1982 Westy runs too hot

jkoch · Post by **jkoch** » Wed Jun 26, 2002 11:24 pm

I have a 1982 Westy with a recently rebuilt engine (600 miles) with new AMC heads & two VDO temp sensors (oil temp & #3 plug temp.) I use Texaco 91 octane gas and Kendal 20W50 GT-1 oil. I live in Colorado: thin air and mtn. passes. On the open road oil gets up to 250 F & plug temp to 450 F. On climbing grades oil gets up to 275 F and plug hovers between 400 to 450 F. Ignition timing & air flow settings have been varied with no success. Any suggestions?

Michael Ghia · Post by **Michael Ghia** » Thu Jun 27, 2002 2:33 am

Oil temp is the critical temp to me. I would use head temp as an idea of what is normal and when something bad is likely to happen

I'd check that the engine bay seal is intact and giving the best seal you can make. Any leak at all will let in hot air from under the van and cause an unbelievable amount of over heating.
Are you sure that the flaps are opening fully?
275oF is too hot for the oil. 250 is the max I'd go to so I'd look at adding a sandwhich plate between the oil filter and engine and run an external oil cooler with thermostat.
What kind of speeds are you driving at when it's getting this hot?
MG

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Modification is a form of Art.

Bert · Post by **Bert** » Thu Jun 27, 2002 8:18 am

Michael, what flaps are you talking about ? Do you mean the heater control flaps ? If so maybe you could tell me how they should be positioned on my '79 the cables were seized so the previous owner had just zap strapped the controls open I think ...this spring I just cut the zap straps and let the flaps hang open ...should I zap them in a fixed position? If so what position should they be in ? Thanks again ,I'll have to attach them before holidays I'm due to travel to Ontario on Saturday via the Trans-Canada ...... wahoo

rich2481 · Post by **rich2481** » Thu Jun 27, 2002 9:10 am

I have to agree, check your flaps, your cable and your thermostat. Maybe someone left the flap out by the oil cooler also

Michael Ghia · Post by **Michael Ghia** » Fri Jun 28, 2002 5:24 pm

The flaps I'm talking about are inside the fanshroud and should be open all the time if there is not thermostat. This is not part of the heating system for the van.
If the thermostat and flaps are not working properly, your engine will be having a hard time of it.
Get yourself a manual with a diagram of the cooling system and then check that all the flaps are atleast open fully.
It may be that one is stuck half closed. There is a spring fitted as standard to stop this from happening but it sounds like someone's been messing with the flaps big time!
Fit a thermostat... it's the only way which your engine will run happily as VW intended. Otherwise it will take longer to get to the normal operating temperature and that causes wear... which causes overheating and loss of power etc etc etc... you get the idea

Good luck.

MG

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Modification is a form of Art.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Thu Jul 04, 2002 9:50 am

I spoke to this fellow a few days ago....

Seems that someone killed his CR, added a bigger cam and proceeded to fiddle with the mixture of the AFM...The engine is "Well done" Another one falls prey to misinformation, to make it all worse, he lives at altitude....

Hmmn, no air to cool or atomize, no vacuum signal for induction, and a big cam to kill his torque, sounds like a rich running, 5 MPG pig..

alsehendo · Post by **alsehendo** » Wed Jul 10, 2002 10:41 pm

No or bad seal around tin will make oil temps run 30 to 50 degrees hotter.

Vgonman · Post by **Vgonman** » Thu Jul 11, 2002 2:18 am

Those flaps will only open on default if the person installing them hooked the little spring up right.........otherwise they just will flop around. You really need to have your exaust gas set professionally. You could be running way lean.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Wed Jul 17, 2002 9:54 pm

it is 100% impossible to set up exhaust gas on an engine with a killed CR, bigger cam than stock(dropping dynamic CR tremendously) and all that plus Colorado altitude...This bus engine is "well done" another one bites the dust..

ray greenwood · Post by **ray greenwood** » Thu Jul 18, 2002 7:47 am

Too low of a compression ratio...especially on the lean burn fuel injected engines has always been a big problem. They ALWAYS run too hot. They get poor mixture, poor combustion and even poorer cooling to the valves from the incoming fuel/air charge because velocities are usually down. I agree that it is nearly impossible to set the fuel mixture up on an engine like that, because what you get at idle on the machine, and without load in the higher rpms...will always be really different that what it runs while in motion. When they originally started dropping compression ratios in engines, it was in response to seriously poor fuel. It was to prevent detonation. The fuel is not the problem so much these days. Now people are in the habit of selling low compression set-ups ...still...these days in the belief that your engine will not survive without them. A low compression type 4 will survive better with carbs. The fuel air mix tends to be pulled into the cylinder during the full duration of valve opening and intake draw. Yes, you will have to run the carbs a little richer than you would need to on a properly set fuel injected vehicle to stay cool, but at low compression in the injected engine, you will have to run grossly rich ...just to keep an even mixture. This makes very poor horsepower. Ray

germansupplyscott · Post by **germansupplyscott** » Thu Jul 18, 2002 10:07 am

ray,

when i was building my '79 bus motor, i had conflicting advice on setting the CR. during final assembly i had to decide on leaving the shims i had off, and going to about 7.9:1 or keeping them on for 7.5:1. i think i may have even pmailed you on this one. i was told by at least one person i trust not to exceed 7.8:1 in a bus motor, so i kept the shims, ending up at close to 7.5:1. it has stock FI. and it does have to be set rich in order to run well and cool. it runs cool, and well, but it is definitely too rich, especially for city driving. it also seems to want quite a bit of advance.

my question is this: what would be the CR you'd recommend for this type of engine in my camper? i'll be pulling the motor in a short while, and i might make some changes.

scott lyons

ray greenwood · Post by **ray greenwood** » Thu Jul 18, 2002 3:05 pm

A lot of people may tell you to keep the cr low because of the load on this engine in the bus. I personnally think 7.5:1 is a tad low. It does cause mixing problems. A chunk of these mixing problems also have to do with the alterations to the vacume signature...and what that does to advance and airflow through either the MPS or AFM...depending on the injection system. Most of it is just poor combustion and less velocity . I would think about 7.8:1 would be a conservative cr. A little more efficient cr, which would definately require careful watch over fuel and advance...but would deliver better power, would be a little over 8.0:1. These seem like very modest and small compression changes...many will scoff, but it is less about increasing the compression for added power than it is for maintaining mixture control by getting the vacume and velocity parameters back into the range of sensitivity the metering unit was set up for. The symptom is that is you lean it out at idle on the machine...so its running correctly, it stays just too lean all the way through the curve, as the velocity gets too low to meter in the extra fuel to go with the advance rate. Setting it rich enough for driving range...usually causes it to be very rich at idle, causing stumbles/sluggishness off the line and poor fuel milage. Ray

germansupplyscott · Post by **germansupplyscott** » Thu Jul 18, 2002 5:03 pm

ray,

mostly what the rich condition causes is a black tailpipe and probably, carboned up rings.

how is compression ratio linked to manifold vacuum? i take it that the increase in compression should create more vacuum?

with the web #73, i have slightly low vacuum at idle, like 15in, as opposed to the 18+ that it "should" be. tuning does not seem to affect this very much. i am already far enough advanced. (11 deg idle). i know that more valve overlap will reduce manifold vacuum, but should higher compression in turn increase it? so therefore, the modified cam i am running would benefit from higher CR, much more so than if i were running a stock cam.

with unlimited time for experimentation, dyno software, real dyno machines and the like, such discussions are somewhat moot, but for me, this forum is in a way my virtual test bed, so all conjecture is appreciated.

scott lyons

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Thu Jul 18, 2002 5:47 pm

The absolute lowest staic CR I will use is 7.8:1, even in a bus...

I have a 73 grind based cam in my company powerstroke 2109 engine with Pauter 1.48 rockers, it has 8.8:1 static CR, runs 350 head temps with a 3000 pound load of engines, 190 degree oil temps cruising 85MPH for over an hour straight,Exhaust Gas Temps are a tad over 1000 degrees at cruise and have touched 1200 once at WOT running 110 MPH racing some dude in a chevy S-10.. The animal gets 24-27MPG with my CIS injection system.

Compression does not make more heat, misconceptions and poor combinations do that!!!

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Jake Raby
Raby's Aircooled Technology
www.aircooledtechnology.com

PEPPE · Post by **PEPPE** » Fri Jul 19, 2002 4:02 am

it' s right.
i had an engine run 20% hotter reducing compression from 8.5:1 to 7.6:1

I installed shims and losed tight deck and power too
Peppe