bad idea?

[geoffinbc]

Uh oh more hybrid talk!

First of all yes I agree it is a cool idea. But I will bet you will blow past any budget you had in mind about tweaking your old 2.8L in a second flat. I agree with ezrollin. Keep it simple. You can do a whole valvetrain upgrade (cam and rockers included) for around $400 bucks and still keep the heads on the motor and not have to go through the task of pulling the motor and replacing every gasket along the way. You already have the intake and headers so changing the cam is a very logical next step with minimal investment.

Don't kid yourself with a hybrid motor in a RWD vehicle you will be into it for a couple thousand at least. Plus with compression that high you will not be running regular gas and tuning will cost more money on top of the hard parts and labor.

If you have a big budget in mind and can have your truck off the road for some time then don't piss around with the 2.8L and jump right to a 3.4L or 3400 block.

[walterdude]

As far as your list goes, with 3100 Heads/Intakes make sure they are 2000 or newer... 99 and older have small ports,, guess what my non-DOHC has?? So,, 2000+ the 3100s and the 3400s are the same.. With the exception of TB size... I think,,, 3100 has 52mm and 3400 is 56mm.. As said, I think,, I know the 3400 TB is bigger tho...
Tom...
Sounds like a fun build!!

[pocket-rocket]

With the 3x00 top end, be SURE you get the metal intake gaskets, not the plastic ones. The extra price is well worth the headache they will save you...

[dusterbd13]

so, back to the origonal not so bad idea of the day.

my shopping list would be
1. pair of 3100 or 3400 heads
2. intake from same motor, as well as the injectors, throttle body, coils, wires, etc
3. set of pushrods from???
4. the crank sensor conversion from wot-tech
5. eiring and pcm from???
6. dremel tool to slot some holes
7. gaskets

am i missing anything? what gaskets would i use? is there a thicker head gasket that could knock some compression down?
could someone double check my compression math? depending on which 2.8 i select, i get on the 12;s, or low 13's.

thanks for the helps os far guys. if were sure this will work, ill add the part list to my junkyard bag. that way when i spot something that will work, i can snag it. especially on half price day.

michael

[pocket-rocket]

swapping a 3100 in place of a 3.1 is easier than swapping a 5 speed in place of a 4t60e.

That would have to be one simple as pie swap. I didn't have any problem at all swapping a 284 into the 91 to replace its 3rd blown 4T60-E.

[robertisaar]

very good info-sad to hear that but are you sure none of the pontiacs came with a 5 speed?

positive. there might have been 3.1(LH0) 5 speeds in 94, but thats as close as it gets.

[no_doz]

very good info-sad to hear that but are you sure none of the pontiacs came with a 5 speed?

[bszopi]

No 3x00 was ever bolted to a 4T60 either, it was always a 4T60E.

[robertisaar]

chart? no, but it would be simple enough to make one. what all do you want to know? ALL FWDs? just 3.1? just 3100?

BTW: you wouldn't find a 5 speed 3100 ANYTHING from the factory. never happened (unfortunately). but swapping a 3100 in place of a 3.1 is easier than swapping a 5 speed in place of a 4t60e.

EDIT: that would actually be a 4t60, apparently only the W's got a -e in 93/94 in 3.1 apps, the others should only be a 3.1/4t60 or 3.1/th125c.

[no_doz]

fantastic info-so i suppose this means i wont be going out & looking for a sunbird 5 speed with a 3100 in it & OBD-I then.

thanks for the clarification guys-also robert is there some sort of chart that shows what computers went in the different gm fwd's?

[RedBird]

no, 94 J-bodies got OBD1. GM didn't feel like going through all the trouble to put OBD1.5 or the 3100 in the 94's, since the V6 was going away in 95 anyway.

[robertisaar]

didnt the 94 cavalier Z24 have OBD1.5 then?

they got the 3.1, not the 3100...

[no_doz]

didnt the 94 cavalier Z24 have OBD1.5 then?

[robertisaar]

werent the 94 ecms obd1.5 for the most part?

about the only 1.5 ECMs in 94-95 were the 3100, 3.4iron head, LT1 and i think a 4-cylinder or two... those were the only flash ones IIRC...

so a 94 3.1 is fine, it should actually be a 16149396....

[pocket-rocket]

http://wot-tech.com/shop/all/external-crank-trigger/prod_42.html

Pure bolt on so that your ECM has the right reference to go by for the ignition and fueling events. Too bad it is out of stock right now.