timestalker45 Posted July 6, 2007 Report Share Posted July 6, 2007 i want to upgrade my 1992 cutlass supreme it has a 3.1 multiport which is on its way out, so i was wondering if possible to eather put a 3.4 in or have my engine rebuilt and bored out, Eather way i want to turbo charge the car in the end but i was wondering the most cost efective way to get the most hp for my money. Im hoping when all is said and done to push at least 300hp from gms sad little v6. I know it can be done with the 3800 but i dont think if i got a tranny and engine it would mount correctly and it would take to many changes. Also is there a sight to order a custom 5 speed automatic transmission that would fit my cutlass, eather way i go? thanks for the time sorry for so many questions Quote Link to comment Share on other sites More sharing options...
slick Posted July 6, 2007 Report Share Posted July 6, 2007 3.4 DOHC or the 3400 SFI in the newer GM vehicles? Simply boring out your 3.1 will do absolutely nothing. Most bang for the buck- Probably nitrous. There is no 5 speed automatic available. There is a 4 speed with overdrive that will work fine 4t60e. Quote Link to comment Share on other sites More sharing options...
timestalker45 Posted July 6, 2007 Author Report Share Posted July 6, 2007 i want to to 3400 sfi i herd bad things about the 3.4 doc Quote Link to comment Share on other sites More sharing options...
slick Posted July 6, 2007 Report Share Posted July 6, 2007 You will want to convert to OBD-II during the swap. You will also need a 4t60e transmission. Tuning won't be much of a problem, especially if you swap to OBDII. The 3400 is a pretty good engine. Be sure to replace the faulty intake gaskets with the new, redesigned gaskets or the Felpro's. Turbocharging is possible, but it will take some work. Quote Link to comment Share on other sites More sharing options...
Andrew Posted July 6, 2007 Report Share Posted July 6, 2007 are the motor mounts the same for the 3400 and the old 3.1 ?? Quote Link to comment Share on other sites More sharing options...
slick Posted July 6, 2007 Report Share Posted July 6, 2007 They can be swapped, if necessary. Quote Link to comment Share on other sites More sharing options...
Supreme Cutlass Posted July 7, 2007 Report Share Posted July 7, 2007 You will want to convert to OBD-II during the swap. You will also need a 4t60e transmission. Tuning won't be much of a problem, especially if you swap to OBDII. The 3400 is a pretty good engine. Be sure to replace the faulty intake gaskets with the new, redesigned gaskets or the Felpro's. Turbocharging is possible, but it will take some work. I was told that it wasn't necessary to switch to OBD II... Quote Link to comment Share on other sites More sharing options...
jeremy Posted July 7, 2007 Report Share Posted July 7, 2007 i want to to 3400 sfi i herd bad things about the 3.4 doc if you are looking for power, a well maintained or rebuilt TDC would definitely be a better option then a 3400..... Quote Link to comment Share on other sites More sharing options...
slick Posted July 7, 2007 Report Share Posted July 7, 2007 You will want to convert to OBD-II during the swap. You will also need a 4t60e transmission. Tuning won't be much of a problem, especially if you swap to OBDII. The 3400 is a pretty good engine. Be sure to replace the faulty intake gaskets with the new, redesigned gaskets or the Felpro's. Turbocharging is possible, but it will take some work. I was told that it wasn't necessary to switch to OBD II... Correct, not neccessary, but if your looking for the most gain, then you MOST definately want to consider it. Quote Link to comment Share on other sites More sharing options...
Dark Ride Posted July 7, 2007 Report Share Posted July 7, 2007 i want to to 3400 sfi i herd bad things about the 3.4 doc if you are looking for power, a well maintained or rebuilt TDC would definitely be a better option then a 3400..... X2, I think a 3.4 DOHC would be an excellant engine to turbocharge. I want to have a turbocharged 3.4 DOHC when I have some extra money, preferably in a Red Z34. I too, have heard some bad things about the TDCs, however, the people I've heard it from are all guilty of neglecting their engine. Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted July 7, 2007 Report Share Posted July 7, 2007 Having only worked on the TDC, I would stay away from them UNLESS its a 5 speed manual. Then they are a bit easier to work on. I wouldnt own one in either case. I wont own any car with a timing belt... Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted July 7, 2007 Report Share Posted July 7, 2007 Anyway.. I think either the LQ1 or the 3400 would be a good swap. I'd much rather have the LQ1, but that's just personal preference and the fact that I don't have some sort of irrational fear of timing belts. That being said, I really wouldn't do either swap without a 5-speed. The automatic DESTROYS what performance the 3400 and LQ1 have. Either that, or I'd try to find an LG5 turbo setup. Good bang for the buck if you can find someone selling it for a reasonable price. Quote Link to comment Share on other sites More sharing options...
slick Posted July 7, 2007 Report Share Posted July 7, 2007 The automatic DESTROYS what performance the 3400 and LQ1 have. I will have to say something about this. If you properly build an automatic, you should have no issues, and it will perform very nicely. I have seen MANY 3400 5 speed powered J and L body's breaking axles left and right, yet a built 3400 behind a homebuilt automatic hasn't broken yet, and neither has the axles. He also has one of the fastest times in the L-body world. Just something to throw out there... Quote Link to comment Share on other sites More sharing options...
White93z34 Posted July 7, 2007 Report Share Posted July 7, 2007 The automatic DESTROYS what performance the 3400 and LQ1 have. I for one was never disappointed with what my 4t60e gave me performance wise, it always shifted great, it is no 12 second car thats for sure, but it got out of its own way plenty fine. for ease of swap and the availability of parts cars, a 3.4/4t60e swap would be pretty easy to do. unless you are very brave a manual swap is a gigantic pain to do. despite what others think a 3.4 mated to a 4t60e is very drivable, with plenty of power on demand. if you are decently mechanically inclined the 3.4 really isan't that difficult to work on, my first timing belt job took me the better part of a weekend, but i know how to do it now, and know i could do it in less then half the time now, the alternator isn't all that awful to do either. but consider the push rod route too, i've heard of people running 3400/4t60es just fine with a 3.4 DOHC chip, and I've heard of people that couldn't get the same thing to run worth anything no matter what chip they tried. and if you are brave a full OBD2 swap is always available Quote Link to comment Share on other sites More sharing options...
Singh Posted July 7, 2007 Report Share Posted July 7, 2007 idk my 3.4 dohc blew head gasket, at 136k miles, and i know other friends with 3.4's who also have blew or have blown head gaskets on the 3.4's around the same mileage. my brother has blown head gaskets on every one of his 3 or 4 regals he owned witht he 3.1 around 125-140k miles. I dont know, i dont beat my car and i always took care but it blew the shit out anyways wat a pos so now im getting 3800 series II, in my opinion a better investment Quote Link to comment Share on other sites More sharing options...
slick Posted July 7, 2007 Report Share Posted July 7, 2007 Other than yours and a select few others, I've never seen 3.4's blow headgaskets without some other issues causing it. Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted July 7, 2007 Report Share Posted July 7, 2007 I agree. It's also extremely rare for a 3.1 MPFI to ever blow headgaskets. What do you do to these poor cars?! Quote Link to comment Share on other sites More sharing options...
timestalker45 Posted July 7, 2007 Author Report Share Posted July 7, 2007 ok i have talked to a few machanics and found out the 3.4 are good for about 50k then they go to crap..so back to my first option how much gain in torque an hp could u gain from a bigger bore sizebigger heads, a port and polish, and a bigger throttle body till i can get the money to do a custom turbo, it really sucks because the 3800 have turbos why dont the make one for the only tue v6 i mean the 3800 is a v8 missing 2 cylinders with a 90 degree bore Quote Link to comment Share on other sites More sharing options...
jeremy Posted July 7, 2007 Report Share Posted July 7, 2007 ok i have talked to a few machanics and found out the 3.4 are good for about 50k then they go to crap.. that's because around that time frame is when preventative maitinence really becomes important and most are not properly cared for..... Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted July 7, 2007 Report Share Posted July 7, 2007 ignorance of certian motors is starting to take place... Quote Link to comment Share on other sites More sharing options...
Crazy K Posted July 7, 2007 Report Share Posted July 7, 2007 replace the upper intake gasket on a 3400/3100... and you could go to infinity and beyond! Quote Link to comment Share on other sites More sharing options...
timestalker45 Posted July 8, 2007 Author Report Share Posted July 8, 2007 but still how much can u gain from a port and polish on a 3.1 multi port also just in opinion which 3.1 you like better the multiport or sfi?? Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted July 8, 2007 Report Share Posted July 8, 2007 but still how much can u gain from a port and polish on a 3.1 multi port Not near enough to make it worthwhile. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted July 8, 2007 Report Share Posted July 8, 2007 50k? all an engine is good for?!?! thats one of the more ignorant things I've ever heard. 178,000 later and my car still screams like it did 80k ago. there have been many, many members here with 3.4s well into the 200k range if you were to modify your 3.1, i'd consider swapping a 3100 topend onto it, i've heard good things about that waking up a 3.1. Quote Link to comment Share on other sites More sharing options...
Crazy K Posted July 8, 2007 Report Share Posted July 8, 2007 First, my dear new member, You must learn the names correctly! 3.1 - mpfi produced 89-94 basically the same as the 2.8 (mpfi) produced in 88 and 89, but bored and stroked 3100 produced 94-on. 3400 produced from 97 on. 3.4 DOHC, aka LQ1, aka TDC Chris... I think he was talking about the 3400, and their constant need for intake gaskets. Quote Link to comment Share on other sites More sharing options...
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