3500 swap questions

[IsaacHayes]

he could still get it running. Not the end of the world..

[CNCguy]

It would be possible to get it running but it would be considerably more work than the LZ9 swap. It would have to run using an OBD-I or E67? ECM since the LZ camshaft has multiple notches and there is no place to mount a 24X sensor.

[Joseph Upson]

i think this is one of those "Uh-oh" moments..... LZ4 is not the 3500 that everyone is swapping. LZ4 is the VVT-3500, and the only person i knwo of running a VVT motor is josephupson, and he's been working on his for at least a year and a half......

The motor we all go for the the LX9..... not the LZ4....

The reason it has taken me so long is that I live nearly 500 miles away from the car and because of work and school can only get 4 days to a week at a time sometimes months apart to go work on it. The project also involved a triple swap, 3900 eng, 6 spd transmission, and turbocharging and at the last moment a major modification with the addition of a front mount intercooler on a rear engine car. It takes some special tools and an AWFUL LOT of time to make the custom parts to put everything in place, otherwise with just the eng swap alone I would have been driving the car within the first month of starting the swap.

The VVT motor will run fine as is however unless you intend to incorporate the VVT function with a simple on off control, the camshaft should be reground to high rpm specifications so that the engine operates like a normal range naturally aspirated engine with the cam in the full advance position.

Cylinder pressures averaged over 220 psi with the cam advanced so there will be no starting problems when wired correctly. The final test after tuning is complete is to see if I'll get a positive result from retarding the cam it runs so strong fully advanced.

There is also the possibility that regrinding the cam may have disrupted the positive effects that would normally be associated with retarding it so that retarding it now might cause a loss in power.

The shift light logic can possibly be used to retard the cam up to about 6300 rpm as long as it can be programmed to sustain the shift light on signal while conditions are met.

[Weatheralls Auto]

To be honest, I did not reread this entire thread to see if this is mentioned but,
I see so many talk about the LX9 from 04-06 G6 & Malibu Vin 8

Why no mention of the LX9 vin L from the U & X vans?

It also uses the Powersteering pump and I think the Exhaust Manis are much more like the 3400 LA1 ?

[robertisaar]

Exhaust Manis are much more like the 3400 LA1 ?

if that's true, that's why. the malibu 3500s got decent "manifolds".

[Weatheralls Auto]

Well, they look like the same style anyways, not sure if they are the same or possibly upgraded.

I had never thought about the U/X vans having LX9 until one of my customers came in this afternoon with one lol.

Never seen any mention of them, just the G6 and Malibu.

At least this give me more sources for parts etc,(Montana SV6, Terraza, Uplander ) if going with header, the exhaust mani wouldn't matter anyways.

[bob442]

is there any pistons avalible to raise the CR on a 3500 block? ben told me something about 3.6 DOHC pistons but wasnt clear on who sells them or what combo will make what.

[bszopi]

ben told me something about 3.6 DOHC pistons but wasnt clear on who sells them

As of right now, only GM. Diamond will most likely be making them in the near future though.

[bob442]

i wonder if some material could be machined off the top of the pistons

[lilredtruck]

Hi, Guys,
I'm in the midst of putting a 3500 into my Isuzu P'up, FWD engine into RWD. Many challenges. What solution do you have for using the 3500 injectors with a 3100 fuel rail (return rail)? 3500's are 1/2" too short. I thought I saw an answer to this some time ago but can't find it. I have a wiring harness from a '94 Beretta, per SuperDave, as well as the complete 3500 harness, PCM, TB. Need to modify the TB to eliminate ETC. Any ideas?
Brian

[wasas9]

You can use multec 2 injectors from a 2000+ 3400 engine along with it's fuel rail and fuel pressure regulator.

It will need to be tuned though for best performance.

[bob442]

As i am finally starting a hybrid swap, whats the best way to tell if i have 22lb injectors or 19lb, i remember browsing a thread and someone said that GAGT's have 22lb injectors, but do all 3400's have 22lb injectors. my other question was answered about using the 3400 rails on a 3500, and now i'm just curious, if i upgrade the injectors, and run my car with a cam, could i stand a chance of hurting the motor? or just loose potential of power till its tuned?

Bob

[3400-95-Modified]

You always run a chance of hurting a motor when it doesn't know whats attached to the ECM, granted it will correct as much as it can, but WOT will most likely be way off.

I'm using 3400 rails on my 3500 top end and have been for years with NO issues, the give about a 1/8th more of compression when installed since they sit just a bit higher, but if your really concerned about them being too tight you can make spacers so the rails aren't applying any pressure... I've never had an issue with it.

Also yes large port 3100 and 3400's from 00 to 05 IIRC are all the same 22lb/hr@55PSI setup, granted p/n's may have changed due to better injector design over the years, but I think they all flow the same amount from 00 to 05. 99 and older 3400's were 19lb/hr and 3100's were 16, both at 43.5PSI. BTW 19lb OBD1.5 injectors should flow ~22lb/hr at 55PSI.

[boomofdoom88]

I just did a 3500 swap into a 00 Grand Am. I used 28 lb trailblazer injectors in the 3400 fuel rail. Dimensionall the same as stock. And at 55 psi is pretty close to the stock 24 lb 3500 injectors which are of course too short to use with the 3400 rail. Probably not perfect but idles and revs fine with a stock 3400 tune. Buying hptuners come spring to tweak it and find out.

[SappySE107]

The trailblazer injectors are 5 lbs more at 55psi than the 3400 injectors. A retune is going to make a big difference. 21.31 are stock injectors, and 26.37 for the trailblaser at 55psi.