A few lessons we learned from that race:
-Hydraulic lifters are a wear item (replace them once in a while)
-Lighter weight hydraulic lifters are not necessarily a good thing
-Drivers come out of the car after driving a stint are not to touch anything mechanical
I purchased a motor that was "recently" rebuilt from an acquaintance I know from the VW world who also works as a non-VW dealer technician. So the thought was "we should be good". The previous owner did run a low boost super charger on it, but assured me that proper tuning was used to keep air/fuel ratios in check. We replaced a bunch of gaskets, installed it in the car, and took it over to DB Performance for a dyno session.
This motor made 11 less HP than our previous motor and smoked quite a bit out of the crank case breather and tail pipe.
Got the car back to the garage, did a compression test, the numbers were: Cyl#1=190psi, cyl#2=180, cyl#3=195, cyl#4=100. DOH! A leak down test on cyl#4 had bad news to. Pulled off the cylinder head and found that one of the ARP head studs had busted through a water jack, I am assuming that the hole had debris or too much oil in it. Remove the motor as it is junk. Pull out cylinder #4 to find the ring lands are busted. Good catch! It would have been moments away from disaster!
A few lessons learned:
-Don't trust other people to build motors, even if they are a dealer technician
-Compression test motor before going to a dyno session
What you are looking at, is a broken coolant jacket. The person who installed the ARP head studs did something majorly wrong to bust it out! Mostly like the bolt hole wasn't clean and or had oil/debris inside.
We acquired another motor with unknown history. A compression test was conducted with it out of the car and it passed, so we cleaned it up, swapped heads, our good bits, and installed it in the car. Got the car fired up, found it has an exhaust leak. Found a crack in the exhaust manifold. Right were the factory crimp on the tube.
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