DragBoss Garage: The Distributor Gear, Something We Don't Think About Often......enough

[@jeffreylee7184]

The thing to remember is that when the engine cam gear is driving the oil pump gear the thrust created by the gear geometry is downward forcing the distributor gear thrust surface against the block thrust surface. The torque required to drive the pump is quite high at all times even at idle. This means the distributor gear is never going to float off the block thrust surface while running.

[@craig8187]

The torque to drive the pump is not high at all. Total myth. Do a torque to permanent twist and then failure test on a stock driveshaft(i actually just did this on a 302W shaft 10 mins ago revisiting something i did years ago but could not remember the numbers) On the 302W shaft which is 1/4" just 10lb tq puts a permanent twist in them. By 15 lb the wrench will not even trigger off. Considering these can run a HV pump with heavy oil for years with basically no gear wear shows TQ to drive is minimal. Gears fail due to tooth shape mismatch and most commonly the sharpness of the initial contack edge on each gear tooth. Compare a factroy cam to most aftemarket for gear shape to see why gears fail.

[@jeffreylee7184]

Poor description on my part i guess. Regardless what the torque value is if the gear is driving the pump the gear is down on the block thrust surface (if the distributor is setup properly). The thrust must be taken up somewhere or the gear doesn’t drive. I know what I mean, that’s all that matters, lol. If the setup Is so poor that the gear cannot contact the thrust surface on the block ( the gear set too high) the thrust will be taken up within the distributor, this will lead to issues within the distributor.

[@craig8187]

@jeffreylee7184 @jeffreylee7184 absolutely for most of the time the gear is being pushed down against the block surface. Yet I have always looked at this and run time there is always a light wear pattern on the non drive side. Then anything high rpm, trans brake, lots of rpm limiter hitting etc and wear on the non drive side is more pronounced. Is this wear from deceleration during rpm limiter use, is it cavitation in the pump, is it the effects of air being passed thru the pump, is it the rotation of the engine not being perfectly uniform particularly at low rpm? I dont really know but there certainly are times where that gear sees some type of minor load on the back of the gear teeth.

[@tommassey4823]

​@@craig8187lost a 408w build years ago by installing a voodoo cam, this Cam ate the dizzy gear off in just minutes during break in. Never had this happen before, called Holley up and they told me basically everybody knows you need to burnish the cam gear with a wire wheel before installing. Have built and change cams in multiple engines and never done this. They wouldn't stand behind their cam, told me kick rocks. Cost me 5,000 to rebuild

[@DragBoss351Cleveland]

Interesting Jeff but read the reply to you below 👇

[@georgedreisch2662]

High volume and high pressure oil pumps oil pumps tend to accelerate gear wear, as the higher torque across the helical gear increases the thrust / axial load. Another thing I got involved with back in the late -70’s was distributor gear backlash, and had made up dummy distributors to measure. Excessive backlash would lead to spark / timing scatter.

[@DragBoss351Cleveland]

George have heard the wear factor before. But not bad at 20 years of use. Can’t see how all the play I had did not have any issues that I know of. Maybe it did ?

[@chimpfoos65]

Tim Tim why is it giving me the guidelines to comment on your channel and then not letting me come in if you received this I received or sent hundreds of things to you it seems like and never been disrespectful ​@@DragBoss351Cleveland

[@chimpfoos65]

​@@DragBoss351Clevelandalso if you get a chance can you let me know if you helped Andy at Unity Motorsports on his distributor or tried to figure out what his problem is can you assist him on that maybe

[@tommassey4823]

I just can't quit think about 20 years of service from that bronze gear, the wear pad was gone but it still looked pretty good actually. If you don't mind could tell us what motor oil you've been using, weight and change intervals thanks

[@DragBoss351Cleveland]

@chimpfoos65 I have know idea, really what you a saying. Hell you never ever been disreputable or disrespectful. Email a pic and or. Let me know what’s up

[@nonenone1249]

the man the myth the legend. The Drag boss

[@DragBoss351Cleveland]

I love it, I wish. If I work hard maybe one day. I did go to Rual King yesterday and guy came up to meet me. 😊 I’m trying

[@dondotterer24]

Thanks Tim. Alot of people don't check it on any type of engine.

[@frankkoppen7281]

I believe the torque from the oil pump pulls the gear "down " alllll the time ,and is tight against the block, your measuring something that dosen't matter..that shaft will never go up on a running engine. I do watch and LIKE your channel..

[@DragBoss351Cleveland]

I would think that it would too, but had so much clearance, I figure hey might as well change it. Thanks for watching, more on the way. 🏁🇺🇸

[@jeffreylee7184]

The conditions to check are that the bottom of the gear contacts the thrust surface in the block when dizzy is installed and that the dizzy shaft is raised slightly when clamped in place and that when clamped in place you can further lift the shaft slightly, creating a clearance between the gear thrust surface and block thrust surface. These checks ensure that that the gear rides freely on the block thrust surface and you don’t bind the dizzy shaft when clamped in place. I don’t have exact numbers off top of my brain but if for example you had .020 total float in the dizzy uninstalled, you could look for say .010 after installation. The blocks are very old and they vary with respect to the distance between the block thrust surface and the surface the dizzy clamps up on. Not sure one can simply trust the specs that are floating around out there.

[@DragBoss351Cleveland]

Yes and a after I installed it, as You see, it looked good to me, so sending it Jeff

[@jeffreylee7184]

Send it DBG

[@DragBoss351Cleveland]

@jeffreylee7184 right on, I will run on my new engine build and run stand. 💯🏁🇺🇸

[@jeffreylee7184]

The conditions to check are that the bottom of the gear contacts the thrust surface in the block when dizzy is installed and that the dizzy shaft is raised slightly when clamped in place and that when clamped in place you can further lift the shaft slightly, creating a clearance between the gear thrust surface and block thrust surface. These checks ensure that that the gear rides freely on the block thrust surface and you don’t bind the dizzy shaft when clamped in place. I don’t have exact numbers off top of my brain but if for example you had .020 total float in the dizzy uninstalled, you could look for say .010 after installation. The blocks are very old and they vary with respect to the distance between the block thrust surface and the surface the dizzy clamps up on. Not sure one can simply trust the specs that are floating around out there.

[@dondotterer24]

I got lucky and bought the GM shims that went between the gear and the housing on a HEI distributor before they quit making them. But still needed to set the height of the distributor to oil pump. engagement.

[@DragBoss351Cleveland]

Some have mentioned them, to me. Great idea shims. looks and measures Good so running with Don.

[@dondotterer24]

@DragBoss351Cleveland great

[@DragBoss351Cleveland]

I will test it on the new Might Mount. Pro, that was sponsored to me. Alaina the Bossette helped me assemble it on Sunday

[@dondotterer24]

@DragBoss351Cleveland cool

[@tommassey4823]

excellent explanation, I used my 351w dist. in my Cleveland same distributor shaft length, and oil pump drive, just different gear. I even used the same drift pin hole and location was in spec. Ford and MSD have different specs, one may be end play in, and one out, don't recall just now. I used Ford spec for Mallory dist. I was really surprised you got 20 years out of that bronze gear, that baby was dialed in. I use melinite gears when I don't know what the cam material is. the 8 to 10 thou clearance looks much better, and I'm glad you stated when dist. is bolted down. My machinist told me 20 years ago the camshaft gear and the dizzy gear have to float ever so slightly for alignment to account for hard acceleration and deceleration, makes sense to me. I suppose a guy could use a thicker distributor gasket if clearance is too tight, just for a get by. You tube guys having this issue right now are Andy on Mixed Up Boss and the Running Rust guys, hope they watch this and figure it out.

[@DragBoss351Cleveland]

It must have, but did wear as you See with comparing the old and new. Use ford and msd are different specs. Thanks for sharing, didn’t know they had issues, interesting. Thanks Tom

[@abcullens2328]

Tim, another informative video, thank you once again. I don't know if the extra clearance caused the excessive rotor wear, probably just from age and use. How's the engine test stand coming along? Looking forward to that episode. 👍👍🏁

[@DragBoss351Cleveland]

AC, Alaina the Bossette and I assembled it on Sunday. You have to sees to believe, don’t want to spoil the surprise, because I could not bring it. It e been came with custom radiator 💯🏁🇺🇸

[@abcullens2328]

@DragBoss351Cleveland tim, I was wondering if they sent you the fully optioned version with all the bells and whistles, I checked them out on the internet, looks like a really nice engine test stand. Are you going to put your newest purchase on it first? Can't wait to hear a Cleveland fire up on it!

[@DragBoss351Cleveland]

@abcullens2328 yes it is the professional model, with changes they made. The 409 Cleveland will be finished on it. I first saw the Mighty Mount at my old builder Bob Beaches

[@johnnycapan6566]

Great work Tim Keeping the clevo singing..🦾

[@DragBoss351Cleveland]

Right on Johnny. She will be breathing fire and singing soon 💯🏁

[@rolandtamaccio3285]

With a crank trigger the wear or even out of spec does not affect timing ° ; however check rotor phasing . Btw , chamfer the oil grooves on the back of the cam sprocket . Especially the Cloyes .

[@DragBoss351Cleveland]

Thank you Roland, what groves are you talking about?

[@rolandtamaccio3285]

​@@DragBoss351Cleveland,,, the back of the cam sprocket usually has them ,,, !

[@DragBoss351Cleveland]

@rolandtamaccio3285 oh, well not worrying about it, this chain is from 2019, so already worn in 😳

[@rolandtamaccio3285]

​​@DragBoss351Cleveland ,,, yes , and another thing . I've only seen the problem on small and big Chevys ; however I would do it on everything .

[@DragBoss351Cleveland]

I get it. An ounce of prevention, is worth a pound of crap, I mean cure

[@MrPoppyDuck]

Easy question - do distributors that don't run points like your MSD still wear out? By wear out I am referring to space growing between the distributor shaft and the distributor housing. Yes, I know that is not a Cleveland motor question. Am asking as years ago I ran points and high spring tension points caused that distributor to wear out over 60k miles. Am asking as the non points distributor that I put 40k miles ago on my mostly stock 351c has never been checked for wear. I just occasionally check the cap and rotor for wear.

[@DragBoss351Cleveland]

Great question, from breaking one for some reason, they out least msd had sealed Roller bearing inside housing, shaft rides on that

[@MrPoppyDuck]

@DragBoss351Cleveland Thanks. I will look for shaft wobble and play when it is time to get the car out of winter storage. Will also look at the MSDs. I like replacing parts only once.

[@DragBoss351Cleveland]

@MrPoppyDuck great idea. I did not plan changing, but Make is right. Buy once, cry once.

[@mariodouehi1284]

Dont forget by the time oil goes through it itll be even a leser end float

[@DragBoss351Cleveland]

Great point Mario, I never even thought about that, it is perfect Then 💯🏁

[@harryharry3193]

Tim, everyone has their own ideas, I have had plenty of those wear. its soft metal on purpose so it doesnt wear the cam gear. thats the theory, but the factory steel gear lasts long on hyd roller engines. could it be used? maybe.......on a windsor block. those bronze gears are problems on all engines. High vol and pressure pumps put more stress on that whole set up. Brings the question, HOW MUCH pressure do you really need? ill leave that to all the experts. solution? if you look closely, there is a oil galley plug right there behind the gear. MY solution, and I didnt come up with this, is to drill a small hole in that plug....i cant remember if its 0.060 or 0.125 but its tiny.....so that it can spray that gear and cool it off. i never was a big fan of bronze gears...but its what we all do with roller cams.

[@DragBoss351Cleveland]

Harry, have heard that trick before. I’m old school and this dang thing lasted 20 years, figure I will use another, probably won’t live another 20!years. 😳. For that new distributor I got, I may get another gear type other than bronze. Just have had good luck so roll with it.

[@cdburlock]

How do you know where to drill ? Measure vertically ? With gear on shaft ... Does the hole go where the old one was ?

[@DragBoss351Cleveland]

I forgot actually, but when I put a bronze gear on 20 years ago, I had to drill the top hole through one side, this time only through bronze gear CD

[@lykinsmotorsports]

Tim, ditch the bronze gears.... They wear quickly, even on low-time scenarios such as what you have. Billet steel cams get steel gears. I haven't used a bronze gear in 17 years. Never have had a wear issue when installed correctly.

[@DragBoss351Cleveland]

What’s funny Brent is I have not changed this in 20 years and never an issue. The other new distributor, going to do that with. Thanks for watching

[@brucekastle4803]

I’m thinking I saw you using a hammer to press the gear off and on ??? Hmm.

[@DragBoss351Cleveland]

Used a center punch and my 40 year old hammer 🔨 Bruce

[@billfioretti3013]

Drift to get the roll pin out. Small steel disc at the bottom of the dist. shaft and a small puller to get the gear off.(This keeps from damaging the shaft and the take-off gear.) Hold the shaft in a soft jaw vice. A long socket of the proper i.d. will work fine for replacement gear installation. Installed dist. gear height is critical for proper full mesh with cam gear. I check this with every new cam and dist. gear. And always use chromemoly oil pump drive. NEVER the O.E.-style pencil drive... EVEN if using lighter oils and a non H.V or H.P. pump.

[@DragBoss351Cleveland]

@billfioretti3013 perfect synopsis. I could get gear off new distributor, need a puller, next on the list. 👍👍🇺🇸🏁

[@roberthollinshead2325]

I see about .040. Why not put a dial indicator on the top of the shaft and measure it accurately?

[@DragBoss351Cleveland]

Because it is better than it was, has clearance, and I’m lazy Robert

[@markcrockford9679]

I would be inclined to put a shim in between the gear and the body so it cannot drive the shaft up on rotation .

[@DragBoss351Cleveland]

Rotating drives the gear into the thrust surface of the block. Mark, is that what you’re saying?

[@stevejohnson6858]

Has anyone else followed this Don Nicholson restoration? I only recently found this kzbin.info/www/bejne/aImWdn6PrN-Sr9E

[@DragBoss351Cleveland]

Yep saw it at PRI, we discussed a live chat so working on it. Steve

[@stevejohnson6858]

@@DragBoss351Cleveland Awesome. I assume this is a restoration of his championship car. I'm a nuts and bolts guy so I always enjoy the details on the mechanical end of these cars. Including the diffs between his and Bob's Cleveland motors etc. That is if those details are even known. Like I've said before, I've always been a Mopar guy but these Cleveland motors especially in old school PS have seriously piqued my interest chiefly thanks to you.

[@DragBoss351Cleveland]

@stevejohnson6858 thanks my friend. I get it me too, if you look back I have videos on dynos heads, and I almost bought his Fairmont, not financially a good decision. I did sell a pro stock tunnel ram. I was talking with Warren Johnson today. He has one of new blocks, we are building a high port Cleveland together. Watch this. Dyno Fairmont lost for years… and I have way more finds. Look back kzbin.info/www/bejne/r3K0cpWdnLVqY8ksi=6vWmWp8CdM_87sUS