HEI Conversion

I have gotten an odd fire HEI and have ground the head are a little and gotten the HEI in.

My question has to do with the movement to set the timing. There is only about 5-10 degrees movement at most until the cap hits the head. Does the head need to be ground more so the cap can move more or is that all it takes?

Thanks

 

Depends... You'll need to fire it up to see. If you need more rotation, you can either grind more on the intake, or your can grind down the cap a little. If my memory is correct, the HEI cap has 4 hold-downs. I have heard of people grinding one of the hold-down "tubes" off, in order to allow the dist. to rotate more. The other three hold-downs will suffice.

 

I just finished that conversion last w/e and I had to file off one of the four hold down tabs to get enough rotation to properly time. I agree, 3 otta 4 is ok - my cap is firmly in place. Timed mine @ 5*.

 

I took one off and it times out fine. The engine now backfires at higher speeds.

Any ideas?

Mike

 

It's possible that you have the distributor 180* out of time. Most vehicles won't run at all like this, but the "funny" nature of the oddfire will allow it to run semi-correctly like this.

Bring it back up to TDC. Pull the distributor and rotate the rotor to where it points exactly opposite of the #1 plug wire, and reinstall it. If this makes the problem worse, reverse the proceedure and go back to the way you had it. In that case, it's probably either a vacum advance issue or it's still not timed exactly right. Try 8-10*.

 

Not only could it be 180* out, it could also be "out of sequence". If you marked the position of the rotor (hopefully positioned @ #1) b4 you pulled the old distributor out and then installed the HEI 's rotor as close as possible to that mark you would pretty much eliminate being 180* off. Print out this article by Rich Motts at the site below. It explains alot about getting the HEI running right in the 225 as well as fine tuning the system after installing it.
The motor will run but it will be weak and may or may not back fire when out of sync. The article says to move the wires one post either way to get back in sequence. This is something that I didn't have to do with mine but it may be the case in your situation.
Good Luck - the trouble is worth it.


www.jeepster.org/swchapter/hei-2.html