Reply With Quotei think it starts at 3500.
And what kind of effect does it have on your motor. Would retarded timing (26deg total) make it worse?
i think it starts at 3500.
Yeah, I was thinking it really starts to drop off around 3500-4000 in most cases and gets worse from there...
So your saying that at 4500, it REALLY sucks ass
and could start to cause misfire and loading up?
[ December 18, 2002, 08:30 PM: Message edited by: DUCKY ]
I was always told that they started to drop coil output around 4500rpm. It is a progressive thing, resulting from decreased dwell time in the module's circuitry. There are several aftermarket modules that claim to eliminate the problem
I think more like whatever speed the starter spins the motor.............Junk
DUCKY:
And what kind of effect does it have on your motor. Would retarded timing (26deg total) make it worse?Retarded timing has nothing to do with dropping voltage @ higher R's.
Retarding the timing is to guard against creating total burning of fuel and O2 in the combustion chamber when the piston is near TDC, creating too much pressure there, and having it push straight into the crank, creating no turning force @ that position on the crank. eek! .
W/ the extra fuel and air (turbocharged) you are putting in the limited room of the comb chamber, the flame speed has increased, leading to a adj (later....26 instead of 35 total) to the timing to make sure the 02/fuel is completely burned when the crank is 20 deg past tdc. Get it wink .
[ December 22, 2002, 08:57 AM: Message edited by: MikeF ]
Motor's not turbo'd yet...
Will be soon.
I was just thinking that the timing being at 26deg instead of 32-34 would make the HEI situation worse.
The problem is that after a 10-12 sec hard run at WOT,(45-4600rpm) the motor did not want to idle and was chugging black smoke. It cleared out after a few minutes, and ran fine, but I figured this was the by product of the HEI crapping out.
Ducky, my brother and I had the same problem with our boats. I would leave the beach and the boat ran great. I would go out for 15 minutes and the boat would not stay started, it ran like shit. Same for my brother. My brother went to Performance Distributors and bought their HEI hop-up kit. Night and day difference. He said that when he first started the boat with the new kit, all kinds of black crap was coming out of the exhaust ( It scared him). After a few minutes of that, the boat idled great. Took it to Smellsomemore to run it, It ran perfect. 2500rpm, 3500rpm, 4500rpm, 5000rpm for about 3 hours, not one problem. He even got some extra rpm and a few mph out of it. I was so sold on the difference in his boat that I bought one for mine. Have not ran it yet, but I look forward to it. I would reccomend this product to everyone with a HEI. Here is the site and good luck...Joe. Oh yeah, make sure that you go to accessories for the hop-up kit unless you want a whole new distributor.
www.performancedistributors.com
[ December 19, 2002, 01:17 PM: Message edited by: Bow Tie Omega ]
Bruce ... I second what BTO said. Modified HEIs with hiperf componets work very well. A lot of SS boats run them and we run in the 7000-8000 rpm for 5 miles at a time. I have to take note with the statement made by Performance Distruibutors that you can run .050" to .055" plug gap and that
"The wider plug gaps will allow more spark energy into the combustion chamber providing a better burn of the fuel mixture and increasing horsepower."
Actually widing the gap lessens the 'spark energy'. Like guys that run Mags have to run .015" to .020" to get the engine started because at cranking speed the spark is weak. The reason for running a wide gap is that if you have a High Energy ignitions system that has the extra energy to spare, the wide gap increases the nucleus of fuel present to better fire the mixture under adverse conditions like lean fuel mixtures mixed with exhaust (EGR) in smog legal motors. The reason someone might think the energy is raised with a bigger gap might be that on an osciloscope the firing line is higher. That only means that the voltage is higher. (the voltage goes up to jump a wider gap) The energy is a function of the voltage times the amperage and as the gap gets wider the amperage goes down. I think I'm starting to ramble. It's just that I haven't gotten to ramble like this since I taught auto shop at a local JC. ramble, ramble, ramble...
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