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Bonneville Salt Flats Discussion => Build Diaries => Topic started by: Beairsto Racing on July 20, 2011, 08:11:24 AM

Title: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 20, 2011, 08:11:24 AM
I've been meaning to start this thread for awhile...

Larry Forstall built the "Double" back in the early 90's. He made a couple of shake down passes with it...then an event got rained out..then life got in the way...then the Hayabusa came on the market and Larry got side tracked  :-D

In 2002, I sat with Larry and his team at the 200 MPH Club banquet and asked him about his earlier years at Bonneville. I was especially interested in the twin engine bike. Larry sent me a few photos and I kept at him for several years to sell it to me...nope it's been sitting too long, it needs too much work...well let me fix it up and I'll ride it for you! A few years went by and I happened to be working on a rig in Mexico, when Larry emailed me that he had reluctantly decided to sell it to me. He was attached to it, he had invested so much time into it. Bonneville has a history of multi-engine racers, I couldn't have been happier. I had it shipped from Pennsylvania up to my local Suzuki dealer in Alberta, I couldn't wait to get home.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 20, 2011, 08:35:53 AM
I mainly work in the Middle East & Africa, so I'm not home much. I poked around the Double a little and tried to figure out how everything worked...lots of emails back and forth to Larry. Still it remained a curiousity in my garage while we worked on the other projects. I borrowed a boreoscope to check out the engine internals and was fairly certain we could make it run when we needed to.
I could have gone with a Busa body etc but I decided to keep it looking period mid 80's and ordered a first gen GSXR competition fairing from Airtech. We got it running just a few days before Speed Week '09, but the first time that I ever put it in gear and let out the clutch was on the start line!
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 20, 2011, 09:01:33 AM
I was pretty nervous riding it on the first pass but soon learned that Larry had built a very stable bike, I went @180mph. On the 2nd pass, I took it up to @190mph but the coupler for the 2 engines started making some noise and I shut it down. Further inspection showed that it got hot, we didn't have enough lubrication...the chain was pretty much welded solid...the bearing for the idler/tensioner was now loose in the aluminium sprocket. We spent the rest of the week trying various farm repairs to keep the bike running, we stayed on the short course, my fastest speed was 203 mph @7 grand. We had found the weak link but knew it would take some re-engineering of the coupler in order to make a serious pass.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: ben james on July 20, 2011, 09:01:47 AM
man i'm so interested in hearing about this bike,love double engined racebikes,
coolest custom bikes on the planet.
ben
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 20, 2011, 09:20:10 AM
I first went to Bonneville in 2000 with an '86 GSXR 1100 that had been road raced, drag raced and abused by many others before I restored it. With big dreams, I was sure that I'd run 190mph but soon learned it was alot harder than that. I ran 162 and Carl Francis went 163 on it. We were addicted and I knew I'd be back. I bought an '01 Busa off the showroom, promptly voided the warranty and came back with a 1397 in '02...when I went to fuel inection, I swore I'd never go back to carbs..now I have 8 of them!

The Double had a pair of 1255cc oil cooled GSXR engines, they worked fine and the bike couldn't hook up as is...but I think aftermarket big blocks on these engines are really cool. Nobody is making new performance parts for 25 year old GSXR's anymore. Sitting in Dubai, I searched for days, emailing and calling people across the USA, Europe and Australia..finally back to the U.S. and scored a pair of brand new blocks at Carolina Cycle.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: oz on July 20, 2011, 02:09:57 PM
Hey Scott how ya doin I didnt realise that was its first run for you on that bike in 09 I remember talking to you about the sync on the engines hope you get the linking sorted.
Way cool

Oz
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 21, 2011, 12:23:01 AM
man i'm so interested in hearing about this bike,love double engined racebikes,
coolest custom bikes on the planet.
ben


Yes, I'm a big fan of them too!
I'm still in awe of Bob Moreland's twin engine Harley. It's huge, it's fast and it's gorgeous!
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Rex Schimmer on July 21, 2011, 12:23:36 AM
I happen to be a big fan of Kevin Cameron who writes in Cycle World mag. I am not even a "bike" guy but Cameron always has some interesting things to say and if you pick up the latest Cycle
World and read Kevin's page you may get a good idea about making your coupling chain live.

Looking forward to seeing you on the salt.

Rex
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 21, 2011, 12:38:57 AM
After Speed Week '09, I went back to work for a few months but hoped to make the November event at El Mirage. The cheap and dirty fix was to replace the aluminium idler/tensioner gear with a slightly larger steel one and add a chain oiler. In the end, I never got back home in time for El Mirage. When I finally did, we decided to strip the bike, rebuild the engines and find a better solution to the coupler issues.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 21, 2011, 12:42:17 AM
I happen to be a big fan of Kevin Cameron who writes in Cycle World mag. I am not even a "bike" guy but Cameron always has some interesting things to say and if you pick up the latest Cycle
World and read Kevin's page you may get a good idea about making your coupling chain live.

Looking forward to seeing you on the salt.

Rex

Thanks Rex,

Agreed..Kevin Cameron always makes for good reading!

Regarding the coupler...stay tuned..we are hopefully going in the right direction.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Queeziryder on July 21, 2011, 04:28:38 AM
Scott,
Many years ago when my dad campainged a twin engined blown Triumph we gave up on chains, and went to gears to couple the engines.
I'm sure that Max has done something similar on the Black Lighning liner, so give him a shout, he can probably help.

HTH
Neil
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Koncretekid on July 21, 2011, 07:29:24 AM
I would not trust that coupling chain past the garage door (sorry).  My little BSA 500  with maybe 40 hp uses a duplex primary chain, and I have broken it, as others have, and I ended up doing somersaults down the front straight at about 60mph because the broken chain wrapped around the clutch and seized the rear wheel. Duplex or preferably triplex, running in oil as a minimum.  Changing to larger sprockets of a size that you do not need an idler (spacing at an exact distance) would be safer, as that idler could self destruct in no time.  Larger sprockets will increase chain speed, but lessen the tension in the chain as well. Gears would probably be better, but then you'll have to add idlers with shafts with very stiff stub axles (supported inboard and outboard or double bearings inboard).  I'm not an expert on these things, but as a retired engineer, I see potential problems.
Tom
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: thefrenchowl on July 21, 2011, 08:45:50 AM
Hi, Beairsto Racing,

Thanks for the insights on your twin engine bike...

Looking at your drive/coupling sprockets, my failing eyes can't quite count the number of teeth...

Looks around 25, which looks low to me since "agreed" minimum is 19, but with such power to transmit, a much higher count will help get rid of the destructive speed oscillations on the drive train and lengthen chain life...

Patrick
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 21, 2011, 09:19:27 AM
Gents, I appreciate your comments and experience. The pictures previously posted are from 2009. We never ran it last year. The coupler has recently been updated with an oil bath and a revised tensioner, it uses a 530 drag race chain.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 21, 2011, 09:28:14 AM
When Larry built the bike, he made brackets by drilling lots of holes around the pattern on a drill press and finishing them by hand with a file. Now we just make a drawing and email it to the factory.

This is the current coupler set up.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: JimL on July 22, 2011, 12:50:11 AM
This looks a lot better to me, and you know my terrible gear experience on my twin engine bike.  I don't believe gear coupling can work with your gearbox arrangement, because there would be no way to keep torque events together.

One thought....it looks like you are running about 5000-6000 RPM on those sprockets (my guess)....can you get smaller on the rear sprocket and stay out of that overdrive top gear?  That would slow this chain down and reduce the kickback losses being fed and rebounded through the transmissions.  Any bucking that occurs in this coupling will be multiplied by the inverse of your overdrive trans ratio and then repeated back from the cushion damping in the primary drives (I think mostly on the front transmission).  On the little trucks, we learned years ago that towing in overdrive (5th gear) would pound the race out of the input shaft bearing (because the trailer bucking was amplified back through the overdrive and up against the spinning flywheel....which didn't want to change speed!)

It's not like your short of power to pull a bigger first gear!!

Regards, JimL
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Koncretekid on July 22, 2011, 06:50:51 AM
Now that idler looks much more substantial. The old one looked like it would collapse on gear down. And as the 530 drive chain is designed to transmit a hell of a lot of torque, it should be strong enough although it normally doesn't run at engine speed.  I suspect your rubbing block will let you know if centrifugal force if raising havoc.   

Excuse my ignorance, but where are you taking the motor drives from?  Are they running at crankshaft speed?

Tom
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 22, 2011, 08:28:00 AM
Jim,
That's a good point to consider...I have a stack of rear sprockets so we certainly have the option of staying out of 5th if that proves to be a solution. Larry had a large selection of rear sprockets for the 18" PM rear wheel. After the 17" race tire rule change, I scored another set of PM wheels but had to get Sprocket Specialists to machine up another batch.

Tom,
The coupler is splined to both of the countershafts, I shift both transmissions at the same time.

Cheers,
Scott
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 22, 2011, 09:31:05 AM
The rebuilt engines are each 1316cc with 14:1 compression.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: JimL on July 22, 2011, 09:37:36 AM
Another thing to check....where is 5th gear on the shafts compared to 4th.  I've seen some transmissions with 4th gear right next to a bearing (good) and 5th gear "one gear away" (not as strong).  That could also be a decision point for running in 4th (plus lower final chain speed, as well!)

Looking forward to seeing this again.

JimL
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 22, 2011, 09:42:20 AM
It looked clean when it was just a pair of engines in the frame...it gets busy when you add the 4 oil coolers, 2 banks of carbs and all the lines and cables.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: WhizzbangK.C. on July 22, 2011, 10:12:54 AM
With the engines coupled through the counter shafts, do you think there will be any issues with the power pulses from the engines wreaking havoc due to not being synchronized?
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 23, 2011, 12:28:23 AM
With the engines coupled through the counter shafts, do you think there will be any issues with the power pulses from the engines wreaking havoc due to not being synchronized?

We have some flexibility with the adjustable ignition timing for both engines.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on July 23, 2011, 01:58:26 AM
I called Race Tech and had them build a new pair of custom rear shocks.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: fredvance on July 23, 2011, 11:36:58 AM
Two shocks in the back, I remember that , sort of. :evil: Looking forward to meeting you, finally.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on December 02, 2011, 11:34:52 AM
I've been working in Kenya since Speed Week...internet has been hit & miss at best, I could usually follow along with WOS or the Cook Shoot Out but almost never enough connection to post. I'm back in Dubai and headed home, it's time for an update...

As the coupler had proven to be the weak link previously, we just wanted to test the new one at Speed Week and cautiously move forward. I made a couple of easy passes on the rookie course to break in the new engines, the Double is too long for a bike dyno. We were very pleased when we removed the coupler's cover and found the chain and tensioner to be in excellent shape! The redesigned tensioner and oil bath gave me the confidence to take it to the long course for the first time.

I made 3 passes on the long course at a little over 200, each run rewarded us with a leaking oil cooler. The bike has 4 of them, (oil cooled GSXR) but the same bottom cooler repeatedly failed. Initially when the cooler first failed and we didn't see anything obvious other than the corner of the cooler mount had cracked, I just assumed it was another character building exercise

We lost a day waiting for a replacement cooler but enjoyed spectating and visiting with friends.
I found the first couple of miles very rough on my 2nd long course run, I could see the front forks flexing and never got a chance to open up the throttle until the 3rd mile. The long course was moved over that evening. When we were loading into the trailer, we discovered the new cooler was leaking. We also had a front fender bracket crack, and I assumed the 2nd cooler failure was the result of vibration.
 
We lost another day waiting for yet another replacement cooler and at this point, had little choice but to just laugh at it...we'd have no luck if it wasn't for bad luck. Again, checked the bike over and it appeared ok. The oil lines were not pulling on the cooler causing stress, there appeared to be enough ground clearance so I didn't think the bike was bottoming out against the oil pan's fittings, again figured it was vibration and we would attempt to isolate it.

It was noon on Thursday before we got the new cooler, it doesn't seem to matter how much I pay for overnight or urgent shipping, the parts show up in Wendover whenever they do. We added rubber to the mounts, double checked the lines and got in line mid-afternoon. The bike worked great but had lots of wheel spin. On my Hayabusa, I can just feather the throttle slightly when it spins and regain traction. When the Double spins, it feels more like an elastic band winding up and releasing, I find that I really have to back out of the throttle before I can open it up again. It's hard to be disappointed with any 200mph run... no leaks! I was determined to just get back in line and go at it again, I wasn't even going to get out of my gear...let's hot lap...the event is over tomorrow...we need to get to impound...and then the corner of the oil cooler started dripping. :-D We were done, there simply wasn't enough time to get a replacement cooler.

No regrets, I spent a week with friends and family doing something that I enjoy, and watching some of the coolest racers anywhere. The coupler issue is resolved, that was previously a deal breaker...we can go fowards, an oil cooler is a much smaller problem.

When we switched from 18" wheels to 17" in order to comply with the 200+ race rubber rule, we lost some ground clearance. However, there is no evidence of the bottom oil cooler or its fittings coming into contact with anything, just salt spray. The oil coolers worked fine when the bike ran last, so that is puzzling. There are no obstructions in the lines. We are fitting a new body and as a result, the oil coolers will all be replaced with a different set up and relocated with new lines and new mounts.

More to follow...

Cheers,
Scott
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Peter Jack on December 02, 2011, 12:34:44 PM
Scott, how about trying a cradle type mount with lots of rubber instead of a through bolt type mount? I've always found them to be more reliable. Otherwise there are some really flexible mounts that can be used with the bolt hole type mounts.

Pete
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Koncretekid on December 02, 2011, 01:38:13 PM
Congratulations on running the monster!  I'm sure you'll get the oil cooler mount solved.  Do you have an oil temperature gauge?  Maybe you can eliminate the one that's failing, or replace it with a more substantial, but not as efficient billet spool type cooler.
Tom
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on December 02, 2011, 02:51:17 PM
Jack,

Yes, we will use a cooler mount that will isolate vibration. The new body will dictate where the new coolers go and just about everything else hanging off the engines.


Tom,

The oil cooled GSXR's need a 2nd oil cooler for the head to keep the valve train cool once you start throwing more compression and bigger cams at them. They just can't shed the heat and the parts quickly lose their surface hardness. 2 engines necessitate 4 oil coolers.
I currently have a pair of Vapor Trail gauges, it was the quick & dirty fix to provide tachometers but I can't read the upper end of the digital bar graph at speed. I'm considering these analog gauges, they are a bit busy but I should be able to keep track of the oil pressure and see what the oil temperature is at the end of the run.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on December 02, 2011, 03:01:45 PM
I got a set of the e-bike body work from Kent @Airtech, we figured it would be a good choice for the Double's long wheel base.
I was able to mock it up on the bare chassis last spring. Again, the body will now dictate where everything else goes and that means new clip-ons, controls, oil coolers and plumbing and the rear mounted fuel tank. I'm undecided on just extending the headers out the side or running an exhaust out back, it will depend on the space available.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Koncretekid on December 02, 2011, 06:09:20 PM
Scott,
Looks like fitting the fairing is same stage as mine.  See my post.
Tom
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on December 03, 2011, 02:35:26 AM
No Tom,
You are much further ahead, I think your progress is remarkable for what has been a short period of time. :cheers:
You definitely found the right people to help with your project.
My fairing photos were taken last spring with the body sitting up on paint cans, I was just happy to see that it looked possible and put the parts back in the box. We needed to focus on rebuilding the engines and the coupler.

After Speed Week, I dropped the Double off with my mechanic, Richard Bak, and left him with a long list, including mounting the body and suspension upgrades. Richard refuses to do body work in his shop and that's fine, we will have to farm that out. However, he did design some body mounts that will give us lots of options and we have a general idea of what we need to do. I did not want to weld mounts on to the frame and wanted something that was easily removeable for the open class.

Now that I'm headed home and the new mounts have arrived, we can make some actual progress with fitting the body, see how much additional fiberglass work is required and find a marine shop that is interested in the project.





Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Peter Jack on December 03, 2011, 03:47:00 AM
Who built the stuff Scott?

CNC and anodizing sure makes stuff look pretty. :-D :-D :-D

Pete
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Koncretekid on December 03, 2011, 07:17:15 AM
Scott,
Looks like you might have some extra body mounts there.  Maybe you should send me some so I can prove that they'll work!

I have become quite interested in CNC machining lately, and am curious if your machinist can take drawings that appear to be "Solid Works" drawings, and proceed directly to the milling machine.  My friend Doug Edwards in Longmont has to first re-draw them on another milling program in orthogonal views and then program each tool, tool path, machining speed, etc.

By the way, I made some mounts like yours -- just didn't paint them red!

Tom
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: JimL on December 03, 2011, 11:25:51 AM
Welcome home, have a fun build season, and hope to visit with you in impound for 2012!  (Though you'll be over there on the "fast guy" course....missed you this year with trying to run in 3 records between the 2 bikes, which turned into an engine swap before we could run the shaft drive bike....and it rained....and it mud...and it stuck the motorhome. :-P)  Sent you an email.

Regards, JimL
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Rex Schimmer on December 03, 2011, 07:27:49 PM
Scott,
Just a thought regarding your oil coolers from a "car" guy. Since you have to completely redo your cooler system any thought about possibly mounting the coolers in a water tank and completely eliminate any intake for the coolers. You probably would not require a lot of water and if you add ice even less and getting rid of the air inlets and flow through the coolers should be good for aero. I realize that with the new body space is probably a real rare commodity. Just a thought. As the saying goes "You are the one having intercourse with this cat, I am merely holding its head!"

Rex
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Koncretekid on December 04, 2011, 06:54:14 AM
Question:  You say you have to have a 2nd oil cooler for the head.  Does this mean you have a 2nd oil pump dedicated to cool the head? Also, do you have a separate reservoir for each oil system?  Just wondering if the oil is in a closed loop system with no reservoir or expansion tank, could the expansion of the hot oil cause additional stress on the radiator?
Tom
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: 55chevr on December 04, 2011, 08:13:09 AM
Tom ... you really are an engineer ... interesting questions.
Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on December 15, 2011, 05:06:50 AM
Jack,
We use several different machine shops and it usually just comes down finding someone who is actually interested in the job itself. There is no shortage of oil field work in central Alberta and most shops would prefer to concentrate on their bread & butter.


Tom,
The Solid Works Drawing and Model are just given to the machinist to convert to another program for clamps, process, sequence etc.
Regarding the auxillary oil cooler, the oil flows through the cooler before it enters the cylinder head. There is only a single oil pump and no reservoir.

Rex,
Yes, I wish we had room for water tanks, they could double as ballast. But no, space is already at a premium...10 pounds of crap in a 5 pound bag. :-D




Title: Re: Beairsto & Forstall 3000 APS/G
Post by: Beairsto Racing on December 15, 2011, 06:05:26 AM
I had an extra front end from an '04 Honda 600RR, the last year for conventional forks, and a spare set from a Hayabusa. It was far easier to modify the parts and fit the Honda unit, rather than the USD forks...no need to re-invent every wheel. Now the Double has a fairly modern front end with adjustments for pre-load and damping.

The bike was never designed for wide modern tires and in order to comply with the current "race" rubber rule, we are left with very few options and they are all 17" and fat. I managed to squeeze in a 190 series rear tire into the swingarm but that left us with very little adjustment, and the left side wall did eventually rub during tire growth. I sorted through a couple of bike wreckers trying to find a used swingarm that we could modify but didn't have any luck. We looked at several different aftermarket manufacturers and we still would have needed them to make a "one off" swingarm for our application, so we are just going to make the "one off" ourselves. Because the rear frame is so narrow and in order to keep the sprockets aligned, we need to use a jackshaft. If the coupler wasn't in the way, it would be a simple matter of using an outboard bearing set up off the countershaft. The design is pretty much finalized, we will make most of what we require on the CNC and Richard will tig weld it together.

I saw the bike last week and the body was sitting loose on the bike. The front engine's header will be a challenge and may require a "blister" on the right side of the body. We did decide to try and run the exhausts out the back of the bike, rather than out the side, to try and keep it clean. We hope to move the 2 side oil coolers (cylinder heads) in closer and gain the necessary clearance for the body. The front engines' troublesome main oil cooler will likely find a new home in the nose of the faring and will be fed air by ducts. The rear engine's main oil cooler seems ok where it is and out of harm's way.