how much octain

[Leadfoot350]

I am using 20cc domes now and I got 14.6:1 compression ratio. I would like to use at least +4 timming or +7. Does anyone have a chart or know how much octaine I will need to run? I had 18's on but I think things might last a little longer with the 20's. Also the 18's turned out to be 17cc when I filled them up with water. Is that normal? I did not use an o-ring just put grease on the edge of the dome and put plexy glass over it and it came out to 17. This makes me wonder if I have 19cc domes instead of 20cc. It does not matter because I measured the compression ratio with everything together.

[FIRST BANSHEE]

160-165 psi cylinder pressure max for pump gas.

[Leadfoot350]

Does anyone know the answer to my question. Kicking comp changes when you port it. Thanks

[rebelbanshee2]

Does anyone know the answer to my question. Kicking comp changes when you port it. Thanks

279672[/snapback]

 

with 20cc domes you should be running more than pump gas anyway...with +4 timing youd deffinately be swinging to the symphony of destruction

Edited November 11, 2004 by rebelbanshee2

[Bigairee]

I ran 19cc on pump gas with no porting. My elevation is about 200ft.

[rebelbanshee2]

Does anyone know the answer to my question. Kicking comp changes when you port it. Thanks

279672[/snapback]

 

with 20cc domes you should be running more than pump gas anyway...with +4 timing youd deffinately be swinging to the symphony of destruction

279740[/snapback]

 

your compression is 145 as stated in your sig. with stock porting and 19cc domes? time for a top end my friend!

[Leadfoot350]

I just think he does not have the right fitting for the gauge. Make sure that the fitting goes all the way in just as far as a spark plug. Well I talked to Rudy Kurts and he said 50-50 ratio and +8 timming. I think I will try +6 to be safe.