When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi guys, have a question about my cam and distributor gear setup. I am a little confused because I am getting conflicting answers from all over the place. So I just built a 331 stroker that I put in my 65 fastback, I put a comp cams hydro roller cam in it while running my Petronix distributor. cam # is 31-422-8 if interested. I have had it running for a few weeks and have about a tank of gas through it now, so I am still breaking it in. When I was online the other night I read a few stories of their dizzy gear destroying their new cam, material getting in the oil pump and completely trashing a brand new motor!!! This obviously scared me, I checked the oil and there is small black metal residue on the white rag ( I figure this is 100% normal break in wear and planning on changing oil once it hits 500 mi) now I called petronix and they said their gears are "hardened steel" then called comp cams and they say it can cause damage to your cam. BUT their website says a hardened steel gear is ok with this setup...... OK?! The "composite" gear can run with ANY cam , so I'm really thinking of just going to that. The question is, Has anyone on here run a hardened steel gear on a hydraulic roller camshaft??
I am running a hydraulic roller cam by Comp cam with MSD dizzy. MSD says you need to use a steel gear with the harder roller cams...I was told by Comp to also run a steel gear.
I did run a cast iron gear on the cam for a bit..the gear on the dizzy wore excessively I switched to a steel gear and the wear seems okay ...both the steel gear and the cam have wear marks but nothing like the scary knife edge stuff you see on dead cams...but yeah its got wear marks. They dont appear to be out of tolerance or getting worse.
I daily drive the car and I think that running the steel gear on the roller cam is the way to go.
However I never saw any metal in the oil but this was not a new engine just new cam and lifters and heads...So if you are seeing metal it better be from something besides the cam and dizzy gears.
Here is a picture of the steel gear I ran for about a year daily...many miles. This gear is fine but was installed by MSD to replace the cast iron gear and it spun off of the dizzy shaft and I blamed MSD for crappy work and cutting corners they replaced the entire dizzy and the new one came with a steel gear on it which I am running now.. Never mind the green arrows
thanks for the reply Gun Jam, so to clarify, the metal in oil just looks like a little dark shiny residue on the rag. Honestly I believe this is 100% normal for the first oil change or two, have seen this in the last 3 motors I have had built.
So just to make me feel better I need to confirm what material the cam gear is made of. This is a "retro fit" roller cam ( designed to go in SBF that did NOT originally come with roller cams. So wondering if the tech guy from comp cams is saying that because they are designed to fit an iron gear like original possibly?? I cant see anywhere where it says what material its made out of
31-422-8 "Magnum™ Retro-Fit Hydraulic Roller Camshafts, For engines that DID NOT come from the factory with hydraulic roller cams, NOT FOR E.F.I."
Im pretty sure mine said the same thing...im using linkbar lifters a spider is the other option which is the retrofit part as far as I know.
Thats all the verification I can provide...did you try asking another tech? Maybe call again and ask someone else and if they say to use a cast iron gear have them explain why and let them know that the rest of the world is using steel gears...why? Is is specific to that exact cam that goes against the grain for hyd rollers???
was thinking the same. Just need to call and talk to them again, it really should be fine the way it is. Im most likely going to just go with the composite gear, they are compatible with ALL cams. I don't know why all dizzy's don't just come with these standard. I understand there more expensive ( about 115.00) which is not cheap but it would be much cheaper than a rebuild petronix or MSD may be liable for. there is a few stories online where summit and jegs says that dizzy has an "iron" gear and summit replacing a brand new crate engine for the damage it did by shredding the cam gear right away by and not stating they are steel.
just an update, talked to comp cams again. they are suggesting a "melonized" gear. its a steel gear with a softer grey coating on it. will run with all cams and types. ordered from jegs it was about 80.00 but I feel this is worth knowing its ok instead of me worrying about it like I have been. I have driven the car a few more times since this. think I have a good 400 miles on it by now, I might take it out once more before I replace the gear next week
Now for the hard part...Good luck getting that gear on there. I gave up directly, A local machine shop ****ed up the first time, MSD hacked the job the second time (See above image of gear spun off dizzy shaft) MSD also screwed the pooch on the 3rd try (bent the dizzy shaft) but MSD appears to have nailed it on the 4th go!
yes
then use a jig and multi ton press to remove the old gear,
Then attempt to line up the pin hole in the new gear with the hole in the shaft, Then press that bitch back on using the jig and hyd press. then hope the hole in the gear is the right depth because MSD states gear to flange tolerance of 4.005 to 3.996...outside of that you risk cam failure. Measure it and find out its not so press the gear back off rotate it 90 deg press it back on until you get something like 3.9985 then drill a new hole and stick the roll pin in and hope the shaft doesn't break due to all the holes in it (This is actually an acceptable method of install per MSD)
maybe if you ask nice the folks at pertronix will do it for you..just double check that its within tolerance when you get it back.
12-22-2016, 06:44 PM
URGENT CAM QUESTION
