What's so great about the Bidgeport?

[RBT]

So why did merc stop making BP engines?

The bridge itself impedes flow ~25%, and the bore area is only has so much real estate. Modern oval(ish) ports equal or better the bridges and no hot spots.

[powerabout]

Uncle Dave ...
Just in case ya haven't heard , OMC built the ..

I have no doubt you have a pristine 2.4L in your collection ..

I just never seen one ..

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Power .. Your boy Bobby Worthead has done more to **** block water based record attempts than any left~wing group of people could ever hope for ..

You happen to know what size jets they had in "the hammer" .. ?

Long , high internal capacity , single end fed , spray bar systems have poor distribution characteristics .
Why wasn't the boat ever run again .. who has the motor ?
I got a canole' that says they hurt it .. kept it quiet .. locked the books , and quit

Yes Bob is not a friend of Ken
I have been emailing Bob about safety issues but I havent mentioned going fast....

The engine seems a bit of a mystery, not heard had anyone ever talk about it, pretty sure it didnt stay with the boat.

[Dave Strong]

Behind the liner porting on the 2.5 was better, no more finicky bridge, more power, less stuck pistons...

True but nothing sounds like a good Bridgeport.

Dave

[Chaz]

Yes Bob is not a friend of Ken
I have been emailing Bob about safety issues but I havent mentioned going fast....

The engine seems a bit of a mystery, not heard had anyone ever talk about it, pretty sure it didnt stay with the boat.

I e-mailed him only once . His non response spoke volumes about his dereliction of duty he holds with the F whatever it's called .. he reminds me of a guy I did some work for on a SCCA "C sports roadster" . He had a big party after a big class win . Yep , he was the only "C sports" car on the property that weekend ..

So they "lost" that piece .. Humm , I reckon your buyin a round of canole's if ya ever make it to Florida ..

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RBT

Originally Posted by Euroski
So why did merc stop making BP engines?



The bridge itself impedes flow ~25%, and the bore area is only has so much real estate. Modern oval(ish) ports equal or better the bridges and no hot spots.

Why did they stop makin 2-strokes all together ..

Hot spot , I agree with .. A deal breaker , for sure . Perhaps , if it had a robust support behind the bridge which could also act as a directional wing .
I can't agree that it killed 25% of the ports potential . Say , that conduit could blow 300 cubic ft/min , they would never settle for 225 ft / min. Let alone times six holes ..
I think what the bridges did do was allow designers to have the thought process to see the ring as being contained .. so now they felt free to build a "second" exhaust port right next to the first one .. making for a greater potential for air flow.
Somewhere along the way , designers relized that the only time they needed more of an effective port , was durring the first 30* of opening to blow the cylinder down before the transfers opened . The only time Mercury did anything that resembled that was with the 300xs exhaust port . Everything else went to aprox 62% of bore size and was pretty slab sided .
They could have done the 300x rings a big favor and brought the bottom corners in .



I grew up in a time when they said don't get the exhaust port and main transfer any closer than 3/8" from each other or the fresh charge would "short circuit" and go right out of the exhaust ..



They started breaking all the "rules" .. this hole looks to be 90% of the bore. And a lot closer than 3/8ths from port to port ..



I don't like the points , but an early attempt to take advantage of a lot of area where it's needed.



I guess port development ended with the "double bridge port" when they started "stacking" secondary ports directly over the transfers .. Talk about rules breakers . I admire guys who dare to step outside the box like that ..

And no , Mercury didn't develop that , they seemed to quit development somewhere between the horse~N~buggy and the Briggs~N~Stratton era .. sad , what could have been ..











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[JR IN JAX]

Due to our lack of expertise, we found we had to burn methanol/nitromethane/castor to keep a huge amount of evaporating liquid passing over the piston top and around the exhaust bridge. Our 125 and 130 cc Kart motors seldom lasted more than a couple of hours due to the 18K RPM they were turning in 20-30 second bursts. We estimated 50% of our fuel was unburned. We left the bridged ports for oval ports.

[Dd24skater]

Had a pair on a 24 Skater BITD, nothing sounds like BP with an offshore can.

[JR IN JAX]

Had a pair on a 24 Skater BITD, nothing sounds like BP with an offshore can.

I love the sound of them and the OMC V8s which have been described as a "bag of howling cats". Every time one would come down the river, everyone would step outside to see it go by.....