That answers that question. Thank you all.
That answers that question. Thank you all.
In reply to noddaz :
I put a lunchtime show on at Seattle International raceways for their Winston West Nascar race in June of 1985. A group of assorted vintage sports cars made up a vintage grid that included a Scepter powered by a Mercury Mk 75, six cyl. It had a morning practice session during which it attracted a lot of attention....it was very loud. As I recall it failed to start for my exhibition race.
In the 1970's I had a go kart with a 4 cyl merc, Norton Burman transmission and four wheel Hurst Airheart disc brakes. I didn't run it but in the early 70's it was clocked at 140 at S.I.R.
I bet they blew up a lot because when you shut off the throttle braking into a corner at high RPM, the bearings get no oil.
Sounds like the reason SAAB had a one way clutch on their 2 stroke engines.
I saw this posted on FB yesterday:
https://www.facebook.com/groups/553331468071450/permalink/7102469709824227/
Sandy MacArthur piloting his Mercury outboard powered Bandini in the 1955 Sebring 12 hour race. The Bandini was a DNF when the Topolino gearbox gave up.
wspohn said:I used to race with a guy that ran a small bore sports racer called a Sceptre. One of the original Sceptres used a Mercury two stroke outboard engine.
See https://bringatrailer.com/2009/07/17/micro-special-1961-h-bomb-mercury-race-car/
Until the advent of the Mazda rotary, it was the loudest car on the track.
Lots of other two stroke cars but offhand I can't think of another outboard example.
The Bill Stevens Sceptre as I remember from the 70’s early 80’s at Westwood
this picture is from Spokane
Damn it I really expected to see a post in this thread for when the top gear guys put it out board on the back of some car and drove it around a lake...
I saw a C or D sports racer in the late 80s/ Early 90s that used an outboard powerhead. The guy had a collection of Cadillac heater cores as radiators. Never saw it on track but heard it running. Loud does not describe it.
The Evinrude Rooney Lakester. Pretty wild, but never went anywhere.
In reply to Dirtydog (Forum Supporter) :
Wow! Never heard of that before. Cool:
https://www.hagerty.com/media/automotive-history/the-evinrude-rooney-lakester-was-both-a-boat-and-a-car-but-not-at-the-same-time/
nocones said:This is my dream for the LMP360. I want to find a 6 or 8 Cyl powerhead for cheap. That way it can be a 2 stroke again.
This is future Dan's problem.
YES PLEASE! future Dan 
I had always heard the big issue is that boat motors are designed to run at pretty high RPM for long periods of time. You tend to go WOT to a fishing spot, then kill it for a few hours, then WOT back to the dock. They are designed for a very different duty cycle.
I think a lot of the marine cost comes from certification vs. production volume. They don't make all that many of them in the grand scheme of things, and I believe marine cert is fairly rigorous depending on the size/output/class/operating region. Last time I was involved in marine stuff, I remember the certification also being very fragmented, so it wasn't like one cert got you global approval. You had various regional and national certifications around the world that many of the bigger units needed to meet.
In reply to pinchvalve (Forum Supporter) :
Sounds just like a race engine to me :)
Pete. (l33t FS) said:I bet they blew up a lot because when you shut off the throttle braking into a corner at high RPM, the bearings get no oil.
Sounds like the reason SAAB had a one way clutch on their 2 stroke engines.
Blip on clutch-in decels with two-strokes, people! And do clutch-in decels.
GCrites80s said:Pete. (l33t FS) said:I bet they blew up a lot because when you shut off the throttle braking into a corner at high RPM, the bearings get no oil.
Sounds like the reason SAAB had a one way clutch on their 2 stroke engines.
Blip on clutch-in decels with two-strokes, people! And do clutch-in decels.
I can speak for Saabs but on Yamaha TZ250 & Honda 125 GP bikes we never did that and they lasted fine. Same goes for my Yamaha RD350 street bike. Most of us who raced two stroke bikes never used the clutch once we left pit lane.
Rons said:
The Bill Stevens Sceptre as I remember from the 70’s early 80’s at Westwood
this picture is from Spokane
Yup. I loved that Bill managed to run in two different sports racing classes. He had a Fiat engine in it for most of the time and ran F sports racing, and then he would attach an electric fan to the intake snorkel so he could claim that he was now supercharged and he could run in the G sports racing class in the following race. class
Keith Tanner said:I don't know what the prices are like for used outboards, but in the new market the $/hp ratio is not good. I can buy a 430 hp crate LS3 for under $10k with a warranty even if I put it in a golf cart. A 400 hp Mercury outboard is $35k - and it's considered a lightweight at only 683 lbs according to boats.com. What do outboards bring to the party other than lolz?
A horsepower sticker on the engine cover to impress other guys.
Tom1200 said:GCrites80s said:Pete. (l33t FS) said:I bet they blew up a lot because when you shut off the throttle braking into a corner at high RPM, the bearings get no oil.
Sounds like the reason SAAB had a one way clutch on their 2 stroke engines.
Blip on clutch-in decels with two-strokes, people! And do clutch-in decels.
I can speak for Saabs but on Yamaha TZ250 & Honda 125 GP bikes we never did that and they lasted fine. Same goes for my Yamaha RD350 street bike. Most.of.us who raced tow stroke bikes never used the clutch once we left pit lane.
I do it on all of my 2-stroke bikes, street or dirt. Today's oil films are much better so it's not as necessary. I'm talking about long decels, not things like corners. So things like long downhills in the woods, off ramps, stoplights, freeways ending. I still use engine braking for short periods.
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