Achieving a 7k RPM redline?

[82-T/A [Work]]

Ok, lets "assume" for a second that the following conditions are true:

1 - Maximum air-flow is not a problem.
2 - Fuel delivery is not a problem.
3 - There is no computer to interfere


I will be using a 2.8 block.

In your guy's opinions... what do I need to do, how do I need to build my engine so that I can achieve a 7k revs, and build power well into the upper rpms. The engine characteristics I woudl like to see is something that's just ridiculously powerful over the entire RPM range. However, I know that's not going to happen, but what I would like to see is something that has decent low-end torque.. it doesn't have to be testicle bursting torque.. but just something that will break the tires loose if it needs to. But I want it to have LOTS of mid-range power, and ALSO be able to produce power above 4,500 rpms. Currently.. in my stock Fiero engine, I'd say that around 4,800 rpms, the engine really starts to let go.. it's an exponential decrease in power. I believe this has a lot to do with the restriction of the intake and throttle body. Since air-flow will no longer be a problem, I'd like to continue to build power at least to 6,500 rpms.

What do I need to do to make sure that I have an engine that's reliable, can withstand those high rpms, and build power to those rpms. What cam would you guys recommend? lifters, rocker arms, pushrods.. cyl head work? What all do you guys recommend?



Thanks,

[sharkey]

beam polish rods (at minimum, or get aftermarket), forged pistons, stainless valves, solid lifter cam, a cam that will support high rpm.

or you could stick a 3.4 dohc in there, thats rev to 7000.

[v6h.o.]

arp rod bolts are a must if your retaining the stock rods. or an aftermarket set of rods, arp main bolts/studs, double roller timing chain, solid roller lifters/cam, i'd go with lightweight valvetrain parts to keep mass down for those higher revs.

[TurboZ24]

arp rod bolts are a must if your retaining the stock rods. or an aftermarket set of rods, arp main bolts/studs, double roller timing chain, solid roller lifters/cam, i'd go with lightweight valvetrain parts to keep mass down for those higher revs.

Um... Have aftermarket Rods, but still using stock GM main bolts (never had problems), head studs, though.... Double roller timing chain, check, solid roller lifters/cam, check. Valvetrain weight isn't as light as it could be (I still use steel retainers/keepers), but otherwise, sure. It shouldn't be hard to do on an iron head 2.8/3.1, but problem with the aluminum head intakes is clearance issues with the lower intake manifold. If you fabricated all custom manifolds, probably work. You would have to probably use titanium or something extremely light on the valve train, though. The aluminum heads really can't take much of a larger diameter spring and at some point, spring pressure becomes an issue (I would never put my 480 lb open pressure springs on an aluminum head, probably pull the valve and seat straight through the head)

The engine is going to have to breath really easily, huge intake, huge exhaust, which precludes it from having much in the way of bottom end.

[donk_316]

My motor sees 7000 rpm.

Its a 2.8 block bored and stroked to 3.4

Stock rods. 3.4 Camaro Pistons. As per GM....Stock rods and bolts will see 7000 rpm.

Rebuild Fiero heads, ported.

Was carb'd with a edel intake

Hyd 272 cam.

Would easily rev to 7000 rpm without a hiccup. Ofcourse the power had dropped off earlier than that. Shift points were around 6000-6100 rpm.

So you dont need "forged" this and 'Stainless" that.

Just watch your tolerances when your putting her together and make sure your oil system is up to snuff.

[sharkey]

of coarse you dont need stainless and forged, but if your going to take a motor that was meant for daily driving up to 7000rpm, its a dam good idea for reliability.

[donk_316]

Tell me....How does SS valves increase reliabilty? What does a forged piston have to do with 7000 rpm?

How many motors have you built?

Dont regurgitate shit you hear on the internet or from a "friend of a friend"

For every instance you can think of, Ill show you 10 times as many SBC and BBC that will see 7250 rpm on stock internals. And thats alot more rotating mass than a little 3.4

[sharkey]

how many motors have you built??? i couldnt count the ammount of motors i have built, from small block chevys, to hemis, pro street, street rods, ot race cars. i even crew on a top alcohol funny car building motors and doing the clutch matinance. dont question my knoledge.

getting a little motor like this to go 7000rpm doesnt take much, just keep your foot in it. to make power that high is a different story. it takes some strong peices to do it again and again, and keep it together. ive seen cast pistons just break apart from constant high rpm because they cant take the stress. and having a sloid valve train is key to keeping it together. to achive 7000 making power, it requires some high spring pressure, and higher spring pressure is hard on valves (well, all of the valvetrain really).

now as i said, its not needed, but a good idea. its possible to throw this together with stock parts and itll last for a long time with constant beetings, or it could brek a piston the first time is sees 7 grand.

and just think about it, whats a small block chevy meant to do??? make power and take a beating. whats a 660 meant to do??? get you from point A-B, and do that for a few hundred thousand miles, not go 7000rpm all day long. there is a reason gm puts a reline on the tach, because its not safe above that point.

[jeffie8696]

I have to admit using stock cast pistons on any motor going past 6000rpm is really asking for it(forces increase at the square to RPM). Using a solid cam is a great idea since it has 0 lifter preload (that takes away from the seat pressure) and pump up will not be an issue. Porting and polishing is a must, of course it makes a difference if the fuel system is wet flow or dry flow to avoid mixture drop out at low revs. I have achieved fantastic results on all the heads I have ported.

[614streets]

Really all you "need" to get power to 7000 rpm is a a cam meant to run well in that range. Everything else will fall behind that. Carb size , a/f ratio (ie jets), mild port work , headers , intake , good compression , quality and up to par fuel and ignition systems , proper springs. At 7k I would run a stock pressure oil pump with a full synthetic. Cast pistons will go a million rpms, just dont get pre ignition or detionation.


One HUGE problem with your build up is this idea that you want tire breaking torque and power past 4500. Um you have a super small v6. You expect an NA engine to give you tire frying torque and power way past 4500? NA? NA?NA?
Aint gonna happen with pump gas NA. No freakin way. Run some c-16 and at least 12:1 compression and a big fat solid bumpstick and headers and you'll get that stellar high end but that low end isnt gonna be there with that stick NA.

Run a mild bump stick and high compression, tire fry? Maybe on some low quality tires.

Run forced induction or nitrous if you want to tire frying torque(slick frying) and rpms that are more long winded than carl lewis lungs.

[sharkall2003]

Forged pistons, sodium filled valves (friend has them on a 4 cyl and he hit 9k) and lots more just no time to list

[dbtk2]

but just something that will break the tires loose if it needs to

On an N/A 2.8 thats gonna take a lot of work and some crappy tires. However, breaking the tires loose is of no use to anyone. If you're tires are gripping you are accelerating more than if they are spinning. I would rather my car not be able to break the tires loose but have just enough power to be right on the edge of spinning them. It just costs you money when you spin the tires.

I would build the engine with forged pistons, crank, rods, etc... a mild cam and a turbo/supercharger if I was looking for the kind of power you are. N/A is not the way to go for large power numbers.

Shawn

[geoffinbc]

A stock bottom end IS rated for 7000RPM. GM even says so in their catalogue. Whats gonna limit you on your stock engine is valvetrain, ignition and fuel.

DOHC guys push engines to 7000RPM PLUS all the time I I dont hear many stories about broken cranks or pistons.

[EspanolaGuitarista]

Harleys....

Harleys use 60 degree engines because they are more stable high rpm. So I think it can take 7000 rpm. But I would use aluminum pistons and forged rods just for insurance. Then get it balanced. That manifold sucks a$$. It will NEVER go 7000 rpm. You have to custom fab a intake and exhaust and do a full port. Then you need a at least a 230 deg. cam.

[akira]

If you want to spin fast the long stroke may not be as good as the short stroke. You can get a crank ground offset to shorten or lengthen the stroke. Lighten the guts as much as possible and maybe knife edge the crank. Balance EVERYTHING possible even the pistons, pins and rods. The closer everything is in weight the smoother it will run, you may not feel the vibration it's so slight but it WILL destroy an engine (harmonics). You need higher spring pressures to prevent valve float but too high also kills power and valves and seats. A turbo would be a good answer to high end and if boost is low you can have enough comp to create some torque. Aluminum flywheel/ flexplate helps. Loose some accesories and use underdrive pulleys. Putting in the roller cam wouldn't hurt (but it might kill you) with solid lifters plus the roller arms. Even a ram air will help your cause if you stay N/A