Beautiful. Do I see belt driven fuel pumps ? If so, who’s ?

Im a small nobody in the turbo world, but Ill give you my experience so far. Gale Banks made the turbos for the Mercruiser 475 package. These were water cooled turbo housings and it was a draw thru system using a rayjay turbo. M&W made a bolt on kit using Rayjay turbos and water cooled housings and their kit was a blow thru into a box that that carb sat in. On my Scarab, I have the foundation of the Mercruiser 475 package except my exhaust housings have water cooled heat shields and rayjay turbos.

Great article:
https://www.msn.com/en-us/autos/enth...7l5?li=BBnb4R5

That's because of turbine efficiency/set up. 10PSI in the intake manifold is 10PSI in the intake manifold. How you get there is what will change the output to the crankshaft. An engine will respond differently based on turbine housing/wheel sizing, supercharger drive losses, ect.

A turbo engine with 2:1 backpressure will make less power than one with 1:1 backpressure at the same boost level for this reason.

Exactly right. At 25# of boost we had 25# of exhaust back pressure.

TomFTM--Thanks so much for the picture. I have those exact exhaust housings, but a different internal wastegate setup. (diaphragm in the housing) I wasn' sure what the small cast "bungs" were for, as mine were plugged. I see I can convert mine over to a more modern wastegate. Pictures of Gentry stuff can be hard to come by. Thanks Again! That's what I aspire to for my engines to be.

Offtopic--- My intercoolers are a bit different but do have the large water inlet and outlet like yours. Are you running you water from the pump there first then out to the motor, or are you pulling water from somewhere else?

Thanks!

sent you a PM...or are we now calling it a DM? Whatever. Sent you a message

Boost is fickle thing, if you efficient intake heads etc. boost will measure lower than what others may say. I know on my motor a blower that would traditionally produce 8lbs only produced 3#, I had to get a different blower to get any numbers above 4#. my heads and intake flow very well. there is an art to boosted flow and very few grasp it. Most engine builders just dont care how heads, intake flow when throwing boost at motor. it is pretty well admitted by them.

Does anyone know who makes the Mercruiser turbos? I have looked for a performance watercooled turbo but I can't find anything. For a while Tial was making water cooled housings but they don't now. Thanks.