10-09-2008, 02:35 AM | #31 | |
No longer MIA
Join Date: Oct 2008
Location: Western NC (The Great Smoky Mountains)
Moto: 1987 GSXR 50, 1996 Ducati M900, 07 GSXR 750, 07 Harley Davidson Night Train
Posts: 984
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Lets ride! Last edited by jeeps84; 10-09-2008 at 02:43 AM.. |
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10-09-2008, 07:24 AM | #32 |
gun totin redneck
Join Date: Apr 2008
Location: South West New Hampshire
Moto: turbo busa 999 Duc Goldwing & Victory
Posts: 1,130
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For anyone who needs me to clarify my opinion. I believe that an OHC at the same displacement and degree of tune will always outperform a Pushrod engine. This is in part due to less reciprocating mass and as always fewer moving parts equals less to go wrong. I also recognize that an OHC is more expensive to manufacture and requires a different skill set to tune and maintain. ( A good illustration of the impact of economic on engine performance is that as far back as the late teens racing engines routinely used overhead valve conversions but it wasn’t until the late 30s early 40s that overhead valves were available on affordable cars)
In terms of motorcycles the best comparison I can come up with is the 2 Air cooled American cruisers on the market today HD using its Pushrod engine producing HD big bore producing 66 -71 RW HP (some one help me with the torque ) and My Wife’s 03 Victory big bore 92 RW HP with 94 ft lbs of torque. (my Victory doesn’t count cause I have tweaked the shit out of it) The numbers are at the rear wheel not the lovely “at the crank” fairy tales that every manufacturer seems to have. The major difference in the engine are 100 CI Victory OHC 103 CI HD pushrod, HD 45 degree V twin inline cylinders requiring “Knife and fork” connecting rods ,Victory 50 degree V Twin off set cylinders using standard connecting rods. Just for the sake of clarity Star (Yamaha’s Cruiser line ) Upper models us a push rod air cooled monster. |
10-09-2008, 08:34 AM | #33 | |
DefenderOfTheBuelliverse
Join Date: Feb 2008
Location: Parts Unknown
Moto: Buell XB12R
Posts: 18,585
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Torque on the Harley air coolers are in the area of mid-70's to low -80's.
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10-09-2008, 07:22 PM | #34 |
Chaotic Neutral
Join Date: Feb 2008
Location: Cherry Hill NJ
Moto: GV1200 Madura, Hawk gt
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i think you just shit on yourself with your own argument. you do know it took TEN YEARS of development for the ls motor to equal the output of the LT5 right? imagine how much more power they would be making if they could drop the pushrod/crossplane architecture?
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10-10-2008, 02:37 AM | #35 | |
Ride Naked.
Join Date: Feb 2008
Location: Flat and Straight ND
Moto: 08 BUELL 1125R, 05 SV650S
Posts: 7,916
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The big HD engines I saw in IA on the dyno were putting down mid 80's hp and around 100 ft/lbs torque at the rear wheel. mostly stock, but many had an exhaust on 'em. |
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10-10-2008, 06:34 AM | #36 |
gun totin redneck
Join Date: Apr 2008
Location: South West New Hampshire
Moto: turbo busa 999 Duc Goldwing & Victory
Posts: 1,130
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Thank you for making my point Larger displacement still less horse power. Oh ofr the recored the numbers on the wifes Victory are corrected raw data saus it was at something like 107 rw hp. Again I'm not saying that pushord engines don't work ( I Chevy 350's and 427s) Just that an OHC will Always do it better.
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10-10-2008, 09:03 AM | #37 | |
Just a Noob
Join Date: Jul 2008
Location: Pensacola, FL
Moto: 08 Green 6R
Posts: 421
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Few years when full electronic valve control comes it'll be an old pointless discussion anyways. |
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10-10-2008, 12:13 PM | #38 |
gun totin redneck
Join Date: Apr 2008
Location: South West New Hampshire
Moto: turbo busa 999 Duc Goldwing & Victory
Posts: 1,130
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10-10-2008, 12:21 PM | #39 | |
Ride Naked.
Join Date: Feb 2008
Location: Flat and Straight ND
Moto: 08 BUELL 1125R, 05 SV650S
Posts: 7,916
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when you only have a 4K range to play with, vs a 9K range |
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10-10-2008, 12:23 PM | #40 |
Just a Noob
Join Date: Jul 2008
Location: Pensacola, FL
Moto: 08 Green 6R
Posts: 421
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Back in the day 1 hp per cubic in. was pretty damn nice, now 2+ hp per cubic in. happens NA. I can see it now...2 solenoids per cylinder. Gone will be the old days of swapping cams and adjusting the timing. It'll simply be plug in your laptop to you ecu and dl your new cam settings. I can see 3-4 hp per cube one day. Wouldn't that be nice. 300+ hp out of 100 cubes. Everyone could be happy, good performance +small motor cheaper on gas. Of course going to need a battery a little bigger then 9v to work everything. Last edited by Shift; 10-10-2008 at 12:25 PM.. |
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