pump gas and compression

[rideblue_06]

I am trying to remember what is the hightest copression that you can run on pump gas. I think 170 and below is ok for pump gas or is that pushing it. I tried searching but couldn't find anything on it.

[Stinger]

I am trying to remember what is the hightest copression that you can run on pump gas. I think 170 and below is ok for pump gas or is that pushing it. I tried searching but couldn't find anything on it.

 

Depends on many things, most notably your altitude. I'm at 1600 feet and was borderline at 155psi and 91 octane.

[FasterThanU90]

yeah 170 below should be fine

[David Keith]

I am trying to remember what is the hightest copression that you can run on pump gas. I think 170 and below is ok for pump gas or is that pushing it. I tried searching but couldn't find anything on it.

Yes, at sea-level to 1500 feet above, you can generally use "pump gas". Remember that the higher the octane rating, the slower the fuel detonates. It actually " explodes" slower. That's why you should advance the timing when you use higher octane fuels.

 

 

I am trying to remember what is the hightest copression that you can run on pump gas. I think 170 and below is ok for pump gas or is that pushing it. I tried searching but couldn't find anything on it.

Yes, at sea-level to 1500 feet above, you can generally use "pump gas" with compression ratios less than 9 to 1. Remember that the higher the octane rating, the slower the fuel detonates. It actually " explodes" slower. That's why you should advance the timing when you use higher octane fuels. At seal-level, the normal atomshpere pressure is 14.7 psi, so it your compression is 10 to 1, you should have 147 psi compression. Generally you can round off to 15 psi for easier figuring.