[DeTomaso] head drilling for air release

[Asa Jay Laughton]

Tony,
All good questions, see responses in-line:

Tony DiGiovanna wrote:
> Asa,
> Here's some more crazy things to check (been to all of them):
> Is the thermostat right-side up?
>   
Yes most definitely.
> Is the thermostat opening?  I usually run without one anyway.  That's not a
> bad place to start.
>   
This is the point most agree needs to be checked.  I'll boil it when I 
get it out.
> Is there an un-supported length of hose on the inlet side of the water pump
> that is sucking closed?
>   
Nope, it's all Green Stripe, extremely short lengths.
> I once had a hose where the inner half separated from the outer half and the
> inner half collapsed shut even though there was one of those helical spring
> supports in it.  It looked and felt fine from the outside (cost me an engine
> it did.)
> You gotta watch new water pumps: There's a crapload of  potential mfg errors
> that can affect you, e.g. impellers designed for the opposite rotation.  I
> once bought two waterpumps of the same mfr and PN.  The impeller design was
> a bit different between them, enough so that one overheated at idle and the
> other did not.
>   
I thought about this on the way home.  I'll compare the impeller photo 
on my Flow Kooler to the photo John Taphorn sent me.
> Try disconnecting the water pipes at the front of the cockpit and use a
> garden hose to flow water backwards thru the radiator.  Sometimes you can
> expel crap that gets caught in the tube entrances.  Once, at a track event,
> I reversed the lines to reverse the flow in the radiator.  Overheating went
> away.  I didn't even miss a session.
>   
A decent idea, but I know all the lines are brand new with no crap and 
the radiator was flushed prior to putting it back in.  I have a TEFBA 
filter on the outlet side of the engine, hoping to catch the crap as it 
exits and before it makes its way to any other parts.  I checked it last 
night and it was clean as a whistle.
> Not sure why, but when I fill my coolant system, I always have some air that
> bleeds out of the petcocks in the back of my heads.  Not sure if it really
> is an issue, but it is there.
I don't doubt this due to the engine orientation.  You would probably 
get some out the front as well, since the coolant has to go -down- back 
into the block before it can exit.  I honestly don't think an excess of 
air was my problem.  Flow was the problem.

I appreciate you sharing, they are all very good points to check.  Thank 
you,
Asa Jay