The 60 degree family tree

[geoffinbc]

As a proud owner of a 1990 Pontiac Transport, I can shed a little light on this one I hope.
It's FWD with iron heads, distributor, TBI, T125 tranny, and from what I can tell is the exact same block as what a Lumina car would've got, just with the Camaro style 3.1 pistons I'm guessing. I know the passenger side motor mount is the style that mounts on the subframe if that explains anymore. I'll take a closer look at it later tonight, and get some pics of the mounts if anyone wants to see them.
Also, on the very early 2.8 FWDs, they had seperate V belt driven accessories, such as water pump, P/S and A/C. There was a Century or something like that at the wreckers a while ago that I was looking over rather closely. The intake on that car looked almost identical to a RWD camaro 2.8 MPFI. Something like a Fiero intake.

Yes pics would be great. So I am guessing the FWD cars had V belts until the aluminum heads came out?

[XLR8ING]

Here's a couple of pics.....one of the lower motor mount, and one of the basic engine compartment.

[gpse3400]

Some events I know of are... the 3100 actually came out in '93 Cutlass Supremes Only, used the newer computer and a coffee can air filter though. There was California Prepped 3.1 in '93 that used all the 3100's IGN sensors plus the newer computer....Plus the '94 FFV 3.1. Suposedly there was a TSB intake design change for the '91 TDC 3.4, '00+ 3100/3400 got bigger valve guides to the run of 9/16".. '00 engines get that smaller more toothed timing set....'97 W cars, possibly '96 got a center exit rear exhaust manifold. I do believe the minvans got the the biggest TB, while even the the VIN J 3100 got the smallest TB still in some applications.. 2.8s in a W car made 130hp and 170 lbsft, 2.8 ran in trucks and in cars south of the US in the early nineties too.... till '88 2.8s had the fuel pump switch separate from the oil pressure sensor, mounted by the oil pump drive..'91 3.1 GEN2 went to that floating upper intake and hexbolts for the timing cover...'94 3.1 T in Luminas used the '94 3100 style air box, '97, possibly '96 and later got the newer style small starter. L cars had a smaller rear exhaust manifold kinda like GEN2...

Just some trivial data I've acculumated...

[Anonymous]

'91 3.1 GEN2 went to that floating upper intake

Would this be the rubber bushings around the upper intake bolts?

[GPXSS]

so that I can confuse everybody.. I know at least the Pontiac Transport got a 3.4 BEFORE the introduction of the 3400 in 96. I do not know what years, (maybe only 95, or 94/95) but I can personally vouch that I drove a Transport with the 3.4 and even remember the 3.4 badge on the side. I don't remember what year it was, it was my Bosses van and I know for fact he never modded it.. so it was like that from the factory. I also remember a picture off GMpowertrain.com of the minivan 3.4 which I have or had.. but its on a system I cannot get to.

Anybody know anymore information on these?

[Anonymous]

From a 1995 Pontiac showroom brochure:

Engines
-------------- 3.1 liter EFI V6 ----- 3.8 liter 3800 SFI V6

horsepower 120@4400rpm ---------- 170@4800rpm
torque------ 175ft-lbs@2200rpm ---- 225ft-lbs@3200rpm

So if there was a 3.4 in 1995 TransSport, it didn't show it in the brochure.

[geoffinbc]

LOL that must be the 3.1L TBI right??? Wow that LOW the 2.8L had mroe power but I guess it could since it did not have to pass the same emission standards... And that 3.8L was the "tuned port" 3800 wasent it?

[Anonymous]

It was the TBI 3.1, and as it says the 3800 was SFI.

[geoffinbc]

Yea but on the Vans it had a badge that said 3800 Tuned port on it. Just because all the intake runners are the same length. The 3400 and 3100 would also be considered tuned port engines now.

[Juglenaut]

DOHCisbeltdriven,not chain driven.
_________________
Ben
List cars here....list mods there.

On the contrary The DOHC is ultimatly controlled by a timing chain that turns the intermediate shaft which powers the timing belt and the oil pump. Timing sequence is driven by the timing chain.

[geoffinbc]

Ok some contradiction. Anyone got a cutaway picture of the engine? Or just a front end view with the timing cover(s) off

[geoffinbc]

Yup your 100% right. So I will ass that

http://www.midtekcars.com/34dohc4.htm

[quaddriver]

this is still up in the air, but id say in 96 the 3100/3400 heads got notched rocker arm stud holes, and roller fulcrum rocker arms. In 96 i know they used aluminum valve covers, not sure about 95. There were quite a few differences with the 3100 v.s. 3.1, not sure how many you want to list.. main ones being introduction of powder metal cross bolted main caps, cast aluminum oil pan, and a windage tray.

93 3.1s had cast oil pans also, I think this change came 92/93 cause I was just under a 92 corsica 3.1 w/stamped

[quaddriver]

Well no kidding... But what about the ones lasting to 1995 and using TBI?

So I gotta add that when did the Lumina APV start and stop production?

this page is not formatting for me, but the 91-93 S10s 2wd only still got a splayed valve IRON head 2.8 TBI motor making 125hp, same time an AL head splayed valve 3.1 was used in isuzu rodeos replacing the 2.8 - still tbi tho (hp unk)

Im not sure if for 94- the 660 was dropped inthe s10, the vortec heads came out first on the 4.3 and this pretty much became the defacto motor for the whole line once you got away from the 4cyl

[quaddriver]

Im having a bitch of a time seeing the page formatted, re: the dustbuster (apv vans) the 3.1 using in it went splayed AL heads 91- (and 3.4 later, with 3.8 option) but it used TBI and a dist - with a different crank that will not work in a t-code so you have to be sure where those motors came from