93 mpfi to later sfi 3.1L

[Snafu]

I just got a free 93 olds cutlass supreme convertible. It runs and drives, but has BAD rod knock. Junk yard  has a 98 3.4L which would be sfi right? If I took all the 3.1 mpfi stuff will it just bolt on to a newer 3.4? I'm sure there were suttle  changes from 93 to 98. I have been down this road with a 80's Iroc 305 to 350 tpi. But will a 3.1 mpfi ecm run a 3.4 well enough or are we talking full harness swap and ecm? I owned a 94 olds and it was sfi 3.1 so i'm some what for miler with it. Thoughts? thanks

[55trucker]

starting a 2nd thread?

 

The older LH0 engine (which would be in your present car) is similar to the later L82 engine. That older engine has the same displacement as it's successor the L82 (3100). That's where the similarities end, the newer series have different heads (ports are improved for flowing), revised intake manifold design, revised exhaust design, different blocks (newer stiffer design, roller cams), different oilpans. Nothing is transferable unless one goes to the effort of swapping the older heads onto the newer block, one uses the newer pushrods with the older heads, one uses the newer injectors with the older manifold, one uses the older exhaust manifolds. Doing that allows you to essentially create a 3400 LH0 engine. You put that down into your engine bay & don't change anything else related to emissions, crank sensors are the same item, one does not make use of the low level oil sensor in the later pan, one uses the older oil pressure sensor, the ECM should not need any re-programming where fuel is concerned. The injector integrator rate should not vary too much from the original LH0 figures.

[Heartbeat1991]

I replaced the LH0 in my Z24 with an LA1.  It is possible to run the LA1 with the intake from your LH0 swapped onto it.  But that pretty much eliminates most of the advantages to the LA1.  The block is different.  I am not sure about what's involved in putting one in a W body.  My J Body required a custom made engine mount.  The W mount may bolt right on.  I'm not sure without going and looking at it.  

 

Personally, I would use the LA1 as is and just get a tune for it.  There are people out there still making chips for this type of swap.  You'd gain a considerable amount of performance.  

[Snafu]

Well I'm kinda old school, as a mechanic I would always replace with what would have came with it. Thats just the way I roll. I know some of the suttle changes like the heads and intake and the roller cam. But my shop really get into swaping 3.1 to 3.4 bla bla if you know what I mean. HOWever I did manage to find a vin T 3.1 mpfi. The guy sold me the whole engine trans,sub frame,struts,brakes the whole sha bang for 150 bucks. His kids grand prix lost reverse and he bought a wrecked grand prix just happen to be the vin T like whats all ready in the olds. I'm am curious about polishing ports and cleaning up the heads. I have way more time than money so this will be a slow step at a time process. I'm not looking for a drag car just a clean smooth 3.1. Might op for the cam for it but the mpfi intake and heads won't flow enough I bet to really make use of it. I'm going to order a master gasket kit for it and a timing chain kit for it. You guys know all the BS that a guy can get to while engine is out of the car. Water pump. HOPEFULLY I can pull the engine out through the top. I'm in the drive way,sucks. I think with some fineness it will just bearlly. I'm also picking up a 94 olds cutlass supreme sl 4 door with the sfi. Has a battery draw, cars supper clean and only 140,000 mi on it little ol lady owned it. Pick it up for 300 drop a battery in it a go hunting for a draw. No power anything inside the car. Peddle the 4 door for money for the olds 2 door. Thanks for the info. I been doing a ton research while waiting for some response from you guys. I didn't mean to start a second thread.