I just replied to your other thread. But to clarify here, you just mixed two different engines. There is a 3.4 DOHC and there is a 3400 OHV (I believe that's the right acronym).

The 3400 v6 looks almost exactly like your 3100. Main difference is bigger air passages and as a result, more out of the gate performance then a 3100. If you look at the Grand Am community, a common engine swap for mid-90's Grand Am owners was to go from a 3100 to a 3400. It's almost direct swap.

Going to a 3.4 DOHC will take a little more work.

 

Yeah I noticed that now lol! Totally different!

Well, I seen a remanufactured 3.4 dohc for a really good price and I was thinking about getting it. How much more complicated is it to install?

Will I need a different tranny?
Will it need a lot of modifacations?

I am trying to get idea of how much more work that will need to be done.

Will I just be better off with getting a 3.4 ohv instead?

Thanx Manic for your replys and help sir!

 

I honestly don't know the difference in difficulty of going from a 3100 OHV to a 3.4 DOHC. I suspect wiring harness issues and PCM issues. Maybe trans issues. I never researched the subject, so some one else may be able to chime in with more info.

What I have read is that the 3.4 DOHC can be a little finicky of an engine (again, I cannot atest that for sure, I never researched it).

If I was pulling a 3100, I'd pop a 3400 in it's place. If you google the subject, I know the was a Grand Am write up on the subject (which would be VERY applicable to what you want to accomplish). When I read it (out of personal curiosity), it appeared very straight forward for the most part. And the write up I saw years ago talked about some of the small (and I mean small/minor) issues this guy ran into. No show stoppers in my book.

 

Maniac - you're right. Overhead valve = OHV

OP, to swap to a 3.4 DOHC you will need the engine, PCM and wiring harness from a '96-'97 Z34, possibly have to modify axles, and your transmission I'm sure could work, but gear ratios would have to be modified in the PCM at least.

If you want a reliable swap, do a 3400. At least there is some aftermarket for them - check out 60degreev6.com they'll have a lot more info about 3400's.

Now if I had to go through all the trouble of swapping a 3.4 DOHC... I wouldn't. Much rather swap a 3800 & 4t65e. LQ1's have a slim aftermarket. I only know one vendor that makes parts for those motors, and they're fairly pricey. There is a guy that put an M90 on an LQ1 though... Lots of custom work.

 

And lots of unreliable down-time too

But man does he have a sweet 5th gen

 

True, and it's a 5 speed! :O

 

Thanks fellas!

After doing some research I am definitly going to go with a 3400 ohv swap! Its not as difficult to swap but I would of loved to give a 3.4 dohc a shot. Forget it lol! Once thanks fellas for your replys.