N00b question... How fast could this spin...and work?

[donk_316]

Say you have a 91-92mm 60 V6 block.

A forged 2.8 Crank.

Good quality H beam 6" rods.

High quality Forged Pistons

Dry sump oiling system...

**Assume the heads can flow enough to support any RPM for this discussion**

Do you think this could hit 10,000 RPM reliably?

[SappySE107]

RE: N00b question... How fast could this spin...and work?

Maybe balanced and ARP bolts, and the rods/pistons are light weight. Hard to tell, as its all theory and well...guessing. I think 8k would be a no brainer. 9k would be doing good. 10k, unknown. Looking at what GM has done to the TT 3.6 VVT to get it over 10k RPM...maybe?

[donk_316]

RE: N00b question... How fast could this spin...and work?

Yeah balanced would be a given and same with the high quality fasteners...

Its more...like you said guessing...I guess someone has got to build it and see what happens!

[SappySE107]

RE: N00b question... How fast could this spin...and work?

Pretty much Would be good in a fiero at least if it works out. However, you gotta make sure the top end is designed for it as well. And the cam.

[geoffinbc]

I dont think it would have a problem. A small block can do it with a longer stroke and heavier components. The slow piston speed of the 2.8L crank would be an advantage.

Do the above mentioned procedure and slap a rev kit on the lifters. I bet it would do it no sweat.

[eliteweapons]

Why do you need to spin it to 10k? Most of the simulations I havr run on the 3100 max out at around 7000 with major modding. The 2.8 show peak hp at 6000 with mods. I don't know how you could even get a head to flow that the geometry just isn't there to support it.This is just a base line of mods but I don't really see a need for 10k. The engine can't support the cfm above the 7000 range.

[eliteweapons]

Ok stupid me forgot to adjust the head flows. If you run a 4 valve per cylinder head to meet the flow demand. it peaks at 5850 with 291 hp ( remember this is a hurry up throw it together sim). At 1000 rpm 224 hp. Thats normaly aspirated with a 550 lift and max lifter acceleration. two 1.422 inch intake valves and 2 1.242 inch exhaust.

[v6h.o.]

If you ask any machinist who does race engines he will tell you:

"An engine Ballanced at 100rpm is still balanced at 10,000 rpm, The limiting factor is the Valvetrain, That is what will determine RPM rev Limit"

It could be done. Anything can be done. $$$ is the factor here.

[Guest]

I talked to a guy tonight on teh phone that used to build 60 degree race motors and knows the infamous Potter dude.

He spun his motors to 7800. Potter didnt' go higher then 8600. That prob tells you something.

[SappySE107]

Would be nice if someone like that would join our forum or send us some useful information. We appreciate what you have told us though

[TurboGTU]

I say it could...but were talking serius hardware here..no 190psi crap..and knife edged light crank and aluminum or titanium rods. Even a destroke would help. Its a mater of crank and rods going into pieces. With the current heads available for the 1-3 gen block...your looking at a destoked 2.8 with max ported 3400 top and 3500 UIM or just small TB on each runner..no manifold. The sping rates wouls sure make a tappet cam last two cranking revolutions before becomming round.

I say 8500 rpm tops in reliability.

[sharkey]

the only reason i can see for wanting to rev a motor that high is for a racing class with tight restrictions.

a good example of this would be top alsohol funny car. most guys were shifting at 9500rpm max a couple years ago. then in order to get the breakage down, the rules changed and dropped the blower overdrive, and it knocked the cars down a good 2 tenths. to combat this, racers changed everything in the car, gearing, clutches, even chaged to a short stroke big borew motor, all so they could rev it to 10,500rpm to get the blower boost back were it used to be.

the biggest question becomes, why do you need it to rev to 10k rpm???

i think the best way to go about this would be a gm performance block with a 3" stroke and 3.620 bore, would end up as a 3.0l. destroking it even more would help. you would need a forged crank, aluminum rods (i wouldnt take steel rods that high), forged pistons, dry sump oiling system, a realy big freaking solid roller cam, 3400 heads (will 3500-3900 heads bolt to a 3400 block???) custom intake, seperate throttle bodies/ cylender. you are talking a serious race engine, and dont expect it to last any amount of time either.

[Guest]

I'll let you know when I'm done.

Seriously, I'm collecting parts for a similar build, the Frankenbeast. A short stroke 3.1L

My (DD2K) dyno sheets show peak at somehwere around 8500 to 9000 RPM and stays flat from there to about 11 000 RPM or so, I'll have to look on my GFs 'puter next time I'm there. Torque peak was around 5500 and slowly dropped off after that to about 9500 where it started dropping faster.
I should mention that this was an OHV 2 valve per cylinder design, it's is also turbocharged.

Personally I was looking for something that had a bit more bottom end, but the more I look at what I want to do with my truck, the more and more this seems like the way to go, for me.

[eliteweapons]

I was only looking at the n/a approach. Giving boost will have a different result. I may tinker with looking at that when I have some more time.

[geoffinbc]

a good example of this would be top alsohol funny car. most guys were shifting at 9500rpm max a couple years ago. then in order to get the breakage down, the rules changed and dropped the blower overdrive, and it knocked the cars down a good 2 tenths. to combat this, racers changed everything in the car, gearing, clutches, even chaged to a short stroke big borew motor, all so they could rev it to 10,500rpm to get the blower boost back were it used to be.

No man we fucking never run our engine that high. Not even close. If we hit the rev limiter at about 9500 then we toss all the springs. Under 8500 RPM is our operating range.