3100/3400 top swap

[Rex 2.0]

Yes your ECM will work with the 3400 top end.

I ground down the inside of mine for clearance instead of buying new rockers and pushrods. I had no money at the time.

[3X00-Modified]

OK so where do I get custom pushrods or roller rockers?

That Pushrod answer wasnt for you. It was for the one asking about 3400 parts on a 3.1L block, NOT a 3100 Block. The new roller fulcrum rockers are stock on some 96 3100's, but all 3400's so it would be on the parts engine your pulling parts from. 3100 3400 and 3500 pushrods are all the same length so if your running any 3100 3400 variation of valve train components you don't need anything custom, minus clearance if you decide to stick with stamped steel rockers.

And on here
http://www.hptuners.com/forum/showthread.php?t=32677
it says they support 02 venture. So I would just need a 96 Beretta harness for the obd II swap?
And how do I re-wire the sensors. Like I'm not gonna do the comp swap till later when I do the full 3500 swap. So will my ecm work OK with a 3400 top end swap?

What wheel are you trying to re-invent here?

No one has swapped to a newer than 97 ECM on a stock harness. You have OBDI.5 you either RUN THAT and leave it be, OR You need to do an OBDII swap as I've done using my thread as a guide and then run a 97 venture ECM and Bin file for DHP, OR a 97 Monte ECM and Bin file to use HPTuners

Or you can be completely different and want to run an 02 venture ecm; which in that case you on your own.

[ShaneLT(ShaneZ26)]

So I couldn't use the 02 ecu if I did the obd 2 swap. And aside from the egr adapter just put the heads on and go?

Also I never got an answer can I use a 3400 AC compressor on my 3100?

[3X00-Modified]

I will quote myself since I said it once already. And Yes you can use the 02 ECM but NO ONE has done it before. First off there is no reason to unless you swap to a 4t65e, and it will take a full re-pinning of the ECM connections, your having trouble grasping whats necessary to do the 3400 top end alone so I wouldn't expect you to want to take on a full re-wire project that you have no one to compare to.

You also nee to tap the outlet of the coolant bypass line that goes to the heater core, the 3400's are not threaded outlets and you need to get a tap so you can thread in the adapter that our cars use, OR you can use the o-ring style line but you will have to change its routing to meet up with the stock line. Thats a little more complicated I welded the O-ring style end on to my stock line so it routed properly but used the O-ring seal.

Shane, you need
-Heads (if you want them)
-Lower Intake (03+ Best but others ok)
-Upper Intake (2000+ best)
-EGR adapter
-3400 TB (swap over your linkage rod from 3100 one)
-96-02 roller rockers for clearance, You can only use those on the new 3400 head, or if your current ones have notches where the rockers mount, you would remove the stud for the ball pivot rockers that are currently there as well as the pushrod guides. If you don't use the 3400 heads with rockers or if they wont fit on your 3100 heads then you need to clearance the corner of the rocker and the lower intake, the stamped steel ones will rub the larger ports on the 3400 intake.

No harness is needed, but you will have to re-wire your coolant temp sensor. You have two choices IF you swap out heads... Put a 2 pin sensor where your current one is and the sensor thats in the back head you can install in the rear block drain port, or you can re-route that wire and make the 2 pin sensor a 3 pin one like on a 96+ beretta.

Stock injectors on a 95 will run fine. I used the 99 3400 Venture injectors when I did mine since 3100 ones are 17lb and the 3400 ones pre 00 are 19lb Slight safety net since I was spraying.

97 Venture is NOT supported by HPT. You would need to use a 97 Monte Carlo ECM... Granted the are both the same ECM but HPT will not let you fully overwrite an OSID to my knowledge so you need to start with the right platform. I can take any one and flash it to the DHP supported venture file I'm using since I can do a full write. But the HPT needs to be linked to a vin or specific ECM IIRC. Cliff can verify that more.

You cant use larger injectors as your planning due to not being able to tune... the 19lb ones the ECM can compensate, and larger and the computer will over fuel the engine and not be able to adjust for it. 02 venture is 22lb injectors.

If you want to do any harness swap to gain tuning support, your best bet is still to find a 96 beretta or corsica and do that engine bay harness and follow my OBDII upgrade thread. Any other harness and your just asking for re-wiring nightmares.

You can only use the AC compressor if the lines/connections are the same, and I don't think they are. The mounting on the block/oil pan should be the same. I have a 3400 block and 3100 pan and the stock 3100 ac compressor works.

[ShaneLT(ShaneZ26)]

Ok so
Heads
intake
egr adapter
TB
Thread coolant bypass output

That's all? in a previous you said the pushrods part was not for me. But need to re-wire sensors?

[3X00-Modified]

Ok so
Heads
intake
egr adapter
TB
Thread coolant bypass output <INCORRECT this is ON your car already you need to THREAD THE LOWER or fab something up to use the O-ring

That's all? in a previous you said the pushrods part was not for me. But need to re-wire sensors?

Pushrods apply to 3.1l blocks, not 3100...

Why am I repeating myself, this isnt a vocal conversation, Go back and re-read the posts above that will answer your questions.

[ShaneLT(ShaneZ26)]

OK so I was right I just had the coolant line backwards. Do you have any pics about the sensor re-wire or little more details?

What 3400's had a blank uim?

[Money pit Beretta]

The blank ones are not the ones you want. There is a big wall near the EGR port on the inside and that hurts flow.

3X00: 3400 TB (swap over your linkage rod from 3100 one)
I did a write up on this, so Shane look for that. It has a sticky(thanks again 3X00).

You could save youself some trouble and use your stock heads. Head swap almost seems pointless if you just plan to later swap in a 3500.
3X00 helped me alot on the grinding of the lower intake when I did mine. Could be in my "I'm nuts" topic. I have alot of trouble with the search here.

[Chad91GTZ]

If you want it blank, send it to me and Ill mill the numbers off.

[ShaneLT(ShaneZ26)]

Is it even worth it to just swap intakes? And I'm having a hard time finding your write-up.

[Money pit Beretta]

I feel that it was worth all the time to do it. The 3100 really needs more air in the top end. Why do you think GM did it later on? Oh and you can get 2000 3100 intakes they are the same size as the 3400. Same goes for the big port 3100 TB linkage.
http://www.beretta.net/forum/viewtopic.php?f=9&t=5704
It's on the TCE, but is the same for 3100/3400 TB's.

[ShaneLT(ShaneZ26)]

Back to the venture AC compressor. Could I take the lines that go with the venture compressor and put them on my Beretta?

[beretta]

so on the older 3.1..
3400 heads.
3400 center intake
3400 upper
3400 Throttle body..

Gaskets and custom push rods

That should be it ? what needs to be done to the heads to work and what rockers do you use the 3.1 ones or 3400 roller ones ? and what head gaskets..

Im thinking about doing this on my 88 since i can get heads from the JY for $20 bucks i have a few intakes laying around already.

Id like to turbo swap it but i just dont have the funds to transport and pay for the rest of the 3.1 turbo engine i was trying to purchase, i gave the guy a deposit last fall and havent been able to have spare cash to get the darn thing here yet.

How much HP gain would i be looking at with this top end swap ? 20?

[3X00-Modified]

Gain in swapping heads is he can use the roller fulcrum rockers on the 3400 donor he is taking apart and NOT have to grind anything for clearance. But if he does use the heads, he either HAS to re-locate the 1 wire temp sensor to the back of the block, OR he has to drill and tap a hole in the rear head just like whats on the 3100 heads to fit it... or re-wire it to the 3 pin sensor like on the 96. If you think "just swapping intakes" seems usless then you know nothing about air flow, volume and how to make an engine breathe... Simply comparing the two sets will answer your question if you know anything about an engine.

Beretta: Use the rockers from the 3400 to not have to grind down anything for clearance... Use your 3.1L headgaskets since that will ensure piston to head clearance and quench being correct.

For both cars, 3100 to 3400 your looking at about a 15-20hp gain. Large port 3100's were quoted at 195 or something for HP stock 3100's were 160, so without a good tune 15-20 is probably obtainable. For the 3.1 I don't know.

[ShaneLT(ShaneZ26)]

I knew it would help out breath better but I didn't think it would br that much of a gain.

Also I dunno if you saw my last but could I swap the two lines that go with the 3400 AC compressor on to my 3100 to make it work?