Compression versus octane?

pholmann · Aug 6, 2015

Re:

skipnrocks said:
Any thoughts on boostane and pump gas?

I wouldn't.

skipnrocks · Aug 6, 2015

I read up on it and it said it can leave yellow deposits on your spark plugs. I decided its not worth it. I probably wont go through a 55 gal drum once a year so it doesn't matter its 9 a gallon I guess. I don't need anything depositing anywhere.

zukimaster · Aug 6, 2015

CHASMAN9 said:
It was, the guy didn't even finish the pull in fear of making it a boat anchor. Didn't know how I didn't blow it up. SPeedSouth guys in Pelham did a great job tuning it, so good, I blew it up at RBD last year, but that was operator error.

. I was standing there watching this take place in person! :****:

al1tonyota · Aug 6, 2015

From my experience my old zz383 was around 10:1 compression when I got it I ran 100av gas mixed 50/50 with 93 it ran good with no detonation but ran really rich. I blew a head gasket and gauged a head so I went threw the motor shaved the heads which were 220cc bowtie fast burn heads 69cc chambers shaved to 64cc. Decked the block to .000" flat top w/valve relief Pistons which brought my comp to 14.5:1 After that I ran 114 mixed 50/50 with 93 and it was a whole different engine!!! Still didn't detonate even with a base timing of 11*

You mentioned lead in av gas, race fuel is leaded also and will over time chalk the O2's and cause them not to read. Nothing else to worry about.

skipnrocks · Aug 7, 2015

al1tonyota said:
From my experience my old zz383 was around 10:1 compression when I got it I ran 100av gas mixed 50/50 with 93 it ran good with no detonation but ran really rich. I blew a head gasket and gauged a head so I went threw the motor shaved the heads which were 220cc bowtie fast burn heads 69cc chambers shaved to 64cc. Decked the block to .000" flat top w/valve relief Pistons which brought my comp to 14.5:1 After that I ran 114 mixed 50/50 with 93 and it was a whole different engine!!! Still didn't detonate even with a base timing of 11*

You mentioned lead in av gas, race fuel is leaded also and will over time chalk the O2's and cause them not to read. Nothing else to worry about.

I didn't realize race fuel was leaded. So if I could get 108av gas then it shouldn't matter and would be half the cost

al1tonyota · Aug 7, 2015

skipnrocks said:
I didn't realize race fuel was leaded. So if I could get 108av gas then it shouldn't matter and would be half the cost

Av gas doesn't react the same it seemed? I don't think it has the same additives as race fuel? When I was running it people told me it didn't have as much oil in it as race fuel? I don't have any facts to back any of this up. I did quit running av gas after blowing the head gasket because I was concerned that it may have been a contributor?