1 reply to this topic

[miniturbo01]

Hi Guys, haven't posted for some time, just worked out compression ratio for my engine, be great for someone to look over my math to check I have blundered.

The engine is 1293 being bored +20 here are the figures in metric.

Stroke 81.28

bore 71.12

piston dish 18cc

bk 450 head gasket 4cc ?

ring land .39

piston to deck .127 which I make 0.5cc

head chamber 23cc

sub total  45.89

 

Swept volume 323.25

 

total 369.14 divided by 45.89

 

gives me 8.04 : 1

 

enjoy your mini's everyone cheers Martin

 

 

 

 

 

 

 

 

 

 

 

 

 

[timmy850]

If I put your numbers in to this calculator I'm getting 8.1:1 compression ratio

71.1mm bore

81.2mm stroke

3.4cc head gasket

18cc piston dish

23cc head volume

0.127mm = 5 thou down the bore

https://www.classicm...cal/compression

Edited by timmy850, Today, 03:24 AM.