Dialing in HEI

Hope every one has had good times getting together with family & friends over the holidays. The time off allowed me to squeeze in some jeep time between family stuff.
I have some questions about fine tuning an HEI distributor. I modified a '78 Regal EF distributor and installed it in the '70 and I got the motor to fire up. I have gapped the plugs @ .046 and timed it around 10* BTDC. It seems to hesitate b4 revving up but runs smoothly at a steady rpm.
I printed up Rich Mott's article on making the HEI run right on a 225 OF. He describes an installation adjustable vacuum and possibly replacing the mechanical advance weights.
I know this mod has been done several times and I was wondering what people making this modification have done / used in getting the system to work perfectly in the 225. Thanks for the advice in advance.

 

5*BTDC is what the factory recommends.

 

How do you modify an EF distributor to run in an OF? As far as the hesitation is concerned I only know of changing the weights but as far as I knew that was moreless for high performance applications to change the advance.

 

The article on how to do it is here.
http://www.cjoffroad.com/writeup.asp?WU_ID=21&noAdd=1

 

I just bought this a few days ago, but haven't installed it yet. I have been running it with the vacuum advance disconnected so far.


http://cgi.ebay.com/ebaymotors/ws/e...&item=7942774956&rd=1&sspagename=STRK:MEWN:IT

 

I re-timed my motor @ 5* BTDC which required me to increase the idle slightly. The motor has lost that hesitation I had noticed earlier. Took the CJ for a spin and is it more responsive! Seems to pull out of low rpm's ( like starting out in 2nd) even better than b4.
I am happy leaving everything as it is now but after reading R. Mott's article, I'm concerned about damaging my motor if I don't change out the HEI vacuum advance to an adjustable type. He claims the HEI vacuum advance is to sensitive to use the ported vacuum on the 2bbl carb. Has anyone who has done this conversion switched to the adjustable advance? I have included a link to his article in case someone wants to check it out.


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

 

Are you getting detonation? I your not, I wouldn't worry to much about it. Good to hear you got it running good.

 

If you are worried about your timing curve, then the best thing to do is to find a local machine/speed shop and have them recurve your dist. If you have an aftermarket cam,intake,carb...ect. be sure to send that info as well. If you have an adjustable timing light you can do this yourself. Weight and spring kits are available through the above mentioned shops.

 

I did the HEI conversion on a 65 225 per the article on cjoffroad using a 75 odd fire distributor. Forget the exact initial timing, but I remember scribing the damper out to 40*, using the advance weights that came with the junk yard distributor, same for the vaccuum advance. I did limit the total timing as suggested ( I think it was 35*total, initial + mechanical + vaccum )by fabricating a stop for the vaccum advance rod inside the distributor, and am planning on slowing the vaccum rate down by installing a piece of copper tube or brake line in the vaccum advance hose and pinching it shut a bit (low buck project). Years ago I used one of the adjustable vaccum advance on a GM and it came with a small piece of metal to be used as an eccentric on one of the vaccum canister mount screws to limit advance and you could insert a allen wrench into the vaccum port to adjust rate of advance. It worked nice, but my low buck method seems to do about the same. Seems to run good with better power and much easier starting in subzero temps. I agree with other post, if no preignition noise no worry.