I am running EMI Thunders with the 16 inch ss tops. After that there is a short run to the back of the boat(7inches). Its wide open in the back. I am dumping a ton of water and was thinking it could be choking off my exhaust?! I do have stock stuff in the tank as far as I know. I do have a fuel pressure gauge on the duel feed line to the carb. I think it is saying 7.5 ish if I can remember.

At the dyno last year we did the brake-in runs and after the first two pulls the shop owner pulled the exhaust off and switched it out for a brand new set of headers. He claimed no way that motor made that HP from what I told him was in it. :blahblah: After tell him the work into it and not just bolt on parts and an exhaust change we pulled again. Loads of tuning a day later we got her dialed in and I got a handshake. Good job son that is one heck motor for your first one.

So after searching on OSO and finding that guys said this AIRTEX 90632 worked I have to say that its not TRUE. I looked it up and it only has 1/4 inch threaded lines in and out. I have 3/8ths. What pump do I need? The old one is a carter 0-2208? This is driving me nuts.

CV products makes a complete pump.. SPIN-MP-2600

Or use a Mercruiser or Airtex top half and change out the bottom half with a CV products one or a KE...

http://www.cpperformance.com/p-12460...6-engines.aspx



I used a CV Bottom half I got used from a Winston cup team... Looks like the part number is cv5505-2
http://i130.photobucket.com/albums/p...e/P1030827.jpg

Is that a steady 7.5 PSI at sustained full throttle? Pressure at idle or even cruise doesn't tell you much. You need to know if you are starving it for fuel while under sustained load. You might have to crack the hatch and have someone keep an eye on it. Or you can do what I did and mount a GoPro camera aimed at the gauge, if you don't have a remote gauge.

Thank you for the good idea. I am going to toss in my gopro and put the old crap back in for a fast test run. Since I am three miles from the ramp a quick spin will reveal all. Fuel pressure and see if the pump seals are weeping.

You can download an app for your smartphone which will allow you to use your phone as a remote monitor and start / stop recording. :cool:

Or use some of that extra -whatever hose you have and move the gauge?

What RPM's did it turn originally, and what prop were you running? Are you running the same prop? Why did you stop the dyno before you found peak power? I believe you should prop your boat for peak HP. ( where the engine wants to run) By over propping and loading the engine you are more prone to detonation. And a 6000+HP 502 you should be spinning close to 6000RPM. What heads did you use and cam now? The boat is the only true dyno.

1/4"npt vs 3/8" hard line, also the number is 60932. It does infact work, bolts right in...I own one.

One thing we never talk about because I don't think anyone has checked, I'm suprised I haven't either, is since the sea water/fuel pump is belt/pulley driven, what it is driven vs crank speed.

A regular block mounted pump is 1/2 engine speed because of being driven off a cam lobe.

If the sea wwater pump is driven faster than 1/2 crank speed, we'll get more pumping action.

Anyone wanna measure crank pulley diam and sea water pump diameter to come up with fp driven speed ?