Foster98GT
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Who has them? What are the good and bad to them?
scarface said:how will you run pullies with a blower?
Snakebit said:scarface said:how will you run pullies with a blower?
im pretty sure the stockers will have to go back on :-\
Snakebit said:i have had them on EVERY stang I have ever had. 1 V-6 car / 3 5.0 cars / 5 4.6GT's / and 2 4 valve 4.6 Cobras and I have NEVER had a problem with them other than the alt pulley not charging enough for a big stereo. They are a good way to " free " up about 10hp for a low price. They average about 100 bucks....some a little more just depends on where you get them from. I would suggest them for a nice bolt-on.
blackfang said:I will not run a UDP for a 4V. The potential for the damage they cause isn't worth the 10 hp for me. They have been known to cause oil pum gear failure being the balancers aren't that great and have chewed up some gears and caused engine failures. Al Papito wont run them unless he has an ATI Dampner along with others. However atleast 9 motors have gone to the sh!tter because of them and Bob Cosby's motor was damaged but luckily he had billett oil pump gears which saved him.
Here's a pic of the crankshaft that came out of Bob Cosby's Cobra.
This engine had 12-15 dyno runs, 200 street miles and 32 1/4 miles passes.
The engine was torn down under an official NMRA protest in Kansas city after Bob reset the National record five times in one weekend and winning the event.
This engine had a small dia underdrive damper. The damage to the flats that drive the pump are obvious. Also obvious are the witness marks on the opposite side of the flats. (As EDO pointed out in one of the many oil pump threads) The crankshaft drives the pump, The pump does not drive the crank.
So.. There should be marks on the crank in only one direction ( Where all the damage is in the picture) Why are there marks on the opposite side?
The answer is the front of the crank is sizzling with harmonic vibration, Just like a giant tuning fork.
This vibration is passed on the the pump,Chains,sprockets,cams,valvetrain.
after the pump the next thing that fails are the cam sprocket bolts. Myself, Carlos Nazerino, and Joe Lynch come to mind. I warned Joe after i blew a very expensive engine. Joe's ran a year or so and was killed when a sprocket bolt failed.
This pic shows the beating the crank took. The only thing that saved this engine was the billet oil pump gears. Bob's engine was the last to leave my shop with a u/d damper, that was 2004.