4.0 head swap, any benefit to carb'd 4.0 TBI intake?

[hancockn]

Greetings. I just bought an 85CJ7 and after reading around am planning to convert to HEI and a Motorcraft 2100.

I've also been reading on the 4.0 head swap and have most of the information saved and filed. I had a few questions that i was hoping to get some more information on.

Would there be any performance benefit to using a carb'd 4.0 TBI intake(log or horseshoe) instead of the AMC 258 i6 / 4.2l intake, other than easier alignment during install? Some people have said it would have better flow, but others questioned how effectively it would flow air/fuel from the carb since it was designed for injectors.

The ebay guy that sells MC 2100's offers an adapter to put a carb on the TBI intakes and block off the injector holes. I figured if there was a performance boost over the AMC 258 i6 / 4.2l intake it would be worth the cost of the kit for the better flow and easier install.

Would this possibly be a bad idea since the TBI intakes do not have the waterlines piped in?

Would the TBI intake require more mods to the PS bracket or about the same as AMC 258 i6 / 4.2l intake?

Are there any issues with factory ac and the 4.0 head? Havnt seen it mentioned so i assumed not, but wanted to ask.

Thanks in advance!

 

[Torxhead]

For starters, I would suggest keeping the oem aluminum intake manifold because of its cooling ability. From my experience blocking the cooling off it resulted in a rich fuel mixture and excessive underhood heating, The oem clean air intake system works best with a carb so I would suggest keeping that if you still have it. For you other questions there are a number of experienced guys that can help you out on this forum.

 

[Lumpy Grits]

:ww:

Do you have any SMOG tests to be concerned about.
Stay with the OEM intake for just what t'head said.
Why the 2100? I have been very pleased with my OEM Carter BBD, and still pass SMOG.
LG

 

[Joebronco]

Junkyard Head and EFI swap.

Passed CA smog
Huge power increase
Way more reliable

Just do it. You won't regret it. I don't. Best $2k I've ever invested in a truck.


Sent from my iPhone using Tapatalk

 

[hancockn]

Thanks for the replies!

Luckily I don't have smog tests to worry about. From all the reading i've been doing, the motorcraft seems to have a lot of happy users and should be a worthwhile investment vs. the carter. It sounds like they arent as cold natured. My Carter ran good after it warmed up completely, but it was definitely temperamental until then. I plan to get a "no smog" 2100/2150 from the ebay guy that sells a lot of them to jeep folks.(Gronk?)

I do still have the factory intake and it's in pretty good shape. Just needs a good cleanup and i'll probably paint it. Most people that stayed carb'd after the swap kept the AMC 258 i6 / 4.2l intake, but i figured it was worth checking into.

I know EFI would be the overall smarter and better running option. I am trying to keep it as simple and clear of wires under the hood as possible. Also, most of the people i know that can assist me with mechanical issues are old school carb guys, so that's my other reason for wanting to stay with one. I don't want to discourage free help. lol