LONG: Faster revs, not more revs...

[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.

[Slammed96]

Cool concept - I would not have thought of it.

its one of those things that really only makes sense after you hear it from another person, I can honestly say I would never have thought of it either. Someday I would really like to see it tried out, or possibly fab something up for myself to get it to work...also sorry to kinda get fixed on a tangent, I just have alot of interest in this haha

[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.

Just a side thought on this, how does one make it work considering the RPM of a turbo? Are we talking about a turbo running what would basically amount to an air to air torque converter or what? I don't imagine that you could run gears and get proper oiling, and a chain or belt would disintegrate.

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.

I was not suggesting that it was a bad idea, just that it MIGHT have some trade off. No, I am not pulling your leg. I know that there will be parasitic loss, and it ought to be more so even then if a person ran a vacuum pump directly as an accessory, because the conversion from mechanical to electric and back to mechanical would lead to significant losses not found in a mechanical to mechanical conversion. I might be missing something there like the losses from the alternator creating the electricity and the electric pump COULD be more efficient (pending mechanical pump option) but it seems illogical. ALL THAT SAID - I do believe that it makes more power, but as more power was not the end goal here, faster RPM were, I am not sure it fits. That being said I would probably do it (in a real world situation) anyway, because I do believe that the marginal losses would be FAR AND AWAY outweighed by the overall performance increase.
It just didn't fit the mold of this question perfectly, that's all.

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

Who said anything about those being on anything (or even existing relative to this) at all? I don't recall saying that this was going to be installed in my daily driver. Not to be a jerk, but it was not what I had asked about.

New thought - what about chain driven accessories? Chains are considerably more efficient than a rubber belt...

[cjriojas]

Lincoln, did you get my pm?

[pl4yboy]

Who said anything about those being on anything (or even existing relative to this) at all? I don't recall saying that this was going to be installed in my daily driver. Not to be a jerk, but it was not what I had asked about.

New thought - what about chain driven accessories? Chains are considerably more efficient than a rubber belt...

I just thought you should take everything into account. I assume when building a motor (especially when you specify LS platform) that it will go in to something. If the motor was going into something, I would assume it would have electronics of sorts. Headlights are a must if you plan on driving it at night. The majority of vehicles have a stereo (Hell my Polaris Ranger has a stereo). Just food for thought. No need to get your panties in a bunch.

[cjriojas]

I assumed this is a concept engine for some type of competition go-kart, not a vehicle driven on any road. The SAE organizations have minimal amounts of electronics: starter, alternator, battery. Lincoln, you never specified the application for the motor. What is it for?

[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.