3.4 swap into 91 Trooper

[greener]

The 3.4 is virtually identical to the 2.8 on the outside.

P.S. how's your oil pressure, if not too bad maybe the lifters are varnished. Add about 5 oz. of Seafoam carbon-cleaning additive to the oil and run 'er for 50-100 miles before changing oil. It may help.

P.S.S. my old 2.8 Trooper likes Valvoline Hi-Miles oil, it helped reduce oil consumption considerably (probably lubed up the valve stem seals).

Awesome feedback, thanks so much. I will try the oil additive remedy and see if things quiet down. My oil pressure is fine, normal reading. I'm still looking forward to doing the engine swap, now that I have some solid answers on the appearance question.

History of lifter problem (as diagnosed via an exhaustive 10 second listen by a gas station mechanic ): Firstly, my troop eats oil. Also, engine coolant gets into the oil, spotted by the oil change guys. Gooey whitish clumps in the oil. I guess a gasket is bad somewhere. So the troop sat around for a week since I commute on my motorcycle to save on gas. I went to start it one morning and it started up with a noticable clacking. I checked the oil and it was low but present. I topped off and drove 6mi to work. The clacking continued. I took it by a random gas station mechanic and he said he heard me coming and knew it was my lifters right away. I drove home and changed the oil, including a cheap oil treatment that claimed to 'quiet lifters'. There was no significant quieting of the lifters, after letting it run maybe 20 minutes at idle, and another 15 driving around the blocks near home. My guess is that the oil was low and dirty, and after sitting for a week it may have drained down out of the top of the engine. Thus when I cold started it it later, the lifters were damaged or whatever.
What do you guys think?
Thanks again, its great to find some solid info on my beloved trooper, I can't wait to do the swap and keep rolling.

[Ed_Mc.]

If I recall, Camaro 3.4 valve covers have the various holes for oil fill, pcv, air breather tube, etc in different places than the TBI 2.8 and may not work. Since the cyl heads on the RWD 3.4 are the same as a 2.8, you can use the original 2.8 valve covers and it'll all match up.

For a custom look, try a set of Fiero aluminum valve covers although you'll have to modify the various holes to fit. This mod should be documented here and also at the S-Series.org 60 Deg V6 page.

BTW, you can easily modify the stock GM fuel pressure regulator to be adjustable within an approx 2 psi range +/-; I did this for my "stroker" 3.1 build for '89 Trooper LS, and it worked fine. Had a bit of cold lean-surging and jacking up the fuel pressure cured that problem.

Here's a link I found that describes how to make it adjustable:

http://www.aces.edu/~gparmer/efi/tbi_adjust.htm

Check out Option No. 5, "Adjust stock regulator"..............ed

[Canyonero]

Yes, that is the case. The 3.4L block is very very similar. Equiped with the TBI system and accessries of the Trooper, it would be nearly indistinguishable from stock. I think the 3.4L valve covers are a bit more 'square', but who would notice...

To fuel the larger displacement, you'd be best upgrading the throttle body, or at least the injectors. A TB from a 4.3L V6 will bolt right up, and your 2.8L intake manifold can be bored to match. Or, you could just use a pair of 4.3L injectors in the 2.8L TB. Also install an in-line fuel pressure regulator to fine tune the mix-n-match 2.8L/3.4L/4.3L system. The stock ECU in your Trooper will run the combo fine.

I've done loads of research on the Troopers, so don't hesitate to ask here.

Hey guys, thanks for your efforts to document this swap project and share information.
I am hoping to do a similar swap on my '91 Trooper, who's 2.8 has some clacking lifters.

A big concern for me has to do with my CA smog laws, which don't allow swapping engines at all. It's my understanding that the 3.4 is the same external size and appearance of a 2.8, as the displacement gain comes from different bore and stroke on the same block size. Is this true?

I hope to swap in the new engine, and have it look indentical to stock during a casual visual inspection. I know the engine serial number and vehicle VIN number won't match, but I think I can squeak by on that.

Thanks in advance,

-dave
1991 Trooper 2.8l 5-spd V6 133,000mi

[Ed_Mc.]

The 3.4 is virtually identical to the 2.8 on the outside. There are some big "X" casting marks on the driver's side (stiffens the block) but other than that no one should be able to tell the diff (except, as you said, if they are into checking serial #'s). I don't know that the original motor's ser # matches the Isuzu VIN anyway, you'd have to check on that. Seen plenty of reports from CA 3.4 swappers in S-10's and Troopers saying that they passed smog with flying colors.

Just make sure all of your emissions control devices are installed and working properly. You'll probably want to replace the cat converter anyway if you plan on installing an upgraded exhaust to help the bigger motor breathe better. The old Isuzu cat's are prone to plugging and after 15 years it probably is no longer running at peak efficiency (if at all).

And plan on replacing the O2 sensor as well, it's cheap anyway.

P.S. how's your oil pressure, if not too bad maybe the lifters are varnished. Add about 5 oz. of Seafoam carbon-cleaning additive to the oil and run 'er for 50-100 miles before changing oil. It may help.

P.S.S. my old 2.8 Trooper likes Valvoline Hi-Miles oil, it helped reduce oil consumption considerably (probably lubed up the valve stem seals).

HTH...........ed

[greener]

biting my nails

Hey guys, thanks for your efforts to document this swap project and share information.
I am hoping to do a similar swap on my '91 Trooper, who's 2.8 has some clacking lifters.

A big concern for me has to do with my CA smog laws, which don't allow swapping engines at all. It's my understanding that the 3.4 is the same external size and appearance of a 2.8, as the displacement gain comes from different bore and stroke on the same block size. Is this true?

I hope to swap in the new engine, and have it look indentical to stock during a casual visual inspection. I know the engine serial number and vehicle VIN number won't match, but I think I can squeak by on that.

Thanks in advance,

-dave
1991 Trooper 2.8l 5-spd V6 133,000mi

[Canyonero]

I ended up borrowing an 18v drill from work, those things rock, loads of torque. However, I don't think the battery packs were topped off. I finally finished up with my cheapie 9.6v with about 45 min on the charger. I tried using my dad's oldschool corded drill, but it only had a 1/4" chuck.

I'm sure you're right on the gasket, it's the right length - but that's it. Ordered a new gasket for the Firebird and a flywheel for the Trooper (have to return the core, or I pay for two). I was going to have my original flywheel resurfaced, but this way I may be able to get the engine swapped in one weekend and only pay for one day of hoist rental.

Hopefully that oil pickup return turns over quickly, that's probably what I'll end up waiting on...

Edit: More pictures with captions can be found on my picasaweb account - http://picasaweb.google.com/343.guil.../34LConversion

[Ed_Mc.]

Yeah, the cordless drills don't have enough pep for drilling in cast iron, I used my cordless on the pilot holes and ended up with a 3/8" Makita corded which had enough torque to handle the larger drill bits.

One thing you might want to do before putting the motor in is to check the mesh of starter gear to flywheel teeth. Just "roll" the starter gear into the flywheel and make sure it's hitting neither too high or too low. You can get a pack of 'generic' SBC V8 starter shims of various thicknesses to shim the starter as required. Your old motor probably has a couple of shims in it anyway and those might be enough for the job.

And I bet on the wrong gasket, they sent you one for a '3400' FWD motor, completely different fitment there!

Don't get discouraged yet, sounds like you're making 'normal' progress!........ed

[Canyonero]

Went through five drill batteries for that project. The threads are beautiful. See also my relocation of the fuel line. I wussed out and got some compression fittings - bulky (and expensive), but easy.

Summit shipped the wrong gasket for my oil pan. Delays delays. I don't think I'm on target to pull my engine next weekend.

I had a question, can't remember it now though...

[Greg55_99]

This site might be helpful:

http://www.lunghd.com/Tech_Articles/Project_XJ/Project_XJ.htm

Greg

[Canyonero]

Uhg, I finally have my engine on the stand now. I got to looking over my exhaust manifolds. Some bastard broke a few bolts off. *sigh* New gaskets on the way. Now I need to get both manifolds off, ez-out the broken bolts, and dig up a new set. Grumble grumble...

Spent some more quality time with the hacksaw; my fuel lines are all chopped to length now. Just need a little touching up with the dremmel, then I'll sweat those suckers back together and paint 'em up.

I'm still shooting for next weekend to pull my 2.8L out. Then I have the week to get the flywheel resurfaced, finish assembling the 3.4L with the necessary bits from the 2.8, and drop'er in the following weekend. You know, if all goes to plan. Which it won't.

[Canyonero]

I've already filled out my return/exchange form, I'll try to get that shipped off tomorrow. Shouldn't be a big hang-up, I have a couple weeks before I plan to yank the 2.8L and still need to get the flywheel resurfaced and whatnot. Good times.

[Ed_Mc.]

DOH !!

Hey, you're absolutely right and I have to apologize for Bum-Doping you, I was reading my notes wrong. The correct part is as you surmised, 245S.

Here's a Summit link to that part:

http://store.summitracing.com/partdetail.asp?part=MEL%2D245S

And yet another source:

http://www.unclemoesengineparts.com/product_info.php/cPath/1000064_1000066/products_id/1586?osCsid=5b623e3430344f55b58387bd7fef08b9

Glad you caught that, a Most Bad thing to have a short oil pickup!

Sound like you're making good progress, Have Fun.........ed

[Canyonero]

in re-reading your post I see they used the shallower Camaro oil pickup? Not So Good!! They should have used a Melling 243s oil screen/pickup tube.

This fits the deeper 4X4 pan, plus it's 3/4" in diameter and is the proper press-fit into the 3.4's oil pump. They couldn't have used the 2.8's original pickup because earlier models were 5/8" not 3/4".

Now I don't have my pan off yet, but I just received my Melling 243S pickup tube/screen and it doesn't seem very deep... I see in other Trooper swap notes to use the 245. Are you SURE it was the 243? Because I can return this thing and get a 245 on the way. I bought mine from Summit Racing by the way (they have both). Also, the 245 is $2 cheaper!

I took the axe (dremmel and hacksaw) to my 3.4L fuel lines. Relocating to the left side facing the engine. Once I dig up some appropriate size sleeves, I'll solder this thing up! Unless there is some taboo on soldering fuel lines. I can weld them, it'd just be harder.

Finally got the bolts to put my engine on the stand. Soon I'll be able to flip it over, pull the smashed firebird pan off, tap my starter holes, and install my oil pickup. Hurray.

[Ed_Mc.]

Yeah, I was pretty paranoid about drilling my block, but I didn't have a jig, either. Did a lot of measuring, re-measuring, & soul-searching before making that first pilot hole!

Judging from comments, the jig works as advertised. I certainly would have spent the $$$ to get one back then.

And not a bad idea to clean out any loose rust/etc from the end of the crank before pressing the bushing in. If you have a bearing driver or even the correct-sized socket you should be able to carefully drive the bushing in place.

BTW do you self a favor and pick up some new pressure-plate mounting bolts when the time comes. On my motor, the old ones were in pretty sorry shape. Just take a sample down to your local screw specialty house and ask for some hi-strength metric pieces. The Stealer wants more for one bolt than it'll cost you for all of them at the specialty house. I used a dab of Loctite on each bolt prior to torquing, don't know how necessary that is but I felt better about doing it!

[Canyonero]

Since your 3.4 came from an auto-trans Camaro, be sure and check the crank for a pilot bushing. Likely the auto-trans motor won't have one. Just pick up a new bushing (cheap) and drive/press it in.

My clutch kit came with a new bushing. Looks to be a tight fit into the crankshaft, suppose I should wire-brush the hole a bit with the dremmel since it's been vacant for the last 13 years? Clean out some of the grit?

In addition to my clutch kit, I also recieved my electric fan (Flexlite Black Magic 150) and starter relocation jig. And might I comment on the jig - I haven't used it yet, but it looks pretty much foolproof. I think it's definitely the way to go for anyone feeling slightly uneasy about drilling into their new engine.