<VV> Corsa update II

[Guus de Haan]

Thanks for all the feedback. Really appreciate it.

This way I can eliminate some things from my list. A summary from the  
answers I got and some answers to new questions from me.

- Temperature yesterday was about 77F. Not very hot I think for a  
normal working car.

- Thermostat doors. The doors fully open when the car gets warmed up.

- Fan belt glazed and/or slipping. I've installed a new one two weeks  
ago because the old one jumped of. Could be slipping, I'll check it  
and retighten it like suggested.

- Air hose on the shroud. The fresh air hose is not on this car  
because I'm missing the connection piece on the shroud. The hole in  
the shroud is now closed with a plate. No air leaks there.

- Dragging from any parts. Brakes seem to be okay, the car rolls on  
when I press the clutch when driving and there's no drag when I turn  
the wheels. The blower bearing turns freely without noise. So does  
the idler pulley. The alternator runs smooth and no noise. As far as  
I can tell this should be pretty much okay.

- Harmonic balancer slipping. This was replaced with a Dale one when  
the engine was rebuild 8 years ago. It seems to be in good condition  
and remember the engine has only done about 2000 miles since. Any  
other way of checking it apart from visually?

- Engine shrouds
My engine is missing the rear sheet metal that runs along the  
harmonic balancer. Of course it should be on but it wasn't on the car  
when I bought it. The previous owner drove the car without it for  
some years. But that was with the old 145 CI engine in it. I replaced  
it with the original 164 CI engine after restoration. It will  
influence cooling but really enough to make the engine run this hot?  
As far as removing the lower shrouds. I've just reinstalled those. Of  
course I could take them off again but temperatures aren't that high  
here. I also think the car should be able to operate with them  
installed in our cool climate, except for maybe on real hot days.

- Air blockages. I've removed the engine two years ago to remove as  
much casting flash as I could. But there are a lot of passages and  
maybe it still isn't good enough. There are no rags or anything like  
that blocking passages.

- Compression issues
Bob and Matt's simple explaination ruled out over tightened valves.  
Over tightened valves would mean low compression. Which it doesn't  
have.  Too high compression for a Turbo-charged engine? Could be the  
case but it was rebuilt with the correct parts as far as I know so  
there's not much I can do about that now. I checked the head no's a  
few years back and they are correct for a turbo car like mine.  
Suppose the compression is to high. Could I set the timing at a lower  
value and check if the temperature stays lower? Like it would be on a  
atmospheric Corvair?

- Ignition issues
Again thanks for pointing out that the retard unit on a turbo of  
course only works when there is pressure from the turbo. It's easy to  
forget these simply things while looking at everything at the same  
time. I can see the mark on the harmonic balancer start to move  
around when I rev it. I'll check again for som values from the  
mechanical advance. That said there doesn't seem to be very much  
indication that the ignition would really cause overheating.

- Temperature reading
Some of you suggested that 400F on the gauge is quite normal. Okay,  
but there are a few things that aren't. When idling the temperature  
drops to 300F or so which is nice and cool. This 400F can only be  
maintained at 40/50 mph! If I take it up to say 60 mph the  
temperature goes up again in the direction of 450 to 500F. This seems  
to be way to high for a car capable of doing over 100 mph eventually.  
Also when the engine gets that hot it starts to run rough like it's  
on 3 or 4 cylinders. Last week when this happened I also noticed the  
temperature/pressure light starts to glow when the engine returns to  
idle. This is definitely heat related. Yesterday I had the same again  
only less because I avoided the engine running too hot. I once had  
the buzzer come one (the first year I drove the car) because of  
overheating. Since then never again. I'm not sure if it's still working.

I'll check the last mentioned things (fan belt etc) but I fear more  
thorough measures have be taken to get this engine running a bit  
cooler. I'm a bit hesitant taking the car and really heating it up  
again. We more or less did that last sunday and like I said the  
result was a bad running and misfiring car.

Regards,

Guus de Haan
The Netherlands
'65 Corsa Turbo-Charged Cvt