smaller water pump pulley
- Thread starter MRHP
- Start date
Showcars shows a 6" pulley #6477 that will overdrive the pump 20% Leo http://www.show-cars.com/02 Engine Ext. 2.htm
You can get a 5 3/4" Water Pump Pulley which are found on 62-64 327 with A/C or 327/300HP engines
or Ecklers has the 6" pulley cheaper... http://www.lategreatchevy.com/chevy...oove-small-block-and-348-409ci-1955-1972.html
or if you want it in aluminum Summit has a 5 7/8" pulley http://www.summitracing.com/parts/CTR-75-150/
or Ecklers has the 6" pulley cheaper... http://www.lategreatchevy.com/chevy...oove-small-block-and-348-409ci-1955-1972.html
or if you want it in aluminum Summit has a 5 7/8" pulley http://www.summitracing.com/parts/CTR-75-150/
Thanks guys! I went to my mechanics house and guess what, he was removing his aluminum 5 1/2 inch pulley from his stock car and replacing it with another one of a different size. You know what came home with me don't you? Yep, perfect fit. Just gotta paint it and get a shorter belt. Thanks guys! Hopefully it will drop my temps 10-20 degrees and make me happy. It never got over 200 but I would like a little insurance as it was still climbing slowly. My mechanic Jesse also has had success with a direct 4 blade steel fan. If my clutch fan still is struggling, I will try it. will let you guys know what happens.
Not sure what is standard on 348-409 engine water pumps as far as pulley size or pump designed rpm. Years ago a friend and myself put together a screamer of a blown 350 with small wp pulley, kept satisfactory temp at idle and around 60-70 MPH but when as you started to give it the revs on the open road it would just get hotter. found out later that we were over speeding the impeller, causing cavitation. had to go to a larger pulley to keep it cool.
i suppose the question is how do you know what RPM your pump is designed for? and how close do you get to over speed at high rpm?
Steve
i suppose the question is how do you know what RPM your pump is designed for? and how close do you get to over speed at high rpm?
Steve
If I recall, the waterpump is overdriven slightly in stock configuration. I am guessing I now am overdriving the waterpump around 25 percent. I ran it up to 120 on the hiway and it saw 180. I am looking at driving my car 3 hours one way to a cruise and car show. I am trying to make sure it goes there and back by its self.
Brian
Sounds like it's working good.
At 60mph how many rpm's are you running?
What does the stock sheave measure?
Seems like when i run my car at 60 mph@2900 rpm highway speed it cools better that at 70 mph. I need to put a gun on it to see what temps actually are......i have both an idiot light and gauge.
Sounds like it's working good.
At 60mph how many rpm's are you running?
What does the stock sheave measure?
Seems like when i run my car at 60 mph@2900 rpm highway speed it cools better that at 70 mph. I need to put a gun on it to see what temps actually are......i have both an idiot light and gauge.
I am about 3000-3100 at 60. I had gotten 13 mpg with the last motor with 3.36 gears and I was happy with that. I can't wait to see what 3.50 gears get me. Maybe 16? I don't even have a vacuum advance! Just lucky I guess. The stock water pump pulley is 7 1/8 to the outside.
