MN71W30

I made a few changes and I can't seem to figure out where I went wrong. My 455 has got up over 215 deg. and I don't remember it getting so hot. I figured the stat may not be working right and I installed a flex fan and a new 160 stat. It seems to run at a lower temp now, it's under 200 but it creeps up kinda fast at an idle and it seemed to run cooler with the old waterpump.
Could the rebuilt water pump be causing trouble? It had an enclosed type impeller not like the one I took out that had open fins. When I rev it up it seems to drop the temp some. The flex fan has got quite a roar that I'm not too carzy about.
Any you guys run electric fans? Do you recommend them?
Thanks for any insight.
Dave

Lady72nRob71

What changes did you make?
Do you (or did you) have a fan clutch or shroud?

The roar means you are at least moving a good volume of air.

You mean your pump does not look like these?
http://www.flickr.com/photos/robsalb...7602930020786/

380 Racer

Flex fans= bad news. Put a good electric fan/shroud setup on it and you will be happy.

MN71W30

My old water pump looked like that for sure . But From memory, The new one has a round impeller like a hubcap with fins sticking up. wihout the individual fins. I'm thinking I'm not moving water like the finned one.
I had a shroud, clutch fan, 160 stat, finned water pump. I now have new 160, new waterpump, new flex fan, same shroud.
Maybe I should leave the old school fans behind and go with electric fans like the racer suggested.
Thanks for the input.
Dave

joe_padavano

The "enclosed" impeller will move more water than the open one. With the open one you get recirculation between the fins. Look at a Flowcooler and you see that all they do is pop rivet a disk onto the back of the impeller. Factory cast impellers with an integral disk are the way to go. The cheapie stamped impellers are all about cost savings.

Lady72nRob71

If you never got a distinct roar from the clutch fan when the engine was hot, then the clutch was defective. I had this issue and a new clutch solved the problem. A thermal clutch fan will disengage when the engine is running in normal operating temps, like when cruising on the highway, greatly reducing any HP drag. This makes electric fans "not a great improvement" over stock.

MN71W30

Well,
Now I'm really scratchin my head. I was ready to bet the farm on the impeller being the problem.
I think I need to get the Olds out on the road and really keep an eye on the gauge. Maybe even trying another gauge.

MN71W30

The clutch fan spun easier when it was hot than when it was cold. It never roared like the flex fan I have now. Maybe your onto something.
Dave

joe_padavano

As it should.

The clutch fan will only roar like that when the clutch gets hot and locks up, causing the fan to spin at full engine speed (again, as it should).

MN71W30

Well,
I went from scratchin my head to scratchin my hind end. I took it out for a 20 minute run @90 degrees and it seems to hold 185-190 on the road @60 mph but heats up in traffic over 200. I guess thats probably tolerable. My 454 Chev with a Beecool radiator will hold the BBC to 160 on the road. If I get sick of the hurricane wind noise under my hood I just may put a good working clutch fan back in.
Thanks,
Dave

380 Racer

Sorry I have to disagree. It may decrease the HP drain but still won't come close to the electric in HP savings. An electric can be more effecient with the proper sensors and switches. A flex fan is old school in that the blades flatten out at higher rpms and supposedly take less HP, not nessesarily work more effecient. Dave an electric will work better in a traffic jam on 494 on a hot afternoon.

MN71W30

You know 494? You must be local. I drove the Olds today down 94 and up 35E from St. Paul and it seems to cool pretty good but the roar of the fan sounds like a P38 taking off. I think I'm going to go electric. My son has got one on his 98 Z28 Camaro and it works nice. He had it re calibrated to turn on at 170 deg. I think I'll see what Summit has to offer.
Thanks

mugzilla

I use a factory heavy duty fan clutch, it works well ...

halfbreed

I've run olds a long time and i use a stock fan and a electric pusher fan set up to come on at 195 degrees and off at 180 and i have a manual override switch in case i want extra cooling sooner ! works good on my 425 cubic inch 35 olds coupe !!!

MN71W30

Theres a good chance it was a defective stat all along. I do believe my clutch fan was a little weak as well. It would be nice to be able to run a fan with a switch at the track for extra cooling.

380 Racer

I have dealt with the Cities a few times. Go 494 when we go up to Brainard. Went up 35W when I was going to the University hospital trying to get a heart transplant. My motors are also dyno'd at R and R up in Spring Lake Park. Attended a wedding a few weeks ago in Chaska. So ya I get up there once in a while.