British-Cars.org

Welcome to the DMR Site for British Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite General - Do oil coolers hum, and other crazy notes

I took the midget out for spirited run just a bit ago...30 miles on la mans JC...my 5 mile public race track

The temps where a chilly 80 F outside...(yeah in augest), water temp 160 F, oil temp 180 F. Oil pressure 65 psi....so boarder line min. across the board,

So now im hearing a hum mainly on acceleration at around 4200 rpm...it tends to come and go....but always on acceration and at 4200 rpm....I dont recall hearing this before....is it the oil cooler or is it engine harmonics resonating.....is this a good thing, bad thing, or a just is kind of thing.....the tone is similar to a power steering pump low on fluid...just more suttle

Remember those temps I posted above, bow here is the fun part....im still cooking the jesus out of my engine bay, dissy is 210, coil is 190, rear carb, 200, front carb 180...(i thought that was strange ...20 degree temp change from front to rear carb...( ill need a gauge for that....hahaha)...so no spark and now vapor lock once turned off till everything cools down

As much as I hate to im going to need to cut holes in the fenders to ley heat out....im guessing this will impact the oil and water temp also for the colder,,,,so im guessing card board is my new friend

Its a hodge podge thread, anyone with ideas, past experiances or comments

Thankks guys
Prop
Prop

Prop ignore the sound
And get that truck bed stuff out of your engine bay!

Tryed shimming the back of your bonet open?
Onno Könemann

No
rachmacb

I'm with Onno.

Anything else you do will just be bodging. The problem is, from what I've gathered, that you have truck bed liner in your engine bay. If you want to fix it, then I do kinda think you should ditch the truck bed liner stuff.

Again, just my €0.02 - I'm sure there are a myriad different ways you can try and work around the overheating issue, but it's going to be flogging the proverbial dead horse.

(And, btw, I'm not sure that 65 psi for oil is "borderline" - at idle, hot, mine drops to a little over 40, and that's with the cooler!)

OSM.
OrangeSpyderMan

It's probably harmonics due the rubber mountings!
Dave O'Neill 2

I'll go along with Dave, my oil cooler is solidly mounted and makes no sound.
I don't understand your fixation on the temperature of the various components in the engine bay. Your engine is running fine, coolant temp and oil temp are great, and oil pressure is good so what's the problem? 210 degrees shouldn't be too high for the distributor to function fine, many newer engines run coolant temps higher than that.
Is the truck bed liner increasing engine bay temps? Probalby, but is it too much, doesn't seem to be now.
I'd think that the temp difference between the front and rear carb indicates pretty good under hood (bonnet) air flow, neither temp should cause any problem with the carbs or fuel vaporization.
Since removing the bed liner will probalby mean having the bonnet and wings media blasted, I'd wait until winter to do it if you can.
B Young

My oil cooler is on the rubber mountings used for fixing weber carbs and doesn't hum - so maybe it's just nothing to do with the oil cooler :)
OrangeSpyderMan

Who has ever measured the under bonnet temps, let alone the individual parts on the engine?
(besides the exhaust manifold....)
Alex G Matla

*hangs head in shame*

I've had one of these for years that I used to use on my RC cars:

http://www.rcplanet.com/Duratrax_Flashpoint_Infrared_Temp_Gauge_p/dtxp3100.htm

Amongst the things I've taken the temperature of :

- my hand
- the oven
- a cup of tea
- my oil cooler
- the manifolds
and, fairly uninterestingly,
- my RC car 'leccy motor

You say it like it's a bad thing :D
OrangeSpyderMan

Prop, my water temps and oil pressure are not nearly as good as what people consider "optimal". I frequently burn my hand on hot components in my engine bay. I do not over analyze it. I've driven thousands of miles on my engine rebuild. When it fails, it will probably be easy to identify the failure point and a some likely causes. Then I'll spend the money time and effort to fix it.

I guess what I'm saying is... I didn't get my engine rebuild/setup perfect. I made a series of compromises. I'll learn from my mistake when the time comes. It may cost me more money, but I'm not going to throw money/time at it right now.
Trevor Jessie

Prop

Where is your fuel pipe routed?

Do you have a carb heatshield?

Have you considered EFI?
Dave O'Neill 2

don't see anything wrong with those top set of temps.

My K-series makes the bonnet so hot you can't touch it, anf the A series needed a hole above the carbs to stop rough running in traffic. But that was with bigger carbs and a minimal heatshield.

What temp thermostat have you got in it?

Drive it, if the noise gets worse then think about it more.

If it aint broke...

might have to get me one of them infra-red thingies
Rob Armstrong

Yes....the temps for water and oil are all great and vary happy with the oil pressure

But the issue is .... I cant drive more the 50 miles at a time and cant restart the car after re-start the car after 20 minutes of drivimg without cooling off the dissy, and coil...which have all test fine, and the carbs dont tend to work after an hour do to vaporisation, I what I found trying to get to wisconsin

Stripping the rhino linner off, is never going to happen....that would be an engine out job, and a huge mess to deal with...its one of those experments we have all talked about in the past, and im the 1st to try it....now we know, the end result. Nothing ventured nothing gained as the say

thanks guys....so is there nothing to worry about as far as the hum, other then try not to drive in that time frame that it is occuring in???

Hey at least the hot oil and low oil pressure issue is resolved

Killing off one grimlin at a time

Prop
Prop

That's the spirit.

I actually googled rhino lining engine bays, and there seems to be more people out there either doing it or thinking about it than I'd ever have thought.

Glad the oil cooler has done its job, though. Are we the only ones in the world with rubber mounted ones? I thought the wisdom was that shaky oil coolers were a BadThing (TM)

OSM.
OrangeSpyderMan

Thanks osm...

Its cool to be a trend setter isnt it....in 50 years people will look back to you and I and say, "WOW, THEY where forward looking thinkers, I cant imagne a world where oil coolers werent rubber mounted agianst vibration...who would have done such a thing as soild mounted oil coolers

Yepp...in 50 years you and I will be heros, and the subject of many engineering books

Hahahahaha

Prop
Prop

OSM - are you sure that the googling didn't just produce Prop - 100x over?!?!?!?!?!

As for your testing - well, to me it sounds like you had "New toy syndrome" ........ ;)

Prop - haven't you done those air holes yet anyway? Your claim to fame in 100 years time will be on google searches (or the equivalent) as the man who took the longest time EVER to build an engine - and had too much time on his hands to fill thinking up crazy mad ideas :)x
rachmacb

Wow, what a change Prop, a couple of weeks ago you thought you'd really messed up with the rhino liner and now it's going to be your claim to fame? When you get some miles on the car in some hot weather without problems then we'll see if you were such a great trend setter or not. Yes your 30 mile test road is fine, but I'd feel better when you've completed a hundred and thirty mile trip without problems.
B Young

Prop

When my son damaged his Bug Eye hood (bonnet)by sand blasting they fixed it as much as possible. He was not completely happy so I suggested louvers. $5 each at a Hot Rod shop and they look like they were always there. Go find another hood and run a couple of rows of louvers they are great at letting the heat out. Or as suggested above raise the back end of your hood.

K
Kelvin Hawkins

Prop just drive it - please!
rachmacb

What tune does it hum ?

Have you tried turning the stereo up, or ear plugs ? could be the simple way around it lol ;-}
K Harris

The hum might be a piece of gasket in the intake or exhaust tract, which is "humming" at the resonant point of 4200 rpm.
JM Morris

Prop,

How about a few photo's of the oil cooler install. As I recall you were not installing using the factory arrangement as most of us have. Perhaps we can better assist if we can see what Dr. Propenstein has been brewing up in the garage this time!

Regards,

Larry C.
Larry C '69 Midget

Ill do larry....but it will be this weekend the earlist

Prop
Prop

Prop,

I'd go with the suggestion of the louvers in the hood. It would look good and also think about it- heat rises!

Unless your temps change a lot when the weather there gets warmer, your oil temps actually look a bit cool to me. I always like to see the oil at around 220. The reason is that it will boil off any condnsation that has accumulated. Modern synthetics can take temps of over 300. We had a belt break on our Porsche and the oil temps went up to 300 or so. Replaced the belt and finished the race weekend and season with no problems.

Instead of cardboard, think about keeping some racers tape in the car. You have the option of how many rows to cover up and it is easily changed almost anywhere.
Tim Michnay

Hi Prop, reading the threads, maybe the louvered bonnet
might help. but a cold air supply to the carbs might
be a new project. i saw a lotus 11 which had spent
a long perfecting this, and was convinced gave him
good increase in performance.
Plus a B which fitted it said his carbs ran cool enough
for condensation!! are running a electric fan on the
radiator? if the temps were that high it would run all the time. regards Pete
P C Knightley

Prop,
IMHO putting holes in the fenders/wings will have little or no effect on the engine bay temp.
The ones you showed had very little space for heat to escape, and as has been mentioned HEAT RISES.

A louvered hood will certainly let much more heat escape than anything else you can do, and it wiill certainly look cool
If you find another hood to louver it will be that much less Rhino Liner

Just my two cents worth
Phil
Phil Burke

I love the title to this thread. Very poetic, Prop.

Do androids dream of electric sheep?
Mothy - '65 GAN3 and '65 HAN8

Hahaha....

Im sure Arie has an app for that.

I talked to Bill Young the other day for a bit, and he made a good observation, that perhaps my pertronix chip is on the verge of dying, so im goimg back to points and condensers and see if that solves anything,,,,as to the dissy not wanting to work after shut off after 30 miles without cooling it back down 1st

Hopefully thats the awnswer


Prop

Prop

Phil,

Pedantic mode on.

Heat doesn't really rise, what you're referring to is convection where heat causes a medium to become less dense so resulting in convection and the hotter medium rising. There are exceptions as water when it freezes exhibits the opposite effect, lucky fishes, as it becomes less dense and rises to the surface even though colder than the water below.

The other 2 means of heat transfer are radiation and conduction, neither of which exhibit a direction preference as such although heat will conduct from a hot region to a cold region.

That's enough being pedantic for one evening.
David Billington

http://www.youtube.com/watch?v=VtEqn-5XHpU

All you need to know, courtesy of Messrs Flanders and Swann.

Well before my time, you have my grandad to thank for this :)
Rob Armstrong

Prop,

Bill Yound is probably correct about the Pertronix, I also think you've baked it. But before you go too much further, humor me. Did you ever establish a proper ground (earth) for the coil and dizzy through that damn mystery Rhino-Liner?

Still waiting for the photo's of the oil cooler producing the strange harmonic's. Another beer, Alice, please.

Regards,

Larry C.
Larry C '69 Midget

You know larry....that is a real thought also,

perhaps I do need to run some extra grouNd wires, I did have some extra grounds over last winter and into spring, but removed them back in june....about the same time this occured, I did do a ohms, voltage xheck and everything looked okay

Sorry no photos of oil cooler as of yet, I worked thur the weekend and no time to play with the car...but ill get some later in the next few days...im burning the candle at both ends at the moment.


Prop

Prop

The answer to all of Prop's problems could be solved if the bonnet could be permanently welded shut.

Dave
D MATTHEWS

Agreed Dave!!
Tim Michnay

David,
Pedantic moment excused
I probably should have said "resulting in convection and the hotter medium rising"
As a 1st year law student (tommorow is day 3) I should have realized the subtle difference between heat and hotter medium.
As I now understand it, heat does not itself rise, the hotter air, medium, is what rises.
I think they are trying to teach me to be more pedantic; pretty tough at 57 years old.
Thanks, I need all the help I can get
Phil
Phil Burke

Prop,

Don't take Dave's advise too literally, put the Mig welder down. Imagine the limited access from below the car, and no one here will be able to assist!


Phil,

Law school, good luck to you sir. I should say, I also will be returning to university when I retire in two years (65), but that will be for non-credit and no tuition fee program for the residents over 60 years old!

Regards,

Larry C.
Larry C '69 Midget

Lol, larry

Thats another good reason for fender vents....access to the engune by

Phil.... hows that latin workin for ya, seriously this is america, you would think they would teach law in english....hahaha
Prop

Prop,
American law makes absolutely no sense whatsoever. By teaching them Latin, they make it easier to disguise his fact.
David "whatever happened to concepts like guilt?" Lieb
David Lieb

Lol...David,

Thats why we need lawers and latin teachers...otherwise the law would be common scence....and god forbid that idea if your a ceo or a politician

P
Prop

Prop,

Back to your original post, you were going to post a photo of the (non-standard) oil cooler installation for us. And, don't forget to add ground wires to the dizzy, and coil for a road test.

Regards,

Larry C.
Larry C '69 Midget

Sorry larry

still burning the candle at both ends....i havent opened the shop door in almost 2 weeks

But its fairly standard installation .... I think, well with some minor changes
Prop

This thread was discussed between 11/08/2011 and 19/08/2011

MG Midget and Sprite General index

This thread is from the archives. Join this live forum now