Gas, you just have to try it, long duration cam with alum heads is more forgiving to knock. E85 is a god suggestion, but you need a dedicated carb, more fuel pump, upgrade any rubber in the system. E85 quality varies widely and would concern me with nitrous, use race gas if you're gonna spray.
If it's actually at 13.5-1 you'd better run race fuel or E85. Especially with the nitrous. Posted using the Full Custom H.A.M.B. App!
I had a 377 13.5 to1 600 lift roller 208 valve 230cc runner 400 piston 5.7 rod in my vega it was the most fun small block I ever owned would blow the turned off at 75mph just stepping on the gas not a ton of down low torque but not terrible shifted that bitch at 8500 more then once. Love rpm they do Posted using the Full Custom H.A.M.B. App!
Street driven and pump gas? I would back it down to 11:1. Not a lot of HP in that extra compression with the street RPM. You can make it all up with the NOS at the track.
Sounds like a badass little ride! I don't think mine will turn like yours to 8500 but I'm thinking it will still be able to put a smile on my face!
I don't think "a couple degrees" would be near enough to keep a 13.5/1 engine from detonating itself to death on pump gas. By the time you got enough timing pulled out of the engine to make it live, drivability would really suffer. But it wouldn't hurt anything to try it for a short drive ---------- maybe.
Making it live on the street by just turning back the timing depends on your cam profile, quench height, and dwell time. Like others have said, I think the easiest way to make it streetable would be to run E85. All you will need to do to it switch over to E85 since you already have the compression, is larger jets and advance the timing.
It's definitely 13.5-1... wish it was a tad bit lower, but that's how I got it and this is a budget build so it's going to stay that way for now. Spray won't be for a while though, want to get everything dialed in first before I hit the button.
A couple of degrees of timing might not be enough to make 13.5:1 live on premium pump IMO. I'd rather be safe than sorry. E85 is an option if it is to be street driven a lot. modifications at the very least mean upping the carb jets about 8 sizes all around and shooters in the 40 range. Really it requires a carb setup for it. Another option is mixing in 100LL Avgas. I've done this a lot. No ill side effects I've seen, lower RVP means it don't vapor lock in the heat also. Per the nitrous, assuming you're running a plate, start with running about 30 degrees total timing when on the hose, 5.5psi fuel pressure for nitrous enrichment, and jets something like 53N 47F for a 100 shot, 61N 53F for roughly 125 hp. Those should be safe tunes yet make that 377 sound primal. Read your plugs. Read your plugs. (said twice on purpose)
I would think at over 13:1 with iron heads it will need more octane than what E85 will have. If I remember right E85 is about 105, I would shoot for race gas in the 112 range. Also, those octane boosters that claim "X number of points increase", a "point" is a tenth of a octane number so 14 points added to 93 will get you a true octane of 94.4, not nearly enough.
4thhorseman and in2hotrodz... thanks for all the advice. this motor is a new ball game for me and im just trying to educate myself as best as i can.
That's what I been doing lately. So far so good. Mines a 400 destroked SBC with about 590 rwhp on the dyno Detroit Road Devils CC. Give None/Take None
They claim e85 is good to 14.5 compression. I don't know anyone that uses it. Too scarce and varies in quality. Race gas is regulated like regular fuel. Spend the $12-$15 a gallon on some 112 and call it a day. Maybe a get a boost timing master so you can just dial the timing back while you drive and then hit the juice. I know quite a few -6.00 second 1/8th mile rides and not a single one is on e85.
The nova is a 14:1 496 with a 500 shot of juice. Runs low 9.s - had traction issues The ford small block is a 347 stroker with 14:1 and runs 5.90 in the 1/8th Both are on 112 because it's the same blend every time. Even a budget build is expensive and damage sucks. I would stick with av gas or better. Ping and lean kills top ends. Make sure your fuel pressure maintains about 7 psi through all rpm ranges. Best of luck to you
E85 is popular where it's available, I think you'd be fine driving on it. If you're gonna use nitrous step to race gas for a consistent octane and tune. 377's love rpm, I used to race against one, that sob would rev, fortunately for me, the owner of the car spent all his money on the engine and he didn't have the gear or suspension to take advantage of it.
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