Good carbs for a 258 with the 4.0L head?
- Thread starter Dawg180
- Start date
- City
- Port Allen
- State
- LA
True that.
- City
- Lynchburg
- State
- VA
True true that!
Since you asked for comments on Webers...
I have never used one on a car, but have had them on motorcycles. Both down and side draft varieties. They ran great when I had them tuned right. But they liked to have a lot of attention paid to them or they didn't stay tuned right.
I have never used one on a car, but have had them on motorcycles. Both down and side draft varieties. They ran great when I had them tuned right. But they liked to have a lot of attention paid to them or they didn't stay tuned right.
- City
- Yorktown
- State
- Va
They guy on eBay now has brand New Motocraft 2100's with the 1.08 venturies. That is a pretty dead simple upgrade for any Jeep 6cyl.
I have used the Weber and they are OK. But they are particularly sensitive to fuel pressure above 3-5 psi and it will lift the float and flood the engine. The motorcraft does not ahve this issues. If you have a good pressure regulator the Weber does fine, but the ford one is more simple.
They Howell TBi is however a nice upgrade and pretty simple to boot.
Carl
I have used the Weber and they are OK. But they are particularly sensitive to fuel pressure above 3-5 psi and it will lift the float and flood the engine. The motorcraft does not ahve this issues. If you have a good pressure regulator the Weber does fine, but the ford one is more simple.
They Howell TBi is however a nice upgrade and pretty simple to boot.
Carl
According to the Ford Carburetor Guide from Pony Carburetors, flow figures for the Autolite 2100 carbs are as follows:
.98 venturi = 190cfm
1.01 = 245
1.02 = 240
1.08 = 287
1.14 = 300
1.21 = 351
1.23 = 356
1.33 = 424
So even up to a 1.21 would work ok, particularly if you had less restricted exhaust.
.98 venturi = 190cfm
1.01 = 245
1.02 = 240
1.08 = 287
1.14 = 300
1.21 = 351
1.23 = 356
1.33 = 424
So even up to a 1.21 would work ok, particularly if you had less restricted exhaust.
- City
- God's Country
- State
- AR
It will most likely be a 1.08. The 1.21's were usually on the 302's and 351's. Every 6 cyl or 289 I've seen has been the 1.08. The MC2100 I have on my green CJ came off of a Mustang with a 289 in it.
My experience with Webers as well. I had a 32/36 on my tan Jeep for about 10 years. It roared when it was tuned right, but it required frequent tweaking. I finally got tired of having to mess with it so often and swapped it for another MC2100.
The Ebay guy is pricey on his carbs, and I used a V8 throttle cable from a 1980 CJ-7 with V8 instead of fabbing up a linkage. That said, Gronk's adapter plates are awesome when compared to the Transdapt/ Mr Gasket adapters. His adapter plate covers up the back of the carb baseplate that is left open with the transdapt and Mr Gasket adapters. On an early MC2100 it doesn't usually matter, but on the later carbs that have the base of the carb more opened up the Gronk plate makes it much easier to get the carb on with no vacuum leaks on the base of the carb.
- City
- Jefferson
- State
- GA
If you have a MC2100 / 1.21 are the venturis something that can be changed/swapped ? Haven rebuilt a carb in over 35 years but about to tackle a MC2100 with 1.21 for my rebuilt, 258 with a 0.030 overbore and a mild cam and Headman Headers.
???
My last Scrambler had a 258 with the 4.0 Head, Comp Cam, JBA Header, Clifford Intake and Holley 390cfm 4B. Truck ran Very well, but it did take some tuning to get it right.
My next one will have the FiTech Fuel Injection System. They have a smaller, 150-400 HP EFI version coming out soon, April 15th, that can be mounted to a Square 4B intake on a modified 258.
My next one will have the FiTech Fuel Injection System. They have a smaller, 150-400 HP EFI version coming out soon, April 15th, that can be mounted to a Square 4B intake on a modified 258.
- City
- West Friendship
- State
- MD