Originally Posted by HabanaJoe

Keith - FYI the Sabre diesels from England were the European Ford/Sabre engines, the Merlin/Daytona engines from Fla were based on the Ford Cargo Star truck enignes from Brazil. The English Ford's were a much tougher old style engins than the light duty Cargo Star enignes.

Diesel2fast4u - I was keeping quite to see where this went but since coolers are a topic now I have a suggestion. Your enemy is heat as you know when you design the cooler make sure there is plenty of fins like a AC condenser, do not use a big cross sectional area cooler compared to the thickness and use a multi pass cooler ie like two or three seperate cooler stacked each being fed by virgin cooling water. What you need is a big Delta T and regardless of how you design a one source of water in and out cooler you will only get so much heat transfer because the water temp will rise and start to be less effective regardless of direction of water flow you will run out of cool water quickly.

Think of a commerical air-handler in a large office building, common manifold of cold water feeding into various coils and then coming back together again. They work on a 15-25 Delta at most, you make yours like I said 2 or 3 independent cores thick and lower the temp vastly. Some people will argue that all that back pressure against so much coil will hurt flow - YES it will. BUT the cooler the air the more dense the less manifolf pressure you'll have and flow is inversely portional to pressure so the lower the pressure (temp) the flow will increase much more than linear.

If you'd like to discuss what you're doing I'd love to talk through things out here in the open if you wanted to, I think people love reading these things?

Joe Gere

Originally Posted by Raylar

Diesel2fast4U:

Be grateful you have someone like HabanaJoe on this forum to consult , offer experience and help you. His 40 years plus of real performance diesel experience and knowledge is priceless! I consider him one of the ZEN masters in how to get reliable horsepower and speeds out of marine diesels. Learn from the experts like Joe and learn maybe just enough to make your project successful. He knows his Sh*t! about diesels!
Glad to see people like yourself push the envelope and make big things happen from small beginnings! Good Luck and keep up the good developments in diesel performance!
I will also follow your project here on OSO with greatfull attention.

Best Regards,
Ray @ Raylar

Originally Posted by HabanaJoe

Just a suggestion, if you run 3 bars that like 40-45 psi, that's high in any book. I believe you will be best served down in the 11.5-13:1 range. Yes, a little hard to start, might need a ether shot on a cold day. You're talking mechanical compression ratios and not taking into account that with all that air in there your actual ratio under boost will be allot higher. The cylinder pressures are going to be extreme with 18:1 and 43 psi of boost, this is not a good combination for a long lived engine, my opinion.

Just some food for thought about what you are doing with the 2 turbochargers for next engine design.

You mention exhaust pressure, that is pressure inside the manifold before the turbocharger not exhaust back pressure and you are spot on if exhaust pressure is as high as boost pressure the engine runs rich and flattens out in the power band - that is why the comment the diesel torque curve goes to a point and stays semi flat, by design standard engines get to a point where they stop breathing and are neutral.

A better route for two turbo-chargers might be where the two turbos are mounted in parallel and not separated like you have them. What you need to build is a gate between the two turbo chargers so only one works are lower speeds and you can open the gate and allow both to run when at higher speeds. This is old school (not compound) and by doing it you cut your exhaust manifold pressure in half when open and doubles the amount of air flow, not pressure but CFM's and will allow the engine to breath much better. This is not new it's old racing SeaTek and Isotta stuff. With the VGT's you accomplish some of it and you can dump xhaust pressure with a waste gate as well but with the twin in parralel and gated you won't be dumping energy you can use - just a thought to throw around next time?

Originally Posted by Steve 1

Why not use a surface drive ?

Originally Posted by diesel2fast4u

Because I don't like them

No serious, It's a waterski boat so I don't want a rooster tail & props are to hard to get for us.
Also the boat was designed for drives (or outboard) and needs that skeg in the water to hold in the turn

Originally Posted by Steve 1

Just the fifty or so horsepower loss Via changng directions through each outdrive and the Arneson'a have a very healthy Skeg system,I did not know you were Sking behind it.