High output transfer case highway speeds?

[Cutter]

Hi all,
I am the new owner of a 1974 series3 109 with a euro spec 6 cyl. The truck was for sale on this forum(deadhead derek's listing). Anyways I am curious the speed I should expect out of it since it has the high output transfer box that RN sells. As is I can get up to 50mph on the highway, but I expect it can go faster. The tires aren't aggressive, so the resistance isn't too bad there.

I know there's still some mixture issues as the truck runs better with the choke out, but I think I need to replace the needle/tube as it's as rich as I can get now. Just curious what I can hope for, the engine seems healthy and if it wasn't for the transfer box I'd be almost satisfied.

[rwollschlager]

Congrats on the purchase!
^^^^ Providence RI? If you're ever in southeastern CT (mystic, stonington) drop a line!
If you need any help with repairs there is Rover Special Vehicles on Jamestown Island (Just outside of newport ...he has my stage 1 109 now...) Or kane's motor sports also in RI. (deal with all sorts of old british vehicles)

As for the high ratio t-case you should be able to reach 60 no problem i think.

Good luck and welcome!

-Rob

[KevinNY]

Is that flat out, foot on the floor? If so you have some tuning to do.

[SafeAirOne]

Is that flat out, foot on the floor? If so you have some tuning to do.

I agree; With my 1973 UK-spec, former euro 2.6, 109, I can get up to 60 with my stock transfer case and transplanted 65-horsepower 2.5 diesel. This is without headwind, of course.

You should be able to do better than that with your 6-cylinder AND hi-ratio transfer case.

[Cutter]

Yep, that's pedal to floor. I've gone faster on downhills.

[KevinNY]

Sounds like you are running too lean, that motor needs more gas. You should be topping out 3rd at 50MPH with a Hi Ratio transfer case.

[Cutter]

Thats what I was thinking too, running lean still. I've got some calls to make. The truck has apparently always lived at altitude in either the Rockies or Alps, so I wouldn't be surprised if the jet was swapped out to accommodate and now it just isn't happy at sea level. Just curious if anyone knows of any carburetor swaps to replace the zenith-stromberg on there? My friend who had a 2.5 SIII swears it will be worth it, but from my research there aren't many options better than what's on there.

Someday I want a turbo diesel in there, but I'm going to have to let the penny jar fill up again for a while.

[greenmeanie]

For the 2.6 the ZS carb is fine. They are really simple to work on too. You just need to find out what needle is called out in the parts book and order that. Throw in a diaphragm and replace the o-ring in the base as well while you're at it. I use Joe Curto in NY when I need parts for the pair on my 101.

[I Leak Oil]

Along with tuning you may want to make sure the accelerator is operating through the full range of motion.
Jason T.

[Eric W S]

In theory, your HO transfer case, if healthy, wouldn't affect you rspeed in anyway. It's the engine that you need to address if you want more speed. If it can't push the gears then...