[T3] Tight exhaust valves

[Jacob Adam Schroeder]

Bob,
Thanks for this information, I have some responses below.


> Your MOFOCO heads are designed and cast in the USA, and that's  where
> they've always been made. They basically copied the VW head, but made  some
> changes to allow for them to be opened up, in both the breathing and size
>  of the
> cylinders. This was something that the original VW heads lacked (being
> able to be opened up for larger engines without welding).
>
>
Now I'm really curious to see what is stamped under my valve covers.  My
memory has faded over the past 15 years, but I thought I got my heads from
MOFOCO (I got several parts from them for my rebuild) even though they have
VW cast into them.  I could be totally wrong, but I am interested now.


> If you  feel that the engine is running hot, then I'd look to make sure
> that ALL of  the cooling tin is in place first. That tin (while seeming
> small
> in places)  was there for a reason. VW didn't just add it to make life
> difficult, they put  it there because they felt it was needed.


When I built the engine, I used every piece of tin that came off of the
original engine.  I believe I'm working from a complete set (including
those little pieces around the cylinders, etc.).  So I should be good on
this front.



> I'd also look to
> see if the  foam pad is in place above the oil cooler so that all of the
> cooling air  passes thru the oil cooler like it was designed to.


I do remember this foam being there on the cooler I used for the rebuild.
The original engine threw a rod, so I did not re-use the old cooler (out of
fear that it would have metal shards in it).  I used a cooler from another
'72 T3 engine and it had the foam in tact.  In hindsight, it was not
pristine, but at this point I don't think there is much I can do.


> Also, make sure
> your  thermostat is working correctly and that the flaps are opening.


My thermostat is not installed, but what I did was remove the flaps from
the fan housing.  Although not stock, this should not  pose an overheating
problem, right?

Make
> sure  there are no tears in the large cooling bellows, and that both clamps
> are in  place.


This is good, for now.  I am using the OTT exhaust so I have been
monitoring the bellows closely.


> I know some of this sounds simple, but you'd be surprised at
> how many  engines are out there with some or all of these little items
> missing or  defective (especially in California). :O
>
You might also want to double check your timing, as that has a direct
> effect on engine heat (too much and it'll run hot, too little and it'll run
> hot).


On the timing issue, I have a '72 and I follow the procedure in Bentley
(roughly: set idle, confirm throttle is closed by pulling 1 dist. hose and
observing timing mark, pull & plug both hoses, reset idle, time, re-connect
hoses, reset idle).  When I have both distributor hoses off to set the
timing, my engine always surges a bit, so the timing mark moves.  I just
get it so the center of the swing is the proper timing and assume that is
OK.

If anybody else has a '72 out there, do you experience this similar surging
at idle when both your distributor hoses are disconnected?  It is maybe a
swing from 820-870 (so still within the 850 +/- 50), but enough to make the
timing mark move.

If my surging idle is not right and part of me knows it probably is not,
perhaps I have a vacuum leak (or maybe I'm not plugging the hoses well
enough).  This could be a culprit of making the engine run hot.  The idle
does not surge when I have all the hoses connected to my distributor, so my
guess is that my "golf tee" vacuum hose plugs are not plugging good
enough.  I have not replaced the vacuum hoses (some may be from the donor
engine 15+ years ago) and I am probably due for that too.  I'll add those
parts to my shopping list.


> If you have FI, then check the fuel pressure as well.


I checked this recently and confirmed 28 psi.


> These are all
> little things that can effect engine temp.
> Sorry, I got into a bit of a rant, but sometimes things just need to  be
> said that us "old guys" sometimes take for granted. ;-) I hope this  helps.
>
> Bob: I don't mind and all and thanks for taking the time.  It helps us
"young guys" to hear the "old guys" thought processes so that we can try to
emulate it when we're diagnosing an issue.  In the 15+ years I have had my
car, it has only seen the shop < 5 times thanks to the help from everybody
here.
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