Engine heat evacuation syste

[kenny38]

Joe, You might consider that some problems are not likely to be solved just because you want to keep your mindset intact.That way has brought on madness to many. The heat from your bloody great lump of assistance to climate change has challenged just about every Jensen owner since 1966. Accept that on this rare occasion you are .......not beat........but just unable, together with the thousands before you, to change your fate. All Jensen owners have the opportunity to exist in dark places with some sunny relief now and again.....especially when driving. Does not the joy of driving a reasonably sorted powerful car that attracts attention take your mindset off what is, to me anyway, a relatively minor matter and not worth any more of your obviously very intelligent mindset time?. Judging by the replies to your highly complicated "problem"(and therefore doomed to fail despite the utterances of the appalling Grant et al to the contrary) there are lots of members of this forum who attempt The Times cross word with a time limit. The duvee beckons and another of those nice pills. Bless you all. Kenny38

[AH1951]

I have yet another really helpful suggestion on this topic.
This is almost good enough to be a TOP TIP:
Move to Calgary, Alberta, Canada and only drive the car on the few days in February when the temperature drops to -40 Deg C. (Which is actually also -40 Deg F.)
I think that could solve the problem of heat soak into the cabin, even if you were to drive the car all day long.

[Joe Schiavone]

Both replys excellent first one written in a very true way second true but not an option because I ain't not making any more moves except driving my Convertable (Drophead). It is a pleasure to read intelligent remarks. Thank you really. I may have met my match. I might have to Check the outside temp befor I go for a ride. Yesterday Sunny 95 degrees. Not a good day to drive. Thanks guys. RacerJoe

[Joe Schiavone]

In reply to AH1591 I should know within two weeks where all stands with my efforts. We are in constant 90 degree weather so the perfect heat soak weather is here for testing. A few things need finishing and I will know success partial success partial failure or total failure My realistic expectations are for partial success as the Big Lump puts out a lot of heat and some things I can not overcome by Jensen Design. I have always been open for challenge and have Picked Jensen as my car to own for life. Like some wives you take the bad with the good. Such is life. Racer Joe

[73nrceptor]

I admire what Joe is trying to do and have followed his work for inspiration. After doing everything but moving to Calgary, finally developed a data logger to record what's really going on under the bonnet with heat. On our recent trip from Annapolis to Vermont for the Jensen East USA Meet, it logged 6452 data points as we drove, one every 10 seconds for about 18 hours of driving in 65 degreeF through 95 degreeF weather. It records 4 temperatures: engine at exit to radiator, radiator at exit to engine, incoming air behind grill, and under bonnet air behind the carb. Also voltage.

Conclusions after looking at the data are that Racer Joe is right on about the under bonnet heat issue and now there are numbers, AH1951 is right about heat buildup after shutdown and the Calgary Option. My focus, after replacing the alternator/regulator now registering 19 volts, will be on the under bonnet heat issue. It looks like the radiator and fans are doing pretty well maybe. Here are 2 chart snips from the drive, the first in cooler weather, the second in an up to 95 degreeF heat wave on the drive back home. When you think about it, the car seems designed to heat the engine bay to the temperature of the radiator with some incidental leakage through the decorative side vents, and that seems to work fairly well. The second chart raises a few questions. This is a small part of the data and conditions logged so a lot more is available.

Note: "engine" is the top line. Colors on the the first chart legend seem to be off for some reason. The bottom scale is minute from start with about 6 readings per minute. 10xVolts was used to bring the voltage line into the center of the chart, so 14 volts = 140 on the chart.

Annapolis to Pennsylvania

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Now the fun begins...

Pennsylvania to Delaware

PeddlersVillage.JPG (167.49 KiB) Viewed 4637 times

[RockyUSA]

Pretty fascinating.

Any way you can get your datalogger on a speed sensor, or on RPM?

I would have guessed on the bottom chart you stopped the car, and idled. The heat started to roast the alternator or something in the electrical system, causing the drop in voltage, similar to the effect at the end of the journey ("Parking Lot / Idle / Off").

Rocky

[73nrceptor]

Good idea about adding speed. (Also radiator fan on/off or speed with the PWM fans.) Am thinking that incoming air speed at the grill may be a better approach for this problem, since RPM does not tell you the gear, and land speed does not tell you about the wind. The problem only cares about how fast air is moving, so why not measure that directly. Otherwise car speed would be OK, just not as relevant on a windy day. Am looking into some sort of anemometer like http://uk.farnell.com/ist/fs5-0-1l-195/ ... dp/1778049 mounted in the grill, but that's going to take some research/development time, especially considering that it has to be waterproof. But it would be a lot easier to install that than messing around with tach pulses or other car electronics.

The bottom chart's fun part was during a slow moving 30-40 mph traffic jam in high heat. From other charts, traffic jams can add up to 20 degreesF to the incoming air temperature and that ripples through to the radiator, engine, and ambient under bonnet temperatures. I agree with your conclusion and plan to wrap the headers and add radiant heat blocks for the alternator and starter. The headers are ceramic coated stainless, so not worried about rust. Radiant heat is not a good thing. That should also bring down the under bonnet temperatures, but now I can measure that for an interesting chart before/after, hopefully in a month or so.

[AH1951]

Tim,
That's very interesting stuff.
Joe's main aim is to get cabin temps down, so he doesn't cook on long trips.
How is your own car for that?
Does the transmission tunnel get hot?
Does your A/C keep cabin temps down to a comfortable level?

[kenny38]

Anyone for a bit of train spotting? Is this 'heat investigation" normal behaviour? Do other car owners (classics) have a history of doing this sort of NASA type investigation into what is a pretty futile and most likely passenger boring exercise. I appreciate it's all very creative and a use of the brain but for Gawd's sake get a life all of you and think nice things about positive pastimes.Perhaps flowers. Your hair will last last longer.Kenny38

[73nrceptor]

AH1951,
All that is good. I used heat shielding from Thermo-Tec above the exhaust and 2 layers of thermal inside - the thin foil covered rubber glued to the floor/tunnel and a layer of "Luxury Liner" laid on top of that. Kills the heat and the road noise. On the hottest situation you cannot feel any heat on the floors. Sanden AC is great, but your ice cream will begin to melt on a 95 degree day. The variable heat/cool control function is shot and needs repair, so AC and heat are are full on or off.

I think Joe's design can easily be used for pumping cool air into the bay to bring down the heat there, or reverse the flow to pump it out. He has a great idea and his use of the the marine fans is brilliant.

Rivet-on exhaust heat shielding

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Streetwires undercarpeting

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Luxury Liner over undercarpeting

DSC06889.JPG (199.19 KiB) Viewed 4607 times

[73nrceptor]

Anyone for a bit of train spotting? Is this 'heat investigation" normal behaviour? Do other car owners (classics) have a history of doing this sort of NASA type investigation into what is a pretty futile and most likely passenger boring exercise. I appreciate it's all very creative and a use of the brain but for Gawd's sake get a life all of you and think nice things about positive pastimes.Perhaps flowers. Your hair will last last longer.Kenny38

You should have learned by now by all the varied posts that we all have our interests, not necessarily yours. Enjoy yours! I plan to enjoy mine.

[ernie100]

Anyone for a bit of train spotting? Is this 'heat investigation" normal behaviour? Do other car owners (classics) have a history of doing this sort of NASA type investigation into what is a pretty futile and most likely passenger boring exercise. I appreciate it's all very creative and a use of the brain but for Gawd's sake get a life all of you and think nice things about positive pastimes.Perhaps flowers. Your hair will last last longer.Kenny38

I thought that the purpose of the forum was to discuss re issues relevant to the ownership of the car, if individuals are not interested in it then no need to read the thread or posts..unless you have a non controllable complusive urge to do so

[Lee Grover]

Hey Tim,

Interesting stuff,nice to see some hard data regarding this. Glad it worked out for you. Have you looked into an aircraft type pitot tube for airspeed measurements? I don't know they can be adapted or not,might be worth a try. They are all weather capable and I believe most will measure air pressure also.

Lee

[73nrceptor]

Lee,
Have not but sounds interesting (to some of us...). Will take a look. Will depend on how complex it is to read.

Thanks!

[Joe Schiavone]

Tim. It looks as if you did a superb job in insulating the fire wall tranny tunnel floor etc plus the exhaust shielding by chance did you record basic temp inside the car in relation to outside temps or to put it differently was the inside temp in your opinion ok or excessive. I believe you said your A/C pumps well and cold but did you run across any heat coming out of heat vents. For some reason I feel heat creeps in behind the air intake. Would love to converse either straight by phone or email. racerjoe7@gmail.com. 336-311-8812