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What did I do wrong ,tore up gear to a MSD distributor in 454 crate engine


Well-known member
May 24, 2001
We Will All Meet Again
1966,and a 1962 thats almost complete
So My daughter says she wants to take the 62 to a car show On Sunday, So I figure I would take it out for its shake down run to clear out the cob webs. The car currently has about 3100 miles on it since I put it together a couple of year ago. The Motor is a 454 performance crate motor with a MSD distributor with a Barry grant Tri power intake manifold. last year or the year before the car became retarded in timing and I had to re-set the distributor a tooth behind to give enough room to re-time the car correctly as the vacuum can was hitting a bracket . I never looked into what that happened.

Well yesterday when i was doing the shake down run it was running a little rough, and as I was accelerating I let of the gas and heard popping thru the carbs I pulled over and had to come home on a flatbed , After some diagnosis I pulled the distributor and found the distributor gear all tore up. The oil pump spins no problem and the cam gear looks fine

On inspection of the distributor gear it definitely looks as though they did not mate up correctly

this is a link to some pictures of the gear
Let me know what you think

Distribuutto gear - larryvsa's Photos

Shooting in the dark here

The oil pump is going.... ( seizing ) have to spin it and get a feel of it.. ( oil pump prime tool )
Something up top is the distrib ( bearings, bushings or cap rotor and or tach cable gearing ) is doing same...
Car sat to long dry and something rusted ( read drag )...
Is the wear pattern centered on the cam gear / distrib gear ?

The good news, those gears are designed to fail ( or be the weak link )...
The bad news is whatever broke , ground off is in your engine... is the cam gear metal ( eg will a magnet stick to it ) ?
Oh and

was the distrib lockdown bolt tight & in place...
Only 1 gasket on the intake manifold ?

(I have no idea who makes that manifold... maybe the boss the distrib sits on is to tall so cam to crank is not lined up properly )
If the engine has a roller cam the cam is very hard and the dist gear you got was soft and not ment for a roller camshaft. Get the correct gear and change the oil and filter.

was the distrib lockdown bolt tight & in place...
Only 1 gasket on the intake manifold ?

(I have no idea who makes that manifold... maybe the boss the distrib sits on is to tall so cam to crank is not lined up properly )
Looks like your crate motor has a roller cam in it. You need to purchase a melonized gear for your distributor. I'm using the composite gear from Comp Cams with my roller cam and I'm very satisfied with it. Make sure you get the correct size gear. The MSD takes a .500 gear not the normal .491 gear.
Thank you all for the input, yes the crate engine has a roller cam in it. the gear it had on it looks like a steel gear and it has a number 5 on it. I just dont remember reading in the manual I needed a different gear .

Thanks again I am hoping to get a gear today to re install and get the car running again
WOW I didn't know that~

Distributor Gears- Car Craft Magazine
I just wanted to post this incase anyone else out there needed the info.

In my sons 400 that we just built, the machine shop told us, along with just about everyone else we talked to and from articles we
, that we needed to run the bronze distributor gear with the Comp Cams hyd. roller cam.
We were also told that the bronze gear will need to be changed every 10k miles. OR we could spend $100 on the new composite plastic dist gear and never have to change it.

We took it as the truth and on Saturday we got close to getting everything buttoned up and ready to fire. A friend had a bronze gear and we miked the inside diameter and found that the dist shaft on the Accel dist was smaller than stock. Apparently the "Blueprint Accel" HEI dist is a reman unit, and if needed, they turn down the shaft and use bigger bushings and then install a smaller bore gear.

Well, being somewhat budget minded and after seeing over $5000 go into this engine, I decided to ck the Comp Cams web site on the gear situation. I just could not bring myself to spend more on one stinking plastic gear than I spent on my Crane cam and lifter kit that went into my 350.

I called Comp cams this morning and spoke to Matt at the cam help line and asked about the bronze gear thing. He said that on almost ALL of their over the counter hyd roller cams, you do NOT need any special distributor gear! The bronze or plastic gears are needed ONLY on the special heat treated steel billet high teck wizz bang high dollar roller cams. His determining question was "is there an "8" at the end of the part number, which there was. According to Comp, if the part number has the "- 8" at the end, you do NOT need any special dist gear.

Hopes this help someone save a hundred bucks on their next rebuild.

I had similar questions about a roller cam I just installed in my on-going engine build. The cam is also from Comp and is a hydraulic roller. I thought all of these cams were steel, but it turns out that is not the case. According to the Comp Cams tech guy, all of their cams with a part number ending in -8 are cast iron, not steel billet (this includes roller cams). In the case of the cast roller cams, the lobes are given a special heat treating to withstand the pressures of the roller tip. But, since they're iron and not steel cams, they recommend a "melonized" distributor gear (whatever that is) or a composite gear. I'm really glad I checked before doing anything with my distributor because I wrongly assumed that all hydraulic roller cams are steel billet and bought a steel distributor drive gear.

Sounds like you are getting conflicting information - but my recommendation is to follow the instructions of the cam manufacturer - just make sure you have the part number when contacting them.

Stock cast iron gears are not to compatible with steel camshafts


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