99TA60

I currently have 317 heads on my LQ4 but I have the option to possibly get some 243 heads.. Can anyone tell me what mite be better for my application.. Like I said I am currently running LQ4 motor with 317 heads, MS3 cam shaft, Full exhaust w/ LT's, LS6 intake (I believe) and 150 shot NOS..???? Thanks




317s OR 243s????????????????????????????

theMOSTWANTED

iTrader: (1)

I hear great things about the 243s. I'm leaning towards the 243s for my future mods when ever I decide to do a cam and convertor swap.

Blackpanther99

iTrader: (8)

Ported and milled at .30 243s heads will be a great option for you. Specially since you will be spraying.

99TA60

Blackpanther are you saying that the 317s are no good if im spraying or are you saying there just not as good as 243s or what...???

conan

iTrader: (5)

317's and 243's flow just about the same amount of air. The big differance is the cumbustion chamber size. The 243's have a 64cc combustion chamber and the 317's have a 72cc combustion chamber. So on the LQ4 with a dish piston and 317 heads it's at 9.5:1 compression. Stick on some 243's and you'll bump up to 10:1 copression range. More compression more power. 317 vs 243 one is not better than the other, it's just what is the better head for the application.

99TA60

Thank you Conan you are very helpful and with that info I think Ill stick to my 317s due to the compression factor.. I eventually want to go FI so dont I want lower comp..???

wooddaniel

iTrader: (28)

The lower the C/R with FI the safer it is, but it really depends on the tune, the bottom end, ETC. If you are running a forged motor you can have a little higher compression ratio and still be ok.


In short, If you're planning on boosting it, I'd just keep the 317s and not spend the extra $$ for 243s.

99TA60

Thank you all ill just stick w what I have.