I am wanting to do an engine swap but can not decide on the best option. I am curious what kind of MPG people are getting out of their swaps. Whatever I decide on will be backed by a 5 spd getrag(already made that change, therefore I am not wanting to exceed the limits of the transmission by too much).
I think the 3400 SFI would be a better choice than the 3.4 PR or 3.4 TDC. It performs better than the 3.4 PR, and weighs a lot less than the 3.4 TDC. Plus, it gets better fuel economy than both.
I think a lot depends on the final drive ration. My DOHC was mated to a 5 speed Issuzu box and it loped along at around 2400 RPM at 70 mph in 5th on the highway but still had plenty of umphh to get up and go when needed without dropping down the gears. The suzzy stood up well to the engine too although I never abused it (things like dropping the clutch etc). Itis a BIG (and heavy) engine though, you'll probably need new springs at least up back because of the extra weight! That's just my experience though. If I thought the wife would not kill me, I'd do another one tomorrow.
------------------ Anything I might say is probably worth what you paid for it, so treat it accordingly!
Thanks for the replies. I never even thought of the 3400, it could be a possibility. I like the 3.4 DOHC for two reasons: stock, I feel it is a good match for the 5 spd getrag and I would love the higher rpm range.
How much more does the DOHC weigh versus the 2.8 stock motor?
Oh, I see what you mean by 'stock' now, sorry 'bout that. Cannot comment on it with a Getrag. On the 5 speed suzzy box I had I found the jump from 1st to 2nd was too wide and the box was 'slow' to shift. I could be screaming in 1st and by the time I got it into 2nd, the revs had dropped right off. Not really meant for 'fast' shifting. Still loads of fun though.
A non-VVT 3500 will make the same power as the TDC/DOHC, but will weigh ~25 lbs less than the stock 2.8.
Yep, and that makes it about 100 lb lighter than the 3.4 TDC. Plus, most of the weight savings is in the top end, which lowers the engine's center of gravity. That's good for handling.
Yep, and that makes it about 100 lb lighter than the 3.4 TDC. Plus, most of the weight savings is in the top end, which lowers the engine's center of gravity. That's good for handling.
Looks like the 3500 is more abundant also,.....not making my decision any easier...lol
I've been checking out the 3500 build threads. It looks pretty straight forward, as far as install, but I would have to have it tuned(I wouldn't even know where to begin). My options are now between lQ1 nd lx9
The only reason to consider the iron head 3.4 is the "original" look. If the original look isn't important to you, a 3500 will be far better, as it makes 50 more HP, weighs less and is only a marginally more difficult swap.
The only reason to consider the iron head 3.4 is the "original" look. If the original look isn't important to you, a 3500 will be far better, as it makes 50 more HP, weighs less and is only a marginally more difficult swap.
IMO the LX9 3500 is quite a bit more difficult of a swap than the 3.4 PR, although this is coming from a newcomer that had never swapped motors before. The 3.4 PR can use the stock ECM, stock plumbing, stock wiring, only need to relocate the starter. Overall very simple.
With the LX9 3500 it's probably easier to keep the new-style timing cover instead of adapting the Fiero-style cover. I did the latter, and it was a pain. The benefit was that I could keep my stock coolant plumbing on the RH side, as well as the stock A/C pump and plumbing, and alternator location. I had a new stock A/C pump that I wanted to use.
Around here 3500's are cheap and plentiful, $300 for the longblock. 3400's were going for around $700 with a lot more miles. It made my decision easy.
I don't know what's involved with the 3.4 DOHC but it does seem like a cool motor.
