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Bonneville Salt Flats Discussion => SCTA Rule Questions => Topic started by: Briz on September 15, 2010, 03:11:56 PM



Title: What class would a bike with this engine run in?
Post by: Briz on September 15, 2010, 03:11:56 PM
I'm pretty new & fairly clueless as regards motorcycle classes, bear with me...
I'm very tempted to go for a deal on a very rare Weslake DOHC V-twin:

(http://www.ukdrn.co.uk/forum/download/file.php?id=6391&t=1&sid=78efc95be6601f11ae1d86d93e9c4ba0)

Production numbers are vague, but no more than 20 were made (they made many more pushrod versions)
Capacity is 1000cc
The thing is; what class would I end up running in? It'd be running on gas and the bike would be a basic unfaired configuration.
While I'd be doing it more for the experience than to set records, it'd be good to think there was some kind of attainable target to aim for!


Title: Re: What class would a bike with this engine run in?
Post by: Nortonist 592 on September 15, 2010, 03:21:48 PM
The simple answer is whatever you build (solo or sidecar) you would be in A.  And as a Weslake lover I am really jealous!!  Nice find.  Hope you snap it up.


Title: Re: What class would a bike with this engine run in?
Post by: nrhs sales on September 15, 2010, 03:29:42 PM
How old is it? Might be able to run vintage class?


Title: Re: What class would a bike with this engine run in?
Post by: Nortonist 592 on September 15, 2010, 03:32:03 PM
How old is it? Might be able to run vintage class?

Not old enogh for vintage.  But it would look absolutely fantastic in a wideline!!!


Title: Re: What class would a bike with this engine run in?
Post by: nrhs sales on September 15, 2010, 03:35:44 PM
So if it is not old enough for vintage and it does not use pushrods that would put it in the same class as a new 1000cc GSXR or CBR engine.   Hope it makes at least 150 hp!!!   :evil:


Title: Re: What class would a bike with this engine run in?
Post by: Nortonist 592 on September 15, 2010, 04:16:22 PM
Thats the unfortunate part of these wonderful engines.  But it should, with decent aero, be able to run 150.  My 500cc pushrod Weslake ran 125.715 at SpeedWeek this year so 150 from a DOHC 4 valve Vee twin shouldn't be a problem.


Title: Re: What class would a bike with this engine run in?
Post by: nrhs sales on September 15, 2010, 04:18:20 PM
150 hp not 150 mph.


Title: Re: What class would a bike with this engine run in?
Post by: Nortonist 592 on September 15, 2010, 04:29:35 PM
Apologies!   I have a very short attention span.  150hp would be attainable on fuel.  Not sure about gas.  Probably around 120 hp.


Title: Re: What class would a bike with this engine run in?
Post by: Briz on September 15, 2010, 04:51:39 PM
So if it is not old enough for vintage and it does not use pushrods that would put it in the same class as a new 1000cc GSXR or CBR engine.   Hope it makes at least 150 hp!!!   :evil:

Thanks for the replys guys.
This is what I was afraid of!  Its rated at 100hp as it is and 120 is said to be fairly easily attainable. The current owner checked compression and reckons it has less than 9:1 so theres some scope for improvement right there. Whats the deal with running race gas? does that bump things into higher classes? How about a blower or a turbo? its likely that this engine is built tough, but clearly any hop-up parts would need to be custom made.
Beginning to sound like I'd be better off with a pushrod motor!


Title: Re: What class would a bike with this engine run in?
Post by: nrhs sales on September 15, 2010, 04:54:55 PM
The good news is race gas does not change your class as long as you buy the approved race gas at the event from ERC.  He stocks gas anywhere from around 101 octane up to something like 118 octane so you should have no worries there.  Blowers and Turbos would put you in the boosted class which often times has slower records than the normally aspirated classes believe it or not.


Title: Re: What class would a bike with this engine run in?
Post by: RichFox on September 15, 2010, 05:11:13 PM
I don't do or understand bikes but a quick glance at the rule book looks like depending on faring and whatnot that I don't understand your looking at records between 175 and 230. Isn't that about right?


Title: Re: What class would a bike with this engine run in?
Post by: 55chevr on September 15, 2010, 05:28:21 PM
The unfortunate answer that it must run in the same class as GSXR 1000, Kawi 1000 and CBR 1000 ... the engine is not going to be competitive against much more efficient modern designs ... I would build a chassis and run it without any record expectation ... be the fastest Westlake .... Joe


Title: Re: What class would a bike with this engine run in?
Post by: Stan Back on September 15, 2010, 05:43:59 PM
And (no offense, Bill) probably the coolest.


Title: Re: What class would a bike with this engine run in?
Post by: Dakzila on September 15, 2010, 05:48:28 PM
Unfaired, special chassis, 1000cc, no added boost? You'd end up running in Special Construction, in the A/G 1000cc class.

Unfortunately for those of us who run in this class they (the powers to be) allow modern sportbikes to remove their faring and run in the same class without any chassis mods, so as Joe said earlier in this string it's hard to be competitive running an older style engine in this class.

Still it would make a great looking ride and I'd like to see it run....good luck.

Ron  B


Title: Re: What class would a bike with this engine run in?
Post by: Nortonist 592 on September 15, 2010, 05:54:54 PM
And (no offense, Bill) probably the coolest.

No Doubt.  And in a wideline ABSOLUTELY no doubt.  But he hasn't run yet.  You know the old saying.  If you want rabbit stew first you gotta catch a rabbit.


Title: Re: What class would a bike with this engine run in?
Post by: 55chevr on September 15, 2010, 05:56:59 PM
The supercharger classes are fast ... ECTA - Dean Sabatinelli has the record at 225 something ... it will be an uphill struggle for sure ...


Title: Re: What class would a bike with this engine run in?
Post by: Nortonist 592 on September 15, 2010, 07:29:02 PM
... it will be an uphill struggle for sure ...

If it was easy everyone would be land speed racing.

P.S.  Stan,  I didn't build mine for pretty.


Briz,  I have to ask.  Whats it going for?   You should contact David Perry at Antig and see if he has any parts on the shelf for such a beauty.  My Norton has an ancient long rod Weslake and he came up with a new rod for it a few years back.  If you don't want it I have a wideline in the garage just waiting!


Title: Re: What class would a bike with this engine run in?
Post by: Briz on September 16, 2010, 04:59:43 AM
Seems there might be a battle to get this lump now, theres another guy who has promised to send the seller a downpayment and he wants to hang on to see if this comes thru.
Whereas I'm sitting here with cash and could be there tomorrow to pick it up. :roll:
He's gonna give the guy until Monday.
Had a look for the Antig site, but it's disappeared. Dont know if they're still in business. I'll make further enquiries if & when the engine is mine.
If I dont get it, I'll be looking for a pushrod one.


Title: Re: What class would a bike with this engine run in?
Post by: Briz on September 17, 2010, 03:38:34 PM
Well, I got it! seems the old boy who sold it liked the sound of ready cash better than a downpayment. And who could blame him!
So; I'm pretty chuffed (thats Brit for 'stoked'!) Had a quick look over it this evening - its a 50 degree V, so HD ignitions will need a bit of alteration. There are provisions for 2 seperate ignitions on the end of each lower cam drive sprocket. The holes into which the ignitions fit are big enough for HD stuff. I might take an alternator drive off the front one.
The engine is about an inch shorter than an Evo (so probably similar to a shovel).
Reckon I'll be starting a build diary soon. :-D


Title: Re: What class would a bike with this engine run in?
Post by: 55chevr on September 17, 2010, 06:38:27 PM
Good deal ... you have it ... now the fun begins .... Joe


Title: Re: What class would a bike with this engine run in?
Post by: Nortonist 592 on September 17, 2010, 07:36:15 PM
Terrific!!!   Looking forward to the build diary.  If you (and I assume you will be) are going to strip it it would be sweet to see some photos of the innards.  BTW They look fantastic in a wideline.  Just in case you want a quick build :-)


Title: Re: What class would a bike with this engine run in?
Post by: wobblywalrus on September 17, 2010, 10:15:57 PM
A frame setup where you could switch back and forth between a pushrod and OHC motor might be handy in the future.  That looks like a great project.


Title: Re: What class would a bike with this engine run in?
Post by: Briz on September 18, 2010, 04:41:22 AM
I understand the appeal & traditional aspect of using a featherbed, but since my main business is custom frame building, I think I can bring more to the party than a featherbed would offer.
An FB isn't exactly optimal for LSR stuff; its height, shortness and steep rake are much better suited to road-racing.
The chassis I'm thinking about would be more based on HD FXR architecture.
On the way home yesterday, I also picked up an early FXR tranny case - those familiar will know early ones had a removeable front mounting plate, which once discarded leaves a 4-bolt flange which will make mating to the Weslake rear flange a simple operation. A quick measurement indicates that FXR short primary centre-to-centre measurements can be used.
Serendipitously, Zodiac (dutch based HD parts distributors) currently have kicker only FXR Primo 3" beltdrives (with clutch) on offer at knockdown prices. So I'm grabbing one of those.
Its probably sensible to build it so that if I do grenade the Weslake irrepairably, a HD lump can be fitted without too much hassle.


Title: Re: What class would a bike with this engine run in?
Post by: 55chevr on September 18, 2010, 07:01:09 AM
I like your plan ... build the best frame possible for land speed racing ... you will have no compromises ... I was able to find a chrome moly drag frame that was untouched and built in the 70-s ... while it is a good chassis for lsr, I will eventually lengthen the rear to get the CG further forward ... Looking forward to the build diary ...


Joe


Title: Re: What class would a bike with this engine run in?
Post by: wobblywalrus on September 18, 2010, 02:19:17 PM
Some thoughts based on my experiences...

The first frame, if I built one, would be a simple no frills rigid.  The engine, trans, primary assembly would be plate mounted a'la featherbed.  The plates would be drilled so I could move the engine assy an inch fore or aft of where I thought it should be.  The engine bay would have enough room to allow me to do this.  The slots in the frame for the rear axle would be 6 inches long.

I would run this creature for awhile with different wheelbase and engine placement settings while making adjustments on the salt.  Sooner or later I would find the geometries that I liked best for different track conditions.  Then I would toss the starter frame and I would build my keeper frame. 


Title: Re: What class would a bike with this engine run in?
Post by: Nortonist 592 on September 18, 2010, 02:26:54 PM
I understand the appeal & traditional aspect of using a featherbed, but since my main business is custom frame building, I think I can bring more to the party than a featherbed would offer.
An FB isn't exactly optimal for LSR stuff; its height, shortness and steep rake are much better suited to road-racing.

True a featherbed may not the optimal frame for LSR but dang!!  J.A.P. or Weslake or Godden Vees look absolutely fantastic in them!  I have a 500 Welake single in my featherbed and it currently holds its class record at El Mirage.  They may not be the optimal frame for LSR but they are a good substitute.  Good luck with whatever design you come up with.  Looking forward to the build and really looking forward to seeing it on the salt.