LONG: Faster revs, not more revs...

[Paulster2]

... I understand the logic behind the vacuum pump, but wouldn't that mean more parasitic loss to running the pump than just directly moving the crankcase air? ...

The vacuum pump is electric and causes no parasitic losses. I would bet every hard core racer out there is running one (or should be). It also helps the rings seal better as well.

[SCIV]

There are guys running 11.5:1 + compression, but that is on 93.

[Frenchy]

I was planning on doing this a little on the cheaper side, with a 4.8 bored out to LS1 specs. Gives you a 313, and the same bore/stroke ratio as some other revving V8s, like 289's, 302's, 340's

[Mr.Cornelius]

http://www.youtube.com/watch?v=BZHCTBkcNsM

Retrofitted ITBs on a LS2,

[Lincolnman]

this thread intrigues me...mainly because I also am always having ideas on theoretical builds for my own projects and always like seeing other people's ideas. I have to say though I'm surprised nobody has mentioned using a full roller valvetrain (unless I overlooked it or it was simply assumed in use) for reduction of friction and quicker response.

Yes, I had figured on roller valve train. I wanted to think of this in terms of roller hydraulic lifters. Since the engine would not ever see over 7,500 I had figured that should be sufficient. Is there any advantage to the solid lifters other than higher (beyond 7,500) RPM? I cannot see how it should matter up to the proven 7,500 RPM, beyond that - who cares? That's the rev limiter.

The vacuum pump is electric and causes no parasitic losses. I would bet every hard core racer out there is running one (or should be). It also helps the rings seal better as well.

Well, that would be a parasitic loss in the long run. For one drag race this would mean that the pump just dragged down the battery, but if it was in a road racer or an endurance vehicle, it would need to work the alternator harder. That's parasitic loss right there. I admit I had not specified long term runs in the opening post, but if it were not for that the 60% under drive would be okay, too. So I still see this as a net loss.

There are guys running 11.5:1 + compression, but that is on 93.

Can only get 91 octane, 93 octane (10% ethanol) or 110 (?) octane ($$$) reliably around here. 93 straight I have yet to see, so I figured the design parameters around what's readily available.

http://www.youtube.com/watch?v=BZHCTBkcNsM

Retrofitted ITBs on a LS2,

Thanks for the link, but I actually just found that last night. I did some reading on ITBs, they sound like a real nightmare to keep adjusted and they don't put filters on them (effectively) that even keep out low flying birds. They are wicked cool, though!

P.S. I guess to join LS1Tech a person just needs an account with Google, Yahoo, or some others. That was easy - same user name if anyone cares.

[Slammed96]

guessing with hydraulic rollers it should be fine, seeing as the rpm will never be astronomical.

but because this is a theory based thread, I have an idea for a retrofit that may help with the windup and certainly help with power. I was talking to a friend the other day about a turbo-esq setup that is linked to the snout of the crank via gear drive and uses the same principals as a turbo, but instead of making boost it aids in spinning the crank. This way you gain back much power lost by friction and parasitic drag caused by accessories. I have also heard of this setup simultaneously running a supercharger as well. Though I have never seen it put to use on a vehicle or standard V block engine, I know it was used on some WWII era radial engine planes. I think it would be interesting to see if and how it would work for a street or race application.

[Lincolnman]

I was talking to a friend the other day about a turbo-esq setup that is linked to the snout of the crank via gear drive and uses the same principals as a turbo, but instead of making boost it aids in spinning the crank. This way you gain back much power lost by friction and parasitic drag caused by accessories. I have also heard of this setup simultaneously running a supercharger as well. Though I have never seen it put to use on a vehicle or standard V block engine, I know it was used on some WWII era radial engine planes. I think it would be interesting to see if and how it would work for a street or race application.

Cool concept - I would not have thought of it.

[Paulster2]

... Well, that would be a parasitic loss in the long run. For one drag race this would mean that the pump just dragged down the battery, but if it was in a road racer or an endurance vehicle, it would need to work the alternator harder. That's parasitic loss right there. I admit I had not specified long term runs in the opening post, but if it were not for that the 60% under drive would be okay, too. So I still see this as a net loss ...

Wow, really? You have to be pulling my leg? How much juice do you think it takes to draw down a vacuum? Less than running your a factory car stereo. I'm telling you no parasitic losses on this. I'll make it really simple ... you should see gains of 10-15rwhp with this addition. No parasitic losses.

[pl4yboy]

If you're worried about something as small as a vac pump, better unhook the headlights, radio, and pretty much anything else.