It has also always seemed when you break in a new motor or car or bike easily, it ends up being a pooch. Those that hammer the hell out of them right from the start usually have the fast sh!t. Like you, not sure why.



Bill

Ever seen this before
 

Very true about hammering motors.. Pantera with
a fresh motor 10 years ago went on the trailer, off
the trailer and onto the race track.... never had any
other motor run over a year and 1/2

Bob

That whole break in thing is old school back when rings were different and tolerances for motors were different. Nowadays - the rings are "seated" by the time you've degreed the cam... and with roller cams - we've eliminated the face/lobe mating... Pretty much anymore - you install a motor - fire it off and go racing.

Good information. I always thought the sheet metal ones looked cheap, but never thought about fatigue cracking like that. I guess they probably don't pump as efficiently, but have nothing really to back that up, other than it doesn't look like much like a turbo scroll.

I agree 100%. It doesn't make sense, but it still seems to me the guys who beat on their cars, have faster cars.
FWIW, this is not the only instance my experiences/ beliefs make no scientific or logical sense. How about those "lucky" people who win all the time playing pull tabs/ slot machines/ or drawings? Or get great hand after great hand playing blackjack or poker? Makes absolutely no sense. Me? I NEVER win. Of course, I very seldom play. Hmmm, maybe that's why.


Bill

The story gets another chapter.
I got the upgraded stage 4 Stewart pump back, put the car back together, and took it for a ride. Got maybe 5 miles on it, and jumped on it in 2nd gear. Ran it up to maybe 5 grand. A minute later, noticed the gauge was at 210. Pulled to a side street & popped the hood. Was greeted to a motor covered with anti-freeze, and a gusher spraying from the pump. When it slowed down, I could see it had blown the gasket for the rear plate of the pump.

Another 2 hour disassembly (I'm getting good at it) revealed this...



http://i1113.photobucket.com/albums/...6/IMG_1508.jpg

My motor builder had tried to warn me NOT to run a thermostat, especially with the upgraded pump, saying we don't need one, and it is too restrictive. He says we control water temp with the electric fans, and the thermostat needs to go.
The pump obviously made so much pressure, something had to give. I have no other idea how to eliminate the pressure other than to ditch the 'stat.
I made a new gasket, glued it in place with Hi Tack, and put it back together. this time WITHOUT the stat. Drove it about 5 miles, it ran up to about 180, the fans kicked on, and dropped it back to about 170 (where they are set to turn on & off). So far, so good.

Of course now I'm gun shy, gonna stay close to home until I get a few more miles under my belt.
In the meantime, I hope I don't get a ticket for inattentive driving while fixating on the temp gauge!

I hope this is the end of the story....


Bill

Lots of folks seldom, if ever, look down at their gauges while driving, so good for you, for catching this in time...again. High rpm's and thermostats usually don't mix. I found that running a restrictor in my water neck, not a thermostat, made my cars run cooler, because it kept the water in the radiator a tad longer, thus giving the water more time to cool. This was not on street engines, but race engines at high rpm's. Something to think about when summer temps arrive here shortly. Don't you hate it when your engine builder is right?

HAHAHA. I sure do. He is the smartest (engine) guy I know. But in his late 60's, he is also pretty old school. And very opinionated. The F/I thing is just a little too new fashioned for him. He still contends the carburetor is a better way to go. It is simpler, smarter, & easier to tune. I think in the hands of a capable tuner, the FI is hard to beat, especially on a street car.


Bill

I'm going to disagree with your engine builders opinion of controlling the temp with the fans, while that will work at low speed in traffic, it will not work when moving at highway speeds with airflow through the radiator. Fwiw I have a 750+ hp enine that spins to 8K and it cools just fine with a stock GM pump and 195* thermostat. Imho there's no need for fancy high flow water pumps, running the engine too cool is not good for it either. Ideally you want it warm enough to get the oil to get to 212* to boil out the condensation.

My builder's opinion/experience is way more complex than what I typed above. I didn't want to type a long diatribe, and most don't want to read it. I don't claim to know all he does, but he agrees you need oil temp. But oil temp runs considerably hotter than water temp, and (in his opinion) you don't need or want that much water temp.
A little more info... My motor has about 11.5:1 static C.R., and the cam timing provides for about 220 lbs cranking compression. I use 92 octane gas. I have a 6 speed & 3.55 gears, so in "touring" mode, I am at about 1500 rpm at 65 mph. Another factor is I can sometimes get stuck in traffic on a 90 degree day, and with a black car, want to be able to run the A/C. (What is the point of having A/C if you can't use it?) With this setup, we want to control the temperature as much as possible. His biggest concern is detonation. And I think we can all agree that higher combustion temps lead to detonation.
My car has the Vintage Air Frontrunner system, which comes with the Stewart pump. Do I need it? I don't know, but as long as it was engineered that way, I will run it if I can.
My motor is new, with more static & way more dynamic compression. I also have a new larger radiator with larger fans. And now the "new" pump. Dialing this in is a learning experience for me. I have always run a 'stat in my cars, and read years ago you needed the restriction the 'stat provides to create higher pressure in the block to prevent hot spots from locally boiling coolant in the heads. I had installed it with the new pump, but it obviously didn't do well with that restriction. I can control the fans with my ECU, and (so far) it seems to work well.
Drove about 60 miles on Saturday... it ran at 150 in 55 degree weather, and about 165 when it warmed up to 75. Drove it about 50 miles yesterday in 80 degree weather, sometimes with the A/C on, and it never went over 180. I am very happy when the gauge is under 200.
Time will tell about the city vs. highway speeds, and 90 degree days with A/C. But so far, so good.

And thanks for weighing in!


Bill