69 Jeepster Commando V6 225 4bbl carb swap

Hi everyone,
I wanted to share my experience with putting a new Holley 4-barrel carb on my 225 V6.
Parts:
Holley 4160 carb (provides 390 CFM)
Offenhauser 6035DP dual-port 4-barrel intake manifold
Holley 20-124 install kit
ARP 200-2401 carb stud kit
Summit G3000 14 inch chrome air cleaner

The install was pretty straightforward. I bolted the carb to the manifold before installing it on the engine, but I would have put the manifold on the engine first if I were doing it again. I had to shave some metal off the corner of the manifold for my distributor to fit, but it appears someone did this to my old manifold as well. These kits come with an excess of 4-barrel gaskets, so no need to buy an extra one as I did. The carb studs that came with the Holley install kit were pretty weak, and I stripped the threads and nuts during the install and threw them out. I recommend a good solid set of heavy-duty carb studs.

While I had the old manifold off, I found that I was looking straight at the cam and was worried about the coolant and dirt that got in there. I just got a quart of oil and flushed it all out with that. After everything was all sealed back up, I also changed the oil.

Cranking was fun. I could feel the bowls filling because every time it cranked, it was just a little more eager to start. About 45 seconds of cranking here and there got it to idle. My timing was off, so I pulled out a timing gun and tuned it to about 10 degrees advance (does anyone have specs on timing???). It's now running great. The carb is pretty much tuned right out of the box. I'll have to drive it around to see if I have any rough spots, but so far, I've had none.

Here are some photos and a video:

http://www.facebook.com/photo.php?pid=469122&l=9a9bc5deca&id=1035303370
http://www.facebook.com/photo.php?pid=1002336&l=37ef99b3a8&id=1035303370
http://www.facebook.com/photo.php?pid=1002338&l=bd6dee25c6&id=1035303370
http://www.facebook.com/photo.php?pid=1008851&l=c6f2d614bd&id=1035303370
http://www.facebook.com/photo.php?pid=1015068&l=5b5ef7bed6&id=1035303370
http://www.youtube.com/watch?v=JOZsyPRv8ak

 

I wanna make that same change when I finally get my Jeep back in my shop.. Glad you are happy with the result.. Please post your driving impressions!


BUBBA

 

Base timing is 5 deg but you're running the HEI distributor so you might be able to get away with 10.

 

My timing appeared to slip after tightening the distributor down. Is there any magic trick to keep the distributor from slipping?

 

Don't know if it's magic, but loosening off the clamp bolt just enough to move the distributor by lightly tapping on the vacuum advance has worked good for me for well over 25 years.

 

Here are some initial qualitative observations:
1. Engine tune sticks, doesn't drift off like the Rochester 2 Jet
2. Engine starts with less than 2 seconds of cranking (even at cold). Old carb required cranking about 20 seconds when the engine was cold.
3. Engine sounds better at idle
4. No black spitting out the tailpipe.

From driving it around the block a few times, I can tell I'm missing a little power when at mid throttle (mild acceleration up a hill), so I need to tune that out. I'll try to post more results when I feel more comfortable driving around with it.

 

Thanks for the update! How is the power overall? Seem to be better than the OEM setup?

BUBBA