JOHN GTPPRIX Posted June 2, 2014 Report Share Posted June 2, 2014 (edited) I want to change my 3.4 to a 3.1 in my 1993 Grand Prix GTP. Does any body know what I need to do this? My 3.4's valve seat dropped with only 29,000 on it and did a lot of damage. It was installed seven years ago and is a Jasper remanufactured engine. So I' am looking to have a 3.1 installed, something a little easier to work on. I need some advice on the matter so if you can help I would appreciate. Thanks Edited June 2, 2014 by JOHN GTPPRIX spelling error Quote Link to comment Share on other sites More sharing options...
55trucker Posted June 2, 2014 Report Share Posted June 2, 2014 Personally, if I was in your position I wouldn't even consider the 3.1, I'd go straight to the LA1 3400 pushrod. Better performance numbers, the 4t60e will bolt right up to it, you can make use of the same ECM, one just needs a different chip other than the DOHC chip. Exhaust downpipe will need modification, intake snorkel might need some work, but it's an easy swap. Why are you considering the LH0? Quote Link to comment Share on other sites More sharing options...
l67ss Posted June 2, 2014 Report Share Posted June 2, 2014 Hell id skip the whole 3x00 swap and go straight to a 3800 (oh wait I did lol). Even easier to work on than a 3100/3400 Quote Link to comment Share on other sites More sharing options...
JOHN GTPPRIX Posted June 3, 2014 Author Report Share Posted June 3, 2014 My 3.4 went bad with only 29,000.Droped a valve seat and destroyed the engine. The engine is a Jasper reman that I had installed 7 years ago and I was considering the 3.1 because it's easier to work on. But please tell me about the 3400 and how do you know this, also what would I pull this engine from, year and model? Tell what chip I would need and down pipe mods. Thanks Quote Link to comment Share on other sites More sharing options...
JOHN GTPPRIX Posted June 3, 2014 Author Report Share Posted June 3, 2014 (edited) Please give details on this swap with the 3800. Thanks Edited June 3, 2014 by JOHN GTPPRIX additional info added. Quote Link to comment Share on other sites More sharing options...
JOHN GTPPRIX Posted June 3, 2014 Author Report Share Posted June 3, 2014 I have been looking for a 3.4 and have found only one that I would try. It has 92,000 and I' am thinking that it is going to have that oil leak from the o ring. This engine is located by a company on the internet for 1,000. Any thoughts as to if it will leak oil? Thanks Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted June 3, 2014 Report Share Posted June 3, 2014 all of the 60V6 engines have that issue until either the HFV6 series or possibly the gen 3.5/4. replace it once with one that actually withstands oil and you'll never have an issue with it again. Quote Link to comment Share on other sites More sharing options...
55trucker Posted June 3, 2014 Report Share Posted June 3, 2014 (edited) That's unfortunate the engine dropping a *valve seat*, I am not familiar at all with Jasper engines as they do not do business here in Ontario, the LH0 engine is a 3.1 pushrod that was first installed into the late 80's 6000 STE's, it was also the default engine in the early 1st gen W-bodies as of 89 (predecessor being the 2.8), it is a low horsepower relatively low torque engine, it was succeeded by the L82 engine which is a similar but stiffer block but a completely redesigned top end (heads/intake), one can identify the two by the top ends, LH0 has cast into the upper plenum *3.1 Multi-Port Injection* whereas the L82 (3100) has *3100* cast into the upper plenum, the LA1 (3400) is the same block/heads as the L82 (3100) but it has a larger bore to give it the 3400cc. For the 60degree pushrod engines before the 3500 series came along this one is the most desirable for it's better lower end torque figures and HP #'s. It is a common choice for Fiero owners looking to improve on the anemic 2.8 engine that was installed into those cars (I have done several of these swaps) and in the W-bodies it has better low end figures than the DOHC and it gets better fuel mileage. The ECM in the 91-93 GTP's is a common unit, it was also used in the 3.8 cars at that time period, the removable *chips* are unique to the engine installed, remove the DOHC chip & install a tuned 3.1 chip for the 3400. Perhaps Robert *RobertIsaar* can point you to whom locally here can tune a chip for you if you decide to go that route, downpipe is not difficult, it just needs to be refabbed at the flange to point it where it needs to go properly under the car. The 3800 is another animal altogether, 90 degree engine, all cast iron, heavier, this all hypothetical, if you DO purchase another DOHC then all of this becomes mute. Best of luck Edited June 3, 2014 by 55trucker Quote Link to comment Share on other sites More sharing options...
runt Posted June 3, 2014 Report Share Posted June 3, 2014 Aren't Jasper engines covered by a lifetime warranty? Quote Link to comment Share on other sites More sharing options...
JOHN GTPPRIX Posted June 4, 2014 Author Report Share Posted June 4, 2014 I wish, but no I had it installed in 2007 and I think it was a 3 years or 30,000 miles. Quote Link to comment Share on other sites More sharing options...
JOHN GTPPRIX Posted June 4, 2014 Author Report Share Posted June 4, 2014 With regards to the 3400 what year and model would I look for and what wiring issues would I have? Doe's the portion of the wiring harness plug into the fire wall determining that type of engine? So in other words if I used a 3.1 I would need only the portion the plugs in to the fire wall and extend out to the engine? In my engine bay I can't see that much of the fire wall to determine what's what. I have a mechanic who would be doing the install at $55.00 an hour so I need to keep this in mind. Thanks for all of your help. Quote Link to comment Share on other sites More sharing options...
55trucker Posted June 4, 2014 Report Share Posted June 4, 2014 (edited) Well, this throws a different light on your situation, if you're relying on a mechanic to do all of this for you, you need to consider if this route is going to be more expensive than just picking up another *good* DOHC and doing a general re & re. The techie doing this has got to be familiar with some custom wiring needed and you need to consider if that is going to take more time than it's worth. Dropping in the 3400 mechanically isn't difficult, the main engine bay wiring harness is still made use of it but has to modified to accommodate the relocation of the coil pack that sits under the forward exhaust manifold of the DOHC to up above the rear valve cover of the 3400, the 3400 block doesn't allow the pack to be placed there. The alternators are *basically* in the same general area, the DOHC is low on the back side of the engine at the front whereas the 3400 puts the alternator just above the rear head at the front. All 3400's are essentially OBDII and MAF driven (Mass Airflow Sensor), so an OBDI MAP (Manifold Absolute Pressure) sensor needs to be picked up, those are in abundance. The rad hoses are almost in the very same location, the lower (return hose) tubing that comes out the manifold (under the throttle body) of the 3400 has a mild bend to it where it curves up over the exhaust manifold, the DOHC is straight alongside the airbox. If you're going to do this I'd suggest looking for a 2000+ Grand Am application or an Olds Alero, take EVERYTHING mechanically attached to the engine (a complete drop-in), flexplate/flywheel as the engines are externally balanced, front engine mounting bracket (large U shaped) as the DOHC makes use of a different front mount arrangement due to the large aluminum support on the nose of the engine. A few years ago one of the forum members (Jay) I can't remember his nickname , pulled out the L82 (3100) from his 94 (OBD 1.5) Olds Cutlass and dropped in a warmed over LA1 (3400), now this was even easier as what went in was essentially the same as what came out but just a better engine. See the wiki link for the vehicles that the LA1 3400 was installed into..... http://en.wikipedia.org/wiki/General_Motors_60%C2%B0_V6_engine Edited June 4, 2014 by 55trucker Quote Link to comment Share on other sites More sharing options...
JOHN GTPPRIX Posted June 5, 2014 Author Report Share Posted June 5, 2014 What would it take to put a 3.1 in this car 93 GP? I know it doesn't have the performance as the 3.4 but that's ok for now and if I can 't find a GP with a 3.1 but if I found a Lumina of the same year would that work? I need to know about the wiring difference etc. I found a 3.4 with 93,000. from automotive engine sales on the internet comes with a car report similar to a car fax not sure if I can trust this company. I can't find them on the Better Business Bureau information data bank. I' am thinking if I can find a 3.1 in a donor car of the same year and if I know what wiring differences there is going to be I would maybe go that route. I thank you for your time. You sound like the person who can help me with this. Quote Link to comment Share on other sites More sharing options...
crunkGP96 Posted June 5, 2014 Report Share Posted June 5, 2014 (edited) Hey John, There is a brand new 3.4 dohc motor on craigslist specifically for your car. I would of jumped on it but my car is a 95 DOHC Here you go. Brand new ZERO miles. its been on CL for a while so id give him an offer http://chicago.craigslist.org/chc/ptd/4502845341.html Edited June 5, 2014 by crunkGP96 Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted June 6, 2014 Report Share Posted June 6, 2014 John, there's a 96 Monte Carlo with an LQ1 and 96k at Crazy Rays Hawkins Point... Sent from my HTC Sensation using Tapatalk Quote Link to comment Share on other sites More sharing options...
JOHN GTPPRIX Posted June 6, 2014 Author Report Share Posted June 6, 2014 Thanks, too much difference in the years. What is the LQ1 any way. Quote Link to comment Share on other sites More sharing options...
55trucker Posted June 6, 2014 Report Share Posted June 6, 2014 The LQ1 is the code name for the DOHC engine. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted June 6, 2014 Report Share Posted June 6, 2014 Thanks, too much difference in the years. What is the LQ1 any way. That's the name of the 3.4 DOHC engine you have. It's the same thing as calling the "3400" an "LA1". It's easier to say "LQ1" than "3.4" since there's many 3.4's. When I bought my car, the person that sold it to me called the engine a 3.4, I didn't realize it had no relation to the 3400 3.4 until after the fact. If your block is what's bad, you can top swap it so you have the newer block with the older stuff so you don't have to deal with switching to OBD2. Quote Link to comment Share on other sites More sharing options...
Taylor Posted June 7, 2014 Report Share Posted June 7, 2014 Why would he have to switch to obd2? I ran a late 1999 LG8 3100 on a 3.1 mpfi wiring harness and 3.4 DOHC chip for many years before I lost my oil and killed the engine. (Oil loss was due to a bad oil cooler gasket and me being a dumbass and saying "it can wait til I get home" instead of pulling over to fix it right away). 3100 into a 3.4 DOHC car would not be that difficult in the grand scale of things. Get a 1993 3.1 MPFI engine harness, lengthen the IAC, and TPS wires, a few minor odds and ends, its really not that bad to do. After having a 3.4 DOHC in my 1994 convertible, I decided I don't EVER want another one of those nightmares again and I would happily swap in a 2.8 MPFI even over the 3.4 DOHC. Quote Link to comment Share on other sites More sharing options...
JOHN GTPPRIX Posted June 7, 2014 Author Report Share Posted June 7, 2014 The cylinder is damaged, but thanks for the information. That's not far from my house. Quote Link to comment Share on other sites More sharing options...
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