jetting for 900 sc
 

I had some new motors built over the winter and am in the final installation process. Paul Pfaff recommends a starting jet of 94 to 96 all around in the 1050 dominators. The blowers are 1071 Mooneyhams with twin dominators on each blower. The prior set up was 572 inches non-intercooled and the jets were 83's all around. My new long blocks are 598's with the only other change being Whipple intercoolers. What comes as stock jets on the 900 sc motor and how much boost do they run? Any imput would be appreciated. Thanks Doug

Re: jetting for 900 sc
 

If your going to all this trouble building this motor and with the caliber of engine . Go get it dynoed!!!

Is is worth taking a chance on guessing?

Re: jetting for 900 sc
 

You'll never get all th HP you would if you dynoed them.

Re: jetting for 900 sc
 

If I remember, the 2001 version of 900 SC dry sump engine had:

98 Jets (.125") in the front carburetor and 96 Jets (.118")
in the rear.

On a big dollar engine like this, money would be well spent
to get them dialed in on the dyno. I would imagine that you
will be able to fine tune it with a little less jet once you get
a baseline of the power band and egt's. Mercury usually
kept them slightly on the rich side.

OR

Re: jetting for 900 sc
 

Thanks for the imput guys, I know that a dyno is an invaluable tool but I started this as a new short block project and then it expanded into a pair of long blocks and now it is time to go boating. I started in January and due to problems gettting cranks this project took me into my busy season, I'm a pool guy. Last week I installed the motors along with the new Huber 1450's and I need to get only close on initial jetting. Pfaff suggested 94 0r 96's all around but they use 1471's blowers which will move a lot more air than my 1071's. I was kind of surprised to see 83's in the carbs when I removed the bowls but they were unchilled motors. I'm sure that they were dynoed when Cobra Power built the motors that were in the Jag when I bought it. Thanks again. Doug