[Marksy_06]

hey i have got a 1.6 mblock which ahs just been bored out had flat tops put in every things been balanced and shaved and i have a 1300 head which ive opened up the exuast ports massively now ive come to the point were ive been told the compression is way to different for this to work ? i am wondering if any one knows how to get around this to lower the compression in the head ? plewase help !

[badger]

take the flat tops back out?

[Damo]

Lowering the comprssion ratio can be done in a few different ways.

As menioned you can change the pistons. You could also increase the volume of the compression chambers in the head, or fit a thicker head gasket.

I would be inclined to calculate what the compression ratio is using the parts you have before doing anything rash. Has your engine builder done this already?

Below are a couple of pages that might help you if you want to learn a bit more about what the compression ratio is and how to calculate it:.

http://en.wikipedia.org/wiki/Compression_ratio
http://www.rbracing-rsr.com/compstaticcalc.html

[Geepee]

fit 2 head gaskets
will help

[royce]

arent standard pistons lumpy top or is that jsut 16valves?

I would learn how to measure and work out your compression ratio 1st, then see what you need to do, best is to open the chambers up some which also allows you to get a bit more flow

[Marksy_06]

thanks guys the guy who is doing all the work is a engine builder by trade makes motor for race car and boats and stuff and has done a couple of these motors ill have a chat with him about making the head chambers a bit bigger and testing it and stuff,