383 troubles
Thread Starter
12 Second Club
Joined: Aug 2005
Posts: 222
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From: Paradise, Newfoundland
383 troubles I have a forged ls 383, built last year, custom cam(230/236, .595/.612, lsa 113), PP ls6 2.5 heads, BBK intake, 80MM TB(I know is prob holding me back) with a compression ratio around 11.3.
..trouble is the first tuner had put the car so rich, that it actually glazed the cylinder walls, so I guess the rings havent seated properly and now I have blow-by..car eats about 1 litre oil every 100k if I drive it hard. The car has since been retuned, as best it can be considering.
couple questions..
bought the car to the track anyway, best run was a 12.4@116mph ...not what I wanted, besides the burning oil, is it possible the car is losing compression?..resulting in lower times(less power). The feels strong all the same.
This is a street car, that will maybe see the track 3 to 4 times a year, and when I re-ring the car in a few months, should I lower the compression?
I cant remember the actual rings used in the car other than they weisco (weisco forged pistions)...is it possible to use a softer ring?, if that makes sense...In the beginning I was planning on using a 150 to max 200 shot someday, but just want to get the engine running correct now before thnking about power adders.
..trouble is the first tuner had put the car so rich, that it actually glazed the cylinder walls, so I guess the rings havent seated properly and now I have blow-by..car eats about 1 litre oil every 100k if I drive it hard. The car has since been retuned, as best it can be considering.
couple questions..
bought the car to the track anyway, best run was a 12.4@116mph ...not what I wanted, besides the burning oil, is it possible the car is losing compression?..resulting in lower times(less power). The feels strong all the same.
This is a street car, that will maybe see the track 3 to 4 times a year, and when I re-ring the car in a few months, should I lower the compression?
I cant remember the actual rings used in the car other than they weisco (weisco forged pistions)...is it possible to use a softer ring?, if that makes sense...In the beginning I was planning on using a 150 to max 200 shot someday, but just want to get the engine running correct now before thnking about power adders.
If the rings were washed out by fuel then they are more then likely not sealing correctly robbing you of compression. Unless the compression ratio is too high for pump gas I would not want to lower the compression. Compression in these motors is worth a lot, especially if you are using a larger cam. Wiseco rings are some of the best as far as oil consumption goes. I would not want to move away from those either, they have a napier 2nd ring which really helps keep oil from getting pushed past the rings.
Thread Starter
12 Second Club
Joined: Aug 2005
Posts: 222
Likes: 0
From: Paradise, Newfoundland
Does the trap speed seem low?? I know that if I am losing compression it wouldn't be 100% bang on, but still fiqured I would trap 2 to 3 mph faster. With a the engine being 100% I was expecting to trap low 120's.
I could way off, maybe wishful thinking.
I could way off, maybe wishful thinking.
With the rings possibly being washed out its pretty hard to know what to expect from the motor. I would expect a 383 to be able to trap 120's in good running order, but the rings not sealing brings in quite a variable thats impossible to make predictions with.
