GM 3.4 & 3.5L engines Donor Vehicles

[Mr Comet]

I thought I'd just thru this out here for general discussion and options. I have a 200 cid I6 I am searching for a donor vehicle to get the EFI parts off of. I have read GM is the most available parts to look for and I need to look for engines with my same displacement 3.3L. With this in mind would the GM 3.4 and 3.5 be too much since the newer fuel injection is more efficient then the old carbd engine were? I am looking for the most bang for my buck. However is there a point in miles where I am taking a risk with the injectors. I would like to see some discussion on this topic mainly to explore areas I have not thought of.

Thanks for looking.

 

[MustangSix]

Rather than displacement, look for engines that produce comparable horsepower at similar rpm's. Power is developed by burning x/lbs/hr of fuel, so if the power is the same, the fuel delivery will be similar.

 

[Mr Comet]

First of all I know my engine is 120 HP but I do not know at what RPM that is. Secondly would that be different once I have EFI any how? Also what are my variance? Maybe 100-140 HP? I know the fuel injectors will have adjustable rates as well. Most of the 2.4L to 2.5L engines are 4 cylinders. Anything fairly recent is. When the equinox went alittle smaller they started putting 2.4L engines in them. The 3.1L GM engine from early 2000s had 135 HP It has been largely replaced with the 3.4L and 3.5L. Would that be too high or not? I appreciate your help.

Thanks

Denny

 

[thesameguy]

I would personally look for the 7730 series of ECUs, fitted to a ginormous variety of late '80s and early '90s GM cars and has huge support. The 7730 works on 4, 6, and 8 cylinder motors with code changes. The L44 (2.8l V6) made 140hp at 5200rpm, which I'd wager is very close to what a 200ci is capable of given proper engine management and 5200rpm .

I would look at:

http://60degreev6.com and
http://www.moates.net/gm-obd1-pre1996-c-64.html

*Lots* of info out there on GM 7730s, and there are configurations to support direct ignition and turbo management if you get the itch.

 

[rocklord]

Rather than displacement, look for engines that produce comparable horsepower at similar rpm's. Power is developed by burning x/lbs/hr of fuel, so if the power is the same, the fuel delivery will be similar.

I'm in agreement with MustangSix. You need to realize that the 120HP rating for you engine is gross, not net HP. The newer engines are rated in net HP (switch was around 1973). Your 120HP gross is about 85HP net. The GM engines you are looking at may have the same displacement, but are more efficient and are rated at higher HP (180+).

If you are not planning any performance upgrades and want to go with TBI (throttle body injection), then look at engines making around 80-100HP. There is a thread on this site where someone used a TBI from a Tempo2.3L/Taurus2.5L four cylinder engine and MS on his stock 200, and it ran well. Others have used GM TBIs from the 2.8L/4.3L engines, but not their ECUs (megasquirt).

If you are planning performance upgrades, then you may be able to look at the complete EFI systems from GM V6s in the 2.8L to 3.8L range, or the Ford V6s in the 2.5L to 3.8L range. Again matched to your estimated HP output.