Hi Got a question guys..Ive just rechecked the cc on my 2 litre heads and they seem to be 53-54?..hmm thought they should be closer to 50cc?..could it be correct or am I doing something wrong.. Cheers Arek Sent from my iPhone using Tapatalk
Yes I only have cleaned them up this morning so all that carbon buildups gone now..filled them up with oil not white spirit like before and yeah give me roughly 53-54 +\- 1..will recheck that tomorrow tho coz 3,4 cc makes alot of difference doesnt it..if I add 1mm shims it will give me then 7.2 cr and I wont b happy with it tbh..if they close to 50cc tho then I will get cr of 7.5 and this sounds better to me.. Sent from my iPhone using Tapatalk
..what minimum deck height I can go in your opinion on stock cj?..some people say min 1mm other 1.3-1.6 max..Im confused really on this subject..think I ran 7.2 before and it seemed low (2mm DH) but years before around 7.5 with 1.3 DH and it felt better..a bit of guessing on this one tho’.. Sent from my iPhone using Tapatalk
Thats what I thought..thing is if it was a beetle I would go for 1mm and higher cr but for the bus hmm..got to make decision quick and carry on with the build.. Sent from my iPhone using Tapatalk
With 54cc combustion chambers - 1.0mm deck = 9.0:1 CR, 1.6mm deck = 8.6:1 CR. That's with flat top pistons.
..using cb performance calc with 1.4 deck and 65ccs gives me 7.6 cr (0.4mm deck with no shims).. if I add lets say 0.75 shims it would be 1.15 deck and 65ccs then I get 7.8 cr..now if Im correct with my head cc measurement then with 1.4 deck and 69ccs I get 7.3 cr and at 1.15 deck 69cc 7.4 cr so it looks like those few cc’s on my heads dont do that much difference? Am I correct on this? It matters tho which size of shims I will go for as with 1mm Im around 7.6-7.8 wich is on rather high side but still accetable?..or 0.75 then around 7.3-7.4 cr rather stock..appologies if its kinda unclear but am I correct in my calculations? Wysłane z iPad za pomocą Tapatalk
If you have 0.4mm deck with no shims you need a 0.6mm shim to get a 1mm deck. 1mm deck and 69cc head plus piston combustion chamber volume = 7.5:1 CR. That’s fine for a bus engine with a standard cam.
