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#1 |
Senior Member
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 894
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HEI Firewall Clearance Issues
I searched around and could not find my specific concern addressed.
A long while back I bought a used GM HEI distributor with an ACCEL Super Coil cap/coil assembly. I just finally got around to installing that yesterday and it is wedged against the firewall with zero clearance for anything, including spark plug wires! So my question...what are you 4x4 and Blazer guys using for cap/coil assemblies? From pictures I have seen online it looks like I might have the big bertha of HEI setups, so anything else might be smaller. Looking for suggestions of brands that leave a bit of clearance, I don't need anything fancy for my half-dead 307, just something I can get at a local store that will not break the bank. Thanks in advance.
__________________
-Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals... |
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#2 |
Registered User
Join Date: Mar 2007
Location: Portland, OR
Posts: 108
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Re: HEI Firewall Clearance Issues
I could not use the ACCEL Super Coil on my Blazer's HEI either. The HEI should fit with a regular coil on it, though.
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#3 |
Senior Member
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 894
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Re: HEI Firewall Clearance Issues
Thanks, so what kind of coil are you using?
__________________
-Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals... |
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#4 |
Old School, New Style
Join Date: Jun 2005
Location: Monroeville, Ohio
Posts: 790
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Re: HEI Firewall Clearance Issues
I had a stock HEI coil on my cap. I think MSD and others make hiperformance coils that are the same size as stock.
Aaron
__________________
The Good: - 72 GMC Jimmy 4x4 - 307 cid / 350 th - 70 Chevy Suburban 1/2T 2wd - 454 cid /400 th - 96 Chevy Impala SS - mainly stock - 98 Chevy Tahoe LT 4x4 - all stock The Bad: - 86 Chevy Suburban 1/2T 4x4 - winter beater The Ugly: - 72 Chevy Suburban 1/2T 2wd - parts truck |
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#5 |
Post Whore
![]() Join Date: Feb 2000
Location: Rose Hill, KS, USA
Posts: 12,684
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Re: HEI Firewall Clearance Issues
I'm using a stock hei on my 70 Blazer and it fits put is very close. If you want to spend the dough, an MSD Ready to Run distributor will fit and have plenty of clearance.
__________________
1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14 |
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#6 |
I'm a poor spectator
Join Date: Aug 2006
Location: San Antonio, Tx
Posts: 2,287
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Re: HEI Firewall Clearance Issues
I've got about an 1/8 inch clearance between my stock cap and firewall.
__________________
2006 Jeep Unlimited IMPACT ORANGE 1993 Chevy 2500 4x4 ExCab LWB 454/NV4500 Tow rig ![]() 1977 Ford F100 2x4 LWB 1st truck I owned, still have it!!! ![]() 1979 Ford F150 4x4 SWB Built Ford Tough!!! ![]() 1971 Chevy Blazer 350 / SM465 / NP205 UNDER CONSTRUCTION Soon to have a LQ4 6.0!!! |
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#7 |
Senior Member
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 894
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Re: HEI Firewall Clearance Issues
Thanks guys, I went to the parts store and bought a generic coil and cap, it fits (REALLY TIGHT) but now the truck will not crank properly/start. I probably should start a new thread but I hate wasting board space:
When I turn the ignition key the engine cranks for maybe 1/2 a turn then the courtesy lights go dim and the starter bogs down something fierce. If I disconnect the +12V lead it will crank normally but of course will not start because it has no spark. It seems like it is getting a huge voltage drop/short from the HEI but I have no idea what would cause that. I have the +12V plugged into my unfused ignition plug on the fuse block. Tach is hooked up, and will start to read something when I try to crank it. Had to "create" a ground strap because it was missing from the cap (and none of the replacement cap, coil, and cover parts came with one). I scraped the paint off the core for the coil at the two screws nearest the plug, landed the coil ground and the plug ground strap. I have not cut out the wire that runs down to the starter; it was past 1AM when I gave up last night (and will not be able to mess with it until Monday now). I am using the original style alternator with the external regulator, but I have never heard that to be an issue with HEI nor would I see how that would effect the ability to start the engine. Thanks in advance for any tips/suggestions?!?!?? Last edited by 69TowRig; 09-01-2007 at 08:04 PM. |
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#8 |
I'm a poor spectator
Join Date: Aug 2006
Location: San Antonio, Tx
Posts: 2,287
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Re: HEI Firewall Clearance Issues
Where is the wire from the starter going? In your original setup with points there should of been a wire going to the positive side of the coil to the starter to provide the system with a full 12-14 volts during startup. The ONLY wire going to the HEI distributor should be the one coming from the fuse panel (10 or 12 guage preferably, and it's a good idea to run an inline fuse holder in there too with a 30 amp fuseo or 25). Timing doesn't seem like an issue concerning the bogging down of the starter since it only bogs down with power (it would bog down all the time if it was timing). It think that wire going to your starter is the culprit. Where on the distributor is it hooked?
__________________
2006 Jeep Unlimited IMPACT ORANGE 1993 Chevy 2500 4x4 ExCab LWB 454/NV4500 Tow rig ![]() 1977 Ford F100 2x4 LWB 1st truck I owned, still have it!!! ![]() 1979 Ford F150 4x4 SWB Built Ford Tough!!! ![]() 1971 Chevy Blazer 350 / SM465 / NP205 UNDER CONSTRUCTION Soon to have a LQ4 6.0!!! Last edited by Jtrux; 09-02-2007 at 12:42 AM. |
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#9 | |
Senior Member
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 894
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Re: HEI Firewall Clearance Issues
Quote:
Thanks for the help, anyone have any other suggestions? |
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#10 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,720
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Re: HEI Firewall Clearance Issues
Are you sure you are OK on the timing? Sounds kind of like too much advance.
__________________
44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
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#11 | |
Senior Member
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 894
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Re: HEI Firewall Clearance Issues
Quote:
I was not able to mess with this last night, maybe tonight instead.
__________________
-Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals... |
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#12 |
Old School, New Style
Join Date: Jun 2005
Location: Monroeville, Ohio
Posts: 790
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Re: HEI Firewall Clearance Issues
If you are changing from a points dizzy to a HEI then the rotor tab should not have been installed in the same location. If you look at the cap on a points dizzy the #1 plug points to the #2 cylinder on the engine, in a HEI it should point almost directly to the #1 cylinder on the engine. I believe this would give you to much advance.
If all else fails bring the engine up to compression on the #1 cylinder, lining up the timing mark up on the timing tab (both valves should be closed) then set the rotor tab to point to the #1 cylinder which should correspond to the #1 plug wire location. Just did this myself over the weekend and everything worked fine. Aaron
__________________
The Good: - 72 GMC Jimmy 4x4 - 307 cid / 350 th - 70 Chevy Suburban 1/2T 2wd - 454 cid /400 th - 96 Chevy Impala SS - mainly stock - 98 Chevy Tahoe LT 4x4 - all stock The Bad: - 86 Chevy Suburban 1/2T 4x4 - winter beater The Ugly: - 72 Chevy Suburban 1/2T 2wd - parts truck Last edited by Long Roof; 09-04-2007 at 10:09 PM. |
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#13 | |
Senior Member
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 894
|
Re: HEI Firewall Clearance Issues
Quote:
http://67-72chevytrucks.com/vboard/s...ad.php?t=17403 I quote: "Remove the old distributor. After lubricating the HEI distributor gear and installing a new gasket, install it so the rotor is pointing in the same position as the old one. " That's fine and all, but of course mine doesn't work. So following y'alls suggestions (except for the little at a time) I clocked the dizzy about 20-25° and tried to crank it, after a stumble she fired up and ran fine. New problem, my harmonic balancer has apparently spun and I will have to manually find TDC and scribe a new mark on the balancer to do the timing. She is a little advanced (spark knock on moderate to heavy acceleration) but drives like a scolded dog compared to with the old points dizzy. I couldn't be happier, I feel like I swapped engines the change is so drastic and noticeable. Thanks for everyone's help, I think I have the last bit figured out...
__________________
-Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals... |
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#14 |
Senior Member
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 894
|
Re: HEI Firewall Clearance Issues
I'll try all the suggestions, I wish I had more time to mess with it looks like it won't be until Sunday now. Travelling jobs suck when you can't drag your projects along with you.
Thanks guys, I will update.
__________________
-Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals... |
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#15 |
Old School, New Style
Join Date: Jun 2005
Location: Monroeville, Ohio
Posts: 790
|
Re: HEI Firewall Clearance Issues
Glad to see that you have it running again. I see that its a 307. Thats what I put in my Jimmy and I like the little mouse.
It's not tough to change the balancer. I would think you could even rent the puller/installer tool from a local parts store. P.S. Here is the diagram for the different dizzies. Maybe the FAQ needs to be changed. Aaron
__________________
The Good: - 72 GMC Jimmy 4x4 - 307 cid / 350 th - 70 Chevy Suburban 1/2T 2wd - 454 cid /400 th - 96 Chevy Impala SS - mainly stock - 98 Chevy Tahoe LT 4x4 - all stock The Bad: - 86 Chevy Suburban 1/2T 4x4 - winter beater The Ugly: - 72 Chevy Suburban 1/2T 2wd - parts truck Last edited by Long Roof; 09-16-2007 at 06:48 PM. |
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#16 |
Senior Member
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 894
|
Re: HEI Firewall Clearance Issues
Well after looking at those diagrams it makes even less sense, since I turned the dizzy clockwise. According to those diagrams I should have had to turn it counterclockwise.
Ah well. Thanks again for the help. If I decide to mess with the Balancer (and I probably won't) I already own a puller for it, they are great for pulling steering wheels and (with the proper pieces of threaded rod) tone rings on certain semi-floating axle shafts... Last edited by 69TowRig; 09-16-2007 at 09:48 PM. |
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