7 replies to this topic

[minilee94]

I'm building a 1380 I have the 7cc dished omega pistons a stage 4 head big valve head

I will be running a sw5 07 cam shaft

And a med crank

Let me know of you need to know anything else to help me

[Artful Dodger]

cylinder head combustion chamber cc, has the block been 'decked' ??

[minilee94]

Erm no I'm not sure to be honest I'm sending it to Swiftune in June so I'm not sure what tere process is they are going to surface skim it tho

[racingenglishcars]

I have a compression ratio program for download. It just uses the standard math but you have to find the right figures to put into it.

[minilee94]

Okay what other things do I new to find out

[Cooperman]

The figures you need are:

Piston dish volume
How far down the bores do the piston tops sit at TDC?
The combustion chamber volume
The engine capacity (1275, 1293, 1310, 1330, etc)

From this the existing C.R. can be calculated.
From the ideal C.R. it can then be calculated what volume the head chambers need to be once the block has been skimmed to bring the piston crowns to block deck level at TDC. That amount of fluid is then put into a combustion chamber and the amount to be skimmed off to bring the head suface down to this level can be accurately measured.

[MRA]

If you are sending it to Swiftune then they will work all of that out for you and advise on a CR for your application

[minilee94]

Okay thanks il ring Swiftune and ask thanks