how would you build your dream engine??

[bobrock]

ported and polished ?? <br />fiberglass reed valves? <br />forged pistons? <br />change the compression ratio?? <br />please describe how you would build a racing engine ...and what would you put it on??<br />hydrostream .... donzi??<br />i hear the 2.5 merc is a popular engine to work up ...what would you do ...

 

[Dhadley]

Re: how would you build your dream engine??

 

[Dhadley]

Re: how would you build your dream engine??

I thought that was a great question and would raise a lot more responses.

 

[bobrock]

Re: how would you build your dream engine??

yea me 2..!

 

[heybaylor]

Re: how would you build your dream engine??

radiator,instead of 1920 design lake cooled, <br />that burns up motors because of failures<br />also a continuous maintenence item<br />same rubber impeller as 1920 Hmmm...oops they had some metal one,s then<br /><br />aircleaner system that would keep trash,and mudobbers out..only thing we got is sound deadening..and the world can get to your pistons<br /><br />would run forever .beating all the others that broke because of design failures that the boat repair guys live on ...<br /><br />c'mon , a watercooled two stroke 250 cc<br />will produce 50 hp ...(Motorcycle)<br /><br />we barely get 150 out of 2500/3000 cc..whas up ??<br />maybe the bike guys do things like research and development..<br />variable exhaust timing, 12 petal reed valves ,<br />a "tuned exhaust system " and on ,and on ..<br /><br />hmm, kinda like detroit ..keep building the same ole block as long as peps buy the ford,and chevy trucks??<br />aint GM now a "junkbond"..?????

 

[Dhadley]

Re: how would you build your dream engine??

The radiator system has been tried many times. The motors always end up back with the proven system and way less headaches. We also tried using a 12 volt pump rather than the standard pump.<br /><br />The air filter thing has been tried too. Didnt have any effect on the piston life. Remote intakes with cooler air didnt help much either.<br /><br />2600 cc recreational motors are now producing 200 hp from the factory. 2500 cc factory performance motors make 280. 3000 cc's have produced well over 325 hp on pump gas with stock carbs (see pic above). 450+ with multiple carbs or injection. 4000 cc's have produced 600+ hp.

 

[heybaylor]

Re: how would you build your dream engine??

with all due respect..<br />piston failure due to insect (mud-dobber wasp)<br />on the throttle plates .<br />most people run a "flyscreen , and/or mothballs in<br />a bag to ward them off<br />is a real problem here in the south.<br /><br />two-stroke technology as in bikes would have a outboard producing 400 HP in only 2000 cc

 

[OperativeK]

Re: how would you build your dream engine??

I love my 1971 1350 wouldn't change a thing. Except maybe turn the clock back to 1971 buy it brand new set it in a secret storage and open it up this year. Would have been nice to see it brand spanking new.

 

[Nos4r2]

Re: how would you build your dream engine??

Realistically though Heybaylor you don't get enough low-down torque from a bike engine and the horsepower is produced in a very narrow band towards the top end of the rev range.Without a clutch to slip you wouldn't get on the plane.<br />I'm not sure I'd want an outboard with bike 2-stroke reliability-or 9-12000 rpm at WOT.They don't last long when you run them hard. There simply isn't room for an expansion chamber exhaust for each cylinder on an outboard either.<br /><br />If I had the choice on an outboard I'd start with <br />a 4-stroke with a possibility of an LPG conversion,all stainless bolts throughout and no mild steel parts at all.<br /> A full ceramic engine would be even nicer-no corrosion problems at all!

 

[heybaylor]

Re: how would you build your dream engine??

good points NOS4r2...<br />I was not talking about a bike engine in a boat ..<br />the 'technology' was the subject.<br /><br />while we are dreaming ...whats wrong with a variable speed tranny to turn the prop with .<br />that would allow smaller engines to turn higher rpm on hole shots..then adjust as you built speed<br /><br />Land and sea had a variable speed prop ..worked good , problem was it used constant engine speed ..<br /><br />seems we are stuck with a one gear $15,000 engine<br />even the chevy powerglide had two gears..<br />boy that was efficient..lol

 

[Paul Moir]

Re: how would you build your dream engine??

I think the rotax engines are sort of the marine equivalant of motorcycle technology. Take the 947DI (2 cylinder 2-stroke, 947cc) putting out 130hp at 7000rpm. I don't really know if they're really desired in the outboard market, but if it is you can bet Bombardier will plunk one on a leg and slap a J/E sticker on it.

 

[Nos4r2]

Re: how would you build your dream engine??

fair enough heybaylor. Point is really that you'll always have to make the trade-off between torque and horsepower-and small 2-strokes can't really produce both. I'm guessing for something like the rotax engine you don't actually need a huge amount of low-down torque on a jet drive?<br /><br />Realistically I suspect we're stuck with the same basic engines as the last 50 years because <br /><br />a)People will buy proven reliability rather than innovation.Lets face it, no-one wants to be the one that's rushed to buy an Edsel...<br />b)R&D is expensive.<br />c)A complete rethink of everything makes for an awful lot of expensive retooling.<br /><br /><br />I'd quite like to see a BIG wankel engined outboard. I did toy with the idea of sticking a Mazda RX7 engine on an old 100ish hp johnrude leg I had lying around a while back.I couldn't find a decent RX7 engine though.

 

[eluder1]

Re: how would you build your dream engine??

How about that guy many years ago using a worked out air-cooled corvair engine on a merc 750 lower unit!

 

[heybaylor]

Re: how would you build your dream engine??

Yes sir , its all about the bottom line ..<br />kinda like my "detroit story"<br /><br />"Orville , Wilbur , stay away from that thing..<br />it cost too much and people wont buy it "<br /><br />If God wanted us to fly ,he would have gave us wings!

 

[Nos4r2]

Re: how would you build your dream engine??

Yeah. I suspect if we're going to see any REAL innovation it'll come from the japs now-that's where the R&D money is. That's IF they can be convinced to do something other than copy and improve.

 

[heybaylor]

Re: how would you build your dream engine??

Nos , OK we agree to agree..lol

 

[CATransplant]

Re: how would you build your dream engine??

Nos4r2,<br /><br />Japs? You mean the Japanese, right? They stopped copying stuff a long, long time ago. When it comes to internal combustion engine technology, they passed the Euro/American stuff back in the 60s for 2-strokes and sometime in the 70's for 4-strokes.

 

[Nos4r2]

Re: how would you build your dream engine??

I'll have to disagree there- most of the concepts for the stuff they are building now (with the exception of fuel cells and engine management) was in use in the 1920s and '30s over here or in Europe-It's just that we really didn't build it that well so it never took off.

 

[bobrock]

Re: how would you build your dream engine??

bump

 

[Clams Canino]

Re: how would you build your dream engine??

Originally posted by OpK:<br /> I love my 1971 1350 wouldn't change a thing. Except maybe turn the clock back to 1971 buy it brand new set it in a secret storage and open it up this year. Would have been nice to see it brand spanking new.

Now there's a true believer <br />I built my monster this year, also a 99ci inline six. 1988 ADI block, 1975 pistons, 1980 reed blocks (modified), generic WMK carbs. <br />1958-1961 paint and chrome work.<br /><br />Tis a thing of beauty.....<br /><br />-W