Hello everyone! I've disassembled my CVH 1.6 (with Hemi (89SM) head) engine. So i decided to tune head: to lighten valves, to make chamfer 30* and to polish the head for compression improvement. But there are some questions - how to measure compression ratio? how to calculate what compression rate is needed? because the piston is with displacer and i am not sure if my cylinder head wasnt polished before.... how to define it? Thanks for your answers.

 

Look at the links in the technical gudes at the top of the technical page, it will explain all in there, its not straight forward

 

Sorry, but I can not find what I'm asking in this topic, please put a link if this question was discussed.

 

http://www.rbracing-rsr.com/compstaticcalc.html

Really should be done with the engine built and parafin!

 

http://www.motorsport-developments.co.uk/stus.html

Here you go fella, bloody good bit of reading here

 

Guys, i know how to calculate compression rate, the main question for me is to measure the volume of combustor because the piston is with displacer?

 

Someone calculated the combustion chamber at all on this motor with these pistons? I really need help ... : (

 

The only way I have used to measure the volume of a raised crown piston is to use some plasticine ( raided my kids play box lol ) and make a mould of the piston crown at tdc , then remove this and measure it volume using the syringe and paraffin , then you can subtract this from the clearance volume . hope this helps .

 

Just yesterday I thought about this way, thanks, I will try

 

I measured, received 17 cm3 Not a bit too much? Did anybody measure a volume of the camera in the hemi cylinder head? It looks like it has to be about 50 cm3