GM crate 350 HO runs fine on regular 87?
 

The recommended fuel for my crate engine is 91 premium which is our 95 here in Australia but it runs fine on regular 87 with no pinging.
Does that motor really require premium?

Re: GM crate 350 HO runs fine on regular 87?
 

A TV show on the Motor Trend network here in the states, "Engine Masters" did a fuel test using different octane levels. The test basically showed little to no difference between grades of gasoline. If you're not racing and not pinging, go for it was their conclusion.

Re: GM crate 350 HO runs fine on regular 87?
 

If it's not pinging run it.
Pay attention in the hot months when you're running it under heavy load like uphill towing at lower RPMs. It may ping under those conditions and not at all otherwise.

Re: GM crate 350 HO runs fine on regular 87?
 

Thanks I think my experience confirms that but nice to know someone has done it in a controlled way.

Re: GM crate 350 HO runs fine on regular 87?
 

If it’s only recommended, then no, it’s not completely required, but you may run into high load situations like hill climbing, towing, hauling heavy loads, etc that may push you into detonation territory. Running conservative timing will help suppress that, but you also may not be getting full potential from your engine.

In a previous industry I was in, it was advertised as 87 min/91 rec. This means you could run as low as 87, but the ECM would pull timing using fuel rated below 91. 87 was just the max it would compensate to.

Re: GM crate 350 HO runs fine on regular 87?
 

No pinging even in hot weather underload on regular. The mechanic who installed the motor said he set the timing conservatively which I assume is slightly retarded. It starts instantly and makes more than enough power for my use.
It replaced a tired 305 so I guess thats why it has more than met my expectations.