Pulley sizes - Page 4

undy · #61 (**permalink**) 05-17-2006, 07:45 AM

Update...

I checked my pulley sizes and found a 6" upper with the 5.5" lower. This is March's "hi-flow" set up.. High flow my arse.. I'm still 9% underdriven on my water pump. I Ebay'd a 6 1/2" lower pulley. That'll bring me up to around 8 1/2% over driven. I guess that's the best I'll get there..

I checked my "at idle" fan voltage, an abysmal 10.9 volts.. no darn wonder I'm not moving enough air. I had a .9 volt drop between the alternator output and the fan too. The other sad thing was that I'm only putting out 11.9 volts from my alternator at idle. The alternator is the same chrome, GM 1 wire alternator that Lone Star installed. I just ordered a Power Master 140 amp, 1 wire, chrome alternator from Summit. It delivers 80 amps at idle. I'll run a new #2 wire from the alternator back to the batterry with some #8 feeding the fan. That should take care of my electrical woes...

I bought some Red Line Water Wetter to run with the water/glycol mix..

I also got a new "hi-flow" Mr. Gasket 180 deg t-stat.

Once I get these done I think I'll be doing better.. we'll see...

392cobra · #62 (**permalink**) 05-17-2006, 06:59 PM

undy,
Just changing to that larger crank pulley would help a lot on your "at idle" charging.That is just another problem with underdriven pulleys.
Been there,done that.

rblong · #63 (**permalink**) 05-17-2006, 08:47 PM

Undy - I posted some pics of fan shroud on my gallery and am working on the inlet - will post more pics of it soon.

I have the same pulley set up as you and have not found a 6.5 crank pulley - where did you get yours and do you know part number.

Sounds like I better recheck voltage drop again after I am done also.

Bruce

rblong · #64 (**permalink**) 05-21-2006, 08:02 AM

Complete! Did some test driving yesterday and all seems good. Ran about 195 down the highway and 195 - 200 sitting in stop and go traffic. Fan would cycle in stop and go traffic. Took a while to cycle off, but would maintain temp. When I got back I was reading 96 in the shade, so it was plenty how. Losted some pics in my gallery. Since last inlet pic I used rubber sheet and filled in gaps on inlet shroud.

Bruce

undy · #65 (**permalink**) 05-22-2006, 03:55 AM

Quote:

Originally Posted by rblong

Complete! Did some test driving yesterday and all seems good. Ran about 195 down the highway and 195 - 200 sitting in stop and go traffic. Fan would cycle in stop and go traffic. Took a while to cycle off, but would maintain temp. When I got back I was reading 96 in the shade, so it was plenty how. Losted some pics in my gallery. Since last inlet pic I used rubber sheet and filled in gaps on inlet shroud.

Bruce

Did you check voltages?

392cobra · #66 (**permalink**) 05-22-2006, 06:46 AM

Bruce,
It seems like your top shroud made a bigger difference than the fan shroud to me.What do you think ?

rblong · #67 (**permalink**) 05-22-2006, 07:33 AM

Undy

I did not check voltages, but will tonight for you.

Fred

I agree the top inlet shroud did the most good running at speed. The fan shroud only helped at idle. In fact I believe the fan shroud actually impedes the free air flow a little at speed since now the air is being forced past the fan only rather than free flowing across the whole radiator. I believe the fan shroud did help in traffic, but I am not sure a higher CFM fan would not have done the same thing. This would allow a little better flow at speed and still maintain stop and go temps (I think).

I will probably stick with what I have for now since it looks to do a pretty good job up to close to 100 degrees, and I can tell you I won't be driving it a lot at 100 degrees temps anyway!!! If I loose my fan I will go to a larger CFM and maybe take the fan shroud back off and see how it does.

I guess bottom line is the inlet shroud looks to be a must and if your fan covers most of the radiator without a shroud (like mine did) I would be using a fan of better than my 2350 CFM. Maybe one of the 3000 CFM styles without the shroud.

Bruce

392cobra · #68 (**permalink**) 05-22-2006, 07:43 AM

"In fact I believe the fan shroud actually impedes the free air flow a little at speed "

I think your right.It looks like you gain 10* on the highway.
But you are still at 200*,even after the tests being run in over 15* warmer ambient tempts.80* vs 96*.

I think you started out with 210* idle with tempts in mid 80's.
No telling what it would be at 96*.

rblong · #69 (**permalink**) 05-22-2006, 08:06 PM

Undy - checked voltage tonight - 12.8 at fan running. Dropped to 12.5 with all lights on bright.

undy · #70 (**permalink**) 05-23-2006, 04:44 AM

rb ... decent voltage, that eliminates that as a problem. It looks like you're close, if not there, to curing your cooling woes. It would appear that the new upper/inlet shroud has helped by reducing "superheated" air recirculation and the fan shroud has produced a more uniform, all core encompassing, pull across the radiator.

I got my 140 amp chrome Powermaster the other day from Summit. It came with a 4 gauge wiring harness for battery/alternator connections. That will help me do better than 10.9 volts at the fan.. I'm waiting for the 6 3/4" lower pulley to complete everything I need. I've got to install the alternator, new "high flow" 180 deg t-stat, water wetter plus all the wiring I've got to redo. If all that doesn't produce the results I'm looking for then I'll re-evaluate my fan/shroud thinking and also consider doing the top shroud boogie..

Dave

392cobra · #71 (**permalink**) 05-23-2006, 07:28 AM

Bruce,
What thickness milled aluminum did you use ?

On the rad shroud,do you think it would make a difference in air flow/cooling if the sides of the shroud were all angled in 45 degrees ?

rblong · #72 (**permalink**) 05-23-2006, 08:24 PM

I used .034 aluminum - stiff enough to hold shape, but easy enough to work with, and yes I thought about the same thing since I think it would help if fan shroud was angled to the fan opening size. Give a smoother flow for at speed running, but I think you would need more length than I had to work with to get an angle that would do any good. If you look at my pics after I was done there was only about 1.5 inches between fan motor and water pump bolts. I am really thinking a 3000 CFM instead of my 2350 cfm fan tight up against the radiator like mine was that covers the radiator (my 16 inch only lacked 1/2 inch on either side to cover radiator) would do a good job without fan shroud idling and give much better flow at speed. I am ordering a new overflow tank right now and will try and drive it again this weekend. I really think the inlet shroud is a must, but am not sold on the fan shroud yet.

The angling would probably help a lot if you have room.

Bruce