dizwiz24

Ive got my 93 lt1 apart for a cam swap (hotcam to blower cam).

While its apart, Im wondering if I should do anything w/ my timing chain.

In the old days of these sites, I seem to remember lots of people swapping out lt1 timing chains for lt4 'extreme duty' timing chains.

Im not sure if people were doing that due to any 'known issues' with the stock timing chain, or just because that was the 'cool' thing to do - to be more like the lt4.

I know there are some other parts I would need to make this work and all-in-all it will cost me a couple hundred bucks to do it.

Lately, I havent heard much about people swapping out timing chains.

This is on a motor that I dont plan on spinning past 6000 RPM.

However, it has a supercharged 93 lt1.

What are my timing chain options?

BTW, heres a picture of the timing chain/gear thats currently in there:

dizwiz24

I did some research:

The issue is some of the parts I need are prob hard to find.

Like why do I need a new optispark for this? I have my 93 lt1 optispark 'mod'd with a late model vented cap. I have the base mod'd (i drilled out one of the weep holes) to accept a vacuum input and epoxied the other 2 holes shut.

What is this camshaft p/n 10224242? Is this just the waterpump drive pin?

Why in the world would I need a new timing chain cover?
I imagine that is really hard to find...

heres what I found out:
This extreme duty timing chain kit is for 1995 and newer model "Gen II" LT1 and LT4 engines. To convert 1993 and 1994 engines, you must use camshaft P/N 10224242, distributor P/N 1104032, timing cover P/N 12552426, vac harness P/N 12554395, and vac fitting P/N 14082470. Included in this kit are the following steel gears: water pump gear, a camshaft sprocket, crankshaft sprocket P/N 14088784, and timing chain P/N 14088783. These parts are not the production replacement components, but this roller chain kit is a great performance upgrade. Use with pin drive camshaft only

Injuneer

The LT4 Extreme Duty timing set only works with the vented (95-97) Opti. It doesn't have the splined hole in the cam sprocket to accept the splined driveshaft used on the unvented (93/94) Opti. It has a plain hole, to accept the pilot shaft on the vented Opti.

The vented Opti is driven by the cam dowel pin. So, instead of a timing cover with a small hole to accept the unvented Opti's splined shaft, you need a timing cover with a larger hole to accomodate the large radius required for the cam dowel to rotate.

http://shbox.com/1/93-94_opti.jpg

http://shbox.com/1/opti_back.jpg

Any 95 - 97 LT1 will have the correct timing cover. 96/97 will have a hole for the crank sensor, but you just plug that if you get a 96/97 cover.

Then you need a camshaft with a hole in the nose large enough to accept the vented Opti pilot shaft (your HOT cam has that) and a longer dowel pin to protrude through the cam sprocket, into the back of the Opti.

http://www.lt1.org/lt1tech_files/99928b.gif

http://www.lt1.org/lt1tech_files/99928c.gif

http://www.lt1.org/lt1tech_files/99928e.gif

lt1-xjs

The stock chain and gears are more than adequate.

pgerst

My stock chain (95) got so loose (100K miles) it was hitting the side of the cover; I went with the LT4 but was an easy swap. When I was doing my wtf? search on the internet as I have never, ever had a timing chain in any of the cars I have owned that was looser than my kids' bike chain, I found this link:

http://forums.corvetteforum.com/c4-t...hain-slop.html

Not sure it solves versus defers the problem; at a minimum I think a new timing set might be prudent depending on how many miles on your current set.

Also if you do the LT4 set (sounds like probably not) make sure you use the supplied water pump drive gear to replace the one on your drive shaft as the metallurgy of the LT4 is different than the LT1 gear.