<VV> Engine Temperature Issue

[Bruce Schug]

On Mar 20, 2007, at 8:06 PM, Luke Duddridge wrote:

> Hello All,
>
> I would appreciate some guidance with my vair.  It is a 150 hp '64' 
> Turbo Spyder.  You guys have given me some pretty good answers up to 
> now, so I am opting for another dip into your well of knowledge.
>
> It seems to be running okay with the exception that, to me, it's 
> running very hot.  On a cool spring day, In normal traffic, driving at 
> about 50 to 55 MPH the cylinder head temperature rises to 400 degrees. 
>  It may ultimately get higher and I am not giving it time to do so.  
> I've had the car for 9 months and I am still in the rebuilding 
> process, so I don't yet drive it far or for very long.
>
> After it gets that warm it gets the vapors and faints when I stop for 
> traffic.  Now, that maybe that I have the idle speed set to low and 
> I'm just not sure.

I presume you mean it vapor locks. Get an electric fuel pump to solve 
this.

>
> What I'd like to know is:
>
> 1.     Is 400 degrees abnormal?

No. The stock temp gauges aren't very accurate though so you can't be 
sure what you're running.

>
> 2.     If it's abnormal any suggestions as to where to look for the 
> problem? I've checked the belt it's good and the fan turns freely.
>
> 3.     I currently have the idle speed set at 800 rpm is that to low??

No. I'm not a turbo guy and can't tell you the correct speed. I'd idle 
it as low as it was comfortable running at, as long as it held oil 
pressure.
>
> 4.     What's the correct idle speed?

It sounds like you are running hot. Be sure the engine seals work well 
and that the winter deflector isn't letting hot air back into the 
engine area.

If you're driving it at too low an rpm it may not cool properly. Try 
downshifting in slower traffic and keeping the revs up. How much? 
Probably not below 1500 - maybe 2000.

The best way to have a cool running engine is to be sure it's clean and 
that the heads have been de-flashed completely. A dirty engine is hell 
to cool.

Re-read the previous sentence.

You might have to remove your lower shrouds to cool it.

Synthetic oil will cool better.

An auxiliary oil cooler will help cool it too.

Bruce





Bruce W. Schug
President, CORSA South Carolina
Greenville, SC
bwschug at charter.net

CORSA member since 1981

'67 Monza. "67AC140"