Texas Manx Club

by **Russhebert** » 19 Mon Nov, 2007 1:22 pm

Just put about a 1800 stroker in my buggy and I have a noise that sounds like it might be peinging from detination. I was woundering if you need to run higher octane gas for a stroker motor. It makes the noise under a load, but it is not consistant. It might be just sheet metal vibrating somewhere but I thought I would ask because it sounds a lot like detination. I have the timing set at 31 full advance and think it could even be set a little higher because it runs good. Any help would be great.

by **Tom Kathleen** » 19 Mon Nov, 2007 6:32 pm

To assist with advice with your "noise", it would help if you knew your compression ratio. Tom

by **Russhebert** » 19 Mon Nov, 2007 9:46 pm

I am thinking maybe 10 to 1

by **MURZ** » 20 Tue Nov, 2007 1:58 am

Compression ratio should be limited to around 8.5:1 ...unless you are running a super wild cam. Otherwise you will have a overheating engine.

Do you know the deck height? head chamber cc?

what are the specs of the engine? 74 x88? please tell me you are not running slip in 88's

Do not run it "pinging" or you will definitely damage the engine.

by **Russhebert** » 20 Tue Nov, 2007 1:30 pm

I am not sure of all that Neil Decker built that for me. We took a stock 1600 case and he put the bigest stroker we could put without having to machine the case.

by **MURZ** » 20 Tue Nov, 2007 9:31 pm

Try backing the timing down to 28-29 degrees at 3000 rpm AND using 93 octane. It is VERY important that you rev the engine until you see the timing stop advancing and then set your timing.

by **David O'** » 21 Wed Nov, 2007 11:47 am

It is detonation, and you need to back the compression ratio down. 8.5 requires 92 octane gas to run in these engines without the pinging.

by **Russhebert** » 21 Wed Nov, 2007 5:59 pm

Thanks for the help. I will put some octane boost in the gas and see, but it is hard to believe that it is detonation because i am running on the rich side. How do you back down the compression ratio.

by **MURZ** » 21 Wed Nov, 2007 9:20 pm

How do you back down the compression ratio

.

You can get copper head gaskets...Or shims for the bottom of the cylinders to increase deck height. Easiest would be copper head gaskets.

For now, just back your timing down.

by **Russhebert** » 24 Sat Nov, 2007 6:12 pm

We allready put shims under the cylinder because we had a small problem with the pistons hit the head.

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