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#900976 01/23/23 12:09 am
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I have a particularly silly project in the pipeline .... a 150mph straight-line blaster ( it will never be road legal) 800cc 2 stroke V8

i see that the speed record for a 50cc is 145mph ( dont ask me how) but with this in mind what do y'all recon would be needed to propel a pile of scrap metal to 150 /.... on a long clear beach?

1 speed direct drive and as dangerous as they come hahhah Brakes and steering are for sissys

interested in all comments


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It depends on how well it's streamlined.

Are you planning to lie flat on the tank and seat in your Speedos and sand shoes like Rollie Free?

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A stripped naked frame lowered bike would need 75 hp at the rear wheel...


61 hot rod A10, 89 Honda 650NT .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
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nah back couldnt do that /// i was thinking more along the lines of a recliner so my not inconsiderable mass could assist in lowering the center of gravity .... motors being behind a perspecs sheet in feild of vision so i colud see any chains being spat off etc

angled so that the wind would help push it down

THIS REPLY WAS TO SHANE .. for some reason the quote didnt work


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I think PRT did something like this on his turbo? A65... Hopefully he will chime in.


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Now lets all have a beer!

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[Linked Image from i.postimg.cc]

149.99 mph at Bonneville, 152.866 mph at Loring, ME. My dyno (not calibrated) says 64 rear wheel horsepower, but likely less than 60.

[Linked Image from i.postimg.cc]
(Scooter Grub photo)

Open class, 130 mph at Loring, 127 mph at Bonneville with about 61 hp (both those speeds with the enlarged 600cc motor). I predict you will need 95 hp to achieve 150 mph without streamlining.

Tom

Last edited by koncretekid; 01/23/23 12:46 pm.

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Tom, have talked to the tuner of the Moto Guzzi that holds the MPG1000 record at Bonneville...157 mph, non streamlined of course...He claims the engine has never seen more that 83-85 rwhp hp on a dyno. However he didn't mention the air density during dyno testing. Guzzi's have a lot of frontal area and that doesn't help....


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But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
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We never attempted to run the black bike naked but with the Cronshaw/ IOM style fairing we bettered 150 numerous times with nitrous only and turbo/nitrous..
BSA A-65 650cc. Carbs/NOS about 90 RWHP. Turbo/NOS close to 120. That whole bike is 'resting' while we work on the MPG bike. Good luck with your thing.

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i still have aspirations for 140mph, naked , production frame, 650cc, NA, gasoline.

maybe delusions would be a better word?


watermelons, and turnips, and a contaminator

and other stuff
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heres what some guys have got out of 50cc DANG why would you bother

http://www.elsberg-tuning.dk/recordbikes.html


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[img]https://www.bennetts.co.uk/-/media/...14C8C4BBDCA4603E51C8CA07B20860FE4DF9DAD7[/img]

A bit off topic but this is what's considered a naked frame in modern hyper bikes....207 Hp, 450 pounds wet, time distortion acceleration, 170 or so mph top speed as geared....


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Think I'll drive to find a place, to be surly"
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150 MPH is only a target .... u have to dream big right?

Im not certain if u are still allowed (as a member of the oppressed public) to buy Nitrous here but it would sure help eh.

should sneeky road tests at 3am make it look that 150mph is not really doable i can always save face by saying

"Oh did i say MPH .. i meant KPH "

surely i can ring 160kph , the tun. out of an 800 2 stroke v8

AND BIG BREAKTROUGH on the project .... my mate who is a master woodworker can get some SPRUCE and will make the engine mount "plate" and various air foils etc for me

So yep it will be a Spruce Goose hahhhahhh


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149.315 mph with a tiger cub engine
using a "mostly" factory stock 200cc tiger cub engined (12hp ? ).... Streamliner , Triumph dealer Bill Martin's
fastest pass at Bonneville in 1959 .
was .... a one pass speed of 149.315 mph
[Linked Image from tigercubandterrier.com]

2 way run was 139.82
[Linked Image from tigercubandterrier.com]

​

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Getting 60 mph out of a Cub was good going.


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Originally Posted by Hillbilly bike
A stripped naked frame lowered bike would need 75 hp at the rear wheel...
What he said.

I have a naked "street bike" with a claimed 90hp at the crank so probably about 80 (at most) at the wheel. I have seen 145mph on the speedo so someone lighter and crouching flat on the tank would probably (with slightly higher gearing) see over 150.

With a single speed and direct drive I think your biggest problem will be getting the thing going from zero unless you are planning to tow it and let it go at about 100.

John

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With a single speed and direct drive I think your biggest problem will be getting the thing going from zero unless you are planning to tow it and let it go at about 100.

John[/quote]

pretty much what i had planned to do to get it moving initially,,, but might use a really long stick and push it with a support vehicle , at about 30mph hit the clutch and hope hahhah


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Originally Posted by kevin
i still have aspirations for 140mph, naked , production frame, 650cc, NA, gasoline.

maybe delusions would be a better word?
Kevin, with the right fuel and conditions I'm sure your bike has 140 in it!


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Originally Posted by Ignoramus
150 MPH is only a target .... u have to dream big right?

Im not certain if u are still allowed (as a member of the oppressed public) to buy Nitrous here but it would sure help eh.

should sneeky road tests at 3am make it look that 150mph is not really doable i can always save face by saying

"Oh did i say MPH .. i meant KPH "

surely i can ring 160kph , the tun. out of an 800 2 stroke v8

AND BIG BREAKTROUGH on the project .... my mate who is a master woodworker can get some SPRUCE and will make the engine mount "plate" and various air foils etc for me

So yep it will be a Spruce Goose hahhhahhh
I would imagine that (8) 100cc 2stroke cylinders should have no problem pushing you to 160KPH or 100MPH. Not sure what base your planning to develop from but even with 12.5HP per cylinder your at 100HP. Will be an interesting project and you should definitely start a build thread with your progress.


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Originally Posted by Ignoramus
....hit the clutch and hope
Apologies for being a pedant but if you have a clutch then it is not direct drive. More of a single speed transmission.

John

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Originally Posted by George Kaplan
Originally Posted by Ignoramus
....hit the clutch and hope
Apologies for being a pedant but if you have a clutch then it is not direct drive. More of a single speed transmission.

John

Well its going to be a bit of both ....the "clutch" will actually be a huge V belt which will be tightened (engaged ) with a toggle lever ... i will be going for the contraption look


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For you pushrod guys. At this years manx GP a norton ES2 had a podium finish and set a lap record of 105mph around the isle of Mann circuit. Some chaps from NZ built and tuned it!!

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TEN H.P will do it, if you ride the bike off a 1,000 ft. cliff.

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Originally Posted by PFribley
For you pushrod guys. At this years manx gp a norton ES2 had a podium finish and set a lap record of 105mph around the isle of Mann circuit. Some chaps from NZ built and tuned it!!


Like many repop bikes, that was a 500 single with a semblance to an ES2.
It looked vaguely like one same as the new Manx nortons and goldies etc.
I won't take/detract from the engineering but they are not even close to
the bikes they are emulating.
I've said before, if you file the head and barrels on a GSX 1200 and say it's an MV
or Gilera 4 (well it's a twin cam 4 isn't it......) you are on the same lines.

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Originally Posted by Irish Swede
TEN H.P will do it, if you ride the bike off a 1,000 ft. cliff.

With that notion I could make a bicycle do just the same. 🤣🤣


Life is stressful enough without getting upset over the little things...

Now lets all have a beer!

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Found a calculator online:
http://www.wallaceracing.com/Calculate%20HP%20For%20Speed.php

Coefficient of drag seems important.

Bill Martin's record bike must have had a very good coefficient, plus some cam work etc.

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drag is the killer, maybe even more than frontal area.i dont know how to calculate drag without a wind tunnel, but i think its possible to look at a motorcycle and decide what makes more drag than what doesnt.

on my own race bike, i think im close to as much horsepower as i can get, or very near anyway.

i keep thinking of where i can reduce drag, and on an unfaired machine im not sure what i can do

Last edited by kevin; 01/28/23 3:50 pm.

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Originally Posted by Bustednukel
Found a calculator online:
http://www.wallaceracing.com/Calculate%20HP%20For%20Speed.php

Coefficient of drag seems important.

Bill Martin's record bike must have had a very good coefficient, plus some cam work etc.

Brilliant !! thanks


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Originally Posted by kevin
drag is the killer, maybe even more than frontal area.i dont know how to calculate drag without a wind tunnel, but i think its possible to look at a motorcycle and decide what makes more drag than what doesnt.

on my own race bike, i think im close to as much horsepower as i can get, or very near anyway.

i keep thinking of where i can reduce drag, and on an unfaired machine im not sure what i can do

Narrower tyres.


Life is stressful enough without getting upset over the little things...

Now lets all have a beer!

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I found out about drag a couple of years ago. shut the throttle and put my head above the fairing at over 190mph, it caused the bike to dance about a bit.
I was hitting 194-195 all day, I saw a photo of me crossing the finish line and my elbows were alongside my knees. I shuffled my bum back a bit so my elbows tucked in front of my knees, my speed on the next couple of runs was 198.
Last year without the cross wind 200.5, 2 run average 200.064


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On an unfaired bike, cardboard and gaffer tape to put a taper behind the fork legs, Keep the headlight shell but turn it backwards. Put the footrests in the region of the rear wheel spindle so your lower legs are horizontal


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200mph, that's going very well for a 350 Greeves.

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Originally Posted by Allan G
Originally Posted by kevin
drag is the killer, maybe even more than frontal area.i dont know how to calculate drag without a wind tunnel, but i think its possible to look at a motorcycle and decide what makes more drag than what doesnt.

on my own race bike, i think im close to as much horsepower as i can get, or very near anyway.

i keep thinking of where i can reduce drag, and on an unfaired machine im not sure what i can do

Narrower tyres.


i ran a set of 2.5 x 17, but destroyed a wheel bearing at 130 mph. i havent had a chance to have the machine shop look over the problem. that is in the works for 2023.

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]

^^^this configuration gives me more sprocket choices than the stock 43 or 46.

[Linked Image from i.imgur.com]

Last edited by kevin; 01/29/23 6:01 pm.

watermelons, and turnips, and a contaminator

and other stuff
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In the early 50's Moto Guzzi did a lot of work on drag. You'll remember they had their own wind tunnel so could explore it to their hearts content.. Fergus Anderson, one of their factory riders of the day wrote about it in one of the weeklies of the day (I think the Blue'un) and described how he spent days trying various riding positions and seeing what efffect moving about on the bike had. He even found the position of his feet on the footrests made a measurable difference.
Looking at racing Guzzis of the day you'll notice some had oddly shaped tanks. These were all the result of windtunnel tests with the rider aboard, not just what someone thought might work but what did work with the rider draped over them.
Full streamlining was somewhat controversial at the time. It was seen as giving factories an unfair advantage over the private rider who couldn't afford it. Guzzi were having a bit of a bet each way as their bikes didn't wear streamlining but much discreet effort had been put in to reduce drag on a naked bike. It didn't last of course. Streamlining won the day and bugger the little bloke.
Anyway, given the above discussion it may be useful to hunt out those old Fergus Anderson articles and give them a once over. It certainly seems the Guzzi work on drag has been lost in time.
After all, reducing drag is free power isn't it.
Chers,

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most of that was with dustbins, wasnt it?


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Andy, I'm wondering what you were riding and where? I see you have a Kawasaki ZZR1400 "Kuro No Senshi" so probably that one, but where can you ride it that fast in England?

Originally Posted by Andy Higham
On an unfaired bike, cardboard and gaffer tape to put a taper behind the fork legs, Keep the headlight shell but turn it backwards. Put the footrests in the region of the rear wheel spindle so your lower legs are horizontal

Although Ignoramus does not mention land speed racing, what you're suggesting puts the bike in Altered Partially Streamlined class for the events we participate in. Which is OK, but you'll encounter way more streamlined bikes in that class than just fork leg fairings and rear set footpegs.

Tom


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Originally Posted by Andy Higham
On an unfaired bike, cardboard and gaffer tape to put a taper behind the fork legs, Keep the headlight shell but turn it backwards. Put the footrests in the region of the rear wheel spindle so your lower legs are horizontal


Quote
2. No streamlining is permitted in the Modified class. Streamlining is any devices or objects
forward of the rider that has the apparent purpose of limiting or controlling airflow around
the motorcycle or rider. Un-modified OEM air inlet scoops, instruments, instrument panels
and/or headlights mounted with un-modified OEM mounts in the OEM location are allowed.

4. Round headlight must be between 5½” and 7” OD at the lens surface with a front radius
>18 in. The front surface must be within 5 deg. of perpendicular to the ground with the
vehicle loaded. Any OEM motorcycle headlight must be installed in its originally intended
position.

7.F.1 Footrests:
Must be ahead of the rear axle by at least by 6 in.


not available for me in the modified class.

i dont think anything up front has as much effect as closing the air behind. i suspect re-configuring the pipes so that they dump in front of the rear tire, lowering the machine by returning to the 17-inch wheels, and adding pizza pans for wheel discs is about as good as i can get.


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Originally Posted by Allan G
Originally Posted by kevin
drag is the killer, maybe even more than frontal area.i dont know how to calculate drag without a wind tunnel, but i think its possible to look at a motorcycle and decide what makes more drag than what doesnt.

on my own race bike, i think im close to as much horsepower as i can get, or very near anyway.

i keep thinking of where i can reduce drag, and on an unfaired machine im not sure what i can do

Narrower tyres.

I woulnt go with narrow tyres on a beach straight liner ....you want to have SOME chance if you hit a soft spot .

I was thinking more of double rear wheels like the Austin 7 powered Brough Superior they made for side cars. NOT spaced much so no smart arse will say "cant you ride a 2 wheeler yet"
For Tyres i was thinking about those bulbous things u see on bicycles used on soft sand. I am going to get one and run it up to 2800 rpm with a 3 phase motor just so i can know if the tyre will shred at high speed ...


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Koncretekid Yes I was riding my ZZR1400 at Elvington airfield. The runway is just shy of 2 miles, the top speed traps are at 2KM from a standing start, there are also other traps to record standing 1KM flying 1KM, flying 1/4 mile and flying 1/8 mile.

I also rode my Ninja H2 the same weekend and exceeded 209mph, the guys stood across from the finish line said they couldn't hear the exhaust, just the sound of the air being pushed aside


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But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
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I have found a delightful Asian lady whose hobby is making strange things out of bamboo.

" Me make long tube you sit in, be very strong for you" "have friend who put cloth on it with special can of stuff .... keep wind off you"

I am getting her to see if she can get another lady to paint a furious looking fire breathing red dragon on it hhahahahah

So i could definitely claim some type of record for ***MPH with 1950s lawnmower engines . spruce components and a bamboo streamliner

Bamboo could be quite good as it is very strong and light .


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It just predates the full streamlining dustbin era, Kevin. Fergus Anderson started to ride for Guzzi in 1950 just beforehand. FIM, the governing body was wary about streamlining and tippy toed around it for years. Everyone knew the theoretical advantages of streamling but how to do it whilst maintaining a rideable and controllable motorcycle was a foreign country. Hence the inelegant attempts in the early 50's with beaks in front, tanks moulded to body shapes, semi enclosed rear wheels and so on.
Everyone knew streamlining was coming but how did you do it effectively and stay within the rules?
Finally the FIM came to the party and we entered the dustbin period. They were gorgeous bikes. I saw them racing at Bandiana here in Oz and have never forgotten them. I was a new apprentice and attending my first real road race meeting with a factory racing team and international riders and all. Those dustbin Guzzi flat singles made a big impression on a gormless lad and to this day remain my ultimate ideal of a proper motorcycle. I've been a sucker for lightweight Guzzis ever since.

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Originally Posted by Andy Higham
Koncretekid Yes I was riding my ZZR1400 at Elvington airfield. The runway is just shy of 2 miles, the top speed traps are at 2KM from a standing start, there are also other traps to record standing 1KM flying 1KM, flying 1/4 mile and flying 1/8 mile.

I also rode my Ninja H2 the same weekend and exceeded 209mph, the guys stood across from the finish line said they couldn't hear the exhaust, just the sound of the air being pushed aside

Andy, ran a ZZR1400 through the online calculator that was included in a previous post. Found rear wheel HP and wet weight on Wikipedia, added a 170 pound rider, guestimated frontal area, and adjusted coefficient of drag to achieve end result of 200 mph.

Calculate HP For A Given Speed
Coefficient of Drag .46
Frontal Area of Car 7.3 Sq/Ft
Weight of Car 770 Lbs
Velocity of Car 200 MPH
Calculate
Using your vehicle Speed of 200 MPH takes 183.39 HP to overcome air drag.
Rolling resistance is 5.34
For a total of 188.73 HP to run 200 MPH

Last edited by Bustednukel; 01/31/23 5:04 pm. Reason: wet not dry weight
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I have 214 RWHP


BSA B31 500 "Stargazer"
Greeves 200 "Blue Meanie"
Greeves 350
Greeves 360
GM500 sprint bike "Deofol"
Rickman Jawa 500 "Llareggub"
'35 & '36 OK Supreme
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Originally Posted by Andy Higham
I have 214 RWHP

The calculation would change if the CofD was changed from .46 or the frontal area from 7.3 sq/ft. I arbitrarily selected those values.

Redid with same arbitrary values and adjusting MPH to achieve your RWHP. Yielded 209 MPH
Calculate HP For A Given Speed
Coefficient of Drag .46
Frontal Area of Car 7.3 Sq/Ft
Weight of Car 770 Lbs
Velocity of Car
209 MPH
Calculate
Using your vehicle Speed of 209 MPH takes 209.28 HP to overcome air drag.
Rolling resistance is 5.58
For a total of 214.86 HP to run 209 MPH

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I think the racing Tridents made about 80 HP and did better than 150 mph.


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Originally Posted by DavidP
I think the racing Tridents made about 80 HP and did better than 150 mph.

Black Bart Racing has been campaigning this Rob North Triple at Loring for years, always chooses a different class to try to set a new record. This photo taken in 2022 but with the full fairing on, his best record in the 750 APS-PG class (750cc A class because it was originally a race only model), Partially Streamlined in 2018 was 152.872 mph. Interestingly, in the Loring record book, my record directly above his at the same event in 650 APS-PG is 152.866 mph. I only have about 60 hp, but I have a lower coefficient of friction with better streamlining.

[Linked Image from i.postimg.cc]

Tom


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Anything worth doing is worth doing well. Steve said that. Anything worth doing well is worth teaching to others. I said that.
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fwiw.... round is a very un-aerodynamic shape. not as bad as square, but not too much better.

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From poster "Porkpie" on landspeedracing.com about wind drag: "It doesn't matter how you open the hole, it's how you close the hole."


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Anything worth doing is worth doing well. Steve said that. Anything worth doing well is worth teaching to others. I said that.
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about all thats available in modified production is a kamm tail

from what i have read, kamm tail design is a lot more subtle than just putting a box behind the seat


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I doubt the heat wrap will do anything meaningful. On a data logger it was 5hp, not much and it rusted stainless pipes before I pulled it off. When I say 5hp it is a lot when you are chasing it, but not much different just riding around. It was the easiest restoration of 5hp taking it off.

I guess that's a limited test, but cured me.

Also, because one Triple did over 170mph at Daytona doesn't mean they all did or will.


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Originally Posted by Mark Parker
I doubt the heat wrap will do anything meaningful. On a data logger it was 5hp, not much and it rusted stainless pipes before I pulled it off. When I say 5hp it is a lot when you are chasing it, but not much different just riding around. It was the easiest restoration of 5hp taking it off.

I guess that's a limited test, but cured me.

Also, because one Triple did over 170mph at Daytona doesn't mean they all did or will.

Mark, are you saying that you gained 5 hp with heat wrap?

I have not seen that kind of claim, but there might be some advantage to heat wrap because the heat wrap insulates thus increasing temperature and hence speed of sound. Getting the sweet spot for the return negative wave to occur at TDC to help scavenge the exhaust and draw in more air/fuel mixture will be affected by the speed of sound for any given length. This will depend, of course, on the length of your exhaust.

And your comment about Triples is right on, as bikes at Daytona doing 170 mph is not comparable to land speed racing because it's reported that bikes coming off of the high banking on turn 4 definitely increase speed thru the speed trap.

Tom

Last edited by koncretekid; 02/26/23 2:21 pm.

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