Gary Anderson

blown1500
What is the hp capacity on an 850 vs a 1050?
I know Merc uses a 1050 on their 525SC, while Hawk uses a reworked 850 on their 525SC. The reworked 850 is supposed to flow over 900cfm.
Gary

HiPerf2000

i run a 174B&M with a 850 nickerson. I also put in the electric (helper) fuel pump in addition to the regular fuel pump. I run about 5-6 lbs at 5200 - 5400.

I believe that the front cylnders (#1) are usually the ones to lean out on this type of setup. I pull my carb every other season and have nickerson go though it, and last year i noticed the he has a bigger jet on the one corner of the carb than the other. He told me that #1 will run a bit lean, and he tries to give it more fuel.

Niuhi

Lot's of good info, thanks all. Yes I'm tossing the idea around in my head. I do Like the ease of the single carb as opposed to the dual. I will have to see how work treats me though before I decide I want to pursue the additon further though cuz I figure I'm going to have to factor in exhaust also.

blown1500

Mr. Anderson,
I answered you once, but it was apparently lost. The hp pjotential of the 1050 carb is greater than the 850, but here the limiting factor is not the carb, but the supercharger. The carb produced by Holley for the 170 series blowers is an 800cfm. In a boat, the 850 or maybe the 900cfm could be a slight advantage, but anything over the 850 seems too much to me. Proper test would be a vacuum guage under the carb at max throtle and rpm.
A carb that is too big will not give the economy, low and mid range, and fuel atomization that a proper size carb will give.
The hp limit on the carbs is not an absolute. Round track racers commonly make 600+hp from a Holley that is supposed to flow only 390cfm and that is a 358 cubic inch small block!!
I do not understand why Mercruiser went with the 1050 on their 525 and I would expect better performance from the Hawk setup-all other factors the same.

Gary Anderson

blown1500
I suspect you're right on the money. The Hawk motors I had were VERY smooth at idle. And they still didnt run out of carb when I change the pulleys to 7psi boost.
I always thought the 1050 was a lot of carb for the Merc 525SC.
Gary

Niuhi

To pose another question to those of you running the smaller blowers, are any of you using Superchillers? What are your experiences not using them or with them.

I have been thinking I could get away with not using one by running low boost and a little larger blower, am I mistaken?

HiPerf2000

i dont have an intercooler on my 174 and have no problems running 5lbs fo boost. I do notice that when there is high humdity i can loose 5 mph. Someone told me the cooler would somewhat help that problem by cooling the intake charge. But i wasn't that important to me.

Niuhi

HP -2000, what motor are you running it on? What kind of results did you have going from normally aspirated to the huffer, and what other changes did you make to the motor?

HiPerf2000

I bought the boat with the charger installed. At that time is was a 454 310hp. The reciepts that i got with the boat included blower setup, stainless marine exhaust, and inconnel valves.

i ran it like that for 2 full seasons with 5lbs boost without any problems. I then pulled the motor and basically made it a mag motor by changing all the internals and heads. i did that for piece of mind in having forged components over cast. I also put in an electric helper pump, and a V-6 module. i still have the stock size fuel lines.

The boat picked up 8-10 mph with the initial blower (62 - 70), then after the rebuild and an additional 100hp i bot another 8 - 10 mph (70 - 81).

Niuhi

Thanks