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low temperature

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tahoe healey

tahoe healey

Yoda
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Since I had the dizzy re-built I am seeing temperatures at 165 almost all the time. I've checked it with an infra-red gauge and they concur. Can this be due to the running at 22 BTDC. This amount was suggested by the re-builder (actually, he suggested advancing 'till it pings then backing off a few degrees). She runs great and has good acceleration. Am I going to get trouble with the lower temps? The interior is even cooler.
TH
 
Hi Rich,
What temp is your thermostat rated at? Maybe switch to a 180.
 
tahoe healey said:
... Am I going to get trouble with the lower temps? The interior is even cooler.
TH
Click to expand...

All I've seen and read indicates the best all-around temperature for an engine to run at is 190F or so. Much cooler and you don't heat the oil enough to boil off contaminants (mainly water, which will form acidic compounds with other combustion byproducts). Hotter and your margin to overheating is less and you risk vapor lock, fuel boiling in the carb float bowls, etc. (I believe modern engines run that hot or hotter, but it's hard to say since most don't have gauges that indicate actual temperature, just relative temps).

I certainly hope your interior is less than 165deg.
 
Hi TH,

Wow, yours is the first post any ware that has states a problem with running temperatures too low. If I were you I would be happy as heck. If it runs good and is reliable, what more can you ask for?

All the best,
Ray (64BJ8P1
 
RAC68 said:
Hi TH,

Wow, yours is the first post any ware that has states a problem with running temperatures too low. If I were you I would be happy as heck. If it runs good and is reliable, what more can you ask for?

All the best,
Ray (64BJ8P1
Click to expand...
I worked on a late BJ8 (one owner car, in Southern Louisiana, no less) that wouldn't go over 165*; I thought it was a fluke, but dared not question it...
 
Do you have a thermostat in ? I'd run a 185. You don't want the pistons expanding more than the block ! This a mistake a lot of people make, they think cooler is better :hammer:
 
I have the standard sleeved thermostat from BCS. Original 4 blade fan and water wetter. I was at 185 to 190 before the dizzy rebuild. (altitude is 6500 ft) Even in Napa Valley a couple of weeks ago when the temps were in the high nineties the gauge was under 190 in traffic. I'm thinking it the timing. I'll set it back this weekend and see if it goes up a little. We do like the more comfortable interior temps.
 
As you know I live right across the lake from you. I too have a re-built Dizzy. Be careful with too much advance as you may not hear a ping while at the same time be over heating exhaust valves. I do not understand you setting Initial or full advance? Both @ 22 deg does not make sense. I must be missing something. Do you know what the new over-all advance of the Dizzy is after the re=build? Thanks for the paint lead.
 
Bob,I just retarded the timing about 3 degrees and there was no change in the running temperature. I'm not sure what you meant about the 22 degrees. It was set at 22 with an advancing timing light at idle with the vacuum disconnected. Now you have me concerned about the valves.
 
The book says 15° before TDC @ 600 RPM. 34° at full advance with the vacuum disconnected. So depending on what your idle is set at, I'd think you may still be slightly beyond those specs.
 
Advance should be about 8 degrees at idle. Then advance at 3000 RPM should be about 34 degrees with full centrifugal advance. I like to set it at 3000 and take what I get at idle. 22 degree advance makes no sense to me.

Marv J
 
The key is 34 BTDC @ 3-4K RPM. You could set it a bit higher at our altitude but you would have to retard it prior to a trip lower. I would not be to concerned about your valves I was referencing the advice about setting it to ping. If you do not have an advance setting light you may barrow mine? Or come up for a beer and we will do it together. I have a supercharger on my boat ignition was set too low and I burned valves. Lots more horsepower in the boat and lots of hard running. Not the case with your Healey
 
I do have a nice craftsman advancing timing light, thanks.I now have it set at 16 degrees (still runs well) and the plugs are a nice brown/tan and dry. My car runs well on beer too. I may take you up on that. It is such a beautiful drive but6 we are expecting thunderstorms this next week.
Rich
 
.. It was set at 22 with an advancing timing light at idle with the vacuum disconnected.
Well TH, as Greg said set the timing as specified in the shop mnual; 15 Deg BTDC @ Idle.

Note @ idle on an uncalibrated tach is an indication of 1000 RPM--OK

Now you have me concerned about the valves.
Well if the Valves were seriously affected they would let you know it OK.----Keoke
 
Thanks Keoke. I just cannot figure out the low temps. I would have thought it was the gauge except the infra red laser gauge is right on with the cars gauge and that gauge is correct with boiling water.
 
Everything I have ever known about too much advance is that it will cause the motor to run hotter, not cooler. But you still need to set the advance by the book, not the seat of your pants.
 
I have always set it by the book until I was told otherwise by the highly respected dizzy re-builder I used. Since the temps have not changed by going back to the book settings, I'm looking for something else as the cause.
 
. Rich dial in 34 deg BTDC into you timing light. Rev the engine to 3K then 4K and change the pre-set to see what total advance you have. Let the engine idle and then set the dial to see what initial advance you have. Record those two readings. I would then adjust the dizzy to max advance (factory 34deg). Now let the engine idle and dial to center on TDC to see what initial results. That final setting should then be your initial with the re-built Dizzy. When I got my dizzy back from re-build I found that the curve was late meaning that the advance came in later than factory set-up. This condition could cause a cooler running engine but not by the amount you are experiencing. I typically run around 190 up here at the lake. You should experience a drop in running temp if the thermostat was removed. Try that and see if your temp is even lower. If so then that means that the thermostat is at least functioning. If you see no change W/O the thermostat then replace it.
 
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