Oil in the #4 combustion chamber!

[Sylvester]

Who knows, maybe it was "too cool" before.

Everything about me is "Too Cool"!

Cool Hand Sluggo! Great story and write up!

[Amskeptic]

According to the VDO It's getting up to 490* on a steep incline. Average highway temps are about 375*.

That is a dangerous sign of why you had a problem. Remember my "Anomalies are the more likely culprit, a short hot day freeway run with a horrible fuel mixture", You betcha. What fuel system do you have on this engine? Factory FI?
Colin

[hambone]

So, you can have a cool engine but hot heads? I thought the engine was like 1 big heat sink, hot is hot allover. It would seem that an overheating engine would be pretty obvious: smells, lack of power, etc. But then again I've never deviated from stock besides an 009.

[Sluggo]

According to the VDO It's getting up to 490* on a steep incline. Average highway temps are about 375*.

That is a dangerous sign of why you had a problem. Remember my "Anomalies are the more likely culprit, a short hot day freeway run with a horrible fuel mixture", You betcha. What fuel system do you have on this engine? Factory FI?
Colin

Dual Weber 36 IDFs with a hex bar. Opened up the mixture a little today and it seems to be better.

[chitwnvw]

490? Yikes, I almost soiled myself when I saw 450! Luckily this engine broke in and this last road trip to Des Moines saw no hotter than 417 on some pretty steep and extended inclines.

[Amskeptic]

According to the VDO It's getting up to 490* on a steep incline. Average highway temps are about 375*.

That is a dangerous sign of why you had a problem. Remember my "Anomalies are the more likely culprit, a short hot day freeway run with a horrible fuel mixture", You betcha. What fuel system do you have on this engine? Factory FI?
Colin

Dual Weber 36 IDFs with a hex bar. Opened up the mixture a little today and it seems to be better.

Remember that only the main jets are responsible for the mixture out on the road. If you are running hot under load at speed, you need to up the main jets. Are these the carbs from your old bus? Geeze, I don't even know what you are running. Was the old bus already at 2 liters?
Colin

[Sluggo]

Remember that only the main jets are responsible for the mixture out on the road. If you are running hot under load at speed, you need to up the main jets. Are these the carbs from your old bus? Geeze, I don't even know what you are running. Was the old bus already at 2 liters?
Colin

I'll check the mains. I have a whole set of jets. I think I have 130's in there. I can bump em up to 135. I changed em right before I moved to Oregon.

These are the carbs from my old Bus and the engine has been 2 liters since I rebuilt it in 2005.

[Lanval]

So, you can have a cool engine but hot heads? I thought the engine was like 1 big heat sink, hot is hot allover. It would seem that an overheating engine would be pretty obvious: smells, lack of power, etc. But then again I've never deviated from stock besides an 009.

If I understand my observational experience right, it's more of a balancing act.

Since the oil is cooling the engine, there is a correspondent rise in oil temp when the head temps go down. For example; if you're sitting at a light, the engine isn't working much ~ head temps down. The oil is absorbing the heat coming off the engine, but isn't being cooled much ~ oil temps up.

Working properly, my AC vanagon would balance out around Colin's sweet spot of 220F oil temp and 350-400 head temp (depending on the rise/fall of the road and other factors). I knocked it out of whack though, two years ago. Drove to Vegas during the daytime in August. Going up the last large incline at 35 mph saw the following temps:

Oil 270
Head 430

That oil was really working hard... Made it to Vegas and back though.

Best,

L

[Amskeptic]

So, you can have a cool engine but hot heads? I thought the engine was like 1 big heat sink, hot is hot allover. It would seem that an overheating engine would be pretty obvious: smells, lack of power, etc. But then again I've never deviated from stock besides an 009.

If I understand my observational experience right, it's more of a balancing act.

Since the oil is cooling the engine, there is a correspondent rise in oil temp when the head temps go down. For example; if you're sitting at a light, the engine isn't working much ~ head temps down. The oil is absorbing the heat coming off the engine, but isn't being cooled much ~ oil temps up.

Depends.
The oil will absorb head heat in the rocker area under load and bring it to the sump. The pistons will absorb bucketloads of heat at the same time and heat up the oil splashing on their undersides. The heads will heat up the quickest on this uphill. Downhill, the heads will cool soonest, but *they are still hotter than everything else* and the heat graph is still going up in the heavy metal like connecting rods and crankshaft. As long as the engine is moving, the crankcase fins help the oil arrive at "homeostasis". When you pull into the gas pumps and shut off the engine, the exhaust and heads cool down quickly 800s on down at the exhaust valves, head material will be in the 400s and falling but that heat is still hotter than the case and the oil and they will *rise* in temperature as you sit at the pumps.
Colin

[Sluggo]

Went on a three hour each way camping trip this weekend. Lot's of hills. Ran like a champ the entire time. Still not even one drop of oil under the engine. The highest temp I saw was 455. Usually ran between 410 & 440 up hills. 375 to 410 on flat land. About 325 at idle.

Checked my mains and they are 135 which is pretty big. I have a thought though. About 10 months ago I changed out the needles to 50's from 75's. Could this have caused the float bowls to be almost drained at full throttle and cause a lean condition thus over heating the heads?

[Amskeptic]

Went on a three hour each way camping trip this weekend. Lot's of hills. Ran like a champ the entire time. Still not even one drop of oil under the engine. The highest temp I saw was 455. Usually ran between 410 & 440 up hills. 375 to 410 on flat land. About 325 at idle.

Checked my mains and they are 135 which is pretty big. I have a thought though. About 10 months ago I changed out the needles to 50's from 75's. Could this have caused the float bowls to be almost drained at full throttle and cause a lean condition thus over heating the heads?

Needles? Numbered why?

Most freshly overhauled engines run hotter with new rings and bearings, etc, but you just have new heads, right?
Colin

[Sluggo]

Needles? Numbered why?

Most freshly overhauled engines run hotter with new rings and bearings, etc, but you just have new heads, right?
Colin

Same heads. 3/4 side was rebuilt. Needles numbered as to how quickly they let fuel into the bowl. Read somewhere that Busses with Weber IDFs need 50's and that 75's were too big. I had 75's so I thought it might help prevent overflow/overfill.

[Amskeptic]

Needles numbered as to how quickly they let fuel into the bowl. Read somewhere that Busses with Weber IDFs need 50's and that 75's were too big. I had 75's so I thought it might help prevent overflow/overfill.

But level is determined by the float adjustment, right? So restricted fuel intake would give you a steadily developing lean-out on the road? It seems weird to me that they would try to meter fuel inlet volume, fricken Italians.
Colin?

[Sluggo]

Went to get my DEQ test today and fail the HC test. First time HC was 2001. Bumped up the idle and advanced the timing slightly then came back and got two tries. First was 1510 then 1591. Way over the 300 limit for HC. Then, when I got home, I saw lot's of white smoke coming out the tailpipe. Made sure the timing, idle & mixture were good but still got lot's of white smoke while idling and more while revving. Any clues? Just had a valve guide replaced and replace the P&Cs with good used ones.

[Amskeptic]

Went to get my DEQ test today and fail the HC test. First time HC was 2001. Bumped up the idle and advanced the timing slightly then came back and got two tries. First was 1510 then 1591. Way over the 300 limit for HC. Then, when I got home, I saw lot's of white smoke coming out the tailpipe. Made sure the timing, idle & mixture were good but still got lot's of white smoke while idling and more while revving. Any clues? Just had a valve guide replaced and replace the P&Cs with good used ones.

Did you smell the smoke? Lots of white is usually a blown head gasket allowing antifreeze into the combustion chambers. That would be a problem in an air-cooled bus.

White smoke in an air-cooled engine is insanely insanely rich UNburned fuel.

You have got to diagnose this thing. White smoke? Is it idling smooth or is there a miss? Dead cylinder? Did you do the pump-the-brake-pedal outside of the testing station to see where your mixture was? No sense in blowing money. I do that test to make sure my mixture is correctly lean. If the idle *ever* went up when I pumped the brake pedal, I would just drive past the station and adjust. Those aftermarket carbs suck. Period.