COMPOSITE DIZZY GEARS

WOw, dead gear in only 2500 miles?

Thats what I worried about also with a roller cam. Our drag race motors kill those every year.
The guy at Crane said the bronze was the way to go and would live no problem. I have one in a Hyd Roller 426 Hemi. Im kind of nervous.

Daniel Jones has posted some info about the new steel gears that are compatible with roller cams.
The info is in this post in page2.
http://pantera.infopop.cc/eve/forums?a=tpc&s=8170058552...360025415#6360025415

Brooke, I don't know anyone with a bronze gear that doesn't have accelerated wear issues, I don't like them.

Cams ground from steel cores like those used by Crane for their roller cams require a steel gear, cams ground from iron cores should be able to run with a standard gear.

Crane sells a steel gear for the 351C Ford dizzy, I'll bet they have one for the Chrysler Hemi too.

The issue with dizzy gear wear cropped up at the same time when lobe & lifter wear became an issue, and is caused by the same circumstances, i.e. the reduction in the amount of ZDDP in motor oil.

Chuck that bronze gear, install the proper gear for the type of cam core that's in your motor, and make sure your motor oil has some ZDDP in it.

cowboy from hell

Ok here is the problem.

I have a roller cam. Most likely it was made by Comp Cams. It has already had about 2500 miles on it with a bronze gear that has now failed.

Based on the earlier post I cannot use a steel gear because:

A)I don't know exactly what type of core I have. The engine builder (MCKeown Motorsport Engineering)regards every part of the motor some big proprietary secret.

B)Based on the earlier post by Dan Jones referenced here, once a gear of another type of material has been used, a steel gear cannot be then substituted.

So my choices are another bronze gear, a composite gear or start over with a new cam and steel gear.

So again I ask the forum members what can you tell me about the reliability and wear characteristics of Comp Cams Poly Composite Distributor gears with a roller cam core?

If you don't get the info you need here go to this link at the GT40s forum. Very informative.

http://www.gt40s.com/forum/gt40-tech-engines-induction-...-windsor-engine.html

One of the posters in this thread is running a composite gear.You could join and PM him.The thread is over a year old so he would have some miles on it by now.
They also claim 2500-4000 miles is typical for a bronze gear.

Using a Bronze Gear and then you cant switch to a steel gear...why not ask our Metalurgist friend if this is true OR call COMP CAMS ... I have only heard problems from COMP CAMS ..cheap china steel.

Ron

BUELLER? BUELLER? BUELLER?

ARE YOU TELLING ME NOBODY KNOWS ANYTHING ABOUT COMP CAMS POLY COMPOSITE GEARS?

quote:

BUELLER? BUELLER? BUELLER?

ARE YOU TELLING ME NOBODY KNOWS ANYTHING ABOUT COMP CAMS POLY COMPOSITE GEARS?

Shhhh...

Please stop shouting.

The comp pieces are pretty new so lack of feedback should be expected.

Did you follow up on the lead from the GT40 forum?

Have you called Comp and asked them your questions?

And are you telling us MME won't even tell you what TYPE (steel, iron) cam they used??!!

Geeesh, those folks have just about erased themselves from MY list of potential future engine builders. I have no need for Prima Donna engine builder snobs.

Larry

quote:

Originally posted by DJEZC:
BUELLER? BUELLER? BUELLER?

ARE YOU TELLING ME NOBODY KNOWS ANYTHING ABOUT COMP CAMS POLY COMPOSITE GEARS?

While all the guys on this site know almost everything it turns out they only know 99.5% of everything and your gears are the other 5% !!
I have heard of the gears, have heard they are better but have no actual first hand experience. All my rollers have had bronze gears. I agree make sure you have good oil with plenty of Zinc. you should get more life than 2500 miles. is your oil pressure ultra high ? that would put more load on the gear.

I believe I have a standard volume oil pump, aleggedly blue printed. Given what has happened to date I don't trust any statements made by McKeown, so who knows the truth about the oil pump.

McKeown at this point is not answering questions, though I may be able to get an answer about the cam core used from Comp themselves. I am going to try today.

I am sure it is steel as it is a mechanical roller cam. I just don't know what grade to know if it is compatible with a steel gear.

As for oil I use either Amsoil 20/50 or Royal Purple 20/50. Both of these should have adequate additives and roller cams are supposed to not need large amounts of additives which is why manufacturers are using less of them since new cars are not using flat tappet cams

Mckeown is not giving you info because you POST IT ALL OVER THE WEB ? How many times have you posted the specs of your engine ?

You figured out your own answer. The oil your using is Tooo heavy try 5w 30 synthetic and guarranteed the gear last longer. The oil your using is too thick and causing the gear undue stress because the oil is too heavy ... its what drives the oil pump ..Ceralli and Olsen dont recommend 20w 50 ... No reason for it ...all the new cars run thin oil . Audi recommends on all the turbo cars 0w 30. You can run a thin oil synthetic because it holds its vescosity. I have run many race engines with this oil and never had a problem.

The Polymer gear may last longer ?

But I have another question ? where did all the brass fillings go from the old gear ?? Impregnanted in the bearings ?

Given the clearnaces on the bearings it was reccomended that I run 20/50.

McKeown is not answering because they really don't take care of their customers, they just try to extract as much as they can from them.

The filings should be in the filter, but I will know that later this week.

George is correct.

Just got off the phone with Crane and they said that I would be lucky to get 1200 miles out of the bronze gear. Crane said that I should have used the steel gear PN 52971-1 (.531 dia). I told them that when I got the roller cam from Summit they recommended the bronze gear. He said that they should not have. Summit is backordered on the steel Crane gear but they have 3 Ford Racing steel gears PN FMS-M-12390-J, I ordered 1. I've got 40 miles on my engine now and things run great. The next problem is that I have 2 holes drilled in the dist shaft so I'm going to have to try to line up the steel gear with one of the existing holes. Crane said that I will see bronze shavings in my oil, even with only 40 miles. I glad you guys brought up this problem befor I was stuck somewhere with a big tow bill.

Well at this point the Comp Cams composite gear is on the distributor and I am going to be putting it back in and re-timing the engine.

I'll keep you updated as to my results. I guess I will be the guinea pig this time.

DJEZC,

Sorry your thread got somewhat hijacked, me included. I'm amazed that MME can't tell you more about your cam, like if it was steel, so you can get the correct gear that would last. Good luck

Some info I found

link to info on composite gearinfo on composite gear

Are you sure that the steel gear on a steel cam will not wear the Cam gear instead ? Comp Cams mentioned that to me 2 weeks ago ...

My Metalurgist friend Mel suggested coating the cam gear with a special coating to make it resist wear using a steel gear. If Mel is at the site maybe he can elaborate on this method.

Ron

Ron,

Not sure but I was thinking about a transmission. Doesn't a tranny have all steel gears? Don't they wear equally? I'm not sure but just throwing that out there. With this in mind I believe that Crane is correct in saying use a steel gear with a steel cam. I'm no expert but it makes sense to me that they will wear equally. Crane said at least 100k miles.

At this point the steel vs bronze argument is moot.

I have gone with the Comp Cams composite gear.

I had my friend Mel install the Comp Cams composite gear on the dizzy. It dialed in perfectly with a spec of 4.033". (The gear needs to be between 4.031" and 4.038")

We installed the dizzy in the motor last night. It dropped in fairly easily.

MME specified 6 degrees initial timing and we got a reading of 8 degrees right from drop in.

Later this week I will adjust the valve lash. Once the valve lash is set I can get the engine up to temp, set the timing and I should be good to go.

I'll let the forum members know what my experience is with this type of distributor gear

Exactly .. we use cast gears on stock engines and comp and crane recommend steel on steel .. in both trans, rears, and everything else in the usa .. the idea of possibly coating the cam is a little overthinking the issue ..but it may save us , you, me or them from having to replace a cam IF the steel on steel combo dont work .. ME I alreayd have steel on steel and owned FORDS my whole life ..and as a young guy building hot rods never had this problem ....MY 351C gear issue was from POOR assembly ... the gear broke one night on my way home from a cruze night on 287 ..I tore her apart and found PERMTEX that was applied to the scrw in OIL PUMP pick up and applied in the THREADS of the pump ... In the PIPEFITTING industry thats a NO NO .. of whichone of them is exactly what happened ..the compund ends up dislodging itself and some where either in a pump or piece of equipment jambing or clogging it up.

My Story with cam gears.

Ron

I guess we will here from you in about 1000k miles or so ..LOL

Ron

Ford started putting steel roller cams in the 302 Winsor in 1985. The distributor has a steel gear. That's over 20 years ago.