosity is in use.......the oil pump is driven by that gear so the higher the load the more wear.

Those cold starts should be gentle.

[Bill Musarra]

Comp Cams will concur about the brass gear. It will go in short order. Great for racing because you inspect it routinely as the year progresses. I used the standard gear that came on the MSD dizzy and it was eaten by the roller cam. Their advice was to use the composite gear. The gear if I am not mistaken is set with a roll pin isn't it?

Bill

[Mike Drew]

Kirby is right. Different kinds of cams (that is, cams made from different materials) require different kinds of gears. The vast majority of cams are made on iron billets and use iron gears. Most roller cams are made on steel billets, and they require steel gears.

If you run a standard iron gear on a steel cam, you'll find yourself being a pedestrian before you know it.

I was a victim of this last year. I had a steel roller cam in my Pantera and knew I needed a Crane steel gear to match. Crane had gone bust for a few months and the supply of gears dried up. Then somebody told me they had one, and sold it to me. Into the motor it went. The car ran fine for awhile, but then I drove it at a track day, and this was the result:





Turns out the guy who sold me the gear was sort of scamming me, and convinced me he had a Crane gear when in fact he had a Mallory/Accel gear. They say right on their website that this gear is NOT intended for use with steel cams.

Bronze distributor gears are designed to be sacrificial--they start to wear out the minute you turn the key. I helped another Pantera guy a couple of years ago who bought his car without knowing it was so-equipped--he took it on a road trip and made it from Medford to central California before the thing took a dump. The gear was totally gone.

As far as I'm concerned, a Bronze distributor gear is NOT a viable solution for a street car. They're fine on a race engine, where the engine comes apart routinely and the gear is sacrificial. But if I'm pulling the distributor out of my street car, that means my street car is broken. Having to replace the gear every 3000 miles or so is unacceptable. That's like installing a tire with a nail in it that will go flat every 24 hours. Sure, you can keep putting air in it and keep it going, but is that smart?

So, start with your camshaft. Determine what kind it is, and then take the appropriate measures.

[David in Durango]

Mike, and all,
I have to agree about the brass gears, as I went through this with my Kirkham.

However, as witnessed by the quotes below, as well as others w/ multiple engine experiences - THE GEAR NEEDS TO BE INSTALLED AT THE CORRECT HT.

"if you have the gear mounted on the distributor shaft correctly"
"If you match the correct gear / cam and have it properly installed on the dizzy shaft it'll last forever.<!-- google_ad_section_end --> "

and I have been told that a brass gear will last if installed properly.

I can't argue w/ what's been said: ask the cam maker to get the correct gear
and install it properly.

David

[Woody]

Hi Guys
The rule is simple, cast iron , which is most oem and replacment cams run cast iron gears. steel cams which is most rollers run bronze. The good quality gears are made from silicon alloy bronze and they will last for years if fitted corectly and are no more sacrificial than the rest of the parts in your engine.
Woody

[Jimmy P]

Guys, I appreciate all your responses. I'll make the advised checks and move forward from there. In order:

Check the type of CAM in the car
Use the appropriate gear type (steel, brass/bronze, iron)
Make sure it's adjusted at exactly the right height.

Would using synthetic oil be a good or bad choice when using a brass gear?

[Frank3]

A good quality Synthetic oil is always a good choice !
I've been under the impression that bronze or brass gears are used with gear drives ( instead of timing chains ) , but my neighbors T-bucket has had a SBC with a Pete Jackson gear drive for the last 5 years , and I just switched the 4bbl intake to a 3-duce set up , and inspected the cam as well as the distributor gear ( which is a stock gear ) , and all is well .
The bronze gear is meant to keep the cam's gear from wearing , not any particular reason to use it with a MSD distributor .
So I guess cam manufacturer is the best source on this .

[Mike Huddart]

Gentlemen,
aren't we missing something here, to my knowledge, certainly all I have seen, all Factory Ford hydraulic roller cams are steel billet and, also, to the best of my knowledge all those Mustangs, pick ups etc, don't have to change their disi gears every 3000 miles.
They use a steel gear on the distributor not bronze, MSD do one as an option, might be worth looking at that.
Mike

[Howard Jones]

Ron is correct. I can confirm same. SBF hyd roller cam engine. Steel cam , MSD small cap billet ready to run, steel gear. All OK, no wear at >12,000 miles.

[Randy V]

Originally Posted by mike huddart

Gentlemen,
aren't we missing something here, to my knowledge, certainly all I have seen, all Factory Ford hydraulic roller cams are steel billet and, also, to the best of my knowledge all those Mustangs, pick ups etc, don't have to change their disi gears every 3000 miles.
They use a steel gear on the distributor not bronze, MSD do one as an option, might be worth looking at that.
Mike

X2....

And resist the temptation to install high pressure or high volume oil pumps ... Simply not needed for any street use engines nor even most engines used in competition.

[Randy V]

By the way,

Most of the distributor gear mfgrs are now color coding with paint. Yellow or orange for steel, blue or violet for cast. Sometimes just a dot and sometimes a stripe, sometimes it looks like the washed the gear with it..

[Bill Musarra]

This is an old thread, but was tring to get some info on the cam in my engine and stubled onto this video by Comp Cams. This, from their web site, is their word on which gear to use with which cam and how to determin which cam you are putting in the engine.

COMP Cams® Quick Tech: Selecting The Correct Distributor Gear - YouTube

Bill

[Cliff Beer]

The standard reasoning behind using a softer metal in one gear v. the other gear is to try to preserve the life of the gear which is more expensive/more difficult to replace...hence the softer (often silicon bronze) gear is the one that is cheap and easy to replace. In theory.

Using a silicon bronze gear on the dizzy drive doesn't make any sense for your average SBF. SBF camshafts are incredibly cheap, and not difficult to replace.

Now, if you have a custom (expen$ive) grind on your highly tuned race engine camshaft then perhaps it makes sense to use a silicon bronze dizzy drive gear. After all, as other's have said, it's likely the dizzy is coming out for inspection on some semi-regular basis. And, it's worth trying to preserve the gear teeth on that custom grind cam.

But for a regular SBF in your average GT40, makes no sense. Use steel/steel or iron/iron, make sure the tooth engagement is correct (use a depth gauge) and you'll be just fine.

[EGLITOM]

interessting thread

Any "how to´s" about installing and or checking the correct distributor height?

Thanks
TOM

[EGLITOM]

Found something here

http://www.cjponyparts.com/images/ar...ll_M12390L.pdf

TOM

[Kevin Box]

This info from Comp cams may help

Personally I prefer the ones listed in the Ford SVO book - after all, the 5.0 roller cam engines run hundreds of thousands of miles without trashing their gears. In the past I have started with a stock 5.0 roller cam and had it custom ground and re-hardened - This combo goes well with even with the stock 5.0 gear - never had one fail !!!!







Cheers Kevin B

[Brett James-McCall]

This is the info I got from Comp Cams recently on my XE274

Brett James-McCall ‏<S>@</S>Brett_GT40
<S>@</S>CPGTech Can you tell me which dist gear I should be running on a XE274H to go in my 302. I have a MSD 8579 dist to go int the engine. Thnx

<SMALL class=time></SMALL>
<SMALL class=time>3 Aug</SMALL> CPG Tech ‏<S>@</S>CPGTech
<S>@</S>Brett_GT40 We have both a roller and flat version of XE724. If flat, you need a cast iron gear. If roller, you need a melonized steel gear