2.8 redline

[Superdave]

Your best bet is just to use the 2.8 for parts and swap in a gen3 engine. A 3400 V6 from a grand am GT will run on the Megasquirt just fine and will actually make power up past 6K RPM. You'll have to make new motor mount plates to bolt to the block since the 2.8's are different but that's cake.


You are correct, the problem with the gen1 2.8 is the heads and intake. The heads flow poorly and the engine will stop making power around 4500 RPM. The rods are rated for 7k RPM (same rods the 3400 uses) but the engine just won't be able to rev that high.


The 3400 responds very well to mods too, if you want to start making stupid amounts of power you have tons of options.

[Wragie]

Unfortunetly this is sort of a how high is the sky type of questions or could be taken that way.

I have a 91 LL2 mpfi out of a s-10. It's going into another car which is way lighter (Locost/Stalker ~1200lbs) so the problem or concern is that the engine will be able to rev enough to make things work. The power is not really the problem but more is always gooder.

First concern is that the stock engine is dead over 4500 rpms as it can't breath. Now if this is so is the problem the heads, the cam the intake or?
Since I don't have emissions to worry about it will be running headers and side pipes so fairly open there. The intake will be stock to start with and I will probably use a a 4.3 throttlebody and megasquirt on it. If the problem is heads and cam I am thinking of junking the 2.8 and finding a fwd v60 with the gen 3 heads to drop in as the starting point and avoid needless parts upgrades. I have research and talked to a few people about dropping the g3's onto the 2.8 block but haven't convinced myself I'd be saving any time/money.

On stock internals what is a good safe redline? I have read that GM rated them good to around 7000 but the engine craps out before that. If thats the case what do I need to change to be able rev and pull to 7K? 6500+ seems to be the magic number to make things work for my setup.

TNX

Dave