47-55.1 Eliminate draft tube options

[TX3100Guy]

Originally Posted by geezer#99

Hei is big and tall.
You gonna have room for it?

I guess I'll find out for sure tomorrow.

Here is a pic of the engine with the ill-fated magneto before it shorted out.

[dsraven]

Hei requires a 10ga power wire so run a relay driven by the regular ign coil power wire. Use a good relay and know that during normal run, not normal starting, the coil gets less than 12v due to the ballast resistor.

[TX3100Guy]

Originally Posted by dsraven

Hei requires a 10ga power wire so run a relay driven by the regular ign coil power wire. Use a good relay and know that during normal run, not normal starting, the coil gets less than 12v due to the ballast resistor.

No problem on using 10 gauge wire with a 20amp fuse inline. My plan was to connect it directly to the ignition wire off of the ignition switch (which is also 10 gauge wire). I wasn't planning on running a relay since none are showing on both the American Autowire wiring harness for a GM HEI, nor or the wiring diagram with the distributor. The same goes for the ballast resistor, none is showing for an HEI type distributor, just for a traditional distributor with an external coil.

[TX3100Guy]

No need to fret any further on how to wire and attach a GM HEI distributor. It won't fit.

It seems that the bottom of the distributor, given its width, hits the pushrod cover and won't seat fully to the cam gear and oil pump drive. I need it to seat another 1/2" further, but that is no bueno.

[geezer#99]

I see Tom has a small cap dizzy.


https://www.12bolt.com/store/p584/Di...6-235-261.html

[leegreen]

some prior art here
https://67-72chevytrucks.com/vboard/...d.php?t=586186
and
https://www.chevytalk.org/fusionbb/s...php?tid/75735/

One guy on last link describes how to DIY a 250 HEI + a SBC HEI shaft to work

Help figure this out for me, the 261 in my driveway wants a HEI

[TX3100Guy]

Originally Posted by leegreen

Help figure this out for me, the 261 in my driveway wants a HEI

So far, no joy on finding an HEI unit that 1) will fit and 2) has the correct oil pump shaft. I may forced to 1) wait for my magneto to be corrected or 2) go the traditional distributor/coil setup.

[dsraven]

pretty sure I seen an hei from an inline 6 used in a 235. just can't remember where I seen that. would likely need a recurve and max advance check. getting the magneto back in would be the coolest and more period correct of course. finding a good used old dizzy would get you running till the mag gets back though. by the time you find one, get t checked and set up with new parts, wire it, and get it all working properly your nag may be back.

[TX3100Guy]

Originally Posted by dsraven

pretty sure I seen an hei from an inline 6 used in a 235. just can't remember where I seen that. would likely need a recurve and max advance check. getting the magneto back in would be the coolest and more period correct of course. finding a good used old dizzy would get you running till the mag gets back though. by the time you find one, get t checked and set up with new parts, wire it, and get it all working properly your nag may be back.

Funny, I've been thinking the same thing. Now I have to drive back to Arlington, TX (about an hour away) and return the ill fated HEI and plug wires. I found another HEI online, but asked the vendor to get me some dimensions before I click on "BUY". Other than this particular one, every HEI that I see online has way to big of a distributor to fit, or it has the same collar as the repaired magneto had that prevented it from fully seating into the oil pump drive.

I thought about just biting the bullet and putting a traditional distributor and coil in, but with all the rewiring and finding a home for the coil, I gave up. I'm going to beg the folks a Joe Hunt to move my mag to the front of the line, since I already had to wait nearly a month for the initial repair.

[leegreen]

Here is a article I failed to re-find yesterday: 250 HEI, cut off the flange and use the flange from a 235. 'looks' easy.
https://www.jalopyjournal.com/forum/...ersion.189074/

also some good points about vacuum advance. Which raises some questions for your application

[TX3100Guy]

Originally Posted by leegreen

Here is a article I failed to re-find yesterday: 250 HEI, cut off the flange and use the flange from a 235. 'looks' easy.
https://www.jalopyjournal.com/forum/...ersion.189074/

also some good points about vacuum advance. Which raises some questions for your application

Wow, that's a bit like heart surgery on a distributor...... Great article and great DIY.

[TX3100Guy]

Originally Posted by leegreen

also some good points about vacuum advance. Which raises some questions for your application

The mag doesn't have a vacuum advance and the tag that Joe Hunt put on it suggests that it needs to be set at 24 degrees before TDC

[dsraven]

LG, thats like the write up I seen but not the exact one. there is another one out there somewhere nut that one is pretty self explanatory if somebody were so inclined.

[1project2many]

I don't believe I would have a problem using an original distributor and an aftermarket electronic ignition. HEI is a readily available form of electronic ignition but it is not the only one. Pertronix may sell a sensor that can be installed in the distributor to replace the points if you'd like to trade points for a completely electronic system.

One consideration for this setup is based on the challenges you've already faced. Magneto service takes time and specialized knowledge. Spending time to design your wiring harness and ignition system for a relatively easy magneto to distributor swap allows you to keep a backup ignition system on the shelf.

For street use, either ignition system will be completely acceptable.