Posted by PARTSMASTER on September 09, 1998 at 23:18:00:
In Reply to: Inlet valves,5.7 ltr GM engines posted by tony smith on September 01, 1998 at 18:20:06:
: Does anyone know where I can get harder grade inlet valves for the 1998 model 5.7MPI Mercruiser engines?
: We currently have a problem with the standard valves overheating when running on LPG and "tulip-ing". No 7 cylinder being the worst.
: Anyone having a similar problem should get in touch.
YES I've seen this problem.Some causes
1.high heat condition do to a lean fuel calibration.
2.Timing not set correctly which causes a detonation problem which causes a high heat condition .
3.YES they make alot better valves than the stock units.BUT you should fix your problem first.
4.A pyrometer gauge can be installed on the #7 cylinder this will tell you when you are ready for a melt down.
5.MSD makes a knock alert gauge you can buy
6.I could go on for ever LETS put the darn thing on dyno and test it.