My trooper recently developed a dead cylinder and I came upon a deal for a wrecked but complete running 88 Impulse with a good 2.3L FI motor. From what I've searched up, the Impulse 2.3L cam has 6 degrees more duration, but other than that I have not found any real differences. At least nothing that would keep me from dropping the whole works in the carb'd Trooper. I have two basic questions though.

First, what sort of difference can I expect from the Imp's longer duration cam running with the Troop's carb? From what I read, more duration means more power in the top end, am I wrong?

Second, any gotcha's I have not thought of on the swap? Here is what I know I have to change, can anyone think of anything else besides little nuts/bolts stuff?

Intake and Exhaust manifolds
Motor mounts
flywheel/rear plate (not sure on these, will have to compare once they are out)
Crank pulley
Accessory brackets to use the troop's stuff
Distributor
Oil pan
Oil pressure sensors (they look different, another compare)
Oil filter adapter looks different too

I think that is the basic gist of things. Hard to see everything with the motor still in the car. The Imp's exhaust manifold has a twin downpipe, might be interesting to compare the two, but this one has a crack in it. Oh yeah, if anyone knows someone with an Impulse, I will have a bunch of parts left over once I'm done.

Good luck on the swap.

You can get more of a response on the 'Pulse parts over at

http://www.isuzone.org/forums

There's a couple of guys over there that are looking for some JR parts.


Madcat <img src="/forums/images/graemlins/kewl.gif" alt="" />

Thanks very much. I had been meaning to do a better search for a forum devoted to 'Zu cars, Isuzone looks like the place to go for info on them. It would be nice if I can recoup some of my costs in parts too, and help keep a few of the Zu cars on the road too. A lot of this car is in great shape, shame it is wrecked so bad. Might be a blessing though, or I'd be parking the troop and trying to rebuild the car. <img src="/forums/images/graemlins/wink.gif" alt="" />

Got the crank pulley bolt broke loose tonight. In 5th gear I just got the clutch slipping, bumping the starter wasn't working after about 50 tries. Gave it a shot of pentrating oil and went and picked up a brand new Optima red top battery. Two clicks of the starter and it was loose. Cheaper than the impact wrench I would have headed to next too.

Found another small snag that somehow completely escaped me until now, no ports for smog pump manifold. I hope I never have to smog the Troop with this motor in it. I read in one of Jerry's posts that a 2.6 will pass the sniff without it, but running a carb I doubt I'd make it.

THE 2.3 IMPULSE ENG IF IT IS IN GOOD SHAPE IT WILL PASS THE SMAG TEST WITH UT AN AIR PUMP UNLESS THE INSPECTOR IS REALLY SHARP AND MISSES SEEING THE AIR PUMP, AS LONG AS YOUR CAT CONVERTOR IS IN GOOD SHAPE THEY WILL PASS THE MOST STRINGENT TESTS AS FAR AS THE STATE TESTS GO , I HAVE AN 89 TROOPER WITH 255.000 MILES ON IT AND JUST REMOVED THE ORIGNAL DUAL BED CATALYST ,NOT ILLEAGLE I REPLACED IT WITH A 3 WAY CAT FROM THE LATER MODEL TROOPER AND DISSABLED THE AIR PUMP IT JUST PASSED THE GA INSP, WITH IDOL AND CRUISE SPECS OF 0.010 % CO, AND NOX WAS 0.001 PT PER MILL, HC WAS 15 PTS PER MIL AT CRUISE , THIS TYPE OF CAT IS LIT OFF BY THE AIR IN THE EX AS IT LEAVES THE ENG WITHOUT HAVING TO HAVE AN AUXILLERY AIR INPUT , THE CARBED ENG IN THE IMPULSE FORM IS 100 HP INSTEAD OF THE ORIG 90 WHER IN THE IMP IT IS 110 WITH THE EFI, THE ENG WILL FIT AND WORK FINE IN THE TRUCK, USING ALL THE MANIFOLDING AND THE DIST AND CARB FROM THE ORIG, 2.3 ENG YOU WILL NOTICE A GOOD BIT MORE PWR,YOU WILL NEED THE ENG MTS OIL PAN, AND ADAPTER PLATE ON THE REAR , AND MAYBE THE OIL FILTER ADAPTER SOME OF THOSE CARS CAME WITH AN AUX OIL COOLER ,USE THE TRUCK FLYWHEEL CLUTCH AND PRESSURE PLATE ASSY , YOU MAY ALSO WANT TO CHANGE THE LOWER WTR PUMP PICKUP PIPE THAT BOLTS TO THE BLOCK SOME OF THEM CAME OUT AT THE WRONG ANGLE BECAUSE OF THE WAY THE RAD IS INSTALLED IN THE IMP , JERRY

All your info has been spot on Jerry. I've been working slowly on this as I don't have a lot of dry room to work in, the car is outside. The motor is out and under cover now, and I've been finding everything you say pretty much nails it right on. I had sort of hoped that I could run the stock mechanical fuel pump for a while, but the pushrod hole does not exist on the imp's head. There is an oil hole in there though, so I've got a plate made up that will cover it. I had figured on going to an electric pump anyway, but now I have a mech fuel pump with about 1000 miles on it that will just sit.

I was amazed to see how much larger the intake ports are on the imp head. I have not measured with a caliper, but there is about 1/4" more diameter than the carb'd troop. That extra breathing room combined with the added cam duration should make for a good HP boost.

Hopefully I'll get time this weekend to get the motor out of the Trooper so I can get all the needed donor parts off of it and get more progress on this project.

THE REASON THEY ARE SO BIG IS THE VLVS ARE THE SAME SIZE AS THE 2.6 ENG WITH A SHORTER STEM LENGTH , AND THE CAM IS THE BEST OF ALL THE STOCK ISUZU CAMS , AND WAS USED IN SOME OF THE LATER RODEOS AND PICKUPS , EVEN WITH THE CARB SET UP YOU WILL NOTICE A BIG IMPROVEMENT , YOU MAY BE ABLE TO FIT THE IMPULSE EXHAUST MANIFOLD AND DOWN PIPE IN THE CHASSIS , SOME OF THE PIPES WILL CLEAR THE TORSION BARS AND SOME WONT, JERRY

Now that I know how much is different I will certainly be sure to take good care of that head. I'm already putting a new timing belt on and all new seals. Every inch of coolant hose will be new, so I guess the last thing to look into is getting a better radiator like a 2 core out of a 2.6L trooper. Any fitment issues with that, or particular years/options to look for to get the best rad possible if I decide to pull one at a junkyard?

Any fitment issues with that, or particular years/options to look for to get the best rad possible if I decide to pull one at a junkyard?

Don't go used. It is not worth your time and money. For about $100 you should be able to find a new radiator and then you do not have to worry about it. With a used unit you are just asking for troubles and those troubles can directly affect that head you are trying to protect.

As for fittament, stick with Trooper. Rodeo/Amigo/Pup may work, but...the Troopers had some different sheetmetal in the front. Just go for a 2 row radiator from 89-91 and call it good. You might have to go with one for a v6 to get the 2 rows, but any place that has them will be able to hook you up.

I've heard good things, but never used, www.radiatorbarn.com

Good Luck,
Michael

DO LIKE MICHAEL SAYS FORGET THE USED RAD TRIP, YOU CAN GET A NEW ONE IN A LOT OF CASES FOR ANYWHERE FROM 100-RIGHTNOW 145 ABOUT MAX FOR THE TROOPER , ASK FOR A 2.6 ANY YEAR 88-91 TROOPER WITH AN AUTOMATIC TRANS AND YOU WILL GET THE 2 ROW AND COOLING ON THE 2.3 SHOULD NOT EVER BE A PROB, JERRY