Pulley reduction help

[CsR41]

355ci on a 4412. Steel heads on gas. Engine builder wants me to run 30% reduction but everything I've seen/read/heard is that is too much for my application and to run 1:1 or at most a 20%.

I bought the Moroso water pump and it says to run 50% but know that's not right!

[CNC BLOCKS]

I Have run the CV Products pulleys that are 30% reduction so far no problems. Just run a bigger restrictor in the goose neck.

[72Dubya]

If the engine builder tells you to do it, I would do it. He probably knows what it will do and he liked it and that is why he is recommending it. If something goes wrong with the 30% reduction, then it wouldn't be your fault either, as long as everything is installed correctly.

[Racer96m]

It all comes down to what type of pulleys you run and what fan. V belt pulleys and a high pitch 4 blade fan the belts will slip a ton, so you run 1 to 1 to compensate for the slippage. At High RPM it slips so much its like running a 20 - 30% reduction. If you go with a serpentine belt setup, it will have little to no slippage, so thats when you need the reduction pulleys. I run a 18Deg 400 and Im chipped at 8K. I ran 1-1 V belt pulleys and a 4 blade fan and it cooled perfectly. Switched to serpentine setup and now 20% reduction, same cooling result.

Dave

[rebel1mcelroy]

Looking for a good serp. Setup myself. Got a brand and part.#? Thanks

[LateModel B23]

This is a good setup:

http://daymotorsports.com/proddisp.php?ln=16615&product=SBC+30%25+WATER+PUMP+DRIVE+KIT&partnumber=KRC-37453000&description=KRC%27s+single+belt+drive+serpentine%2 C+water+pump+only%2C+drive+kit+includes+a+water+

[rebel1mcelroy]

Thanks but im looking for something with power sreering also. I also run a racing alt. But it has its own pulley that goes between the w.p. pully and fan spacer

[rebel1mcelroy]

I agree. Ive been running 1 to 1 v belt for the past 3 yrs seems like ive got to get a shorter belt after a week or so of running a new set of pulleys.

[Racer96m]

Nothing wrong with running a V belt, it just slips and wears the pulleys, But ran that way for years and years and was fine. I run the Jones Setup, no tensioner, Surp belt from crank to H2O pump and a V belt pulley off the crank to the steering pump. Very nice setup, Call Jones, they will get exactly what size pulleys you need, based on RPM and what fan and what size pulley is on your steering pump. I didnt want to buy a new steering pump with surp pulley and they were like, no problem, we will put a v belt pulley on the crank mandrel and you will be fine. Great people to work with.

Dave

[ford396]

I think that the main question that needs to be asked is: how fast does the manufacturer want their pump to turn and what is the expected rpm??? Not all pumps are the same and not all engines run at the same rpm.

Bob

[Racer96m]

Thats why I talked to Jones directly. They will set you up with the pulley diameter based on what RPM you run, and also will consider the pulley size on your steering pump and what speed that needs to turn. Even if you dont buy there stuff, they are very helpful. I got everything I needed for under 400.00 and its top shelf goods.

Dave

[ric78]

http://daymotorsports.com/proddisp.php?ln=10412&product=PRO-TEK+1%3A1+POWER+STEERING+KIT&partnumber=PS-RK400H&description=The+PSC+Power+Steering+kit+includes+a+ steel+serpentine+pump%2C+serpentine+pulley%2C+This is what we run also with one wire alternator

[Hurst390]

what about single,double or triple bypass radiator? determining drive ratio...