Building a race bike.

Posted: Tue Jun 10, 2014 6:49 am

There's a guy who's in the UK CBX club called Carl Woodcock iirc
Who modifies the X using GSXR750 pistons and rods giving 1233cc engine, now it's far too early in the morning for me to work out the bore/stroke with any accuracy, now does the 750 and X have a similar stroke? If it does then there's a lot of piston kits,for the GSXR couldn't that be an avenue to explore?

I seem to remember that he used the rod/piston combo from one of the liquid cooled Gixxers, :Edit: I think he had custom rods done iirc.

The 1997 to 2005 V to K5 models all have a bore/stroke of 72mm X 46mm, so the Bore sounds perfect for the job..... but i'm sure it depends on a ton of other things as well, but i'm sure that you'd be able to get hold of a piston to do a bit of measuring.

Regards Rob...

Just found his Facebook page, this guy know's his way round an X that's for sure....

https://www.facebook.com/carl.woodcock.3?fref=photo

Posted: Tue Jun 10, 2014 12:03 pm

Jebbysan wrote:

F-crazy wrote:

Don't want to step on any toes here, but...

I don't put a whole lot of thought into rod length. I would rather get as short of a compression height on the piston as I can. Then take the total deck height of the engine and subtract half the stroke and the compression height. The number that you get is your rod length. The rod/stroke ratio ends up wherever and I don't care too much.

What I'm saying is I'd rather have a lighter piston than some ideal r/s ratio. I think that is more important.

Of course I could be wrong...

Nich

Short CD's on pistons compromise the integrity of the oil land for endurance engines....something to consider....there are other ways to lighten a piston...
Window milling and under deck milling are two of those.....

Jebby

All true. There is a point of diminishing returns.

Posted: Tue Jun 10, 2014 12:24 pm

krgood0 wrote:

jkotsi wrote:

Is it possible to modify the 1100 stock carbs or 29mm CR's to flow better and still be legal under AHRMA?

Reading the AHRMA handbook looks like you can run the stock 32mm CV Carbs @1025cc, wonder how good they could be using the RSC Carb mod on them?

I've always wondered that but never did anything about it...

Guest

JJam wrote:

You guys are making my brain smoke. The problem is that I like it. Very Happy

I love challenges!!

Motocanada, PM sent. Thank You.

Keep the thoughts and info coming guys. I'm building this motor with your guys experience to keep me straight. If Dennis wins on this bike? We all win.

Jim

Not entirely true Jim. Well...since I RACE in that class...if he wins...I lose! Smile

It's all good though...I'm REALLY happy there's still development on these old girls! Smile

Posted: Tue Jun 10, 2014 5:44 pm

You never know Darren. You may twist the grip harder the he does??

This also all depends on Dennis getting back into shape with his shoulder. I don't envy him in that area.
I have had 3.5 yrs of heal up time in my life and can't afford anymore. Hence Dennis gets to race my bike and I will do some track days. Very Happy

OK, WE HAVE BRAKES!!
Pulled the trigger and ordered these.
http://www.apracing.com/products/motorcycle/brake_calipers/solo_and_classic_machines_plus_sidecar_2_piston_caliper.aspx

Who's keeping a tally? They retail for $235.00 a piece and Jeff at GP TechLLC gave me a shop discount so his decal's will go on the bike.
Really nice guy and fully into road racing. Here'ss a link to his site. Tell him I sent you if you shop with him I'd appreciate it.
http://www.gptechllc.com/

I decided to go with these calipers because they are twin piston with one piston on each side. This allows for solid mounting and sense I have to make caliper mounts.
Solid mounts are easier to make then floating ones.

I'm so excited to watch this bike come together that I can hardly sleep. Cool

Anyway your all up to the latest speed on the build. The calipers are 6 weeks lead time so I needed to make a decision. Its done.

Keep it in a wheelie, Jim

Posted: Tue Jun 10, 2014 5:53 pm

Quote:

Oil rings, who needs oil rings?

Yoshimura

You could go nuts and do a piston with just a drain back under the scraper. More conventional would be a single compression ring and a narrow 3 piece oil ring. They're usually good for 20-30 race hours. Assuming they've got infantisimal skirts.

A narrow ring on a stable piston will seal up like a drum. It also reduces the ring drag. This goes back to the post Nathan was doing on getting the bore and hone done hot so everything is flat and square at temps.

It'd also be worth sending out the entire bottom end for cryo and REM finishing, transmission and all. Ive got a guy in AZ if you need a reference. It's a last step.

Start counting tenths of HP everywhere and you end up with a pretty good sized stack.

Posted: Thu Jun 12, 2014 8:54 pm

Today went fro super happy. To completely heart broken.

The wheels got here and they are completely straight.
I put them in my trueing stand and both were perfect just need to be PC'd Black for my bike.

I weighed them compared to stock wheels and end up with a 9lb 13oz. saving in weight compared to the Comstars.
Plus my 320mm discs mounted right up and have the same offset. Perfect.

Then the USPS showed up with the RSC cylinders and I am VERY SAD to say they didn't fair the trip well. AT ALL. Crying or Very sad

I can't get photobucket to download pictures right now so no picture yet. They look stock on the outside.

They got rough housed and the skirt on one of the outside cylinder got a huge chunk broke out of it. It will have to be replaced. Then 5 of the fins got broke. Crying or Very sad

I can fix the fins but will have to come up with a new cylinder and make it fit.
Brent was very gracious to send me them and some new 750 length guides and he foot the shipping so no complaints. Its still less work then doing a set of stock cylinders in the 750 length.

I'll post up pictures as soon as PB starts working again.

Also in my spare time I have a good start on the Frame jig. Lots of machining to do before I can weld them up but its on the way.

Peace, Jim

Posted: Thu Jun 12, 2014 9:09 pm

OK got it to work.

Crying or Very sad

There are 2 other fins that didn't brake but got cracked.

I have some work to do but should be able to make this work one way of the other?

Cya, Jim

Posted: Thu Jun 12, 2014 9:12 pm

Insurance?? At least you might get some money to purchase what you need to fix them. New sleeves and such.....

Posted: Thu Jun 12, 2014 10:40 pm

I honestly couldn't have imagined that it'd be that fragile. Amazing.

Although, obviously, devistating. And I hope that UPS does something to make this better.

Cheers from Toronto.

Posted: Fri Jun 13, 2014 12:09 am

Toronto, cylinders and heads are very fragile as far as the fins go. I was surprised with the cylinder busting but have you ever seen the airlines packing stuff into a departing plane. It gets thrown repeatedly.

Oh well, I can fix it.

As far as insurance goes. Brent must have thought that we pay Tax's like the rest of the planet, so he priced the guides at $50.00 and the head at $100.00 so not sure ins. will do much?

Posted: Fri Jun 13, 2014 12:28 am

Have you seen how much Brent cuts out of the bottom of the cylinders when he windows them? More than that. If it's not way out of round at the bottom then remove the sleeve, turn it 180 reinstall and machine the Brent windows. Bore and hone as you normally would. Problem solved?

Of course you don't know how much to remove without a piston...

Posted: Fri Jun 13, 2014 12:47 am

F-crazy wrote:

Have you seen how much Brent cuts out of the bottom of the cylinders when he windows them? More than that. If it's not way out of round at the bottom then remove the sleeve, turn it 180 reinstall and machine the Brent windows. Bore and hone as you normally would. Problem solved?

Of course you don't know how much to remove without a piston...

I guess I could swap that cylinder out with another to get the window on the correct side? I'll see what I can do and planned on doing the magic windows anyway.
Will just have to weld up the fins and do some fine tuning. Hopefully the bores in the block will allow for this?

I'm over it now but I was pretty crushed earlier today.

Peace, Jim

Posted: Fri Jun 13, 2014 1:39 am

F-crazy wrote:

Have you seen how much Brent cuts out of the bottom of the cylinders when he windows them? More than that. If it's not way out of round at the bottom then remove the sleeve, turn it 180 reinstall and machine the Brent windows. Bore and hone as you normally would. Problem solved?

Of course you don't know how much to remove without a piston...

+1 that's what I was thinking when I say the pic before I read your post Nich! Laughing

Posted: Fri Jun 13, 2014 1:51 am

nathanhouse wrote:

F-crazy wrote:

Have you seen how much Brent cuts out of the bottom of the cylinders when he windows them? More than that. If it's not way out of round at the bottom then remove the sleeve, turn it 180 reinstall and machine the Brent windows. Bore and hone as you normally would. Problem solved?

Of course you don't know how much to remove without a piston...

+1 that's what I was thinking when I say the pic before I read your post Nich! Laughing

Ha. We do think alike!

Posted: Fri Jun 13, 2014 1:54 am

JJam wrote:

I'm over it now but I was pretty crushed earlier today.

Peace, Jim

I would have been too

Posted: Fri Jun 13, 2014 1:55 am

The problem is that there are flats machined in the lips of the cylinders. If I turn it I would have a dead pace under the gasket. Not sure if that much area would matter with a copper gasket .038" thick?

Or I was thinking. Rolling Eyes

Maybe I could window both sides of the skirts like a two stroke. This doesn't seem like it would hurt anything to me???? I hope to get slipper pistons anyway and they won't even touch that area.

Thoughts?

Peace, Jim

Posted: Fri Jun 13, 2014 4:04 am

JJam wrote:

The problem is that there are flats machined in the lips of the cylinders. If I turn it I would have a dead pace under the gasket. Not sure if that much area would matter with a copper gasket .038" thick?

Or I was thinking. Rolling Eyes

Maybe I could window both sides of the skirts like a two stroke. This doesn't seem like it would hurt anything to me???? I hope to get slipper pistons anyway and they won't even touch that area.

Thoughts?

Peace, Jim

Could cut them all off that short if the piston doesn't go down that far. Id check that cylinder for roundness before I spent a lot of time on it.

Posted: Fri Jun 13, 2014 4:14 am

Or just clean it up and leave it alone? Or do them all?

The shorter piston is a thought, might not matter if it's still round.

Posted: Fri Jun 13, 2014 3:10 pm

Yes will check the cylinders for round as the #1 cylinder isn't cracked but it got dented in as well.

Posted: Fri Jun 13, 2014 3:30 pm

What is the big deal about the RSC jug?
It has eight fins so it isn't short stroke......
The 1980 superbike in tech docs has 7 fins for 1000cc's

What am I missing?

Jebby

Posted: Fri Jun 13, 2014 5:22 pm

At Mid Ohio one year was a bunch of Honda race bikes. I asked what size the were because had some 750 high compression pistons to sell. The cylinders were just like 1100 but 8 fins tall and solid between cylinders. So other than that I don't build little engines. Don't know were they came from but were solid and were not cut down 1100. So I guess Brent doesn't know it all.

They said where do you think the idea came from for the 1100.

Posted: Fri Jun 13, 2014 5:26 pm

Jebbysan wrote:

What is the big deal about the RSC jug?
It has eight fins so it isn't short stroke......
The 1980 superbike in tech docs has 7 fins for 1000cc's

What am I missing?

Jebby

Its an 8 fin 750 block that's just been bored to fit the larger cylinders. Other then that nothing special. Just the work has already been done but it's looking like at least 2 different cylinders for this barrel set? Need to do some more measurements for being round still?

Posted: Fri Jun 13, 2014 5:33 pm

We are talking stock cylinders,correct? 750 is 8 fins tall and 900/1100 is 9. My big block are heavy fins but look nothing like stock.

Posted: Fri Jun 13, 2014 5:51 pm

Its not a big block. Its a stock one with big barrels. I know you don't like this set up Bill with the big cylinders but its just about my only option to make the class rules and run big carbs. Just can't see running a 1020cc and only have 29mm carbs. What a restrictor plate IMO.

Posted: Fri Jun 13, 2014 6:56 pm

Ugh....I am slipping...I thought 750's were 7 fin.....but I don't have one here to look at anymore.

Jebby

Posted: Fri Jun 13, 2014 7:51 pm

me to, thought it was 7 & 9 fin jugs

Posted: Tue Jun 17, 2014 12:42 pm

Jim & others,

I'm in the US right now but I lost my phone in Italy !!!!!! I have sent PM's to those I have arranged to meet giving my friends phone # that I can be contacted on, so please call so I can "lock on" and get contact #'s

Captain

Posted: Fri Jun 27, 2014 4:26 pm

OK have the 35mm CR carbs. Thank You Headless for picking them up for me!! Cool

Just ordered the Kibblewhite shim under the bucket tappets with the Ti. retainers required to use them.
They weren't cheap Rolling Eyes

What did I expect?
http://www.dynoman.net/engine/cam-followers.html#dohc

Shipped my 461 head, new guides and SS valves to Ivan in Italy. I can't wait to get all the parts but can't order rods or pistons until I get the head back.

She's going to have more high performance parts on it then any bike I have ever messed with. The coolest part is. My wife just says keep going you can't stop now. You put your foot in your mouth so shut up and produce. Then she laugh's. Shocked

I found the perfect wife for me!!

Just wanted to keep you guys in the loop of how the bike is coming.

Peace, Jim

Posted: Tue Jul 01, 2014 4:25 am

Hey guy's,

so today I talked with Tom again that run's Precision Cranks. (He is the guy that built the cranks for AHM, Kawasaki and Suzuki. He has also done cranks for V&H) Needless to say he has the experience that I am looking for.

I was discussing with him the way that I planned to knife edge my crank to lighten it on my lathe. He doesn't approve of doing this on a lathe and said that in his opinion the lathe beats the crank to much and puts too much stress on it. He does them with a 4" belt sander and hand grinder.
He also said that years ago he was doing crank balancing for a company that did their own lightening/knife edging and just had him spin balance them.
The customer's cranks were failing and he told them it was due to their method of lightening the cranks. He did a couple for them complete his way and never had another complaint.

What is the consensus of this subject?

Peace, Jim