Cooling problems...

[rebel]

Help guys, please! 

I know there is a cooling thread, but more about towing busses and I need info about a street bug.
My clubmate has a freshly built 94x78.8/42x37 044/FK10+1.4 (biggest enginge in town so far) and he has serious heat problems... The project is in the works for so long, that he's loosing the faith.
And the worst thing would be to loose a clubmate moving to different hobby... We are already so few here in Poland

Engine after a few miles is going hot - 110 degrees Celsius.
The fan shroud is a modified 1600 doghouse type, so no problem with crappy aftermarket shrouds. No auxiliary cooler yet though...
Is it possible, that poorly ported heads make the engine go hot?
We'll try everything - the thermotec tape will be installed this weekend....

What would you suggest?

[181]

Hi Rebel, you are from Poland right? Im in the CZ and have an 82x94, 10:5 CR combo with ported 043 and dual 48DRLAS (see my build thread). I run on at least 98RON fuel, better 100RON Shell. Keep an eye on your timing - no more then 28°BTDC at revs and check the A/F ratio, if you don´t have an A/F meter you can find out a lot by "reading" plug color. I have a 10W30 oil and small alu auxiliary cooler without electric fan.

Good luck!

[rebel]

Friend told me that the timing is about 28 @ revs and AFr reading vary from 10.8 to 12.5 I guess. I'm waiting for a more detaild written spec, so I could post here.
The cooler is on the way. I suggested him cutting a hole under the licence plate to get more air.

[Diederick/DVK]

try decklid offset stands first before cutting things up 
i aint an expert on AFR, but 10.8 sounds a bit lean and a lean mixture is not beneficial to the temperature...

it might help to get a reading of the head temp too. let's hope some of the knowledgeable loungers will respond!

[rebel]

Thanks for the input, Dieds I also suggested hit to get himself a headtem gauge. Do you possibly know which store has them?
As far as I know 10.8 is hellova rich He has shots in the muffler just after shutting off.

[Diederick/DVK]

my mistake then.
i bet csp can help you out and you'll have the parts quick.

[Bruce]

What oil is he using, and what is his oil pressure like?

[Jim Ratto]

Hi Rebel

the oil temp is going 110C in a few miles? (230F). I would rule out any easy fixes first.... could be as simple as a rag or something in fan, or maybe tar-board firewall got sucked to front of fan housing (covering the air intake), I've seen both happen a few times, sometimes destroying a motor.
If the OIL is getting that hot, that fast, something is wrong, really wrong and I do not think the problem lies in the tune of the engine. The heads would overheat, and eventually the oil as well. An easy way to see if the heads are baking, is have him pull valve covers and look in rocker chambers. If the heads inside (under rockers) is a dark-gold color, then the heads are running too hot. If they're silver, probably ok.
If the motor is getting air (no debris in fan/opening clear) I would say there is someting wrong internally, causing massive massive amounts of friction. I had a rocker gall up on rocker shaft years ago and it reacted like you are describing. Could be coil bind too. Could be rod bearing going away. I don't cutting holes or haging another cooler on the car is going to fix the root problem.

[qubek]

...(biggest enginge in town so far) ....

nope 

Still, I hope you will find the real source of the overheating soon. Just don't loose time on tapes and stuff like that.

[deano]

Don't know if this could be the problem, but here goes. I have seen some new cylinder heads coming out that have some serious problems with their lack of open space around the fins....These heads are from Auto Linea, and do not allow cool air to pass through around the ports. You can see this plainly if you look down around the intake ports, on either side near the spark plugs. Instead of being open, they are plugged or solid. We've seen sky-high head temps even with a stock compression/1600 engine. The fix was to drill out this area between the fins carefully, to open them back up. Temps went down right away.

[kingsburgphil]

Couple of thoughts. Has he verified the accuracy of his temp gauge/sending unit? Like others here I'm suspect of
the ignition timing setting/procedure. Of course it could be something stupid, like a foreign object in the muffler.
Or even over compensating for a gross vacuum leak? Sight unseen we're all just guessing, but between a parts issue
and an assembly procedure. I'd guess the latter of the two. 

[Fiatdude]

100 C =212 F and that really isn't that hot for oil (This is not a water you're monitoring)-- especially with no external oil cooler -- now if it was over 350 F now you should be worrying

[Torben Alstrup]

100 degree C. in a few miles, is hot.
There can be several problems.
- oil pressure relief valve is stuck so you bypass almost all of the oil.
- Bypass spring is broken.
- Bypass spring is too weak for the oil viskosity used. (that´s a long shot when its over a few miles, I know)
- As menthioned, tarboard gets sucked into fan.
- Seriusly lean running (but if the gauge is correct its not, more like too rich)
- Ignition is seriusly out. (Check with another timing gun)
- Too high CR for the combo.
- One of the main bearings, most likely the middle one has gone south due to lack of oil pressure or the engine has stood still foir too long, or simply worn.

Poor ported heads increase the engine temperature, but not that fast.

Find the problem instead of just adding an extra cooler. An engine like that should not heat up that fast, not even in warm weather. and extra oil cooling should not be needed unless you do sustained freeway speeds, or multiple stoplight races.
T

[Chris Andrews - The Mailman]

Rebel,

Perform an engine leak down test. http://www.aa1car.com/library/leakdown.htm The test may direct you to the source of the problem.

Keep the Lounge informed of your findings.

Respectfully,

Chris Andrews - The Mailman