High reving SR

[drifter_for_life06]

chunkidori, the game is jsut what got me thinking about the topic that is all

[Nismo_Freak]

the rods dont necesarilly hove to be heavier--they can be titanium. Strong.

You really didn't understand what I said... I can make the n/a engines rods out of titanium too and they can be thinner because they deal with less impact force.

The cams would have to be set to a bucket and shim design or a solid roller. You cant rev that high on a hydrualic valve train--it aint gonna happen.

Agreed

Youwill have to have VERY low stroke and as big of a bore as you want as long as its close to square--but square is optimal.

No, Oversquare motors are optimal for high rpm... you want a long ROD not a long STROKE.

Thats whay f1 cars use v8s with about 2500cc motors.2.5 liter V8 is pretty nasty--and f1 cars are turbo--but the replace them after every race. The cars rev to like 12-14k for hours on end.

F1 cars use V12's ... and are not turbocharged.

[Dookie]

F1 cars use V12's ... and are not turbocharged.

I thought BAR Honda used a v-8? Or was that just the honda guys that won the Indy 500?

[wild_maxx]

i have a traxxas t-maxx rc truck that has the trx 2.5 motor in it that has a 50,000 rpm rev limit. :pface just thought i would share

[Fish240]

my friends B16 hatch revs to 8500, he has the USDM tach that has a 7500 rpm redline and it looks funny when goes past it

[drifter_for_life06]

wild-maxx i too have a rc car liek that, not quite that high tho

Fish are you sure thats the redline and hes not over revving that B16?

[redamnavit]

At some point having a square engine isn't even sufficient. Take a look at what's run in competition motorcycles; many designs pretty severely oversquare, with rod ratios you could only dream of in a car. Eventually this is no good either though, because the larger the bore the longer it takes to burn a full load of fuel. So you end up with what heavyhips pointed out; lots of small cylinders instead of a few oversquare ones.

From a practical standpoint this is all moot though. For any engine with a single cam profile for its entire rev band, the more you do to make your engine breathe at high rpm the more it suffers at low rpm. VTEC and its ilk are moderately successful solutions but the problem still persists. The only production engine I'm aware of that can dodge this issue is made by Ferrari. It uses something of a... ramped cam profile, for lack of a better term, giving it a quasi-infinitely adjustable lift. Even it doesn't adjust duration.

As a final note, F1 cars run those small displacement engines because the rules limit them. Barring engine weight displacement is never a bad thing to have.

[Nismo_Freak]

Yeah basically displacement limit and I think they have unlimited no. of cylinders (or is it 12?).

Indy cars run V8's AFAIK.

[Def]

F1 cars use NA 3.0L V10's - mandated by rules. BMW, BAR-Honda and Ferrari are making the most power right now, somewhere between 960-1000bhp from speculation. They rev to around 18-19k RPM to do this. Strokes are usually in the 45-55mm range, and they have BIG bores. Rods WERE made from tungsten berrylium(talk about expensive!) back in the turbo era.

It's Real Lame(IRL) series use V8's with very low pressure turbos - I believe they're down to 3.5psi now, but make GOBS of power by revving them up and making sure the heads flow VERY well.

Interestingly enough, pressures on qualifying engines in the mid-late 80's F1 turbo era were upwards of 60-70psi. This produced ~1500bhp from 1.5L 4 bangers according to Honda(most estimates put it closer to 1700-1800bhp by analyzing acceleration). They also experimented with alot of anti-lag strategies which involved diverting some of the pressurized intake air into the turbine while running very rich on throttle lift. Basically STARTING combustion in the turbine. They say 60psi could be developed with no load on the engine at a VERY low RPM - much lower than what the engine would normally spool to that level. The turbines were replaced very regularly, and they used extremely exotic materials to be able to withstand temperatures like that.

F1 engine technology is pretty badass, but it's kind of boring now compared to the turbo era. They were on the path to make such high horsepower that the cars would be hitting over 250mph on most tracks, so there came the ban on turbos.

They're about to limit engine size to 2.4L V8's in the near future - I think the 2006 season.

[redamnavit]

They also experimented with alot of anti-lag strategies which involved diverting some of the pressurized intake air into the turbine while running very rich on throttle lift. Basically STARTING combustion in the turbine. They say 60psi could be developed with no load on the engine at a VERY low RPM - much lower than what the engine would normally spool to that level. The turbines were replaced very regularly, and they used extremely exotic materials to be able to withstand temperatures like that.

This is similar to the strategy that some (wait for it) competition tractor pull machines employ. They dump raw propane into the exhaust just after the head. The exhaust temp is enough to start a secondary combustion.

[drifter_for_life06]

wow, so rednecks do think. lol j/p thats actually kinda kool.