3800 Series II S/C-heated throttle body?
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Correct. The TB blockoff is really not the right solution.
Keep in mind the coolant on the L36 UIM is probably intended to keep the EGR stovepipe area COOL. On an L67, there is no such problem.
Keep in mind the coolant on the L36 UIM is probably intended to keep the EGR stovepipe area COOL. On an L67, there is no such problem.
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From: Gilroy, California
Will: One of the things Bill and I discussed by PM was that under almost all conditions (excepting boost for the SC cars) there is a substantial vacuum within the UIM that probably should severely limit heat transport from the small-diatmeter stovepipe to the sleeve.
At freeway speeds, engine vacuum is porbably at least 15 inches of mercury. I don't know what the vacuum inside a thermos bottle is, but I'll bet it'* not much more than that.
So, you're probably correct in asserting that, rather than throttle body heat, the primary purpose of the UIM coolant passages is to cool the area after a hot shutdown.
At freeway speeds, engine vacuum is porbably at least 15 inches of mercury. I don't know what the vacuum inside a thermos bottle is, but I'll bet it'* not much more than that.
So, you're probably correct in asserting that, rather than throttle body heat, the primary purpose of the UIM coolant passages is to cool the area after a hot shutdown.
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From: Gilroy, California
Originally Posted by 1993 SLE
the FSM for 93 States the the coolant is passed through (underneath) the TB to Prevent Icing on cold startups
Icing takes place only under very discrete conditions (but at surprisingly high air temperatures, ask any pilot!)
It strikes me that if an airplane engine gets away with heated air deicing, an automobile certainly can, noting that most aircraft engines are air cooled, so hot air'* all they have to work with.
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Do you suppose iced over TB'* were really an issue though? Or would that just be in the supercharged models that are pulling more air? I do know that top fuelers spray some de-icer on the throttle plates before running because they ice over in 60* weather still, but that'* apples to oranges I suppose.
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Originally Posted by MyLittleBlackBird
Do you suppose iced over TB'* were really an issue though? Or would that just be in the supercharged models that are pulling more air? I do know that top fuelers spray some de-icer on the throttle plates before running because they ice over in 60* weather still, but that'* apples to oranges I suppose.
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You know, I was looking at this N/A LIM I got yesterday and it occurred to me when i turned around and looked at a blower manifold for the traditional Pontiac V-8 I have hanging on the wall that if I couldn't fabricate a cool little 4-71 blower manifold (Maybe even a 6-71) out of it, I ain't no hot rodder. 
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From: Montréal, QC
Originally Posted by Bob Dillon
Originally Posted by vptruman
whatcha thinkin' about?
I drive the car all winter like this and so far I've experienced -30*C weather without any signs of trouble. Safe to say you'd be ok in California.
Cheers,
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From: Bolingbrook, IL Location: Clarkston, MI
Originally Posted by willwren
If you look at my latest engine bay pic at http://bc.atcx.com/cotm/2006/03/s_performance.jpg , you'll see I have little temp strips all over? I have 8 on the top end now. Trying to see if the coolant flow actually helps COOL the SC and TB at higher boost levels after long hot runs. The coolant obviously heats it after starting, particularly with a drilled thermostat, but what is the net effect when the SC is creating heat itself?
I'm figuring out all aspects of your question as we speak. I will not be using a 'permanent' method of plugging the holes in the lIM if I go that way. I'll be plugging it with either a threaded plug that can be removed later or with a freeze-plug type device. But first, I have to know what high-rpm, high boost run does in the heat of summer.
I'm figuring out all aspects of your question as we speak. I will not be using a 'permanent' method of plugging the holes in the lIM if I go that way. I'll be plugging it with either a threaded plug that can be removed later or with a freeze-plug type device. But first, I have to know what high-rpm, high boost run does in the heat of summer.