air cooled engine overheating

[Rincewind]

Me again

this van i'm considering going to look at is alledgedly over heating after 4-5hours driving

is this normal or is it hinting at problems within the engine somewhere??


if so where and what??

[HarryMann]

The cowlings and tinware, its rare for them to be correctly and fully refitted after any major work..

Plenty of threads on this and prob stuff in WIKI

Imperative tinware surrounding cooling fan is complete and sealed

[HarryMann]

Oh, weak mixture, air leaks

Overly retarded ignition timing

Leaky valves seats


But basically poor airflow around engine usually

[Rozzo]

how does he know its overheating? they do get hot, it's their speciality so what does he mean?

[dugcati]

4 or 5 hours is a heck of a long time to wait to see an engine overheat - if an engine has overheating issues I would expect it to show up in about 30-50 mins tops on any engine...

[HarryMann]

Good points...

So Rince, what is making him say that, has he an oiltemp gauge installed for instance?

Or is it starting to pink or detonate?

Loses power?

etc?

[dave friday]

if the ignition timing is too advanced it will over heat,sometimes the van will accelerate faster so some people set the timing this way [by ear] it may pink a bit but as they are quite noisy it's often over looked.

[Rincewind]

thanks for the replies guys

he just said that's just what Aircooled do

providing its nothing terminal, i'm happy to get it set up properly and make sure all the relevant tinware is where it wants to be

he did say that the van needed a good tune....

[toomanytoys]

4-5 hours then overheats...... rubbish........ it will do it within 5 mins of running up the road if its got an issue...

lots of factors can influence it..
is the thermostat working (if fitted... if its been removed then its always in the "max cooling" position)
Air leaks on carbs/manifolds
Badly adjusted timing
badly adjusted carbs/blocked jets
missing tinwork (the amount of engines I have seen with missing tin or seal... I am amazed there are not more engines broken...) Missing/badly fitted tinwork and seal is like not putting water in a water cooled and you wouldnt do that would you.......????
Low oil level
Blocked oil cooler.. this is a big one... the oil takes away something like 50% of the heat in an Aircooled....
Blocked fan...
poor adjustment to fan belt (no an issue on the type 4 engine and 1.6 CT as the fan is bolted directly to the crank.)

Badly adjusted ingintion timing is prob the biggest killer... and its regarded that the vw settings are a little retarded... this generates far too much heat in the heads...

A top tip for any aircool'd is.... after a hard climb or a motorway thrash... NEVER just turn the engine off... let it do 2 or 3 mins of fast idle (1500rpm) this will cool the engine and oil and prevent "heat soak".......

[Rincewind]

i feel that, with being in north lincs, and you in South Lincs, i could well be employing your time...

[toomanytoys]

Just give us a shout...