What did I find in my oil pan?

[A26B]

Here's a photo of the Guide, LH Upper Chain. You can see the end just has a sort of U-bend that clips over the end of the guide. Your broken pieces may have some of the U-bend still intact. The other end is held in with a roll pin.

http://jerrysgaskets.com/store2/root/index.php?main_page=product_info&cPath=2_5&product s_id=177

[VetteMed]

Thanks Jerry... think it's worth pulling the balancer and the front cover to swap this out?

Originally Posted by A26B

Here's a photo of the Guide, LH Upper Chain. You can see the end just has a sort of U-bend that clips over the end of the guide. Your broken pieces may have some of the U-bend still intact. The other end is held in with a roll pin.

http://jerrysgaskets.com/store2/root...roducts_id=177

[A26B]

It would bother me. You can see from the following photo of a used guide, the chain contact does lessen towards the end. Who knows how long it's been broken off & whether it's causing the wear strip to wear more, being loose on the end. My concern would be the chain eventually contacting the exposed metal in the guide & wearing the chain. Difficult to say how deep the wear is on the guide strip now with the miles on your engine & when the chain will start rubbing the guide. Bad enough with the abraded metal floating around, but a broken chain can cause alot of damage.

As I understand it, (never tried it myself) removing the balancer with the engine in the car is next to impossible & more time consuming than pulling the engine. Also, like Johnny said, you're bound to find more questionable parts to replace. Pretty hard to know just how much life is left in a chain..... new chains on worn sprockets is hard on new chains.....etc.

[VetteMed]

Well, if the issue can't be remedied with the engine in the car, then it's staying that way. If I'm pulling it, it's not going back in with 188k miles on it... So I'll just drive it until something lets go, or until I have the cash to do it right... That was sort of the gamble upon buying the car, so it doesn't come as much of a surprise to me.

[A26B]

Will probably run for a long time yet. I'm glad it is an easy decision for you. I had the same guide in my used parts that broke the same as yours, so it's not a unique happening.

[SAM/CH ZR-1]

Don't wait to long with replacing the guides. After about 90'000 miles they should be checked and replaced.

[DDSLT5]

Originally Posted by SAM/CH ZR-1

Don't wait to long with replacing the guides. After about 90'000 miles they should be checked and replaced.

Interesting - I wonder just how many LT5s have suffered loss of the guides (I assume this is what happened to your motor in the photo above - the guide was lost, and then the chain wore through the metal beneath it). One of my ZR-1s has 75K miles on it, runs like brand new, but that is the highest mileage I have on a motor - the other two are stroker builds with less than 15K miles on the build - only 4K miles on the other.

How did you discover this worn item? Just lucky? Or was there noise coming from the front end of the engine?

Thanks Sam,

[SAM/CH ZR-1]

Originally Posted by DDSLT5

Interesting - I wonder just how many LT5s have suffered loss of the guides (I assume this is what happened to your motor in the photo above - the guide was lost, and then the chain wore through the metal beneath it). One of my ZR-1s has 75K miles on it, runs like brand new, but that is the highest mileage I have on a motor - the other two are stroker builds with less than 15K miles on the build - only 4K miles on the other.

How did you discover this worn item? Just lucky? Or was there noise coming from the front end of the engine?

Thanks Sam,

Actually when you hear significant noise from the cam chains it's mostly to late. Many parts (chain, guides, guide holders, etc.) need to be replaced. As you know LT5 parts are not a bargain.

I blowed my engine on german autobahn while I was on the way to a international Corvette meeting in Prague/Czech Republic.
The reason for the blow was the use of another engine oil viscosity.

While disassembling the engine with about 100'000 miles on the clock I noticed the bad chain guides.
I work on several LT5's. Do all maintenance and tuning works for the ZR-1 gang from some countries here in Europe.
You don't need to replace all 7 (2 cam cover, 1 primary chain, 4 secondary chain) guides.
Only those where the chain tensioner press against have a high wear. The guides on the opposite side look even after high milage like new or have a little wear. The small primary chain guide should also be replaced.
For these works the engine need to be taken out of car body.

If you wait to long with replacing the guides the cam chains rub on the chain guide holders. The swarfs can contaminate the oil-circulation system and damage the main/rod bearings and scratch all other rotating assemblies.

When you have the engine out of car you can clean it, replace all leaking gaskets/seals and time the cams perfectly.

If you guys want to prevent expensive engine failure (especially those who like to challenge the beast), check your chain guides after about 90'000 miles of use.

Just my advice.

Sam

PS: Attached a pic of the primary chain guide (used & new)

[DDSLT5]

Originally Posted by SAM/CH ZR-1

Actually when you hear significant noise from the cam chains it's mostly to late. Many parts (chain, guides, guide holders, etc.) need to be replaced. As you know LT5 parts are not a bargain.

I blowed my engine on german autobahn while I was on the way to a international Corvette meeting in Prague/Czech Republic.
The reason for the blow was the use of another engine oil viscosity.

While disassembling the engine with about 100'000 miles on the clock I noticed the bad chain guides.
I work on several LT5's. Do all maintenance and tuning works for the ZR-1 gang from some countries here in Europe.
You don't need to replace all 7 (2 cam cover, 1 primary chain, 4 secondary chain) guides.
Only those where the chain tensioner press against have a high wear. The guides on the opposite side look even after high milage like new or have a little wear. The small primary chain guide should also be replaced.
For these works the engine need to be taken out of car body.

If you wait to long with replacing the guides the cam chains rub on the chain guide holders. The swarfs can contaminate the oil-circulation system and damage the main/rod bearings and scratch all other rotating assemblies.

When you have the engine out of car you can clean it, replace all leaking gaskets/seals and time the cams perfectly.

If you guys want to prevent expensive engine failure (especially those who like to challenge the beast), check your chain guides after about 90'000 miles of use.

Just my advice.

Sam

PS: Attached a pic of the primary chain guide (used & new)

Great response - thanks so much! This is definitely an item that requires attention, and likely not something that Lotus figured would wear so much with so few miles, IMO. As you said, if anyone is pushing the engine hard, it is a good idea to tear it down after 100K miles and inspect these items. If you're mostly cruising at 1500 rpm on the highway, I'm guessing these items will look quite pristine upon inspection at the 100K mile marker.

Thanks for the advice!

[ScottZ95ZR1]

Originally Posted by SAM/CH ZR-1

I blowed my engine on german autobahn while I was on the way to a international Corvette meeting in Prague/Czech Republic.
The reason for the blow was the use of another engine oil viscosity.

What engine oil were you running Sam?