THose who have done the "MPFI Hybrids"

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[3100MPFI]

I was doing a high compression 3100 with 1996 GREEN BAND 3100 injectors, and a hot cam.  

It ran fine, but on takeoff it was getting too much fuel and would sometimes want to stall.  I had to ease into the acceleration, but once it hit second gear, I could get on it.  

Idle was fine, just a little rich.  

For some reason (and I keep forgetting to tell people this), my 3100 did not perform like it was expected too.  At the time I built my 3100, my friend built a 3400.  They were done IDENTICAL.  Mine would run on the 3.4 DOHC chip.  His would not.  Also, he had a hell of a lot of power off the line, but mine was all top end.  My 3100 would not start making power until 4000 RPM, and it pulled all the way to 7000 RPM.  

There were MANY people that were a little more than mildly suprised at that.  I took the car to one of the 60 degree meets, and everyone that drove it was shocked at how it performed.  Especially for it being a PUSHROD.  It drove more like a DOHC.

I am having some issues now with it, but I think the HIGH COMPRESSION is what made it run good on the twin cam program.  The way it is NOW (with the normal compression), it does not want to drive at all, and is getting WAY too much fuel.  I have to get it totally reprogrammed.

[3100MPFI]

I forgot to add this bit of info.

I drove my 3100 from LONG ISLAND, NY to CANADA for one of the meets, and I drove it all the way on the 3.4 DOHC chip.  I also got really good fuel economy on the highway.

It was not until the meet in canada that Ben started tuning the car.  That is where I got my chip, and I had already been driving the car for a couple of months with just the stock 3.4 chip.

After I moved back to Texas (south of Houston), I went to visit a friend in Oklahoma City, OK.  While up there, my friend tried to modify my custom chip, and accidentally FRIED it.  I had to drive back home on the 3.4 DOHC chip.

Now that my engine has the NORMAL compression, the 3.4 chip will not run it.

[Jay]

Now Steve, all you need is the car to start doing this swap.

And I need to start looking for a U van that isn't junk.

[crazy k]

wow!  I want to drop a 3100 with large intakes into my 93.  this would be the unmoddified engine, except for larger 3400 intakes, pulled from my 95.  can you send me packing in the right direction to get said chips?

[3.1cutlass]

Cant you swap the 3.4 top end to a 3.1?

[crazy k]

Cant you swap the 3.4 top end to a 3.1?

yeah but you would loose the roller lifters and such, and then need custom pushrods.

I want to either use a 3100 with 3400 topend, or a 3400 in place of a 3.1.

[3100MPFI]

Cant you swap the 3.4 top end to a 3.1?

Do you mean swap the 3400 top end on a 3.1, or a CAMARO 3.4 top end onto a 3.1?

You can do either one of those.  I KNOW with the 3x00 swap, you have to use the heads, and upper and lower intake manifolds, as well as the exhaust manifolds, and downpipe.

I have not really looked into the 3.4 camaro, but seeing what I have I am not sure that it would work without swapping the heads.

I am thinking about using a camaro 3.4 for a future project, but for now it is on the back burner.

[3.1cutlass]

so if i got a 3400 heads, upper, lower, manifolds and downpipe it is a direct swap?
What years 3400?

[3100MPFI]

Well.  For the years, you can use any 1996 and newer 3400.  I seem to be thinking that the 3400 came out in 1996.

If you get heads, you might want to look for either NEWER 3400 heads (around 2002 and newer), or 3500 heads.  the 3500 heads flow even better.

The heads will bolt right up to a 3.1 block.  The downpipe meets in a different area so you have to use the newer one.  There are other things you will have to look into.  You have to use the older AC bracket because the newer one will not bolt onto the older block.  You will need to get the power steering resevoir for the 3100.  I also had an issue with power steering pump.  I am using the 3100 front cover, so I don't know about the 3.1

There is a LOT of factors to take into consideration when you do this, but if you go for it, you will have a lot of support (if not in person, then in spirit).

[3.1cutlass]

ok so 3500 heads what years? 3500 downpipe. Would i want new gaskets? old ac braket from a 3.1? 3100 ps resivoir is that all then upper and lower from a 3500

[3100MPFI]

DEfinantly want new gaskets.  You would want to use the 3100/3400 exhaust manifolds and downpipe.  Does not matter what year 3500 heads.  At this point I think they are all the same unless there is a VVY thing that would make them different (just get them from a MALIBU).

If you use an older 3.1 block, you will need the older AC bracket.

Using the 3500 upper intake manifold, you will have to slightly modify it for the fuel pressure regulator.

There is a lot to take into consideration.  One is that by using a newer block, you get the added benefit of cross bolted mains, and the aluminum pan, but by using the older style, you have the benefit of being able to drill into the pan for an oil return line for a turbo.

Lot of things to consider.

If I was going to do a HYBRID (which is what you are planning to the best of my knowledge), I would use a 3.1 block with high compression pistons, custom cam, 3500 heads, 3100/3400 exhaust manifold (unless I was feeling brave and figured out a custom way to do the newer 3500 exhuast), and then top it off with the 3400 lower intake, 3100 fuel rails, and injectors, and a 3500 upper intake with EGR adapter, and TB adapter.

Of course doing this will also require custom tuning, and chip.

And there is a WHOLE LOT to consider on top of this.  Front cover, PS pump/resevoir, alt, etc.

[3.1cutlass]

I am interested once my project blazer is done i am going for it. Just so you know iam using the stock block in my 91 cutlass so everything will the old stuff.

[Euro]

I think the 3400 came out in 1997 in the Venture/Montana mini vans?  I could be wrong tho