speedg33k

i have a 96 formula LT1 motor is stock, has been run on synthetic faithfully since the car was new, has about 121K on the dial now. had a buddy tell me when he was following me when i first started up for the first 2 minutes there was a slight amount of blue smoke. i have noticed a decrease in the torque the last 6 months in the lower rpm. i have been told that rislone is a piston ring aid and that might help. eventually i will probobly rebuild the motor but for the time beign i cant afford such a thing. working for GM can really suck somedays. has anyone had any luck in their LT1 with such a thing?

bw_hunter

Blue smoke on start-up that clears up after a short while isn't likely a ring problem, it's more of a valve seal problem. When the engine is shut down, oil pools around the valves. Oil can seep past the compromised valve seals and enter the combustion chambers where it'll burn on start up. It doesn't take much oil to generate the smoke.

It's easy to test for ring health using a compression tester or a leak down tester. All you have to do is test compression and then retest after adding a little oil to the chamber. No increase in compression pressure and the rings are fine and the problem is elsewhere. You should have a value of about 165psi or so and lesser values don't necessarily mean anything is wrong....

I'd be a little concerned about that oil entering the catalytic convertor but it probably isn't much and you might not even have one (I didn't look that closely at you signature). Luckily, changing the valve seals isn't either expensive or difficult to do at home....


Good luck

maverickmk

You need new valve seals as stated above.

speedg33k

would that merely requre me removing the heads and having them sent to a machine shop? would you recommend replace valves at this time too? or is that more of a case if there are signs of wear obviously.

maverickmk

You can replace the seals without taking the heads off. You will need a valve spring compressor & either turn the motor over by hand bringing the piston to the top of it's travel so the valves don't fall into the motor or there is a special air chuck that screws into the head where the spark plugs goes and the other end plugs into an air hose from a compressor. If while you're taking the springs out and find there is a lot of play in the valve stem then the heads will need to come off and sent to a machine shop for new guides. I have never replaced the seals on a 4th gen, but I've heard the hardest part is getting to the back cylinders as there is not a lot of room to work a spring compressor back in there. Just takes some patience & attention to detail and you should be OK.

bw_hunter

That's a big 'merely'. You can do it at home if you're mechanically capable.

You only need to replace the valves if they're damaged and I doubt they are....

Good luck!