Lifespan of bronze distributor gears

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wikd69
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Lifespan of bronze distributor gears

#1 Post by wikd69 » Fri Jun 18, 2010 2:29 am

I seem to be going through these bronze gears pretty quickly - who else uses them and how much engine time do you get out of them ? And how do the composite gears compare and last ? I'm running a billet cam and can't run the iron gear, so it'll have to be bronze or composite.

I wiped the splines on my bronze gear last nite - I should have been checking it for wear and I let it run too long. Not a big thing but I'll need to peel filters now for awhile.

Image
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

505r10
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Re: Lifespan of bronze distributor gears

#2 Post by 505r10 » Fri Jun 18, 2010 7:45 pm

wikd69 wrote:I seem to be going through these bronze gears pretty quickly - who else uses them and how much engine time do you get out of them ? And how do the composite gears compare and last ? I'm running a billet cam and can't run the iron gear, so it'll have to be bronze or composite.

I wiped the splines on my bronze gear last nite - I should have been checking it for wear and I let it run too long. Not a big thing but I'll need to peel filters now for awhile.

Image

My last bronze gear experience was pretty good. My street driven roller cammed 427 Chevy powered 10 second 1974 Ford Capri ran for three years on the same gear. In the summer I drove it every day, commuted, ran for parts, cruised on the weekends, never had a problem. The car would swing the oil pressure gauge around to 150 psi if I revved up a little when cold. Never seemed to be a problem.



582R10

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wikd69
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Re: Lifespan of bronze distributor gears

#3 Post by wikd69 » Fri Jun 18, 2010 8:08 pm

505r10 wrote:
wikd69 wrote:I seem to be going through these bronze gears pretty quickly - who else uses them and how much engine time do you get out of them ? And how do the composite gears compare and last ? I'm running a billet cam and can't run the iron gear, so it'll have to be bronze or composite.

I wiped the splines on my bronze gear last nite - I should have been checking it for wear and I let it run too long. Not a big thing but I'll need to peel filters now for awhile.

Image

My last bronze gear experience was pretty good. My street driven roller cammed 427 Chevy powered 10 second 1974 Ford Capri ran for three years on the same gear. In the summer I drove it every day, commuted, ran for parts, cruised on the weekends, never had a problem. The car would swing the oil pressure gauge around to 150 psi if I revved up a little when cold. Never seemed to be a problem.



582R10
I'm not getting anything like that. Rob says it may be due to my using a gear drive up front.
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

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supernova
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Re: Lifespan of bronze distributor gears

#4 Post by supernova » Fri Jun 18, 2010 9:52 pm

Hey Harry,
Gear drive's are hard on everything. The harmonics a gear drive creats reeks havic and causes premature falure of lots of parts. Think of it this way, the hit on the valve train is solid and harsh every time a cylinder fires. No cushion what so ever.......

I run a good true roller chain for now and will add a belt drive soon.
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evil16v
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Re: Lifespan of bronze distributor gears

#5 Post by evil16v » Sat Jun 19, 2010 10:40 am

In the Buick world it is pretty standard to run the bronze gears because of large oil pressure numbers needed. I don't like bronze gears though. I use the iron one, standard pump, and pay close attention to oil distribution and bearing clearances. I also make certain the gear is getting oiled. I saw some one else do this and copied it. Works well. this is someone elses pic but mine looks the same. Note the compression to NPT adapter and copper line.
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Rob
'70 GS Stage 1, 466 BBB, 11:1,wiesco pistons, stock rod, ported Edelbrock heads, 1.55 rollers, single plain intake, 950 Quickfuel, aeromotive ss pump, TH400, 9" PTC converter, 3.90 12bolt, NOS Mini, NX Single entry Crossbar

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wikd69
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Re: Lifespan of bronze distributor gears

#6 Post by wikd69 » Sat Jun 19, 2010 1:14 pm

evil16v wrote:In the Buick world it is pretty standard to run the bronze gears because of large oil pressure numbers needed. I don't like bronze gears though. I use the iron one, standard pump, and pay close attention to oil distribution and bearing clearances. I also make certain the gear is getting oiled. I saw some one else do this and copied it. Works well. this is someone elses pic but mine looks the same. Note the compression to NPT adapter and copper line.
thats pretty clever, I like that. The problem I have is my cam - it's billet and they tell ya not to run iron distr gears against it.
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

K-Star Automotive
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Re: Lifespan of bronze distributor gears

#7 Post by K-Star Automotive » Sun Jun 20, 2010 9:10 pm

It's so hard to tell with pictures. To me it almost looks like something ran through it. Are all the teeth tore up like the ones in the picture??

A few things, How much end play do you have in your camshaft?? Have you checked it since the engine has been built?? Are you running a high volume oil pump??? what part number? Have you removed the cam and carefully inspected the drive gear on it?? did you ever check the lash between the distributor and the cam when the distributor was installed??

I have a customer with 10,000 miles on a 406. When I freshend the engine I re-used the bronze gear that was in it.


Keith

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wikd69
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Re: Lifespan of bronze distributor gears

#8 Post by wikd69 » Sun Jun 20, 2010 11:29 pm

K-Star Automotive wrote:It's so hard to tell with pictures. To me it almost looks like something ran through it. Are all the teeth tore up like the ones in the picture??

A few things, How much end play do you have in your camshaft?? Have you checked it since the engine has been built?? Are you running a high volume oil pump??? what part number? Have you removed the cam and carefully inspected the drive gear on it?? did you ever check the lash between the distributor and the cam when the distributor was installed??

I have a customer with 10,000 miles on a 406. When I freshend the engine I re-used the bronze gear that was in it.


Keith
Naw, the end play is ok. It's a bit hard to see but the teeth on that distributor gear are paper thin. Under thottle, they just folded over. This has happened before, but I caught it before it failed the last time. I should have pulled it before this - I was starting to get timing scatter that you could see with a timing light.

And if I recall correctly, I'm running the high volume Melling 55.
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

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CDR Performance
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Re: Lifespan of bronze distributor gears

#9 Post by CDR Performance » Mon Jun 21, 2010 7:52 am

There are some "cheap" replacement gear out there. Make sure to get one from US or one of Comp poly gears.
they work better than the bronze. but need to be watched as well, just not as often.

Last If you pre-heat the oil is does make the gear last longer.
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wikd69
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Re: Lifespan of bronze distributor gears

#10 Post by wikd69 » Mon Jun 21, 2010 10:29 am

CDR Performance wrote:There are some "cheap" replacement gear out there. Make sure to get one from US or one of Comp poly gears.
they work better than the bronze. but need to be watched as well, just not as often.

Last If you pre-heat the oil is does make the gear last longer.
10-4

I run Valvoline 20-50 in the summertime - remember, this is a street car - it's like pumping tar until it warms up. When the engines cold I'm pulling 80 psi - thats got to be a pretty severe load on those bronze gears.

I may end up with a composite this time.
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

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Re: Lifespan of bronze distributor gears

#11 Post by ERV JR » Sun Jun 27, 2010 4:01 pm

Another thing to check is when the dizzy is dropped in that it sits flush with the intake, sometimes the dizzy flange will be slightly be off the intake and the clamp draws it down. bad idea since its drawing the gear into the cam and oil pump driveshaft. I have small steel shims that i have used between the dizzy and intake

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