THose who have done the "MPFI Hybrids"

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[Dirty Rockstar]

You know what I mean. The MPFI block, SFI heads and intake..

..WHat all was involved? I know I'll need it all from the heads up..

..FOr those who don't know, I am buying The Whale as soon as the GFs hooptie is sold.. As much as I like the 3.1, I think the SFI top end would yield that extra little gain, especially at the high end, because in my 90 Lumina, I would punch it at 55, and it felt like I was staying right at 55..

..I had a link for a step by step walkthrough, but I seem to have lost it..

Thanks guys!

[Dstanic]

I noticed a huge difference from my old MPFI 2.8 when I first got my 95 GP.  Of course I got used to the "less than average" power it provides, but at least it can almost get out of it's own way.  I spanked my friend's 92 GP (3.1) from a dig to 30mph by a couple car lengths, and about a bus length from 50-75mph.   If I gave a shit about my car I'd do the 2000+ top end swap, but could care less.  If you're gonna do it I'd at least put on the newer stuff.

[Euro]

interesting topic...i'd like to know whats done for this swap

[DiscoStudd]

With all of the "adapting" you'd need to do, why not just drop in a 3400?  You'd probably have to do just as much adapting to get the 3x00 top-end to work, so why not go for the extra displacement?

I bet you could find a complete low-mileage 3400 for less than the individual 3x00 top-end parts would cost you (at least less than the "good" stuff anyway.)

This is under the assumption you could get the 3400 to run using the MPFI's PCM.  If it won't, then nevermind ...

[Dirty Rockstar]

If I go through the hassle of a swap in the whale, I'd go LQ1.. I LOVE the DOHC motor, and would LOVE to have it in there.. IF I were to swap of course!

[TurboSedan]

If I gave a shit about my car I'd do the 2000+ top end swap, but could care less.  If you're gonna do it I'd at least put on the newer stuff.

i'm in the middle of deciding whether or not to do that with my car.  i'd do it if i knew i was going to keep the car.  definately go with '96+ 3400 heads/intake or '00+ 3100 stuff.  '94-'99 3100 'L82' is small port/smaller intake valve and it has the log style rear exhaust manifold.  if you're going to do the swap you might as well use heads that have a bigger intake valve and the large port LIM/plenum and runner style rear exhaust manifold.  or really, just swap to a complete 3400  then you'd have a roller cam and better oiling system not to mention the increased displacement.  for the cost of a complete ~50,000 mile good running 3400 engine being around $500 i'd go that route.  i bought mine for $150 knowing it was blown (milkshake oil thanks to the stock LIM gasket) but all i wanted was the top end.

for a 3.1/3x00 hybrid you would need the heads, LIM, plenum, custom length pushrods IIRC , rocker arms ?(i forget), valve covers, fuel rail, exhaust manifolds, crossover pipe, downpipe, ICM/coilpack and bracket with new spark plug wires, new radiator hoses, newer throttle cable to match 3x00 TB and possibly newer TV cable and cruise cable as well, new PS lines?, lengthen the existing wires on your engine wiring harness for the ICM and other sensors that need it, i'm sure there is more but that's basically what you would need.

i wanted to do the swap and had all of the stuff at one point (besides new gaskets really) but i sold it all off.  now all i have is a blown 3400 block in my garage i don't know what to do with heh.

i'm going to give my Cutlass a chance to sell or trade and if by fall it doesn't happen then i'll probably be doing the swap to the Cutlass.  i would be getting the 3400 i have rebuilt with forged 9.0:1 Wiseco pistons.  i think the stock higher CR 9.5:1 pistons are availale as well and the pistons include pins and rings for around $700 IIRC.  then just continue on driving the car while i did that and get turbo manifolds, crossover pipe with T3 flange, and downpipe custom fabricated.  it would be alot of work though and alot of money, so i'd really rather just be happy with the car as is then trade it or sell it if i can.

but for your car, it can probably be done for undre $300 total.  i've never done a hybrid swap but it can't be that hard.  i'm sure it's a good bang for the buck type of mod, ecspecially if you just go full 3400 transplant.

[pat]

This is under the assumption you could get the 3400 to run using the MPFI's PCM. If it won't, then nevermind

it'll run and idle nice,  but the injectors are peaked out rather quickly and it won't rev for crap.  it defintiely needs a tune to be done,  but a hybrid will need a tune to run to its potential anyway.

steve,  look around for a 3500 and get the 7x crank position sensor kit from the 60* store.  i'm on the lookout for a deal on a 3500.  i'm not a fan of hybrids because you still keep the old school flat tappet cam.  roller lifters are the greatest thing since hot dogs on a stick dipped in cornbread batter and deep fried.

[Dirty Rockstar]

Id DEFINITELY consider a 3500 if I could find one! Id also like to do the 5.3L LS4 (I think that's what it is)

[Euro]

good info...maybe i'll just hold out for a little while  :neutral:

[TurboSedan]

Id also like to do the 5.3L LS4 (I think that's what it is)

now that would be some $$$$ and alot of work (drive by wire TB, DOD, variable valve timing etc).  i wouldn't bother, i'd just use a turbo on a 3x00 intstead if you wanted 300hp.  i don't think it would take too much to get 350whp out of a turbocharged 3400...just look at 89jyturbo's car here:

www.khturbo.net.

it's remote mount with no intercooler, but still made 328whp on only 10psi.  with the forged 9.0:1 Wiseco pistons he now has, he could likely crank the boost to 15-20psi and see huge gains.....past 400whp i would imagine.

[19Cutlass94]

a built 3400 with 3500 top end using a turbo would get you well past the 300whp mark. With the LS4, your very limited.

[3100MPFI]

The 3400 can run on an older ECM.  I am currently running a 1996 3100 SFI block with 2000 3400 heads, and intake.  The car is wired up to run off of a 1993 3.4 DOHC ECM with a custom chip from Ben.

Getting it to run is not the probem at all, but I do agree,  For the work involved, just get a complete engine, and go from there.  That way, you don't have to do any hunting for parts.

If you are willing to get an engine that needs some work, you can get a complete engine for CHEAP.  I just bought a 3.4 DOHC V6 for my 1995 Cutlass Supreme for only $150.  And that is a COMPLETE engine WITH accessories.  I don't know what is wrong with it, but as I told the yard, as long as the block is good, I don't care.  They are also willing to warranty the block.

I am replacing my 3.4 DOCH that knocks with another one, so nothing is really involved.  If you do a 3.4 DOHC swap into your car, you will also need to do some work to the suspension.  Your cureent springs can't handle the weight of the 3.4.

A 3100, and a 3400 would be the easiest to get running on the older computer because you don't have to change out any parts.  The 3500 will take a little more because you need the crank sensor adapter, and the throttle body adapter.

Either way you go, you can't lose.  I think the 3400 is the way I am going to go (I am thinking about all of this for my 1990 Grand Prix STE right now as well).

This is under the assumption you could get the 3400 to run using the MPFI's PCM. If it won't, then nevermind

it'll run and idle nice,  but the injectors are peaked out rather quickly and it won't rev for crap.  it defintiely needs a tune to be done,  but a hybrid will need a tune to run to its potential anyway.

steve,  look around for a 3500 and get the 7x crank position sensor kit from the 60* store.  i'm on the lookout for a deal on a 3500.  i'm not a fan of hybrids because you still keep the old school flat tappet cam.  roller lifters are the greatest thing since hot dogs on a stick dipped in cornbread batter and deep fried.

[pat]

notice the "definitely needs tune to be done"

my comments were based on people thinking they could drop a 3400 in with 3.1 injectors and a stock 3.1 chip and run it.  it just doesn't work.

[3100MPFI]

actually, surprisingly, you can run a 3100 the way I had it built off of a stock 1993 3.4 DOHC ECM with a stock 3.4 DOHC ecm chip.

I think it suprised Ben when he first started tuning my car and it was running pretty good the way it was.  It was a lot better when he got done.

I did not mean to quote you.  I just forgot top clear it out.

[pat]

i tried running the close to stock 3400 off a 3.4L chip and it stalled when i tried anything past 20% throttle.  with 3.1 injectors,  3.4 injectors, and LT1 injectors.  also tried with the 3.1 chip and the LT1 injectors and the 3.1 injectors and couldnt get any of the 5 combos to be drivable.