Fast Fred's OMC Mod 50 secrets Thread #2

[Allen J. Lang]

Hi Tim- When are you going to build yourself and engine and get back into driving? Building engines for everyone else and exotic FE engines are time consuming. Haven't seen your name in a race report in years.

[Tim Kurcz]

Hey Al,

Race time has been limited by family and work committments, and to a great extent by the needs of the mod racing community. Engine builds are accomplished in a shop only 50 ft from the house, and this winter's work is almost done. Once the last customer project ships I'm concentrating efforts on five of my own. The goal is to display all of them at Mark Suter's this fall. You never know, there be some race testing along the way!

Tim

[scud]

what pump are you using to lubricate the turbo bearings ?

[Tim Kurcz]

Ahhh, a good question.

Oil will be provided by a electrically driven helical gear pump (located in the boat) with an engine mounted sump. It will be slaved to the fuel pump switch as a failsafe.

Tim

[scud]

if it's not a bother what brand pump is that and where could I find the specs like pressure , volume ,amp draw and max temp?

[Tim Kurcz]

Go to http://www.rbracing-rsr.com/oilsystems.htm to see RB racing for the best documented history and information about turbo oil feed and scavenge pumps. The 03-1034 pump selected is rated for 180F oil, requires 12V @ 3A continuous to deliver 2.6 GPM @ 30-40 PSI for the GT22 Garrett journal turbo selected.

In case you're thinking of a 2-stroke turbo project, there is solution that requires no oil pump. It's called an "Aerocharger" (formerly Aerodyne), typically used for snowmobiles and other 2-stroke applications because it can be run in any attitude. Go to http://www.aerocharger.com to details.

The primary reason I chose the Garrett was due to cost - the Aerocharger is more than double the price even with the oil pump - but it is not recommended for draw through applications. In the case of "Virgo", horizontal packaging of the Garrett is perfect for oil feed and gravity scavenging, and it is approved for draw through. Given this and that it may only a run few hours in it's lifetime, I couldn't bring myself to spend the money.

All said and done, if "Virgo" responds well to forced induction and proves durable, I will consider the "blow through" only Aerocharger for the next one. This would allow intercooling and thus able to deliver more power.

Tim

[Mark75H]

There was a guy who posted on Screamandfly a few years ago who used one of those on a 44. His set up was successful.

On the cheap side I have often wondered if junk yard car turbos and power tilt pumps might make something that worked on an extreme budget.

[Tim Kurcz]

Hey Sam,

That turbo 44 guy is Dixon Smith, who also owns the Merc 2.5 drag hydro posted last fall. Dixon is an excellent fab guy and has built many interesting engines. Indeed his Aerocharger system worked quite well. The only issue was wasting reeds after only an hour or two of operation. Repetitive maintenance made it less than fun for regular use. I'm hoping the front loaded OMC pyramid reed system is more durable. If not, at least the engine won't require full tear down!

Tim

[Powerabout]

There was a guy who posted on Screamandfly a few years ago who used one of those on a 44. His set up was successful.

On the cheap side I have often wondered if junk yard car turbos and power tilt pumps might make something that worked on an extreme budget.

Trim pumps have bushes on the armature.
You would need roller bearings to run continuosly

[Powerabout]

Hi Tim
Can you still get straight in fronts from seaway or did you have to find one elsewhere?