'93 LT-1 engines

[Steven S.]

I have heard that the new LT-1 motors have a problem around 68 to 70,000 miles with waterpumps. When the pump goes out it distroys the distributors. Is this a correct statement, if so, what can be done to prevent it? Change pump early?

Steve

[Chas Kingston]

Re: '93 LT-1 engines

My '96 Buick Roadmonster station wagon has an LT-1 engine and the water pump had to be replaced at 50,000 miles. The Opti-spark distributor, mounted directly below the water pump suffered only minor damage, but I was lucky. Some on the Caprice/Impala board have replaced the water pump early and added a pipe fitting on the weep hole, with a length of tubing to redirect any weepage from there. That wouldn't have helped me, though, as my pump was leaking out the back. That distributor is a repair bill time bomb, just waiting to go off. An Engineering nightmare.

Ol' Geezer

[Terry M.]

Re: '93 LT-1 engines

My experience with the Gen II LT1 in the B-body (iron head, former police cars) is that the water pump can be good for twice that mileage, especially if the cooling system is properly maintained. That includes every other year flushes and replacement of the coolant (regardless of the color of the antifreeze).
Failure of the water pump need not be the death knell for the distributor if one is alert for the slightest leak from the "weep hole". If one allows the cooling system to deteriorate to the point that sudden catastrophic failure of the water pump occurs, the bath of hot coolant can sometimes damage the distributor.
All that said, if the water pump needs replacing, one might as well change the distributor as well, if the mileage is close to 100K. I had a water pump fail suddenly at 128K. There was no sign of distributor issues, but I elected to change it anyway, since I was half way to the distributor when the water pump was off. Both parts were original to the car, so it seemed to me they had served their normal life span, and driving peace of mind was worth the cost of parts.
Unless you are keeping your Corvette for the day when NCRS judges it, I recommend the modification of the distributor to allow vacuum scavaging of the distributor. There used to be a site that explained how to modify the earlier non-vacuum distributors to work like the later ones with vacuum, but I couldn't find it just now. Maybe someone else saved the link.

This one will be useful:

http://www.charm.net/~mchaney/optisprk/optisprk.htm