Author Topic: Dan Gurney's new engine (Read 8846 times)

Seagondollar · « **on:** January 06, 2016, 12:55:15 PM »

Saw this article in Cycle World and thought it's an interesting engine, from a vibration standpoint. Don't get me wrong, I love the way the Guzzi rocks, but it still makes for an interesting engine.

http://www.cycleworld.com/2015/09/09/dan-gurney-moment-canceling-four-stroke-motorcycle-engine-patented/

Chuck in Indiana · « **Reply #1 on:** January 06, 2016, 01:02:10 PM »

110 cu in.. 280 peak hp. (!)

jlburgess · « **Reply #2 on:** January 06, 2016, 01:52:59 PM »

My uncle was his second employee at the race shop in the '60s. Lots of cool stories and souveneirs. He passed away a few years ago but my Aunt has the stuff still. She even has his original open face helmet from his Lotus days.

She's a cool lady too and loves car guys. She lived with Joe Parkhurst when I was young. She went to ISDE with him and met just about every racer of the era due to Cycle World Magazine. Kenny Roberts and many others. When I was a kid I looked in Joe's garage and saw my first Ferrari. I think it was a Daytona but I was only about 8 so can't remember it that well. I've been hooked on bikes and Italian machines ever since

oldbike54 · « **Reply #3 on:** January 06, 2016, 02:00:30 PM »

OH MY ! Gurney remains one of my heroes . Slightly reminiscent of the Cysz designed 4 cylinder .

Dusty

jlburgess · « **Reply #4 on:** January 06, 2016, 02:05:18 PM »

I know him too! He used to do a lot of trackdays at PIR on his Aprilia and designing the E bike. Very friendly and approachable guy. He has had some cancer battles recently so hope he is well!

oldbike54 · « **Reply #5 on:** January 06, 2016, 02:07:57 PM »

Quote from: jlburgess on January 06, 2016, 02:05:18 PM

I know him too! He used to do a lot of trackdays at PIR on his Aprilia and designing the E bike. Very friendly and approachable guy. He has had some cancer battles recently so hope he is well!

That's pretty cool . Seems his first love was always motorcycles

Dusty

jlburgess · « **Reply #6 on:** January 06, 2016, 02:28:47 PM »

http://www.motorcycle.com/features/motorcycle-therapy-michael-czysz-story.html

Sorry for the thread hijack, but thought this is an interesting article. Looks like Czysz has traded in his RSV4 for a Superleggera

charlie b · « **Reply #7 on:** January 06, 2016, 02:39:52 PM »

Always loved Gurney's driving and his work. Like running pushrod V8's at Indy and driving the Ford GT at LeMans.

keuka4884 · « **Reply #8 on:** January 06, 2016, 02:45:52 PM »

One of my favorite stories is Brock Yates describing his ride with Dan Gurney in the first Cannonball Baker Sea to Shining Sea Memorial Trophy Dash. A highlight was Dan Gurney at the wheel of their Ferrari going through Pennsylvania at 1 in the morning with one hand on the wheel doing over 130 and carrying on a conversation with Brock. If I remember right the story was in Road and Track. Bloody awesome.
Two big thumbs up to Dan Gurney and his new engine.

not-fishing · « **Reply #9 on:** January 06, 2016, 03:08:33 PM »

Looks nice but man it's complicated. Two crankshafts and a balance shaft, four inductions on a twin piston rig.

My head hurts looking at it.

Antietam Classic Cycle · « **Reply #10 on:** January 06, 2016, 04:08:57 PM »

Want some cheese with that whine?

With all of those straight cut gears, it probably won't be quiet...

LowRyter · « **Reply #11 on:** January 06, 2016, 05:54:24 PM »

Twin crank twin cylinder, gear driven together.

What is so special that will create all this horsepower?

jlburgess · « **Reply #12 on:** January 06, 2016, 06:31:13 PM »

I'd have to get out a calcumatooter but I think 110 cubic inches is a lot of cc's. 1700 range. Likely heavy and claimed at the crank. Apparently the Alligator is a prized possession so who knows?
Survey says 1803cc. Don't think that's going to fit in anything sporty.
Further research shows current F1 dispacement limit at 1600 cc making 600 hp and strangled by fuel consumption. Not sure what the target audience is?

flip · « **Reply #13 on:** January 06, 2016, 06:41:53 PM »

I read about that engine in another magazine. There is something unique about the intake runners shape. I don't remember the details though.

Muzz · « **Reply #14 on:** January 06, 2016, 06:52:40 PM »

Quote from: Antietam Classic Cycle on January 06, 2016, 04:08:57 PM

Want some cheese with that whine? With all of those straight cut gears, it probably won't be quiet...

I suspect that would be addressed with helicals in the very near future.

Seagondollar · « **Reply #15 on:** January 07, 2016, 04:50:50 PM »

Quote from: LowRyter on January 06, 2016, 05:54:24 PM

Twin crank twin cylinder, gear driven together.

What is so special that will create all this horsepower?

Counter-rotating cranks and counterweights that cancel each other's vibrations. And no turn counteraction from the cranks. (when you turn a rotating bicycle wheel left or right, there is a counter-force up or down. Try it.)

LowRyter · « **Reply #16 on:** January 07, 2016, 05:11:54 PM »

uhm? huh?

Muzz · « **Reply #17 on:** January 08, 2016, 01:14:18 AM »

Quote from: Seagondollar on January 07, 2016, 04:50:50 PM

Counter-rotating cranks and counterweights that cancel each other's vibrations. And no turn counteraction from the cranks. (when you turn a rotating bicycle wheel left or right, there is a counter-force up or down. Try it.)

Didn't the Arial square Four have gear linked cranks? Not sure whether they counter-rotated or not.

LowRyter · « **Reply #18 on:** January 08, 2016, 08:43:19 AM »

Quote from: Muzz on January 08, 2016, 01:14:18 AM

Didn't the Arial square Four have gear linked cranks? Not sure whether they counter-rotated or not.

several of the 500cc two stroke GP engines had twin cranks. One reason was to retain the rotary valves are the ends of the cranks.

I am still uncertain why twin cranks are reason for the tremendous power expected from Gurney's engines. I do understand that twin cranks would have self cancelling vibration but would also have more friction with all the gears.

oldbike54 · « **Reply #19 on:** January 08, 2016, 10:24:16 AM »

Quote from: Muzz on January 08, 2016, 01:14:18 AM

Didn't the Arial square Four have gear linked cranks? Not sure whether they counter-rotated or not.

Yes . Turner was years ahead on that design .

Quote from: LowRyter on January 08, 2016, 08:43:19 AM

several of the 500cc two stroke GP engines had twin cranks. One reason was to retain the rotary valves are the ends of the cranks.

I am still uncertain why twin cranks are reason for the tremendous power expected from Gurney's engines. I do understand that twin cranks would have self cancelling vibration but would also have more friction with all the gears.

Any true square 4 requires two crankshafts . I do agree , not sure what the counter rotating cranks have to do with high specific output , except for a slight decrease in frictional loss .

Dusty

jlburgess · « **Reply #20 on:** January 08, 2016, 04:21:05 PM »

I don't think there's anything in that design that is going to make higher power. There might be a slight advantage on turn in. If it was a huge difference it would already be in a GP bike. I had an RZ500 that had twin cranks.
Current production 4 cylinder engines in the liter bike class are 170 hp per liter, so if you made one 1800 cc it would be 306 hp at the rear wheel. This only makes sense to quell vibration. I'll have my Auntie give him a ring to see what's up?

organfixsing · « **Reply #21 on:** January 12, 2016, 05:42:25 AM »

Thedesign looks like ""Heron" heads to me. I can't see magnificent horsepower!
Cheers
Brian

Muzz · « **Reply #22 on:** January 12, 2016, 01:21:58 PM »

Quote from: organfixsing on January 12, 2016, 05:42:25 AM

Thedesign looks like ""Heron" heads to me. I can't see magnificent horsepower!
Cheers
Brian

I have seen the inside of the Brittan head and it looks very similar to that, very steep intake angle, 4 valve (the Brittan came out with a 5 valve later) and a slight dish in the head. Can't actually tell if they are showing a full combustion chamber in the piston or not.

The valves on the Breva are vertical, and the chamber in the head is flat.

Kiwi_Roy · « **Reply #23 on:** January 12, 2016, 03:06:22 PM »

The Velocette Roarer also had twin counter rotating cranks but that didn't make it to production.
Some of the Ariel Square Fours had a chain coupling the two shafts, I don't know which came first chain or
gears. The Kawasaki KZ1000 had a straight cut primary drive, it's surprisingly quiet.

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Author Topic: Dan Gurney's new engine (Read 8846 times)

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