Over heating.. after the fact?

Moderators: Sluggo, Amskeptic

Post Reply
User avatar
BumbleBus
Addicted!
Location: Whitefish, Montana
Contact:
Status: Offline

Over heating.. after the fact?

Post by BumbleBus » Tue Sep 27, 2011 3:14 pm

Not really finding an answer to this sorry. I've been taking my bus camping a couple times in upper 80s ambient recently. Taco place oil temp never goes above around 200-210 (I know it reads a little low probably though) and when I pull over the engine is cool to the touch and she's running very well as far as I can tell. However, when I get to camp and shut'r down after a couple minutes the dipstick and area highlighted below are uber-hot... like searing, can't touch them kinda hot. Is this normal or should I be worried that the natural cooling off process is not working properly. Thanks for any info. I'm still paranoid I'm missing a buried mouse nest or three.

Image
'72 Sierra Yellow Campmobile

I'd rather have a bottle in front of me than a frontal lobotomy.

User avatar
airkooledchris
IAC Addict!
Location: Eureka, California
Contact:
Status: Offline

Re: Over heating.. after the fact?

Post by airkooledchris » Tue Sep 27, 2011 4:16 pm

That's called heat-soak I believe, where it's hotter to the touch a little bit after you turn it off because the fan isn't cooling it all down anymore.

It's why you don't pull over and just stop suddenly when you are running hot, rather you slow down and drive gently so it can continue to cool itself off without the heat soak.

how do you know your taco plate reading is low?

if your really worried, get a CHT sensor from Dakota Digital. then you can freak out about how it's too hot ALL the time. ;p
really though you could then at least get an idea of where your at.

how do your plugs look? if they look like your running way lean it might be abnormally hot. I certainly wouldn't assume you have any kind of problem solely based on the fact that your engine is hot 10-15 minutes after shutdown.
1979 California Transporter

User avatar
BumbleBus
Addicted!
Location: Whitefish, Montana
Contact:
Status: Offline

Re: Over heating.. after the fact?

Post by BumbleBus » Tue Sep 27, 2011 5:27 pm

airkooledchris wrote:It's why you don't pull over and just stop suddenly when you are running hot, rather you slow down and drive gently so it can continue to cool itself off without the heat soak.
That makes sense. I'll make a mental note to at least idle for a minute or three after a hot drive.
airkooledchris wrote:how do you know your taco plate reading is low?
I don't necessarily, but have read that because the sensor is in the undercarriage airflow it's always getting cooled a little bit by the air. I'm building patterns with it more than anything and so far am comfortable with the patterns I'm seeing.

airkooledchris wrote:if your really worried, get a CHT sensor from Dakota Digital. then you can freak out about how it's too hot ALL the time. ;p
Heh, heh.. yes, good idea. I have no money for that currently though. One of my parts busses came with a VDO oil temp so that was my first route.
airkooledchris wrote:how do your plugs look?
Plugs were on the blackish side when I last checked and that plus the roughly 15-16mph I'm getting makes me think too rich if anything, but I'm still learning the ins and outs of this unknown motor so figured running a bit rich is better for now than running a bit lean.

Thanks for the info!!! I'll keep track of it. I just couldn't believe how hot it got. :rr:
'72 Sierra Yellow Campmobile

I'd rather have a bottle in front of me than a frontal lobotomy.

User avatar
SlowLane
IAC Addict!
Location: Livermore, CA
Status: Offline

Re: Over heating.. after the fact?

Post by SlowLane » Tue Sep 27, 2011 6:56 pm

Well, um, this ain't gonna help a bit with the heat soak (and frankly, it sounds pretty normal for driving in 80+ degree weather), but you really ought to consider putting an air filter on that carb.

I know, I know, the air is cleaner in Montana, but it isn't that clean.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

User avatar
BumbleBus
Addicted!
Location: Whitefish, Montana
Contact:
Status: Offline

Re: Over heating.. after the fact?

Post by BumbleBus » Tue Sep 27, 2011 8:55 pm

SlowLane wrote:I know, I know, the air is cleaner in Montana, but it isn't that clean.
Haha.. old photo during a state of disrepair, but it was all I had to work with.. there is an oil bath filter on there. :drunken:
'72 Sierra Yellow Campmobile

I'd rather have a bottle in front of me than a frontal lobotomy.

User avatar
BumbleBus
Addicted!
Location: Whitefish, Montana
Contact:
Status: Offline

Re: Over heating.. after the fact?

Post by BumbleBus » Tue Sep 27, 2011 9:02 pm

There... just to prove it to you. Heh, heh. For being a progressive it's really not been bad so far as near as I can tell (I can't tell much with my lack of experience). It's a Solex TCIC 34, which there isn't much info out there for, and I recently tuned it to "best lean idle" based on Weber's specs and there really isn't any dead spot or stumble or any icing issues etc. so far. Seems like a decent carb actually. Dwell dipped a bit to around 45.5 after my most recent tweakings, but she really is running pretty well as far as I can tell. Not that I don't want to go dualies again someday, but for now it's ok since I'm broke as a joke. She's getting me out camping in the backwoods nearby so that's good.

Image

Image
'72 Sierra Yellow Campmobile

I'd rather have a bottle in front of me than a frontal lobotomy.

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: Over heating.. after the fact?

Post by Amskeptic » Wed Sep 28, 2011 8:58 am

BumbleBus wrote: Haha.. old photo during a state of disrepair, but it was all I had to work with.. there is an oil bath filter on there. :drunken:
That is not an oil bath air cleaner, like the original VWs all had up to 1973. The oil bath air cleaners were magnificent. The K&N style washable elements that you apply a smear of oil to, are actually pretty lousy at filtration.
Colin
(p.s. I have recently discovered that there is next to nothing that you can do to mitigate heat-soak. Even after a hot desert highway run, the heads cool down amazingly quickly down the exit ramp or into the gas station. Sitting there idling to help it cool is almost a waste of our precious time. These stupid cars keep telling me "just drive us.")
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
BumbleBus
Addicted!
Location: Whitefish, Montana
Contact:
Status: Offline

Re: Over heating.. after the fact?

Post by BumbleBus » Wed Sep 28, 2011 9:51 am

Amskeptic wrote:That is not an oil bath air cleaner, like the original VWs all had up to 1973.
The local FLAPS guys could not get a replacement filter nor had ever seen a Solex carb like the one I have (despite it being a progressive clone) so I bought the "oil" recharge kit. I should have been more specific. I would hope it's better than nothing anyway. :drunken:
Amskeptic wrote:These stupid cars keep telling me "just drive us.")
Thanks for the info on the heat. I won't worry about it anymore. :rr:
'72 Sierra Yellow Campmobile

I'd rather have a bottle in front of me than a frontal lobotomy.

Post Reply