What is the advantage of the water crossover instead of the water pump. I noticed that alot of the HiPer motors do not have a water pumps, just a crossover. In building my 454, HP range should be around 450-500, should I drop the pump and add a crossover? Do I need a different raw water intake, instead of the pick up in the drive? I run mostly at the lake 3500-4500 rpm range. Is the crossover for WOT runs?

Thanks-
Chris

In most applications it is really just a power/aggravation saver. The water pump does take some horsepower to turn and gives you another rotating part to fail or leak. In very high HP engines the water pump can actually hinder water flow so a crossover is less restrictive. There are also some apps where a crossover will give needed clearance. You can use a drive pickup and the stock raw water pump to do the system.

Harden Marine sells a crossover with a idler pulley on it, so stock belt setup can be used. A lot less headaches.

Keep your pump. With the crossover you'll have pressure and low temp problems.

I ran with the pump for two years and with a crossover and therostat housing kit this past year. Far as i can tell I have lost 20+ pounds weight "merc pump and t-stat housing" probably gained 5+ hp lost to drag. No temp problems at all + it really cleaned up front of engine. I boat on gulf coast in fairly warm water if that is a factor.

Mark

This got me curious so I weighed merc pump/pulley & merc t-stat housing + unused hoses =32lbs. I have also found a couple of vendors that claim 10 or 15HP gain from not using pump. I didn't mention that I would always use a sea strainer before raw water pump either way you do it.

Mark

What if you have closed cooling. Can you use a crossover pipe???? Looking for all the cheap HP I can Get.

I don't know about closed cooling mods, there are times when I wish I had it. Though I hear that bigger than stock horsepower and closed cooling can be a problem.

Mark

Not for use with closed cooling. How much horsepower could you possibly put thorough a 3/8" fractional horsepower belt?

Mine had 3 belts going round water pump pulley + drag of water pump. as far as how much horsepower could a 3/8" belt hold. I have seen a a/c compressor with 1 belt pull a motor down by over 30 hp on a rolling road dyno at 6000rpm.

my guess would be that a properly fitted belt could hold upwards of 40hp.

Mark