HEI conversion "pre work" / need pg3 measurement

[racerecks]

I'm planning on doing the HEI conversion to my 1989 2 stroke TXT this weekend, but since the cart is at the cabin, I want to do some pre-work to make it go easier once I get there.

Like some others have discussed, I want to make an aluminum plate to mount the HEI coil in the place of the stock coil, but don't know the spacing of the mounting bosses on the fan housing. Can someone take a quick measurement and let me know?

Also, I'd like to buy a one piece spark plug wire since I've never liked the "make your own" kits. Does anyone know either 1) the approximate length of the stock wire on a PG3, or 2)a suitable automotive replacement (with the proper boots and length) that I could pick up at a local supplier?

Lastly, any other things to think about before heading up? I should be good with all the standard hardware and wiring needs. My biggest concern is for specialty stuff that would need to be fabricated or require a special trip to car parts place.

Thanks

Tim

[BrewCityMusic]

the spacing for the mounting holes on my GM HEI module is 2 1/16" on center, although I have an Accel HEI (they *should* be the same across the board, though) ... Also, bring either a pair of sidecutters or a drill with you, as there are 2 plastic alignment pegs on the rear of the HEI that will either need to be nipped off or better yet, holes drilled in the mounting block for, in order for the rear of the HEI to fit snugly against the aluminum for best heat transfer.

As to plug wires, I went with a high-output coil, so I use a standard 20" GM wire (fits perfect) - if you're using the stock coil, you can just get any wire with a right-angle plug boot and cut the other end to length, then push/thread it onto the coil, otherwise I'd just go with the custom, if you take your time and crimp everything good, they usually are just fine.

[BrewCityMusic]

OH - almost forgot, make sure you bring extra hookup wire (16ga) as well as a good handful of female spade connectors to make the connections to the HEI - keep in mind that the 2 spade terminals on the HEI where the pulser wires go are 2 different sizes (one standard, one narrow) and you want to put large female connectors on BOTH the pulser wires (at least temporarily) as some HEI modules run better with the pulser wires reversed (which is hard to experiment with if you go ahead and install a narrow connector on the red wire as the diagram shows)

Lastly, make SURE the HEI module is grounded well - they like a really, REALLY good ground on the right mounting hole (again, as per the diagram)

Good luck with the conversion - keep us posted on your progress!

[racerecks]

Thanks for the info... the other measurement I need is the spacing of the mounting bosses on the pg3 fan housing (where the stock coil bracket bolts up). I will be making a plate at home to bolt to the bosses and then hold the new coil.

Also, I've seen the comments about grounding the module well. Do any of the terminals on the module carry the ground too, so I could just ground through a wire, or does it need to be through the back of the module?

[BrewCityMusic]

My module has a built-in tab that connects the mounting hole bushing to the back of the module, therefore carrying the ground everywhere it needs to be - in fact, if I recall, when I looked at a standard NAPA module (when first contemplting the conversion) it was the same way, so you should be fine grounding there (at the through-bolt) ...

If bychance, you DO have to ground the rear of the module, be careful that you don't interfere with the contact between the rear metal plate and the heatsink (aluminum plate) which would counteract any heat-dissipation you were trying to accomplish with the plate!

Just a thought, but with a little creative wire extension, you could mount the module right to the curved frame rail by the battery (I've seen that done in other threads on other forums) - as long as you scrape the paint away behind the module you'd be killing 2 birds with one stone, namely a solid, failproof ground AND relatively efficient heatsinking.

As to the coil, you're on your own - my 88 has the coil on the "firewall' and I had to fab a bracket for my new high-output coil anyhow, sorry about that!

[tguellich]

BrewCityMusic has given you great advice. I have a few things to add. He talked about maybe mounting the HEI to the curved frame rail just across from the original coil. That is exactly what I did. Check out this pic http://www.buggiesgonewild.com/membe...onversion.html Note how I removed paint down to bare metal behind the HEI and I also used a good Di-electric grease for great/continued contact with the bare metal. The only problem you may have is clearance if you are using a stock air cleaner housing, as you can see, I routed the air cleaner out the back and into the bag well.

I wired everything so none of the original parts were actually removed. So, if by chance the HEI cut out on me, I could reconnect the original wires and be up and running until I could firgure out the HEI problem. That is why you see a small bundle of wires right near the original coil.

[BrewCityMusic]

Thanks TG - it was your conversion I was actually referring to (and used as an example for my own mount)

http://i645.photobucket.com/albums/u...0Stuff/HEI.jpg

The module I bought came with the grease (which I used) - as you can see, I also threw a ground lead on the mounting grommet *just* to be safe !!!

We were thinking alike on the original Ignitor, too - I left about 3" leads on it and installed male spade connectors for exactly the same reason

[racerecks]

Okay, the $64 question... have you found a place to buy individual spark plug wires? I've exhausted just about every retailer in my area.... I'm thinking a junkyard is about the only kind of place that will sell them this way.

[BrewCityMusic]

I just took a peek on Ebay, you can pick up a set of GM 6 or 8cyl wires for around $10 shipped, that sounds like a pretty good option as you can use the one that's the best fit, then you have a *close* spare on either side of it, size-wise (some I saw even have 90deg boots on the plug end, which is perfect) - of course, the junkyard isn't a bad idea if you have one close ... Did you try getting a rough measurement of what you need and hitting a tractor/farm supply (think lawnmower) or if you're by the water, a boat shop/dealer?

If all else fails, you should have a NAPA around (most cities, at least here in the Midwest do) and they'll make you a wire if you're uncomfortable doing it - prob cost less to just go the Ebay route though

[tguellich]

Originally Posted by racerecks

Okay, the $64 question... have you found a place to buy individual spark plug wires? I've exhausted just about every retailer in my area.... I'm thinking a junkyard is about the only kind of place that will sell them this way.

Do you know any friends who are racers? My dad changes wires like he changes socks so he always has scraps of wire laying around. He threw a 20" piece together for me in less than 5 minutes and the price was right, free.

Originally Posted by BrewCityMusic

Thanks TG - it was your conversion I was actually referring to (and used as an example for my own mount)

http://i645.photobucket.com/albums/u...0Stuff/HEI.jpg

The module I bought came with the grease (which I used) - as you can see, I also threw a ground lead on the mounting grommet *just* to be safe !!!

We were thinking alike on the original Ignitor, too - I left about 3" leads on it and installed male spade connectors for exactly the same reason

Thanks, everyone has always been so helpful here, I am glad I can help a little too.