Distributor gear wear discussion.

Distributor gear wear discussion.

Joined: August 28th, 2002, 6:51 pm

November 27th, 2011, 6:19 pm #1

I know a lot of this has been talked about before but I couldn't find what I was looking for in the search so let's talk about it some more.

My friend Jim came over yesterday to help me pull the engine/trans out of my 68 to start the miser build.
We pulled apart both my "good" engine and my spare engine. I was very disappointed to see my distributor gear AND cam gear showed some wear on them.
I have a Comp solid roller cam and used a dizz gear that was recommended by Comp.
Last winter when I pulled the engine and inspected everything, the gear and cam looked great. Now they aren't ;-(
I installed a blue printed standard volume oil pump last winter replacing the blue printed high volume pump I had previous. So the high volume used before had the dizz and cam gear looking good and the standard volume didn't ??? That doesn't sound right. I used the same oil brand and viscosity as in the past. Break in on Valvoline racing and then switch to Amsoil 10W-30.
I know the dizz gear was set at the correct height. It was set in the middle of my up and down free play, not binding in either direction also I didn't do squat with that last winter when I pulled the engine apart for inspection.
Jim said the gear wear looked like it was worse on some ares of the gears than and just wasn't even. I haven't looked carefully as yet. I may do that today and can even post pictures if needed. I was upset with the news that my good roller cam was damaged and will have to be replaced in the future. I didn't feel like inspecting things at the time... I only put a couple thousand miles on it this summer, less than usual.

Here are the factors I remember about gear wear. Please add some if I failed to list them.

* Using the wrong material for the gear. i.e. cast iron gear on roller cam.

* Not having the gear height set correctly either binding in the dizz as it is pulled down by the cam or jammed down on the block as the dizz is tightened.

* A bad or chewed up block mating surface for the gear.

* Thick cold oil and high rpm starts. Hmmm I did recently start it a few times when it was about 32 degrees out. I had to goose it a few times to keep it running (no choke).

* Not enough oil getting to the gears. Another hmmm, I have big oil clearances in the rods and mains (0.003-0.0035) and my hot idle oil pressure was about 18 psi. I spent a lot of time idling this summer in slow cruise traffic.

* Oil pump drive shaft that is too long. (They jam when dizz is tightened down, been there done that in the past).

* Using oil without the proper zinc/phosphorous additives.

* Sloppy fit in block to dizz shaft. (Mines seems fine, will check this in weeks to come).

* Binding oil pump or crap inside pump.

* Incorrect temper or hardness of cam or dizz gear as in some sort of material problem with either one.

I really would like to know what caused this. True, I will be using a different block, different cam and new cam gear in my miser build, but some day this engine will go back in the car.

Let me know what you think.
Thanks.
Damford1
Last edited by danford1 on November 27th, 2011, 6:29 pm, edited 1 time in total.
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Joined: June 12th, 2009, 1:31 pm

November 27th, 2011, 8:24 pm #2

What was the distributor gear made out of and what brand? I have the same cam that you have and I am using the Mallory comp SS 42 series distributor with there steel gear and have lots of hard hours and abuse on mine, the gears are not worn at all, the contact patch on the teeth is just starting to polish the dark color of the hardening on the teeth to the point that I can see the steel color, but no material wear. i use my truck all year with 20-50w oil and it has many cold starts at or below freezing.

If I recall Comp Cams told me that they had a hardened iron gear that they recommended to use with the cam but I went with the Mallory instead, I didnt like the idea of iron with a billet steel cam. I hope you get it worked out, maybe Comp Cams will make it good for you if there recommended parts are not lasting.
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Joined: July 24th, 2008, 10:06 pm

November 27th, 2011, 9:07 pm #3

I experianced the same thing with my 302 comp roller with the Comp bronze gear, although I know the gear hight was set properly mine was set with the fromt cover off! Comp insisted that improper installation is why my gear failed.
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Joined: November 18th, 2003, 6:49 am

November 27th, 2011, 9:26 pm #4

I know a lot of this has been talked about before but I couldn't find what I was looking for in the search so let's talk about it some more.

My friend Jim came over yesterday to help me pull the engine/trans out of my 68 to start the miser build.
We pulled apart both my "good" engine and my spare engine. I was very disappointed to see my distributor gear AND cam gear showed some wear on them.
I have a Comp solid roller cam and used a dizz gear that was recommended by Comp.
Last winter when I pulled the engine and inspected everything, the gear and cam looked great. Now they aren't ;-(
I installed a blue printed standard volume oil pump last winter replacing the blue printed high volume pump I had previous. So the high volume used before had the dizz and cam gear looking good and the standard volume didn't ??? That doesn't sound right. I used the same oil brand and viscosity as in the past. Break in on Valvoline racing and then switch to Amsoil 10W-30.
I know the dizz gear was set at the correct height. It was set in the middle of my up and down free play, not binding in either direction also I didn't do squat with that last winter when I pulled the engine apart for inspection.
Jim said the gear wear looked like it was worse on some ares of the gears than and just wasn't even. I haven't looked carefully as yet. I may do that today and can even post pictures if needed. I was upset with the news that my good roller cam was damaged and will have to be replaced in the future. I didn't feel like inspecting things at the time... I only put a couple thousand miles on it this summer, less than usual.

Here are the factors I remember about gear wear. Please add some if I failed to list them.

* Using the wrong material for the gear. i.e. cast iron gear on roller cam.

* Not having the gear height set correctly either binding in the dizz as it is pulled down by the cam or jammed down on the block as the dizz is tightened.

* A bad or chewed up block mating surface for the gear.

* Thick cold oil and high rpm starts. Hmmm I did recently start it a few times when it was about 32 degrees out. I had to goose it a few times to keep it running (no choke).

* Not enough oil getting to the gears. Another hmmm, I have big oil clearances in the rods and mains (0.003-0.0035) and my hot idle oil pressure was about 18 psi. I spent a lot of time idling this summer in slow cruise traffic.

* Oil pump drive shaft that is too long. (They jam when dizz is tightened down, been there done that in the past).

* Using oil without the proper zinc/phosphorous additives.

* Sloppy fit in block to dizz shaft. (Mines seems fine, will check this in weeks to come).

* Binding oil pump or crap inside pump.

* Incorrect temper or hardness of cam or dizz gear as in some sort of material problem with either one.

I really would like to know what caused this. True, I will be using a different block, different cam and new cam gear in my miser build, but some day this engine will go back in the car.

Let me know what you think.
Thanks.
Damford1
How bad is it worn? I have a picture of mine, with similar cam to yours (308R) and this was after a two months on the new motor back in 2007, but i never did change it, and it didn't seem to get worse. Allthough i havn't looked at it for two years.

[/IMG]
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Joined: December 16th, 2003, 1:59 am

November 27th, 2011, 10:11 pm #5

I know a lot of this has been talked about before but I couldn't find what I was looking for in the search so let's talk about it some more.

My friend Jim came over yesterday to help me pull the engine/trans out of my 68 to start the miser build.
We pulled apart both my "good" engine and my spare engine. I was very disappointed to see my distributor gear AND cam gear showed some wear on them.
I have a Comp solid roller cam and used a dizz gear that was recommended by Comp.
Last winter when I pulled the engine and inspected everything, the gear and cam looked great. Now they aren't ;-(
I installed a blue printed standard volume oil pump last winter replacing the blue printed high volume pump I had previous. So the high volume used before had the dizz and cam gear looking good and the standard volume didn't ??? That doesn't sound right. I used the same oil brand and viscosity as in the past. Break in on Valvoline racing and then switch to Amsoil 10W-30.
I know the dizz gear was set at the correct height. It was set in the middle of my up and down free play, not binding in either direction also I didn't do squat with that last winter when I pulled the engine apart for inspection.
Jim said the gear wear looked like it was worse on some ares of the gears than and just wasn't even. I haven't looked carefully as yet. I may do that today and can even post pictures if needed. I was upset with the news that my good roller cam was damaged and will have to be replaced in the future. I didn't feel like inspecting things at the time... I only put a couple thousand miles on it this summer, less than usual.

Here are the factors I remember about gear wear. Please add some if I failed to list them.

* Using the wrong material for the gear. i.e. cast iron gear on roller cam.

* Not having the gear height set correctly either binding in the dizz as it is pulled down by the cam or jammed down on the block as the dizz is tightened.

* A bad or chewed up block mating surface for the gear.

* Thick cold oil and high rpm starts. Hmmm I did recently start it a few times when it was about 32 degrees out. I had to goose it a few times to keep it running (no choke).

* Not enough oil getting to the gears. Another hmmm, I have big oil clearances in the rods and mains (0.003-0.0035) and my hot idle oil pressure was about 18 psi. I spent a lot of time idling this summer in slow cruise traffic.

* Oil pump drive shaft that is too long. (They jam when dizz is tightened down, been there done that in the past).

* Using oil without the proper zinc/phosphorous additives.

* Sloppy fit in block to dizz shaft. (Mines seems fine, will check this in weeks to come).

* Binding oil pump or crap inside pump.

* Incorrect temper or hardness of cam or dizz gear as in some sort of material problem with either one.

I really would like to know what caused this. True, I will be using a different block, different cam and new cam gear in my miser build, but some day this engine will go back in the car.

Let me know what you think.
Thanks.
Damford1
when you checked for clearance & binding?

http://www.network54.com/Forum/119419/t ... ar+trouble

there'll be phantoms, there'll be fires on the road... and the white man dancing
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Joined: August 28th, 2002, 6:51 pm

November 27th, 2011, 11:41 pm #6

Yes I tightened the dizz down when checking back when I set it up.
It was fine last winter. Unless I totally ignored looking at the gears which I highly doubt. If there was wear I would have seen it. It is POSSIBLE it was wearing and I didn't notice it. Anyway it is now worn...

I looked through my box of receipts. I had an important point wrong in my original post. When I installed the cam and ran it in 2010 I had a blue printed Standard volume oil pump. For the 2011 season I switched to a blue printed high volume pump. Thinking back it was because I was not all that happy with the lower oil pressure due to my big bearing clearances. I thought the HV would help that. At first it had more pressure with the HV pump, but after it was broke in and running a couple months, the pressure went back to where it was...
So, perhaps the HV pump helped wear my gears???

I looked and looked for my dizz gear receipt so I could answer exactly what gear I have. I can't find the receipt.
The gear does have a number stamped into it which looks like 2865 if that helps. It also appears to be steel not cast.

In looking at the wear on the cam and dizz gear I can clearly see where there is more wear in half of it. Like lets say if you look at the worse part then rotate it 180 degrees, the wear is less. Like something was out of round.
I tried to take pictures of both the cam gear and dizz gear but just can't capture it well in a picture. I'll post what I have now and try to improve my photos. The flash changes everything and without a flash, it is too dark. I need to try in daylight and see if I can get better results.
We did put the cam and dizz back in the block and rotate them. we tried turning the cam feeling for a bind and then tried turning the dizz. Jim said he could detect a tighter spot while rotating things.
We tried to wiggle the dizz in the block and check for play but couldn't feel any. I'll inspect the hole for the dizz in the block better at a laer date.
I did make a video trying to show the wear patterns on the gears. Here is the youtube linkhttp://www.youtube.com/watch?v=GhmjwPMKtT8

Below are the pictures i tried to take also.

One position




Rotated 180 degrees




Dizz gear.




Danford1
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Joined: November 26th, 2003, 2:49 am

November 27th, 2011, 11:57 pm #7

Maybe its just the pic but the gear does not look square on the shaft ???
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Joined: June 12th, 2009, 1:31 pm

November 28th, 2011, 12:05 am #8

Yes I tightened the dizz down when checking back when I set it up.
It was fine last winter. Unless I totally ignored looking at the gears which I highly doubt. If there was wear I would have seen it. It is POSSIBLE it was wearing and I didn't notice it. Anyway it is now worn...

I looked through my box of receipts. I had an important point wrong in my original post. When I installed the cam and ran it in 2010 I had a blue printed Standard volume oil pump. For the 2011 season I switched to a blue printed high volume pump. Thinking back it was because I was not all that happy with the lower oil pressure due to my big bearing clearances. I thought the HV would help that. At first it had more pressure with the HV pump, but after it was broke in and running a couple months, the pressure went back to where it was...
So, perhaps the HV pump helped wear my gears???

I looked and looked for my dizz gear receipt so I could answer exactly what gear I have. I can't find the receipt.
The gear does have a number stamped into it which looks like 2865 if that helps. It also appears to be steel not cast.

In looking at the wear on the cam and dizz gear I can clearly see where there is more wear in half of it. Like lets say if you look at the worse part then rotate it 180 degrees, the wear is less. Like something was out of round.
I tried to take pictures of both the cam gear and dizz gear but just can't capture it well in a picture. I'll post what I have now and try to improve my photos. The flash changes everything and without a flash, it is too dark. I need to try in daylight and see if I can get better results.
We did put the cam and dizz back in the block and rotate them. we tried turning the cam feeling for a bind and then tried turning the dizz. Jim said he could detect a tighter spot while rotating things.
We tried to wiggle the dizz in the block and check for play but couldn't feel any. I'll inspect the hole for the dizz in the block better at a laer date.
I did make a video trying to show the wear patterns on the gears. Here is the youtube linkhttp://www.youtube.com/watch?v=GhmjwPMKtT8

Below are the pictures i tried to take also.

One position




Rotated 180 degrees




Dizz gear.




Danford1
I do remember when I installed my 288R cam that it had very sharp edges all around the cam gear, I spent hours with a die grinder and a wire brush cutting off and polishing all the sharp edges so it would not cut into the distributor gear, I would recommend doing that to any billet cam.
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Joined: August 28th, 2002, 6:51 pm

November 28th, 2011, 12:34 am #9

Maybe its just the pic but the gear does not look square on the shaft ???
It's just the picture. If you watch the video you can see it better when I spin it.
I remember when I installed it, that it had a tight fit to the shaft...

Danford1
Last edited by danford1 on November 28th, 2011, 12:37 am, edited 1 time in total.
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Joined: June 16th, 2004, 4:57 am

November 28th, 2011, 11:58 am #10

I know a lot of this has been talked about before but I couldn't find what I was looking for in the search so let's talk about it some more.

My friend Jim came over yesterday to help me pull the engine/trans out of my 68 to start the miser build.
We pulled apart both my "good" engine and my spare engine. I was very disappointed to see my distributor gear AND cam gear showed some wear on them.
I have a Comp solid roller cam and used a dizz gear that was recommended by Comp.
Last winter when I pulled the engine and inspected everything, the gear and cam looked great. Now they aren't ;-(
I installed a blue printed standard volume oil pump last winter replacing the blue printed high volume pump I had previous. So the high volume used before had the dizz and cam gear looking good and the standard volume didn't ??? That doesn't sound right. I used the same oil brand and viscosity as in the past. Break in on Valvoline racing and then switch to Amsoil 10W-30.
I know the dizz gear was set at the correct height. It was set in the middle of my up and down free play, not binding in either direction also I didn't do squat with that last winter when I pulled the engine apart for inspection.
Jim said the gear wear looked like it was worse on some ares of the gears than and just wasn't even. I haven't looked carefully as yet. I may do that today and can even post pictures if needed. I was upset with the news that my good roller cam was damaged and will have to be replaced in the future. I didn't feel like inspecting things at the time... I only put a couple thousand miles on it this summer, less than usual.

Here are the factors I remember about gear wear. Please add some if I failed to list them.

* Using the wrong material for the gear. i.e. cast iron gear on roller cam.

* Not having the gear height set correctly either binding in the dizz as it is pulled down by the cam or jammed down on the block as the dizz is tightened.

* A bad or chewed up block mating surface for the gear.

* Thick cold oil and high rpm starts. Hmmm I did recently start it a few times when it was about 32 degrees out. I had to goose it a few times to keep it running (no choke).

* Not enough oil getting to the gears. Another hmmm, I have big oil clearances in the rods and mains (0.003-0.0035) and my hot idle oil pressure was about 18 psi. I spent a lot of time idling this summer in slow cruise traffic.

* Oil pump drive shaft that is too long. (They jam when dizz is tightened down, been there done that in the past).

* Using oil without the proper zinc/phosphorous additives.

* Sloppy fit in block to dizz shaft. (Mines seems fine, will check this in weeks to come).

* Binding oil pump or crap inside pump.

* Incorrect temper or hardness of cam or dizz gear as in some sort of material problem with either one.

I really would like to know what caused this. True, I will be using a different block, different cam and new cam gear in my miser build, but some day this engine will go back in the car.

Let me know what you think.
Thanks.
Damford1
<div>After having 1 street Cleveland with a stock volume/pressure oil pump chew up the cam/dizzy gears, (and down into the dizzy gear pad in the block) I actually tapped into the lifter valley main oil passage on the next 2 nitrous builds & plumed a 3/16" line through the front bulkhead to spray oil on the gears. I guess it helped because with the higher volume/pressure oil pumps in the nitrous builds I never saw any of the accelerated gear wear that screwed up the street build. </div><div> </div><div>460's can have a similar cam/dizzy gear wear problem show up too. Paul Kane on the 460 site came up with a method to drill a tiny oil passage way on the 460 up to the block's dizzy gear pad to pressure oil the gears. it's kinda the same effect I was doing with my Clevelands but without all the extra pluming.</div><div> </div><div>It might be possible to use Paul's dizzy gear oiling method on a Cleveland. I guess it would depend on if the Cleveland dizzy pad is as big as the 460 pad. </div><div> </div><div>I forget where Paul's post is on the 460 site, I will have to look for it. </div>

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