Temp

Details I didn't but probably should have supplied:

Engine is out of a 1967 or 1968 std beetle, though car is 72 super. I Am not sure but I think it's a single port 1600. I know it's not dual ported.

Sensor is the VDO 300F installed with a T adapter with the stock oil pressure sensor. I am not sure where that puts it in the line, but you probably know.

I checked the oil before leaving this morning, it was fine but slightly low so I added a quarter quart. I do not have an oil filter, cooler, or sump.

Everything else is pretty much stock, 12V, alternator, non-doghouse style shroud and fan, std (but new) carb.

Where I'm coming from, is that I don't know if 220 would be insanely hot and I should stop the car and run away screaming, or what. (or even better stop it before it gets that hot). For all I know 240 is too hot, or maybe 300. I expected around 180-190 based on reasearch. So to me it seems like it's a little hot. But I'm not sure if it's, you know, really hot; or if it's ok.

Thanks,

Chronologic

It's on the high side of what I would expect, but not outrageous. That same engine running in a Bus would easily reach 250F and purr all day long.

I would go over the cooling system. Check that the flaps fully open (you DO have flaps?) and that there are no blockages in the fan inlet, like the tarboard.

It's hard to do, but if that engine sat in a garage for a while, there could be rodent nests buried deep inside the cyl fins. You would be surprised how ingenious those little critters can be,

Speedy Jim

Hey Speedy,

I think I'm safe from rodents! I had the cylinders out for inspection last fall. I also cleaned out the fan shroud with hose and let it dry before putting all the tin on. It did sit in the garage over the winter so I guess there is a chance. Thanks for the idea.

Um....I'm going to have to claim semi-ignorance here. I am not sure what you mean by flaps. My knowledge of the air passage is that it enters from the front (FIF) of the shroud by the fan, gets pushed down over the cylinders inside the cooling tin, and out, or if you have your heater channels open, some of it will come into your car to heat it.

The only flaps I know about are the ones that control the heater boxes. Those are closed, since it's summer. I can't think of any other flaps. If you could please give me roughly where they should be and what their basic function is I will check to see if I overlooked the little buggers. I feel like I know the parts of the car pretty will since I pretty much took the whole thing apart and put it back together. But sometimes you don't know what you don't know. Maybe my flaps were always missing....

So you are saying that if I stay below 240 I should consider it a "problem" to be fixed, but not necessarily something to freak out about?

Thanks,

Chronologic

Jan's write-up on flaps. and:

Great as usual. Thanks for the info.

Chronologic

FYI you guys are spot on every time. My bug does not have the thermostat or the "flaps". The PO must have been one of those people that didn't believe in them.

So I'll have to figure out how it was supposed to work and how to buy the replacement parts.

Thanks as always to the incredible VW wizards that you are.

Chronologic

I'm glad I saw this out there, I'm putting my engine back to together and someone told me I didn't need the flaps. I guess they were wrong. Luckily my car still has the original thermostat. Hopefully it is still good.

Thanks guys!

The flaps should be open if the spring is attached even if the thermostat has been removed so it should not cause overheating. Dennis

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Hi, I was told by a mechanic that in the seventies, it came as a manufacture order to take those flaps out... is it? I'm overhuling my engine this week and I've been "arguing" with him - he said it can make troubles... "maybe the thermostat will stop working etc". I thought maybe i'll put a cable to it - and do it manually... (helped by a temp gauge). what do you think ?

nachche

Absolutely. It was on the same bulletin that told the mechanics to neuter themselves with a ball-peen hammer.

Now what 'mechanic' told you that. Name!

Now that the stock type thermostats can't be had new any more, I've been toying with the idea of a cable operated system connected to a solenoid triggered by a thermocouple on the cylinder head. The flaps would be pulled open by springs and only close when there is power to the solenoid so it would have the same failsafe as the stock unit. There's a lot of little details to work out and right now it's only an idea...

Fortunately I don't need to do this right now. My Baja has a good thermostat but who know how long it will last.

Tony

For the guy that said that missing flaps couldn't cause overheating. I have done some reading on this, and I would be tempted to agree with you but here are some ways it could cause overheating:

1) the holes that are left in the fan shroud allow air to flow improperly. If you know anything about the bernouili (sp) principle, you know that air can do weird things when you are traveling at road velocity. That's why you need to have your decklid closed. It seems logical that an open decklid would provide better cooling, but the argument is that at road speed the air actually ends up sucking OUT of the engine compartment, which causes more hot air from the engine to get sucked into the intake for both the fan and the carb.

2) Your cylinders never get cooled properly. They run hotter. Your engine now has more of a temperature differential between the case and the heads. This can cause problems due to the thermal expansion properties of metals (of which there are several kinds along the line from the case to the heads).

3) In my case I think I am also missing a vital piece of tin at the top of the cylinders, intended to deflect air over the fins instead of straight down through the middle. I don't know for sure yet if this is part of the flaps assembly that was removed but if it is it fits in the "keep your flaps" category.

I have noticed, although I'm not yet positive, that my temp rises mostly only at highway speeds. If I'm cruising around town in 3rd gear (35mph-1500rpms) it doesn't seem to heat. But on the highway in 4th (70mph-1500rpms) it does. This would point to an air leak problem: IE my engine compartment is not properly sealed (maybe those flaps holes in the fan shroud) leading to hot air from below coming up and being recycled over the cylinders.

I tend to agree with the folks that say that VW spent a lot of money with the best engineers and equipment they had (albeit early equipment) measuring temperatures all over the engine in a variety of conditions. I'm pretty sure they didn't put the flaps on because they seemed cute. I'm pretty sure that they did it because they were having a problem and they were trying to solve it. Although they could have made a mistake, if I were to put money against me and the top VW engineers of the 60's I think I'd have to put my money on them!!! That's my take at this point. I don't claim to know everything but some of what I have read does make sense and even if it is not causing my extra heating it still sounds like a good idea to get those flaps back.

If nothing else, the flaps should heat the cylinders more quickly during warm up which would decrease wear, since without them the air is spread out over both the cylinders and the heads.

That's my contibutory two cents after reading up on the matter for several days.

By the way, I think you can still get a Mexican thermostat and from what I've heard they work fine. They aren't OEM for true classic show cars but other than that they should be a good option.

Chronologic