Neighbor:
What the hell are you doing ??? Crap on my lawn???
Carl
My entire ignition box was bad (wiring quite corroded), ended up buying new one from SNG. They donāt even come with capacitors anymore.
No , Iām just messing with you Carl!
Letās see if I have this right. After doing a conversion to Fahrenheit (cos weāre simple folk down here) The amplifier was 197 degrees F when you started the engine, and went to 242 degrees F after 5 minutes. Wow.
Glad the idle stumble went away, not sure about the temperatures.
Me too!!! Not sure why, but, I am in a good mood this AM!!!
You know when you put it that way , those numbers do seem high. (According to my Ryobi) temperature gun.
We need someone else to do the same measurements on their car. Start it up wait a minute take a measurement, idle for five minutes and take another one.
I must admit, I think it was driving around with a pooched ignition module, and did not even know it.
The car runs way better, feels like more power, better idle and not sure if this is a coincidence or not, Iām in stop and go traffic in a heat wave and that temp gauge is not budging from below the N.
If I was to suggest to anyone here on this forum, pull out your module, see what it says on the bottom (not Singapore) and make sure you have a proper AC Delco (made in the USA), there I said it . No affiliation GM doesnāt pay me any royalties LOL!
Still impressively hot. The AB14 is supposedly bolted to the intake manifold to serve as a heat sink, but evidently itās not doing too well in that regard! I guess any heat generated in the HEI module itself is conducted to the top of the AB14 case, and has to work its way from there around to the mount bosses and down into the intake manifold. Might make more sense to mount the whole thing upside down, actually ā except IIRC the mount bosses on the intake manifold donāt exactly present a broad area for heat dissipation.
That finned plate is sounding more and more like a good idea.
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BTW, the reason I suggested idling for five minutes is that I believe thatās where the ignition amp gets hottest. At higher RPM it sends more energy to the spark plugs and dissipates less internally.
Of course, at idle thereās also less cooling airflow inside that intake manifold. All in all, a fan connected to the brake lights is sounding like a good idea!
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I did attach the finned GM heat sink they sent me,set up the whole thing on a couple of washers just to give a little lift and airflow. Iāll take a few more measurements tomorrow. Iām curious now to see if this makes any difference. Stay tuned for more temp measurements.
You spaced it away from the cool intake manifold?
When i measured temp of mine couple years ago it was about 160F-200F at idle.
Technically, I guess I sort of did, by thinking that a couple of washers might add a little more airflow, so itās not sitting tight to the intake manifold but maybe some heat (or cooling ) transfer via the securing bolts.
Now you have to help me out here as Iām not a mechanical engineer. But did I miss a line or paragraph in The Book. The car runs better, the temp gauge is staying lower, but I didnāt read anything in The Book that suggests the module will actually make the car run cooler? Iām not kidding here but I gave it a serious shake down run in the middle of a heat wave followed up by stop and go traffic. The gauge did not budge.
A bad module could mess with ignition timing? If so, if it retarded the timing, that would make it run hotter. More advanced at idle runs cooler.
I would remove washers, the triangular surfaces provide much heat dissipation, and you dont want module box too high, where it may touch hood.
I built a similar heat sink on top, but i scraped off paint and used heat sink paste in between to help. I measured a 20F reduction.
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Thank you sounds like a plan, I know Iāve probably beat this one to death, but I really didnāt know what was going on
Interesting finned plate. Only cools that one spot rather than the entire top of the ig amp.
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For what its worth my old ignition module had made in Singapore on the back of the unit,
Cheers.
Bruced
Yah kind of weird , thatās the one that came from GM with the ignition module. I just mounted it that way as one of the mounting holes lines up with the mounting bolt.
One more question though what do you suppose the air intake temperature gets down to if itās the other source of cooling. Maybe another excuse to route the trumpets further forward up to the rail where the radiator banjo bolt is located. Sort of like the XJR setup.
To clarify, you ordered a GM ignition module and the aluminum heat sink came with it? Interesting. I ordered a GM/Delco module a couple months ago and go not such extras!
That heat sink has a unique GM number and specific application (which Iāve long forgotten, if I ever knew). I donāt think it was intended to be routinely used in module replacements. pretty cool, though (no pun intended)
Cheers
DD
Gary, on later XJS, like my 1995 6.0, the air intakes get their air from in front of the radiator rather than from within the engine bay.
I have seen on this forum where folks with older cars have engineered their own method of getting air to the engine from outside the engine bay.
My recently purchased Delco D1906 wasnāt made in the USA. I canāt remember where it was made, but it wasnāt the USA. I donāt think theyāve been made in the USA for a long, long time. The ā990ā stamping on the module refers to the original part number 1875990, which goes back to the mid-1970s. From memory the first of several number changes was in the early 90s and I think corresponds to the substitution of beryllium withā¦something else. But, parts numbers also often change when a different manufacturer is contracted.
Also missing from my new D1906 was the unique grounding tab. The significance (or lack thereof) of this tab has been discussed from time-to-time over the last couple of decades. The genuine GM/Delco modules have generally been preferred over the others because they work better and last longerā¦and this tab was a difference that was immediately visible, setting the genuine modules apart from the multitude of replacements. But is it really important? I dunno.
Cheers
DD