Convince me to use an HEI...

I just ordered PN 8860 and 8861 from the attached diagram. I was told by an MSD tech support guy I had to do this (I contacted them because it was not working with mine when hooked up like Sparky's; it idled fine, but lost spark completely above ~800 rpm). Sparky may have a different module than I do (5 pin or 6 pin), but I've seen 1st hand that his works well.

I am sure you know this, but the MSD increases the spark duration for more complete combustion.

Edit: forgot to attach

 

Sparky,

What I'm saying is the MSD is what makes the big difference. Did you try the MSD with points? I don't think there would be a noticable difference between points with MSD vs. HEI with MSD.

 

i came across this website when exploring the possibility of HEI on my buick 215. lots of info in here....

http://www.rowand.net/Shop/Tech/BuickHeiConversions.htm

 

Just to throw another curve in here. I replaced my Prestolite with a Mallory dual point about 9 1/2 years ago, the points have never been changed or reset, the difference was night and day between the old and the new. If your distributor is going out Brian, by all means replace it, the HEI is probably easier to get than anything and will work better than a replacement pointed distributor, I'm sure. I have a Delco with a pertronixs in it but I also have an MSD to install with my points, I'll use the Mallory until it gives me problems.

 

I can say from past experience with HEI that it is a no brainer to go to it. Granted mine was on a small block Chevy, but I would think that the difference would be equivalent. Cold starting was better and it just ran smoother with the HEI. I don't have a ton of experience with the 225, but from my small block knowledge the HEI was a no brainer. The only drawback I saw with the HEI was high RPM, which in a Jeep the 225 won't see a ton of that (5,000 and higher.)

 

I have HEI on my swapped in 231. Had to search for a 4 pin module dist to replace the computer controlled 7 pin that came with the motor. About a year later I added the MSD, mine replaced the hei module also. Made it run a little better, not sure I would have been happy but got the MSD cheap off ebay.

I keep the module as a trail spare.

That said, I have been driving HEI equipped vehicles for 21 years and never a failure.

I will never buy Jacobs (are they still around?) bought 2 porducts and both crapped out on me within 2 years.

Nice thing about MSD is you can add the rev limiter. I did this AFTER some main/rod bearings gave up from excessive rpm on the trail (first motor=RIP).

Anyone ever use a timing computer? I am curious about a msd timing computer, eliminate the stock vacuum advance and timing weights. I have had problems with HEI timing weights sticking/bushings cracking and coming apart.

 

I'm not trying to beat a dead horse, so please bear with me. I believe a MSD can make points "that" good. When running a MSD box, it controls the dwell, current, etc. to the coil. The points or the magnetic pickup in a HEI are only a switch to tell the MSD the proper time to fire the coil. Granted, a HEI coil is much higher output than an OEM points coil, so for the two to be equal the points coil would have to be upgraded to a higher output aftermarket unit.

I'll shut up now.


Matt

 

I'll bring this thread back to life. I finally got my MSD hooked up tonight (after receiving the correct wires to replace the 4-pin HEI ignition module two weeks ago), and afterwards I immediately noticed an improvement in both acceleration and crisper throttle response. Keep in mind that I already had a DUI distributor, with their $$$ "Dyna-mod" $$$ module.

For the price I paid for the MSD ($100, shipping included), I think it is well worth it if your engine is as tired as mine.