Klaus

I'm gathering parts for my cam / heads swap on my '96 LT1, and I am at a loss what timing set to buy. I've ruled out the EWP, so that leaves me with the following options:

Comp Cams 3207
Cloyes 9-3151
GMPP LT4 ED
GM Stock LT4
GM Stock LT1

I have read posts where the WP teeth on the cam gear wore away on both the Cloyes and the GMPP ED sets. Has anyone used the Comp Cams timing set? I know it is expensive, but I'd rather not have metal shavings in my engine!

Since the quality of the gears seem to be so hit or miss I'm almost inclined to just buy a new chain for my stock LT1 set, as it only has 60,000 miles on it.

I've already purchased the stock LT1 stock WP drive shaft assembly in case the shaft is worn at the seal, and a new GM waterpump.

Any info / insight would be appreciated!

2000GTP

I haven't heard of any feedback regarding the Comp set, the Cloyes double roller and the LT4 set are the two popular choices. Personally, I haven't heard of problems with the LT4 ED set. Maybe it is possible that people are using the stock LT1 water pump drive gear instead of the LT4 drive gear causing the teeth not to mesh right and wear off. When comparing the gears of my LT1 set and the LT4 set, there is a clear difference in the teeth pattern between the two water pump drive gears.

Don 97 SS

Ditto, the remarks above. The GMPP ED set is stout and hard to beat. It much better than the LT1 oem or LT4 oem. It has been several years since I studied the GMPP install that I did, but I recall the need to use the GMPP ED set's water pump gear and not an oem LT1 version. I hope remembered correctly.

SSNoMad

I had big problems with the LT1/LT4 ED from GM. I even bought the new waterpump drive and removed the new gear (you can't buy the drive without the stock gear on it), and then I had my engine builder press on the new ED hardened gear. The teeth on the gear distintegrated and sent trash through my engine. It took about 3000 miles to fail. I have since heard from many others that have had the same thing happen.
I have used the LT4 set (mot ED) on 2 engines and not had a problem. On my 383 I have the same chain as ED and cloyes sprockets without the gear for the drive, I use the Mezeire HD electric and have had no problems.

Klaus

Thanks Rich. I have concerns about the Stock LT4 set as well. Here are some threads on the Corvette Forum about timing set failures:

http://forums.corvetteforum.com/show....php?t=1251482

http://forums.corvetteforum.com/show....php?t=1197015

http://forums.corvetteforum.com/show....php?t=1407693

http://forums.corvetteforum.com/show....php?t=1408075

http://forums.corvetteforum.com/show....php?t=1273724

http://forums.corvetteforum.com/show....php?t=1200779

The first link says that the Cloyes 9-3151, GMPP LT4 ED, and the Stock GM LT4 timing sets all have "soft" waterpump drive teeth on the cam gear! However, the Stock LT1 timing set was not "soft". The conclusion made in that thread said to either use the Stock LT1 set or to use the SBC double roller timing set and an EWP.

I wish we could do a hardness test on the cam gear that comes in the Comp Cams kit without having to buy it first! It's $500!

2QUIK6

But you can buy the whole shaft/bearing assembly with the ED gear already on it, (gear, shaft, retainer, and bearing) is part# 12551727 which is a few dollars more at $62 than the stock assembly, part#10219554 which was $51.

Here's some good pics on the gear differences. First pic shows wear on my cam sprocket from just about 1k miles of running the stock wp gear.

http://web.camaross.com/forums/showt...ght=LT4+timing

tim95z28

Damn, I'm pissed. I have the same problem. Only 2k miles and this gear is worn bad.

RUDEDOG

I used the lt4 extreme duty and left the stock wp gear in. 20k and no problems.

speed_demon24

Same here, I just did a cam swap and they both still look fine.

2QUIK6

That's the LT4 gear already installed on there with only 3 holes in it....the stocker non-LT4 is the one in your hand with 6 holes in it.
In my case, it was the cam gear that had some strange wear on it.
Be sure to check the clearances of the cam retainer bolts to see if they are making contact on the rear of the gear like mine did...either that or the gear was making my noise I had.
I can't tell what your gears look like in the blurry pic. The LT4 gear looks ok in the top pic, a little shiney on the teeth but I think that is normal.

tim95z28

it is worn...a better pic. ed on top, stock on bottom with 60k mile (ED only 2k miles)

Z95m6

Same here. I did the LT4 ED chain about 45k ago and used the stock waterpump drive shaft with it. I've had my chain off twice now and both times it looked great. Here in the next month or so i'll of have it apart again for the new BRE cam and i'll check it over again.

2QUIK6

Both your ED wp gear and cam gear are a different color than what I had, yours sure are silver colored, mine were more of a dark grey color. More like the color of your stocker pictured above.
Anybody else notice this difference?

hott95z28

You should get rid of the water punp drive I had the LT4 set and my water pump drive broke what a mess. Spend the money and get the electric pump

Z95m6

Do you guys check your bearings on your driveshafts when you're replacing the gear? When i put in my LT4 set i used my buddies low mileage driveshaft that he removed in favor of an electric pump. Maybe your bearings are shot and allowing the gears to move and cause excessive wear.