No replacement for displacement - really???

[383hq]

Thanks Sir,



When I have bought it, everybody told me 9,5:1 is too much static compression and no one wanted to see that I am after a low boost setup, with maybe 10PSI, and that I will run LPG (Propane, 105-110 Octane) or CNG (rated to 130 Octane), so I wont see ping.
Now I can build from new and realize that the trend is going to raise the static compression to 9-9,5:1.

What are your toughts on that engine-project?

Here in australia LPG (Propane) is readily available. You need to foucs on DCR not SCR.
I have supercharged my LPG (ex daily driver) sbc motor due to environment and cost benefits. you will really struggle to see those numbers on LPG.
I run a twin converter GRA throttle body setup with twin LPG tanks and twin lines in a WB ute. The system maxes out at around 590 engine hp. Note that packaging gets complicated at this point.
To go bigger (I have seen 3&4 convertors used -ugly engine bays). The restriction becomes the fuel from the tanks (twin lines etc over 360kw).
I believe the guys with unlimited budgets really struggled to get the gaseous fuel into the combustin chamber from 800hp on.Drag racers here with great budgets, experience and reputations all seem to switch to petrol (gas) at this point. -Unlimited budgets here in Australia have seen no better then 800-900hp on LPG.
I cannot speak on the new liquid injection that occurs with LPG, this technology has occured in the last few years, but I am unwilling to spend another $5K to replace what I have for a few more rwkw. The benefit is in the increased timing available from the natural intercooling effect of the liquid converting to gas . I have learnt there comes a point where the engine overpowers everything else chassis brakes, tyres....

As far as driveability goes comparing force feed SBC to BBC back to back, I prefer the force feed sbc - increased torque cannot be described through dyno numbers.

[gearbanger]

If I ws starting from scratch with a Chevy, I would not even consider another engine than an LS based combo. That being said, I would build a large cube engine regardless, because I think it is smart to start with the most cubes you can. It will require less boost to reach your target and the engine will have more torque while not in boost. I am not that knowledgable about boost, but from what I do know, I wouldn't do a long stroke engine with much boost because of increased dwell at TDC causing potential for detonation. For a street car that will sit in traffic and heat soak, you need to always keep detonation resistance in mind. So, if you go BBC, I'd probably stick with the 502 or something like that to keep the bore>stroke and the stroke not so huge.