I'd like to do a top end swap on my 3.1 v6 but I'm not sure on some things. Couldn't find anything on all 10 search pages.

Can I just take the top end of a 3100, switch over to DIS, keep rwd pistons, and be able to work fine without a tune? Not too confident on doing the tuning myself.

When doing a hybrid swap, do you NEED a tune? Or does it vary? All the hybrids I have seen have turbos or require a tune.

 

if you just swap the heads you will end up with about 11.5-12:1 compression ratio iirc. It most likely won't run very well with out a tune and with a stock cam. On the j-bodys years ago we ran around 11:1 on a stock tune but with a much larger cam and premium fuel. But that was probably not the best idea. Lol

 

You'll need a tune.

 

well if that's the case I guess ill just wait until my engine blows and then swap it with another one. ill just need to save more money.

btw someone is selling a 2002 gtp engine for 150. I think I might pick it up. I remember reading that the 3.8 II sc will just bolt up to the 700r4. ill just rebuild it and when my other engine blows drop this one in.

 

Id highly suggest rebuilding the engine if youre gonna do the swap any way plus you wouldnt have to worry as much about bearings spinning or other bs. Make sure to get the large port stuff however if you want i have a small port set already painted and ready for install ish. One head needs a new exhaust valve and some retainers but they are in great condition. That should at least get you started untill you can find the good stuff

 

yeah that's what I initially wanted. however I rent a house with no garage, I'm on the top floor, and on street parking, so the work I can do on the car is limited. I wanted to rebuild the short block (with fwdpistons), the 3400 heads, uim/ lim, delta 260 cam, and coils. however I don't feel comfortable tuning. that's why I was wondering if it where possible to somehow do swap but without tuning. i know that if i increase the compression i would probably need to run 93 gas. ill probably ask around some local shops. how much i can expect for a swap/ tune. there might be a mobile tuner around this area.

 

Just because ive messed with both here is my opinion. If its not a all out race car, then keep the compression lower and use the front wheel drive pistons with the FWD heads. I know its more complicated because you have to hone or bore out the block for the new pistons rings, and so forth but its well worth it. I ran the 12.x:1 compression for a bit and honestly for the HP and Tq gained over the lower compression its just not worth it IMO. So much more abuse on the tiny engine. But with the lower 9.6:1 ish compression you can run wild cams, p and p the snot out of the heads and intakes which flow alot, and if boosting or adding n20 it likes that as well.

If running the high comp 12+:1 you definitly want to run 93 and watch the tune. If there is too much timing even 93 wont be enough and youll have KR. I ran E85 and never even saw KR even under boost and when i bent my rods from the Tq and pressure....lol

You will always need a tune if doing a hybrid swap even if its a 3.4 swapping a 3400 on top. The fueling will be much different in different areas and to gain the most HP a tune is down right necessary. Im sure you could get by without it while running MAF systems but why do it that way when tuning is so cheep to do and for at least the obd1 stuff, its not too hard either.

Just my 2 cents

 

Consider that bone stock engines can benefit from a custom tune, then realize that a custom engine's purpose is to improve on where a stock engine left off, so why go through all the trouble of fitting all of the mechanicals that will be better, just to make it all worse by not tuning it?

 

hmmmm. well it would appear that the easiest thing to do is the 3.4 longblock boogie. Just swap block keep pretty much everything from the 3.1 and just use 91 or better gas?

 

well ill be going with the 3.1 hybrid. only question for now is the crank trigger. can I add notches to an existing damper or would I have to fabricate one from scratch? I have this as a reference.

 

if you can get some one to machine that and be darn exact. It would work. If not then you can also buy a ring or a balancer kit like I used for a few years from brittish car conversions. A true bolt on kit. I never had any issues with it

 

ok cool. I will go ask at a cnc/ machining place in town and see if they could do the work or create one from scratch. could I use this?:
https://www.msdperformance.com/produ...its/parts/8655

 

Not with the stock ecm... it has the magnet on the wheel.... opposite of GM in laymans terms.

And the msd one is ungodly exspencive.

Seems brittishcarconversions is down right now but below that link will help as well. IIRC they make kits for the 3500 so you could call them tell them what you have and see if they have a kit for ya. I sold mine last year when i went with a 3.4L as they have them already on the crank and were DIS.

http://www.milzymotorsports.com/engi...conversions-1/

 

That MSD trigger kit doesn't look like it would have the provision for the home trigger point either, in addition to the sensor being wrong...