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4bbl on a 4.0

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Apr/21/2023 at 5:53am
Not all factory intakes were the same for the 4.0l. Too bad the pictures don't come with this but this post identifies a factory intake swap with larger runners and flow:
This is a fuel injected intake, but there are people taking the AMC V8 FI intakes and bolting on carburetors for better flow. Don't see why this would be a different situation.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jcisworthy Quote  Post ReplyReply Direct Link To This Post Posted: Apr/21/2023 at 12:40pm
Thanks for the replies. I would have to look at the factory intake better before making a decision to mid it to a 4bbl. 

It is the big plenum intake and not my engine
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 72gremx401 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/21/2023 at 6:47pm
I would like to see a 4 liter with a 232 crank build . 258 stroke, pistons dont last long with high RPM .
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Apr/21/2023 at 7:31pm
Originally posted by 72gremx401 72gremx401 wrote:

I would like to see a 4 liter with a 232 crank build . 258 stroke, pistons dont last long with high RPM .
  the stock 4.0 has a shorter stroke than the 232.  The 4.0 has a bigger bore than the older 6s
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jmerican Quote  Post ReplyReply Direct Link To This Post Posted: Apr/22/2023 at 1:05am
I dig the idea. I do agree with Heavy, and I also think that you know what to do, John. I have one sitting around if you want me to measure or mock up the deal. Maybe I will anyway. 
I don’t know what that last post means with the small runner thing. They are nice ports, as you already know. 

Here is a caveat. The manifold is truly made for the late late head. It will bolt up to earlier 630 heads and such, but the late curved big plenum manifold has raised ports; raised by like .100?
It’s workable and fixable, but just know. The Edelbrock is not raised like the last of the  head castings. Pretty sure, not positive. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jmerican Quote  Post ReplyReply Direct Link To This Post Posted: Apr/22/2023 at 1:10am
 My 99 XJ has the 630 head - and the late manifold that you’re referring to. The port was a bit off. I have a late late head, as a mock-up, and  it’s raised. The 99 was a bit of crossover. Luckily it did t have that casting that cracked. I have One that’s cracked, it’s the raised port. I’m not sure how out there that lil tidbit is known. 
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Post Options Post Options   Thanks (1) Thanks(1)   Quote wittsend Quote  Post ReplyReply Direct Link To This Post Posted: Apr/22/2023 at 11:07am

FWIW I too had thought about the idea of welding a 4 bbl. plate to a milled top 4.0 manifold. And by "big plenum" I assume you mean the Horseshoe intake. I was just going by the externals when I pondered it, not knowing the I.D. of the passages. My concern was the plenum was too big, not that the passages were too small.

Sometimes folks (of lesser means) have the manifold just sitting around, are in a trade school..., have an uncle with a machine/weld shop or some similar situation. They are inquisitive and for nothing more that their "hobby" time want to give something like the manifold adaptation a "go." To them it makes more sense than earning the money to buy a product.  45+ years ago I welded up a 90 degree adapter out of sheet steel to fit a Datsun down draft manifold with a side draft SU carburetor. It actually worked pretty well. So, you never know. For YOUR application, budget and needs your idea might be sufficient.




Edited by wittsend - Apr/22/2023 at 11:10am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Javelin_GT Quote  Post ReplyReply Direct Link To This Post Posted: Apr/22/2023 at 12:01pm
Check with these guys.....I seem to think they have done this in the past but dont see it on their website.



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Post Options Post Options   Thanks (0) Thanks(0)   Quote 72gremx401 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/22/2023 at 4:50pm
yes the 232 had a 3.50 stroke compared to the 3.44 of the 4 liter ,  not many have done it . so i have seen few results . Might be a good mix of torque and power ?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jcisworthy Quote  Post ReplyReply Direct Link To This Post Posted: Apr/23/2023 at 4:02am
Specializing in dyno services, engine building, and cylinder head porting

rbjracing.com
Phone Number 518-915-3203
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