800xl wrote:
As usual, Bob has a lot more info to add to the mix. I just have a few comments to add, but I have to say he has even given me an idea here.
rodeobob wrote:
The other thing about the manifold is if you get a 2.3L donor you can also get the fuel pump that mounts up under the carb, if youve got the push rod you can use that pump. If youve got an electric pump you need to block that all off.
Quite often the hole for the pushrod for the mech fuel pump isn't even drilled on the head if its not a carb'd 2.3L head, so figure on blocking this off and running the stock electric pump. At least that has been my experience..
On the 2.6L heads ive got here the holes are open. The 2.6L (and JDM for the smaller Efi motors) manifold is different on the face between 2 & 3 runners, its flat, and the gasket seals up over the pushrod/drain back hole in the head.
800xl wrote:
rodeobob wrote:
I wouldnt write off the factory 2.6L exhaust manifold. They are 4 into 2. The 2 into 1 bit that bolts to them can be tuned in length and size. They did that sucessfully over here on the G161Z motor in production racing. It was a factory manifold with the factory carby, an off the shelf set of performance tube headers cant enven match what they got all those years ago.
4 into 1 will never work on one of these motors as the are a torque motor and being well under square wont rev hard happily and make power. Id be chasing the stump pulling grunt over the HP figure.
I've seen the 2 into 1 manifold on a 2.3L fuel injected impulse motor, but that has been it so far. The 2.6L in Troopers has a bigger outlet than the 2.3L troops, but its still one big port. You folks down under get all the fun stuff. That reminds me, I should get the crack on my imp manifold welded up... Anyway, this is exactly why the Calmini header is nice, it is a tri-y design, 4 into 2 into 1. It runs better where it counts instead of just bumping high RPM horsepower like a 4 into 1 tends to do.
Ive got my cast factory header for the Luv for one reason. It looks stock, im going for the "It looks like my Grandpas Luv but its got realy shiny rims" look. They were found on the first of the Geminis (I-mark), they have the square ports. The one on the 2.6L pickup (thats what mine came off) is the same but bigger diameter (round too) holes. The flange bolt pattern for where the 2 into one pipe bolts up is the same its just the pipe diameter thats different. The 2.6L ones were a bit crack prone, a mob here make factory replacment heavy duty castings.
No one can say i started my luv up with no exhaust, it got the 2 feet of 2 into 1 bolted to it. lol.
The single outlet cast manifolds varied a fair bit with the pipe flange diameter and the angle it mounted at too.
Ive also got a set of extractors here for a 2.6L. There are a few different mobs that make them here. I got them off eBay real cheap.
We call manufactured tube manifolds extractors.
Factory performance cast manifolds are headers.
800xl wrote:
rodeobob wrote:
One other thing you could do would be to put the 2.3L head on the 2.6L motor. This will bump the compression up, you dont loose out much in port and valve size if you leave the head std. I havent do this co i cant tell you the results, be sure and check that youve still got valve to pistion clearance. I doubt it would be an issue but its worth checking.
If you can find a head from a 2.3L Fuel Injected Isuzu Impulse it has the larger valves and ports coupled with the smaller chamber. That would make the perfect high compression head 2.6L head swap, plus you get the long duration camshaft to boot. I had actually not thought of this before, but I never really wanted to build a high compression 2.6L.
See thats something trick that we didnt get. The 2.3L EFI Impulse. All we got was the 2L turbo as a factory offering. The splattering of G200 and twin cam Piazzas are all private imports.
Cheers, Bob.
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Current project, 1979 KB Isuzu Ute.
Daily driver, '86 Rodeo Spacecab.
Chasing parts for Isuzu Impulse.