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post #1 of (permalink) Old 01-06-2002, 05:43 PM Thread Starter
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Big HEI conversions Question!

alright, i installed my HEI distributor and everything its just perfect, more lowend torque, idle is wonderful. but this is my problem, at 4th gear and above i have noicably less power than i should...timing is right on, and always has been. I didn't move the gear back one like some people did, is that it? or is it somthing more complicated..

any help would be great!

YJforever...man, forever is a long time

89' jeep wrangler yj, saraha, 4" skyjacker, HEI conversion.
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post #2 of (permalink) Old 01-06-2002, 06:00 PM
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Re: Big HEI conversions Question!

Check and make sure the vacume advance is working right. It's also possible you have it to the wrong vacume source too. Power at higher RPM's demande more advance. If it's not getting it it will feel like you put a leash on your motor or are smothering the carb at a certain RPM. Check these things first. It can also be the advance curve for the springs are wrong. You can always go with a lighter spring to bring it in faster. I never had to do this on mine when I had the HEI in it though.
Look at these things (in detail), then if that doesn't fix it, ask TR. I'm a schoolboy compared to him on this stuff.[img]/wwwthreads_images/icons/tongue.gif[/img]


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post #3 of (permalink) Old 01-06-2002, 06:07 PM
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Re: Big HEI conversions Question!

Hi Dustin! This may be an issue of "Total" advance instead of "initial" timing. You may not have as much advance at freeway RPM with the HEI distributor as you had with your stock distributor. I couldn't tell you what it is supposed to be on a Jeep (TR might), but to check total advance, check your timing as you usually would, only at around 3000 rpm. I'm guessing it should be around 34-36 degrees(?).
To gain more total advance you can grind away a bit on the advance weights in the distributor. Just pull your cap and rotor, then with your thumb, move the weights out to their max position and mark where they hit on the inside. Pull the weights off the shaft and only take a bit off at a time with a dremel tool, and do it evenly to both weights by clamping them together. Or you can do it the easy way, I think Mr. Gasket or one of the aftermarket companies makes "Hi-Performance" advance weights for HEI distributors.
This may also just be a 258 that isn't supposed to have power...like mine![img]/wwwthreads_images/icons/smile.gif[/img] Good luck in your quest for more power!


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post #4 of (permalink) Old 01-06-2002, 10:30 PM
 
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Re: Big HEI conversions Question!

I say never grind on advance weights, but that's just me...
(we drill them and add heavy metal, but never take weight off...)

You can't gain anymore advance grinding on the weights, There are limiters both high and low.
You can extend the limiter slot, but that will only gain you a little...
There is only so much travel those weights will give you...

All grinding on the weights will do is bring in the advance later.
Lighter weights don't fly out as fast, so the advance comes in slower.
Using heavier springs will achieve the same thing with out permanent damage to the advance head.

Answer me this...
Did you connect the GM HEI to the factory power wire in the harness?
Answer that and I'll tell you what your problem is...

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post #5 of (permalink) Old 01-06-2002, 10:42 PM
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Re: Big HEI conversions Question!

Thats why I said I was "schoolboy"..........
The factory power supply IS NOT enough to power the GM HEI.
I should have thought of that too.
Aaron.........did you ever read "Dirt Bike" in the 70's to early 80's? Remember Mr. Know It All?
"I should have known"..................[img]/wwwthreads_images/icons/tongue.gif[/img]


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post #6 of (permalink) Old 01-06-2002, 11:00 PM
 
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Re: Big HEI conversions Question!

Heavy load, high gear, coil not saturating due to restricted input through the factory resistor wire...
The 14 or 16 gauge factory wire isn't enough to power the GM HEI anyway...
GM Used a 10 Ga. wire, and if you watch the connectors, you will notice they are burned a lot of the time.
(It will kick a relay just fine)
<hr>

40 Amp, Hella Relay.
Heavy Duty Relay Socket.
8 AWG lead (Black)- Main Power In.
10 AWG leads(Blue & Green)- Power Out.
12 AWG leads (Red & White)- Relay Activation.
All Leads Are 18" Long.
With connector, $29 with shipping.


<hr>
It could also be rotor phasing. My bet is on coil starvation...



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post #7 of (permalink) Old 01-06-2002, 11:02 PM Thread Starter
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Re: Big HEI conversions Question!

i connected the power wire from my harness that was 12vDC start and 9.5vDC run.....i think it was yellow

89' jeep wrangler yj, saraha, 4" skyjacker, HEI conversion.
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post #8 of (permalink) Old 01-06-2002, 11:06 PM Thread Starter
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Re: Big HEI conversions Question!

ok, sounds like a right combanation, but, tell me where i can get these parts, all at once perferablity...and thanks man

89' jeep wrangler yj, saraha, 4" skyjacker, HEI conversion.
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post #9 of (permalink) Old 01-06-2002, 11:31 PM
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Re: Big HEI conversions Question!

Sorry, I probably should have made it clearer. The grinding I have done is on the "Out" limiter which is actualy on the "Inside" of the pivot point. This allows the weights to move out farther, and since no weight has been taken off the heavy end of the wieghts, it does not affect how fast they come out. This has only been used to fine tune the full advance curve (maybe a degree or two, not 5 or 10) and is experimented with using different weight springs on a Sun Distributor machine.
It's been a long, long time since I had a HEI distributor apart, so I may be confusing the proscess with Big Block MoPar stuff as well. I apologise for any confusion this may have caused.[img]/wwwthreads_images/icons/crazy.gif[/img] And sorry I couldn't be more specific Dustin.


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post #10 of (permalink) Old 01-06-2002, 11:37 PM Thread Starter
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Re: Big HEI conversions Question!

hey thats ok, i'm now just trying to find out how i go about getting all these parts i need, and possibiliy a wiring diagram!

89' jeep wrangler yj, saraha, 4" skyjacker, HEI conversion.
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