sothpaw2

No offense, but no, I don't think I'm being harsh at all. Their failed component has cost me an engine. Yeah, you have bad parts now and then. But if I get a bad opti or a bad stock water pump or a bad radiator that leaks, bad thermostat, etc etc etc, these do not destroy the motor.

This destroyed the motor. And it wasn't that the machinist or whoever had a bad day. IMHO they just omitted part of the process altogether.
And, how do I know that there aren't more? I bet partially it's because not too many push the engine, get the oil to 240 for a while.

SouthernSon

Andy, I just checked my new, unused gear and you are correct. It does, indeed, have 3 holes. I hope you can definitively ascertain the cause of the failure. Do you think that something could have been amiss in the alignment of the chain gears?

(sorry for the double post above, there was a bunch of lag time in the uploading for some reason)

steve40th

The ED gears are also serialized with a number on the gear. Does yours have the correct gears, ie they all are mathched?

steve40th

Did you have any gearwhine or any tell tale signs. Mine has less than 30 miles on it now, and its quiet, and I installed all the gears with red line camshaft lube, as it just felt right to help it wear in.
How many miles on the ED chain did you have?

sothpaw2

15 k mi, and 4 days of road course (4 20 minutes sessions/day).

No gear whine.

My metallurgist does not suspect gear misalignment as you can see that the wear is even along the length of the tooth. Also, the water pump gear does not show abnormal signs of wear.

Water pump gear's bearing is destroyed though.

Called Cloyes and they don't know anything about this. Don't know the hardness spec., but would not say if what I'm reporting is low.

I have microscope photos of the damaged partial teeth remaining if someone can tell me how to post pics.

sothpaw2

Too hot--what was your experience? Was the water pump gear damaged? What chain system did you go to??

steve40th

You said the bearing was destroyed, do you think it may have been bad and caused the water pump gear to drag and cause the breakeage?

sothpaw2

Possible but improbable. The water pump gear should have been destroyed because it's much smaller, the big gear has the torque advantage.

For this to happen, the big gear just has to be much softer.

Oiling the gears up during the build was a good idea--I plan it.

steve40th

Pics of gears.
http://www.shutterfly.com/add/upload...21b35da7544526
You might have to sign up for this, but it is free. I am new at posting, or trying to,

tobijohn

Well, if this turns into a big hassle for everyone, send the pics to me and I'll post them on my site...

MSR

how did you find out? debris in oil? strange noises? catastrophic failure?

sothpaw2

Loud noises. Awful sound. Can't believe it really happened.

MSR

this is interesting to me, since my engine "expired" this past weekend. the noise was definitely from the very front of the engine, i had assumed it was a bearing and/or rod problem. (i installed my chain set, so i know for sure the correct gear was installed.)

so let me ask more... on yours, was the noise periodic, varying with engine rpm, or random?

thanks.

-michael

sothpaw2

In the last 40 miles before it was in the shop (this includes driving it there, which was 25 miles) it made a noise constantly, but it got considerably worse with rpm. I really didn't push the engine beyond 1800 in the last 30 miles for this reason.

Looking at the gear it was lucky that I made it to the shop at all and maybe I would have saved the water pump if I had had it towed immediately. But that would have been a pain--I had a passenger and he wanted to go home.

tjwong

Anyway the water pump could have caused all of these problems?

MSR

the symptoms appear to match what i experienced. unfortnately, i'm going out of town on business and won't be able to tear it down for a month to see.

tjwong, that definitely occurred to me. i'll make sure and look at that closely as well.

thanks.

-michael

sothpaw2

Not really. The water pump gear is much smaller and is not torn up.

The key is this: Hardness test showed 64 Rockwell A as the hardness of the ED gear in the tooth area and even softer , 60 R A, in center.

My plain Jane, stock LT1 gear showed 68-71 RA in the tooth area.

This translates to 130 ksi ultimate for the ED gear vs. 188 ksi for the stock gear.

Gears should be made hard to avoid wear. You don't want them too hard or they would be brittle, but hard.

My metalurgist at work says 64 R A (which is 28 R C) is too soft, he would never allow a gear like that. He recommends RC 32-36 minimum, if you want toughness. Harder if toughness is not an issue.

steve40th

Have you called Cloyes? They may have some numbers to compare to as to what the gear should be?
Also, can the heat caused by the mechanical malfunction cause the Rockwell to change?

sothpaw2

Michael,

If you have a few minutes, to put your mind at ease (if you're lucky), go pull the oil plug on the pan and drain the oil. Also, pull the oil filter.

If it has started to get loud, and you have what I had, you will find metal in the oil and filter. If you knock on the empty oil pan, you should hear it.

sothpaw2

Yes. Cloyes claims to know nothing about it. They further would not provide a hardness spec as to what it should be, didn't know (and didn't call back).

I only talked to an engineer/application guy, not management.

As for the mechanical malfunction--no. The only thing that will affect the hardness is the heat treat ment so it would have to get up very hot to do that (? over 1000 c). Hardness is set by how the part is manufactured. Unless you start re-manufacturing it (take it and start peening it with shot--that makes it harder).