Holley 4180

[cldonley]

Mornin'! Scored a complete 1993 5.0 out of an F150 including all the EFI pieces, block fresh from the machine shop all standard with new cam bearings and a new 347 stroker crank. Need some advice on how to proceed:

Don't plan on using the stroker, will go with my OEM 69 302 crankshaft after it's inspected.

After researching the EFI install, think I'll stay carbed. Now for the questions:

I have a Holley 4180 off of an 85 Mustang. I've done a little research and I'm wondering if it's worth the trouble, and whether I'll need an upgrade over the stock 2bbl anyway. My 2bbl has the 1.21 venturi so it provides 351 cfm, which will support up to about 4500 rpm with 85% volumetric efficiency or so with my rough, uneducated calculations, so prolly need a little more carb. The 4180 is a 600cfm carb, but would require some mods and is difficult to tune according to the mustang forum.

Second question: What cam? I've done a lot of reading on the subject, and most are of the opinion that the best low rpm torque comes from the stock cam. What do y'all think? I've looked at Comp, Edelbrock and Isky for some advice, but haven't made any calls yet.

I haven't seen the heads yet, the guy I bought it from forgot to bring crank and heads with him when he dropped it off. I'm assuming truck heads as opposed to the GT40s. (He works for me, so I'm sure I'll be seeing them soon!)

Interested in your opinions. Looking for good low end torque and reliability. Don't want to be stuck in the back 40 of Big Bend walking back to the ranger station!

 

[jckkys]

The 4180 is an excellent carburetor. The tuning process is identical to the 4150/4160 series Holleys, so are the parts. Easy modifications allow 4 corner idle mixture adjustment. The only place where tuning is a little harder is the main air bleeds, just like the 2300, 4150, and 4160s. The fact that 4180s are a later model that was OE in Mustang GTs, 351 HO, and 460 trucks means it had to meet emissions standards. The 4 corner idle mixture adjustment was part of this. So were the unique diaphragm choke pull off, anti percolation accelerator pump, huge float bowl vents, 2 stage power valve and annular discharge booster venturis. All these except the bowl vents are desirable in any carb. The odd bowl vents can be replaced by swapping the float bowls with any 4bbl float bowls you like.
The idle air bleeds are a little too big leaning the transfer mixture for less emissions. So there is often an off idle flat spot. This can be corrected with idle air bleeds that are about 0.002" smaller.

 

[cldonley]

Can you just cap or plug the bowl vents? Sounds like this carb is a pretty good option.

 

[jckkys]

Sure I think the vent tubes are 3/8" so simple plugs will work. To expand on my first post I want you to see the air bleed tuning procedure I was referring to here;http://vb.foureyedpride.com/showthread.php?77631-Help-With-Troubled-4180-Carb. Another point, is that the '79 4180s have idle mixture adjustment screws that are interchangeable with Ford Autolite 4100s and many 2100s. It wouldn't be hard to set up any 4180 with these same screws on all 4 corners.

 

[jckkys]

Just found an even better description of the air bleed tuning proceedure;http://www.ifsja.org/forums/vb/showthread.php?t=162618. I didn't know 4180s could be found in Jeeps or IH trucks but it's a good write up.

 

[cldonley]

Thanks for the links!