11:1+ Compression on Pump gas?

[90mustangGT]

Is it possible without problems running 93 octane?

I am rebuilding the engine, just considering options.

 

[Motorhead6T5]

My 65 has almost that much compression and runs fine on 91.So you should be fine with the right tune.

 

[MustangPunk302]

My civic has 12:1 and the mustang is about 13:1 and I run both on 93 octance... Though the mustang takes full advantage of 100+ of cousre . You shouldn't have any troubles.

 

[giddyup306]

I'm runnin 11.5:1 on my 347 with 93. I have the MSD retard box so in case if I get some bad gas, I can retard my ignition timing from the drivers seat. It also depends on your altituede. If you are at or near sea level, it may be iffy.

 

[giddyup306]

You are talking about aluminum heads right?

 

[willys1]

I believe the new Vette is 11:1

 

[giddyup306]

I believe the new Vette is 11:1

It is also OBD II and can retard timing according to the knock sensor. The prius is 13:1.

 

[willys1]

It is also OBD II and can retard timing according to the knock sensor. The prius is 13:1.

who makes Prius??

 

[giddyup306]

The Toyota Prius. Might have spelled it wrong but I think this is right.

 

[dirtracer]

My 408C is 11:1 and I run it on pump gas with iron heads. The tune up is a bit soft just for safety sake, but it runs good.

 

[Ford_Racing]

I have been told 11:1 is the limit to run safely on pump gas.

 

[thumper460]

tons of things will be needed to run the 11:1 on pump. Dont "lug" the engine around.. like 1800 rpm in 3rd and mash the gas.. or pull hard up hills in a high gear and low rpm. Or run hot.. blah blah...

I run 11:1 and use a set of gears and rpm ranges to keep the engine from detonating !! My ign timing is at 38* total at 1800 rpm and the Cam is in advanced!! but I drive at 2500-2800 rpm!! I keep the rpm up and the temp down!! ( I add Fuel when I race...) To me... Using that compression ISNT worth the trouble for the few extra HP gained!! drop to 10:1 and beat the mess out of it!! Rocking??

Just me..........................

Thumper

 

[QDRHRSE]

You will not be able to really run 11:1 all the time on pump gas. You will have to pull back the timing and drive very conservatively. You will probably have to avoid hot weather and traffic. I'm saying the same thing as everybody else but I'm attempting to be more practical. If the car is a dedicated toy you might be able to get away with it. Otherwise, I wonder why you'd want a 5.0 that you'd have to limp around town in?

 

[BlackDrop50]

I run 10.7:1 with 91 octane no problems

 

[88GTStreetRod]

I ran a 466ci with 11.5.1 on 93, ran fine. The motor really liked 110

 

[willys1]

It is also OBD II and can retard timing according to the knock sensor. The prius is 13:1.

What does OBD stand for??

 

[Mike86Stang]

On Board Diagnostics

 

[willys1]

On Board Diagnostics

Thanks So the OBD-II started as the OBD-I ??

 

[bluevenom867]

Hehe, I run 93 octane in my 351W with 10.7:1 and hit it with a 125 shot with 34* of timing.No detonation.

 

[Mike86Stang]

Si senor.