|
Author
|
Topic: Pro's and con's of underdrive pullies
|
266
Journeyman Posts: 12
From: Columbus,NE
Registered: Nov 2006
|
posted 11-22-2006 06:11 AM
 
I am thinking about going with underdrive pullies on my 347. What are the good and bad points of them. The car will see mostly street driving.Thanks
|
indyphil
Gearhead Posts: 3394
From: Senoia, G.A. USA
Registered: Jul 2002
|
posted 11-22-2006 09:09 AM
it really depends on the engine and the change in ratio.If you have a high revving engine, then it might help to protect parts (like alternators) from the high revs. but if you have a street motor that rarely goes over 6000RPM I wouldnt bother. By underdriving the water pump your going to find it getting a little hotter in summer traffic. The horespower benefits are small, not enough to really notice. The one big thing thats worth doing is an electric fan or a clutch fan at least. The fancy aluminum pulleys reduce rotating mass on the engine, but I dont know how much difference that really makes. My immediate impression is not much.
|
266
Journeyman Posts: 12
From: Columbus,NE
Registered: Nov 2006
|
posted 11-22-2006 11:42 AM
I was wondering about the water temp. I think I will just stay with the regular size pullies. Is there any place to get chrome ones anymore? I have not seen them in NPD's or Summit's books.
|
indyphil
Gearhead Posts: 3394
From: Senoia, G.A. USA
Registered: Jul 2002
|
posted 11-22-2006 12:47 PM
Mustangs plus has a bunch of pulley options, some plain chrome ones.http://www.mustangsplus.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=MPFMP&Category_Code=pulley
|
Hans olsson
Gearhead Posts: 936
From: Sweden
Registered: Apr 2000
|
posted 11-22-2006 01:19 PM
A smaller crankshaft pulley helps keep the fanbelt in place. ------------------
- VIN 1F05M139343
- 71 Mach 1 Ram-Air
- 351C 4V 285 HP
- E-F-G/SA
- Stockers are way cool!
|
V8 Thumper
Gearhead Posts: 4777
From: Phoenix, Arizona
Registered: Dec 2001
|
posted 11-24-2006 08:51 AM
I put 'em on my motor, and I don't know why I waited so long to do so. The underdrive crank pulley alone as got to be damn near half the mass of the OEM steel pulley. 25% underdrive... at 7000 engine rpm my alt & water pump are only turning 5250. Like Hans said, pitchin' belts is a thing of the past. I didn't see any increase in engine temp at all due to the water pump underdrive. Haven't seen chromed underdrive pulleys, but the aluminum March pulleys are clear coated and do look sharp  ------------------
1965 GT coupe, 333ci aluminum headed/solid cammed stroker, four speed, 3.70:1 9" 12.58/110 on street tires, more to come;) All Blue Oval, no blue bottle
http://mustangsandmore.50megs.com/V8Thumper.html
|
