carb

[shredeagle]

are there any carb upgrades for my 81 2.5 gm? thanks.....

[BenM]

The progressive Rochester carb on those is pretty good. You could pull a TBI setup from a Pontiac, it should go together easily. The hardest part would be finding a vehicle speed sensor.

[carnuck]

What's the pulse output for the GM one? Jeep used TBI on the '86-'89 XJs and MJs with 2.5L AMC

[Monkeyjoe]

I see this thread hasn't had any action in a while but I have the same questions.

I did a few performance upgrades to my 2.5 Iron Duke when I rebuilt it, larger bore, Zero Decked the block, milled the head for higher compression and mild cam to name a few.  Now I need external upgrades, Carburation and exhaust.  It has the 2bbl, carb, cant remember the make.  Are there any tricks for the original carb or is there another that will bolt on?  I am pretty good with fabrication and could build an adapter plate between the manifold and carb for another 2bbl.

I did see the post about TBI, Not sure how to set up a speed sensor either,

[captspillane]

Vehicle speed sensor is easy. Basically transfer case hole gets filled by an adaptor with 7/8 inch threads, the speed sensor threads on, and then a CJ or FSJ speedometer goes from there to the stock speedo. It should cost about $60 total.

[Monkeyjoe]

Wow, that sounds easy.  So what is the sensor reading?  Is it a spline or gear teeth in the transfer case?

[Monkeyjoe]

what all would I have to scavenge off the donor car.  And what car?  Pontiac Fiero?

[captspillane]

This is the exact same unit just marked up crazy high. It is included with a Howell TBI kit. I'd take the parts from a 1988 era GM car to match the TBI systems I'm using for the Eagles. Going to the Binder Planet forum and looking at their TBI page will give you much more information on what years are what.

http://www.ebay.com/itm/Painless-Wiring-60115-Chevy-Performance-Speed-Sensors-7-8-18-Thread-TBI-TPI-/141058713033?pt=Race_Car_Parts&hash=item20d7c125c9&vxp=mtr



This can be found for much, much, much cheaper but I posted the link so you can see what I'm talking about. For more information on speedometer solutions go to my project thread here (specifically a post from October 2012):

http://forums.amceaglesden.com/index.php?topic=36839.30

[captspillane]

Here's a quote from the October 2012 post on my project thread:

I have been looking for a speedometer solution for the two Eagles I'm currently working on. The first one is a TBI setup with a VSS that has 7/8" input and 7/8" output. The second is an MPI setup with a VSS that has 7/8" input and 5/8" output. For both of them I am using a transfer case speedometer gear and housing from a 1992 Jeep Cherokee. That housing is pictured in this first picture. It goes right into a stock Eagle transfer case or any of the "New Process" Jeep transfer cases.



For the TBI Eagle the speedometer cable is easy. I put the 92 XJ speedometer gear and housing into the Eagle transfer case which ends in 7/8x18 male ends, then put the 7/8 female to 7/8 male VSS on it, then purchase a common 7/8 female to 5/8 female speedometer cable to go up to the Eagle speedometer, which has 5/8x18 male threads on the back. A speedometer from a J10 or a CJ7 will work, so I ended up bying a CJ7 speedometer cable for about $20 from Rockauto.

On my Eagle I also added a 40" lower cable from a 1987 Monto Carlo which has 7/8" male threads on one end and 7/8" female threads on the other. That cable goes from the transfer case up to the inside of the vehicle so that the VSS will be better protected from the weather. My VSS is under the driver seat.

[Monkeyjoe]

OK, That is awesome.  I had no idea. 

Thank you for that, I will do that when I get home.

The TBI?  Are there any modifications to the manifold or is there an adaptor to make the TBI fit.

[captspillane]

I should mention that the VSS on the TBI is kinda optional. It has a purpose and is important, but I still drove around without it for several months before getting around to installing it. The TBI is smart enough to keep the mixture close to right even when it doesn't know your speed.

I'm making my own TBI adaptor for the 6 cylinders and another for my Mercruiser Iron Dukes. I'll offer them for sale afterwards. For the Mercruiser motors I'm using the Holley non-crossflow intake manifold original to a 1977 Chevy Monza. I can look into making that one work with the AMC Rochester carb too but I personally hate the crossflow head and won't be using any. It makes the engine very difficult to work on when everything is stuffed in one corner.

Honestly if you gave me even less than the cost of a Howell kit ($1200) I'd drop everything and mail you a ready to go Iron Duke kit this month. Its pretty easy and I have everything sitting there I just took off for this purpose. You'll save alot of money if you wait or do it yourself, however. The hardware itself would probably only be about $600 worth. The rest pays Howell to heat and roof their building. My building needs heat too. I just know better than to expect to make a living selling parts to AMC cheapskates haha.

[IowaEagle]

Yeah we are cheap. 

[Monkeyjoe]

I would say "resourceful"

[IowaEagle]

In the Army we used to call it "Field Expediency".  Steal  from the Air Force as they had better stuff.

[Monkeyjoe]

Funny, we still do that. 

When I was in the Marines, they said Marines never steal.  We acquire.