The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 12-22-2023, 09:57 PM   #1
xs-cash
Registered User
 
Join Date: Aug 2017
Location: Edmonton Alberta Canada
Posts: 100
MSD-6AL with HEI ?

Are we able to add a MSD6AL on a HEI? If so is it worth it ?
xs-cash is offline   Reply With Quote
Old 12-23-2023, 07:36 AM   #2
Wikid61
Post Whore
 
Wikid61's Avatar
 
Join Date: Aug 2013
Location: anamosa iowa
Posts: 48,093
Re: MSD-6AL with HEI ?

https://www.youtube.com/watch?v=SMZWvIi6Ke0
__________________
Westcoast got's da most of them.
Wikid61 is online now   Reply With Quote
Old 12-23-2023, 07:37 AM   #3
Wikid61
Post Whore
 
Wikid61's Avatar
 
Join Date: Aug 2013
Location: anamosa iowa
Posts: 48,093
Re: MSD-6AL with HEI ?

https://www.youtube.com/watch?v=ApBu9BEMBfQ
__________________
Westcoast got's da most of them.
Wikid61 is online now   Reply With Quote
Old 12-23-2023, 07:05 PM   #4
MikeB
Senior Member
 
MikeB's Avatar
 
Join Date: Jul 2000
Location: North Texas
Posts: 3,430
Re: MSD-6AL with HEI ?

Yes, you can add it to an HEI. Hard to say if it's worth it. Depends on what you're looking for. Its advantages are better spark at higher RPMs, and multiple sparks up to 3000 RPM for more complete combustion.

It does mean another point of potential failure, but I've seen them last for a decade or more. Good grounds and spiral wound plug wires are pretty much required.

From 6a and 6AL instructions:

MULTIPLE SPARKS
The MSD produces full power multiple sparks for each firing of a plug. The number of multiple sparks
that occur decreases as rpm increases, however the spark series always lasts for 20° of crankshaft
rotation. Above 3,000 rpm there is simply not enough “time” to fire the spark plug more than once,
so there is only one powerful spark
__________________
Mike
1969 C10 LWB -- owned for 34 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes.
1982 C10 SWB -- sold
1981 C10 Silverado LWB -- sold, but wish I still had it!
1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming.
Retired as a factory automation products salesman.
Worked part-time over the years for an engine builder and a classic car repair shop.
Member here for 23 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!
MikeB is offline   Reply With Quote
Old 12-24-2023, 03:28 PM   #5
PbFut
Registered User
 
Join Date: Feb 2022
Location: Ca
Posts: 408
Re: MSD-6AL with HEI ?

Just curious.. once the flame has lit, whats to burn for the subsequent sparks? If it does find a combustible mix, isn't that akin to detonation where the flame is not controlled as the piston drops and you get a ping. It must work or they would not sell. It just goes against how I thought combustion took place in a cylinder. Hurts my pee brain to think about this stuff.
PbFut is offline   Reply With Quote
Old 12-24-2023, 06:33 PM   #6
MikeB
Senior Member
 
MikeB's Avatar
 
Join Date: Jul 2000
Location: North Texas
Posts: 3,430
Re: MSD-6AL with HEI ?

Quote:
Originally Posted by PbFut View Post
Just curious.. once the flame has lit, whats to burn for the subsequent sparks? If it does find a combustible mix, isn't that akin to detonation where the flame is not controlled as the piston drops and you get a ping.
I think it's just to make sure the flame does get lit, and lit completely. Above 3000 RPM RPM it's a single spark, but long duration.

I always thought detonation occurred before TDC, not after. That's why you can create it with too much advance.
__________________
Mike
1969 C10 LWB -- owned for 34 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes.
1982 C10 SWB -- sold
1981 C10 Silverado LWB -- sold, but wish I still had it!
1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming.
Retired as a factory automation products salesman.
Worked part-time over the years for an engine builder and a classic car repair shop.
Member here for 23 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!
MikeB is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 11:38 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com