Distributor Gears

General engine tech -- Drag Racing to Circle Track

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Powertrip
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Re: Distributor Gears

Post by Powertrip » Thu Oct 12, 2017 5:43 pm

BradH wrote:
Thu Oct 12, 2017 9:07 am

I'm switching from SFT to solid roller for the first time with my build in progress. A couple of steps I'm taking to reduce bronze gear wear are deburring the cam gear using a wire brush attachment with my Dremel, and using a collar on the distributor shaft that limits the movement of the oil pump shaft when the distributor is installed. I'm also packing the spaces between the teeth of cam and oil pump gears with JGR/Driven assembly grease to help during the initial start-up.
Brad, have you considered drilling the main oil galley to squirt a small stream of oil directly into the interface between the gears?
The price of progress is trouble.

canada1
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Re: Distributor Gears

Post by canada1 » Thu Oct 12, 2017 5:44 pm

The Crane steel distributor gears will wear the camshaft gear - most do not inspect the camshaft gear.
The steel distributor gear looked fine after a few years, however when looking at the camshaft there was a fair amount of wear.
Out came the camshaft. I would rather have a sacrificial distributor gear than a sacrificial camshaft. Gears cost much less and are much easier to replace than the camshaft.

Just my experience.

tuffxf
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Re: Distributor Gears

Post by tuffxf » Thu Oct 12, 2017 6:23 pm

Gday
In my opinion which means jack!
Ring cstraub and buy one of his bronze gears, they are the real deal and a quality piece.
If in any doubt the bronze gear can be used successfully with any material cam.
As long as its setup right they last for ages.
Big difference in quality now days.
Cheers

BradH
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Re: Distributor Gears

Post by BradH » Fri Oct 13, 2017 8:21 am

Powertrip wrote:
Thu Oct 12, 2017 5:43 pm
Brad, have you considered drilling the main oil galley to squirt a small stream of oil directly into the interface between the gears?
Not sure on a BBM how that would be done. Too late for this build, but something to think about for the future.

BradH
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Re: Distributor Gears

Post by BradH » Fri Oct 13, 2017 8:37 am

As has been already posted, Hughes does not make the Melonized gear themselves, and they don't recommend using one for a HV/HP oil pump, which makes me leery of using one at all.
Crane says not to use their melonized gear with HV/HP pumps; that's one of the reasons I chose not to try one out with my first solid roller cam build.

Dwayne Porter ("PRH") also brought up the question of if the melonized gear DOES where for some reason, what's that sh!t gonna do to the engine vs. when a bronze gear wears?

At least a bronze gear is a known quantity, whereas -- for me -- a melonized gear is uncharted territory.

turdwilly
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Re: Distributor Gears

Post by turdwilly » Fri Oct 13, 2017 10:13 am

For some reason Bullet ground my cam on a 1050 core instead of 8650. Mark told me I can run the OEM-type distributor gear on the 1050 core. I couldn't find an OEM gear, so I used the Crane Melonized gear, which is supposedly the same material, hopefully it will not wear the cam.

mag442
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Re: Distributor Gears

Post by mag442 » Fri Oct 13, 2017 2:19 pm

These two engines that I have noted excessive bronze distributor gear wear, 1 we built and one is from another builder. The one built by someone else is chewing the gears out at an alarming rate. the engine we built, we set up a collar on the distributor to control the gear movement and drilled a squirter for oiling directly on the gear {as someone here has suggested} In our build, the timing has retarded 8 degrees in 500 miles with a new cam and new distributor gear, so nowhere near the wear of the other engine. We did these mods to our build, because we had seen the excessive wear in the other engine. The modifications appear to have slowed the wear. I have only checked it once, so maybe it has bedded in and I wont see to much more movement-wear. A straub bronze gear may be the answer and worth trying.

Geoff2
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Re: Distributor Gears

Post by Geoff2 » Sat Oct 14, 2017 4:53 am

I am running a 8620 Custom Ground sol roller in my Pontiac. I had a steel dist gear nitrided [ melonized ] locally [ Australia ] which I am using. Because of the hot climate, I use 10w/60 full syn oil, as do many other racers/hobbyist I know. 60 lb oil pump.
I am monitoring ign timing, has done about 800 miles & has gained [ advanced ] 1 degree!! I also adjust dist length for centered & maximum engagement of the dist gear & cam gear. This keeps tooth backlash to a minimum. For this block & this dist, it reqd machining about 0.030" off the dist base & shimming the gear to minimise end play. Commiserations to Chev owners with all the variables involved with dist gear centering.

An opinion. When roller cams were first used in the 50s, pretty sure all the dist gears were cast iron, not steel. And were c/iron for decades. Hence the reason for using bronze dist gears. Now, some companies are making steel dist gears, treating them with the Melonizing process & claiming they can be used with any cam material. So is the reticence about using steel dist gears with steel roller cams 'Much ado about nothing' to quote Shakespeare....

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