"Name That Outboard"

[Tomtall]

Well -------------- Sam was absolutly correct in saying

Its the Frankenstein of Formula E ... the Kurcz 45 OMC twin Cosworth overhead exhaust valved 2 stroke. Its other unique feature was fixed motor with rudder steering as used on inboards

and sorry for the delay in responding Sam with the answer. Tim Kurcz built this wild 45 OMC mod with the addition of a Cosworth duel overhead cam cylinder head cut in half. It was fabed up over several years in Bud Parkers shop when Tim took the project on. Tim said the compression of this high breed two stroke was a whopping 235 PSI. It requird timming the cams and the roll over point perfectly and putting 24 volts to the starter to get it to pop off. You had one shot to get it to take. Tim said he had problems with the cylinder head getting steam pockets traped (due to poor casting design) causing hot spots that would cause the Alum. combustion chamber to sag causing poor valve seal and lose of compression. The exhaust was dumped out all four valves per cylinder (once, two intake/two exhaust) and the block was re-sleeved to use intake and exhaust ports as intake ports only. Twin two barrel carbs. feed the juice. To see this engine up close is to realize the hundreds of hours required to make it work. The engine was to be raced at Dayton Ohio record runs but after much discussion about it amoung the tech. commitee it was not allowed to run due to the boat sporting a remote rudder. Tim said this approach of engine design is similar to todays two stroke diesel engines. It just happens to run on gasoline. This and several other one off mod engines of Tims will be on display at The 2009 AOMCI fall meet at Mark Suters.

[John (Taylor) Gabrowski]

TomTall:

With wicked compression like that what kind of fuel mix was relied upon?

With a valve train like that was some kind of oiling system used to lubricate valves etc?

[Tim Kurcz]

Well John, I completed a very complete explanation of the development program, but lost it to cyberspace! For now, the fuel used was 115 Avgas with 16:1 Johnson GT (at the time). If you look at the port side image, you'll see two fuel pumps. One suppies gas/oil mix to the carbs, the other circulates Mobil 1 5W synthetic oil to the valve train.

For Sam, I'll be posting images in the tank and lake testing soon as I dig them out and scan them.

As Tom pointed out, you'll see this engine at Mark Suters next fall. Perhaps I'll even dry fire it a few times! -Tim

[Mark Suter]

For anyone interested in seeing Tim's motor, my 2009 Antique Outboard Motor Club swap meet is scheduled for October 24th and will be located in Byron, Michigan (between Lansing and Detroit).

[Master Oil Racing Team]

It's sure to be an excellent meet Mark. I know you guys will take pics to post.

Tim...I know exactly what happened to you and it happened to me many times before I figured it out. When you go into a lengthy explanation of things,sometimes you get logged out. Most of the time, you can save what you wrote. Instead of logging back in at the box in the northeast quadrant, go down to the middle of the page where there is a larger and wider box that says you are not logged in. Go ahead and log back in there and punch the button. Most of the time it will post your reply. Sometimes it seems like it didn't, but after you push it again it will say that it is a duplicate post that you just submitted. Within less than thirty seconds your post will appear and you will breathe a sigh of relief. I know what it feels like to put everything into a post only to lose it. You never go back and rewrite it like you did the first time. I hope this helps and maybe you will get the urge later to give the long version another try.

[John (Taylor) Gabrowski]

Tim:

Installing and using a lower pressure pulse fuel pump to put light oil into the valve train was a novel idea. Was the oil lost or recirculated back to a tank like a little dry sump system? Looking at the octane and compression the ignition timing must have been kept conservative anyway? When it came to pipes I take it having valves dispensed with anything longer than the short zoomies it had? Must have still crackled like some small psuedo Indy car engine!

[Master Oil Racing Team]

OOPS! Sorry John.

[John (Taylor) Gabrowski]

Its alright Wayne. It might be a while before Tim gets back here to provide some insight, so go on with what you were go to.

[Tim Kurcz]

Spark timing was 22 degrees BTDC, same as run for my 45SS. Valve train oil was simply recirulated using the primer bulb as a reservoir, screened by the pump cover. The exhaust had 12" megs which you will see in images soon.

Tim

[John (Taylor) Gabrowski]

Tim:

It sounds like a lot of timing but then Merc 55Hs used around 40 degrees with lower octane gasolines it was based on. On the oiling side and head hot spots would more water flow and a larger oil resevoir with a small oil cooler helped with the hot spotting and warpage or was it all at some limits nothing could realistically help? It is some wild innovative engine! It got me looking at YouTube at some old USA and Italian speed record engines, they were also pretty wild in their times.

From what I gather you always had a spark for the exotics, the ones you could build. You had the vision and have the ability to fabricate what may or may not be available or for the fun and adventure you would have done it for yourself anyway. Being able to do it within class rules came to be the challenge and your projects sure do mirror the interesting and theoretical made real. You sure do instill some interest that is spreading, me thinks.