Originally Posted By MR_P_BODY
Originally Posted By B3RE
Originally Posted By Jamie McGrath
Hummmm, just throwing this out there but same issue with two different brand heads? I assume the same brand housing/wp and thermostat? We all have our pet brands, could the hole in the thermostat not be bleeding?

No stat during test or dyno runs. No issue with Edelbrock heads, only the Trick Flow heads. We also tried a Shogun stand alone pump with the same results, so I'm reluctant to blame the water pump in this case. For all I know, there may be something hinky in the block passages that I couldn't see. No matter, I gave the customer instructions to purge the air and avoid overheating once he gets it in the car.


I had a issue on all of my W-type heads... I had a
piece of clear plexi tubing in the upper radiator
hose to see if water was moving... I would run the
engine(in the car) and get it to about 140* and shut
it down.. then turn on the pump(electric) and it would
start to flow..let the pump run about 5 minutes then fire
up the engine... once it purged the air it never had any
more issues unless I drained the water.. and had to do it
all over again... but the clear tube was a BIG HELP
wave

Mike, That's pretty much what I had to do, sans the clear tube. That would have been a big help. On the test stand, I would start the motor and the temp would slowly start coming up and then start climbing rapidly, so I would shut it down. I had to repeat that about five or six times. Not such a big deal on a roller cam, but now I'm working on a flat tappet build with these heads, and I don't want to be shutting it down multiple times during the cam break in. A judiciously placed bleeder port would be a good idea, if I knew where judicious was.

Don, not a bad idea, but I don't have one because I've never needed one before. Surprisingly, no, I've never hotrodded a VW Rabbit grin. We used to drive a diesel Rabbit like it was a hotrod though. I might have to invest in one for instances like this.

Mike Beachel

I didn't write the rules of math nor create the laws of physics, I am just bound by them.