Turbo Grand Prix 3500 swap

[SappySE107]

The ports wont line up if you use 3.1 manifolds on a 3500. You can't even use 3400 lower on a 3500 head.

[Jonpro03]

It does line up actually. You can see in the picture the 3.1 gasket sitting on the 3500 heads. It seems like the 3.1 had larger intake runners than the 3500!??!

However, I've decided not to go that route anyway. I'll be using 3500 LIM and 3400 UIM.

Tonight's progress:

All of the parts removed from the old 3.1. There are a handful of items that won't transfer over to the 3500 because of differences in the block.
The lower engine mount won't transfer - we will get one off of a gen3 3x00
Passenger dogbone mount won't transfer - we will get one off of a gen3 3x00
A/C compressor won't transfer due to pass. dogbone mount - gen3 3x00
Turbo oil feed line is a different size - will be heading to the hardware store
ICM and coilpack won't transfer - gen3 3x00 with wiring harness for splicing


Wont fit due to the car:
3.1 water pump will not be used - get heater core lines from 94-96 grand prix
3500 UIM won't be used - Using a 3400 UIM from u-body van to retain egr
3500 fuel rail won't be used - 2000+ 3400 fuel rail (55psi)
3500 throttle body won't be used - get 56mm TB from 3400
Throttle body cable mount will be 3100 custom for kickdown cable

Stuff that did transfer (so far)
Oil pressure adapter and Oil cooler
160* tstat
Coolant feed fitting
Driver side dogbone mount
Turbo exhaust manifolds (minus bolts... TOO RUSTY!) Im using both 3.1 and 3500 gaskets.
Alternator mount bracket / alternator

We are off to the junkyard tomorrow as I have a hefty list of things to get. That gen3 3x00 engine mount is going to be the worst.

Sorry I didn't snap any pictures. I basically have two empty motors right now and a slew of parts all over the floor.

[SappySE107]

No, the 3.1 manifolds cannot be used on 3500 heads. Install one, don't just set a gasket there and post that it can work. The 3.1 doesn't have larger intake runners. It has a taller port on the head, and the lower intake has to match that but further up the runner its no bigger than a quarter. The 3400 manifolds won't retain your old EGR. No way. They changed in 96, the first year for the 3400 van. Gen 2 is not 3x00. Those are gen 3 motors. Gen 2 is what your car had stock. Gen 1 are iron head.

[Jonpro03]

No, the 3.1 manifolds cannot be used on 3500 heads. Install one, don't just set a gasket there and post that it can work.

I didn't

It does line up actually.

The 3400 manifolds won't retain your old EGR. No way. They changed in 96, the first year for the 3400 van.

Is there no way to make this work then? I know that the minivan had a large port intake manifold that used the small port 3100 egr setup. Or would I be better off getting the EGR block plate that I bought for my LG8

Gen 2 is not 3x00. Those are gen 3 motors. Gen 2 is what your car had stock. Gen 1 are iron head.

Fixed

[SappySE107]

I have adapters for the 2000+ upper EGR style to use the old 87?-95 EGR. The 00+ uppers flow better anyway. I would not use a minivan lower either. They flow the worst of all the large ports. 2000+ are best there as well.

[Jonpro03]

I got very... VERY lucky today. Earlier last year, I helped a buddy build a megasquirt2 for his camaro. He's going to sell the car now and I GET THE MEGASQUIRT!

YAY ME!

Now I don't have to buy a external crank trigger saving me $150. AAAANNNNDDD I now have unlimited tuning capabilities.

[Jonpro03]

Is there any advantage to running the new style ICM/CP that came with the 3500?

[robertisaar]

i believe the new style is a "quick sync" ICM. compared to when the old style had to rotate potentially 360* before there was a spark event(to find notch 7), the newer style does it in less than 120* IIRC thanks to the coded wheel.

[Jonpro03]

Is it compatible with the old system?

Does it require a different set of inputs?

[robertisaar]

depends.... the way it worked with the old system was that the ICM read all 7 notches and sent a pulse to the ECM 3 out of the 7 times(once at the +1 notch(or was it at the normal notcth before/after it?) and then two other times when every other notch passed.

with the newer ones, i'm not sure what kind of signal they send... i may be able to look it up.

[robertisaar]

whoa, new ICM is WAY different in terms of controls.... it looks like the crank position sensor is directly connected to the PCM, not through the ICM like the older ones... the newer PCM also individually controls the coil packs, instead of supplying a signal to the ICM for it to control them.

[Jonpro03]

Ya, I don't think megasquirt is going to run that.

[Driver_10]

Mark at TCE just got through fitting my 3500 crank with an internal relucutor wheel. He made a run of about 15 wheels in all I think. You may want to consider sending your crank to him and get it fitted with a wheel also. Then you can use a 95 Camaro ICM and then be able to use the megasquirt.

Its a bit more expensive then using the external wheel because you will have to remove and send the crank to a shop unless you have a means of aligning the crank position prior to mounting (hence the reason I sent my crank off to TCE). It may be just as good to wait on the external trigger.

Its just an idea that Im tossing out there for concideration if you need options.

[CNCguy]

The LX9 trigger wheel is unique and I don't know of anything that will work with it except the stock ECM. The good old DIS system with the 7x trigger is hard to beat. Simple and reliable.

A batch of trigger wheels where shipped to WOT-Tech yesterday for those in need.

Thanks for the plug John. The new internal wheels require removal of the crank but they can be installed by the owner without being sent here. The install procedure is to mark the crank with a center punch, remove the old rings, heat the new ring to 450 in your Easy Bake oven, drop in on the crank, align the marks and let it cool.

[Jonpro03]

Does anybody have a diagram of the lx9 trigger wheel? I have to figure out how to make megasquirt read the signal it's putting off. Does it have a notch every 6 degrees except for 2 to mark tdc or something like that?

The ignition control module from a 3400 requires a 7x signal doesn't it?