Building a race bike.

Posted: Wed Jun 04, 2014 3:12 pm

This is awesome stuff Jim. Thanks for keeping us COMPLETELY in the loop. It's like I'm right there with you my friend! Wish I lived close. I am a decent wrench and take instructions relatively well. Would love to help!

Posted: Wed Jun 04, 2014 4:25 pm

JJam wrote:

Wow, Thank You for mailing the parts and the sponsorship Brent!!
Vince & Hyde decals will be needed to run on the bike as the second sponsor. I need to email Randakks Cycle Shack and see what he can do to help this venture out?
I'm trying to see if I can get a little help from Race Tech for the suspension parts. I will do all of the re-valve and set up myself.

No turning back at this point.

Brent, I was thinking that I would go for one of your Primary chain tensioners as well for this motor but not sure that it will work with the 750 set up?
Do you have any of these made up? I can afford to build it right the first time but not afford to build it after it scatters so I need this part.

I am SO LUCKY!!, Told Cristi (My wife) how much this bike is going to set me back and all she said was well I'm sure that it will pay off for you. Shocked

She's the best and backs me up. Full steam ahead on this bike!!

Have a great day.

Jim

Hey Jim -

I know that Randakk's deal with me involves his stickers going where I go, so let me get ahold of him (right now) and put you two in touch. I'll send him your personal e-mail.

Also, Matt Wiley is the guy at RaceTech to talk to. I know he and Randakk have collaborated in the past and Matt put me in contact with someone at Race Tech to work with when I was building Randakk's 350 and working on suspension stuff.

This is turning into a very big collaborative project spanning the globe - north & south hemispheres, both coasts, etc. Smile

Dennis

Posted: Wed Jun 04, 2014 5:34 pm

OK, Just sent my email to Race Tech so we will see what or if they can help on the costs. Maybe even a set of their Ubber Trick piggyback shocks??? Very Happy

Anyway, It will be awhile until more updates on this bike as I have jobs to get completed. My spindle bearings came in yesterday for the mill so it's time to put it back together and get the parts out the door.

Keep it in a wheelie, Jim

Posted: Wed Jun 04, 2014 6:18 pm

One more update.

These just came in and will be the foundation for this motor. 82 CB750 cases. Donut style with extra webbing and solid rear motor mounts. The best set of cases to start with and learned from Bill.

These cases have different Head and cylinder bolts then my 80 750 motor.
I may make my own?

Peace, Jim

CB1100F Joined: Jun 18, 2006 Posts: 2529 Location: UK

Hi Jim the 750 studs are about 7mm shorter than the 900/1100, just cut a set of them down to suit when you check the height of the RSC cylinder Brent has sent you

Looks like your project is coming together well

Keith

Posted: Wed Jun 04, 2014 8:46 pm

Don't make your own, use the "spiral wound" OEM studs only. These studs are very good quality and most importantly are designed for controlled and even stretch/tension and that is something you cannot easily do with aftermarket versions unless you reduce the diameter between the threaded ends. Just install (OEM type recommended) in the case using oil until they bottom in the threads and no more. They will do everything you need and have the additional benefit of not costing any more money.
Once you get to final assembly and installing the head, torque to 35 ft lb.

Captain

Posted: Wed Jun 04, 2014 10:26 pm

The stud stretching is important on an air cooled engine. We found that out on Bug engines. The early ones had giant cut thread 10mm studs. When the engines got hot, the aluminum expanded, but the iron studs didn't stretch (enough) and the cylinders would dent the heads where they normally seated. When it cooled off...head leak...not to mention an oil leak at the bottom of the cylinder too usually. Change the studs to a rolled thread 8mm... this issue evaporated.

I have a question for Captain; If the existing studs are all rusty and nasty (between the ends) would bead blasting and replating them hurt them ya think?

Posted: Wed Jun 04, 2014 11:34 pm

Welcome back Shawn Wink

Posted: Fri Jun 06, 2014 9:44 pm

Shawn_Mc wrote:

The stud stretching is important on an air cooled engine. We found that out on Bug engines. The early ones had giant cut thread 10mm studs. When the engines got hot, the aluminum expanded, but the iron studs didn't stretch (enough) and the cylinders would dent the heads where they normally seated. When it cooled off...head leak...not to mention an oil leak at the bottom of the cylinder too usually. Change the studs to a rolled thread 8mm... this issue evaporated.

I have a question for Captain; If the existing studs are all rusty and nasty (between the ends) would bead blasting and replating them hurt them ya think?

Yes, bead blasting them is fine in order to prep for re-plating. As they are Hi Tensile and will suffer from hydrogen embrittlement after the plating process they need to be soaked in an oven for a couple of hours at around 150 degree C afterwards. if you don't, you run the risk of a stud breaking whilst under load.
This I suspect is why so many used/aged cam cap bolts appear to snap as they are Hi-tensile and I believe they haven't been de-embrittled correctly.

Captain

Posted: Sat Jun 07, 2014 12:02 am

Captain wrote:

Shawn_Mc wrote:

The stud stretching is important on an air cooled engine. We found that out on Bug engines. The early ones had giant cut thread 10mm studs. When the engines got hot, the aluminum expanded, but the iron studs didn't stretch (enough) and the cylinders would dent the heads where they normally seated. When it cooled off...head leak...not to mention an oil leak at the bottom of the cylinder too usually. Change the studs to a rolled thread 8mm... this issue evaporated.

I have a question for Captain; If the existing studs are all rusty and nasty (between the ends) would bead blasting and replating them hurt them ya think?

Yes, bead blasting them is fine in order to prep for re-plating. As they are Hi Tensile and will suffer from hydrogen embrittlement after the plating process they need to be soaked in an oven for a couple of hours at around 150 degree C afterwards. if you don't, you run the risk of a stud breaking whilst under load.
This I suspect is why so many used/aged cam cap bolts appear to snap as they are Hi-tensile and I believe they haven't been de-embrittled correctly.

Captain

Awesome info Brent!! Thank You.

I looked around and found a junk set of 750 cases here at my shop with the correct head bolts so I will do as you suggest.

OK got all of my funds in order so this bike will live as long as it doesn't go over $15,000.00 to build the bike, I'm good to go. Shocked

I always wanted to see what I could build with the proper funds and now is my chance. I sure hope that Dennis can get along with the modified frame that I'm building? If not then maybe we will have to put my motor in one of his frames? Time will tell.

Paid for the GSXR wheels so they should be here next week and I'll start on wheel spacers and getting the wheels centered up.
It's going to take a few days to build the frame jig. I could do a simpler design but I want an adjustable jig so I can make any frame in the future. I really want my own RSC perimeter frame and hope to build my own and then sell it.

That's all for now, Jim

Posted: Sat Jun 07, 2014 4:10 pm

JJam wrote:

I always wanted to see what I could build with the proper funds and now is my chance. I sure hope that Dennis can get along with the modified frame that I'm building? If not then maybe we will have to put my motor in one of his frames? Time will tell.

I can't imagine that a properly built & braced frame wouldn't be better than my STOCK 900F frame and a solid mount motor.

I've been told by a couple of people who own and have raced real RSC/AHM CB-Fs running the modified steering head that if I can ride mine stock and do well I can only do better with one that has the modified steering head. Brent is the 4th person I know to say that...

Posted: Sat Jun 07, 2014 4:33 pm

JJam wrote:

One more update.

These cases have different Head and cylinder bolts then my 80 750 motor.
I may make my own?

Peace, Jim

Credit where credit is due... Sonicrete has been preaching the spiral studs since the beginning of the F site.. I thought you knew that Bro.. Very Happy

http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=4461&highlight=studs+spiral

http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=3719&highlight=studs+spiral

http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=30737&highlight=studs+spiral

Posted: Sat Jun 07, 2014 6:02 pm

I did but have you ever tried to get them F'ers out and not F them up? I have a set of APE cylinder studs but they are heavy and I mean twice as heavy as the spiral wound stock ones.

I am always afraid that using two nuts locked together on the top and trying to unscrew them will twist them. I also don't like to use vise grips on them at the bottom because I don't know what the jaw marks will do to the studs?? Maybe I'm just too anal for my own good???
I found my very 1st CB750F top case and it has the studs. I will do my best to get them out and not F them up.
If they come out? I think its pretty cool that my 1st CB will be donating parts for this motor.

Who would have thought that 30 some yrs later I would be trying to make a living working on CB's? Not me. When I was a kid they were cheap enough that I would ride them into the ground and then just go get another one. Never even adjusted the valves on them back then. Just ride and throw away.
Times change for sure.

Peace, Jim

Posted: Sat Jun 07, 2014 6:47 pm

JJam wrote:

I did but have you ever tried to get them F'ers out and not F them up? I have a set of APE cylinder studs but they are heavy and I mean twice as heavy as the spiral wound stock ones.

I am always afraid that using two nuts locked together on the top and trying to unscrew them will twist them. I also don't like to use vise grips on them at the bottom because I don't know what the jaw marks will do to the studs?? Maybe I'm just too anal for my own good???
I found my very 1st CB750F top case and it has the studs. I will do my best to get them out and not F them up.
If they come out? I think its pretty cool that my 1st CB will be donating parts for this motor.

Peace, Jim

Two nuts locked on top and a heat the cases your trying to remove them from around the base of the stud with a MAP gas torch, or a really rich mixed Oxy/Acetylene. When I say rich, add Oxy until you just get past a big smoky orange flame. A neutral flame on a Oxy Acetylene setup (perfect cone on the tip) is like 6500 degrees. That's why you wanna run it a tad rich. The case will expand and let go of the stud. Another way is a short burst on the top of the stud with an air hammer. Sometimes that white electrolysis stuff will grow in there and lock steel to aluminum like its a single piece. You break that stuff loose, then heat the case, double nut it (tight) and try an impact in reverse to get it moving. You may not want to run them all the way out with an impact because of the heat they can generate and the twisting over the length of the stud isn't ideal.

Posted: Mon Jun 09, 2014 3:27 am

Seamus wrote:

Well, deciding the bore size is barrel dependent. You want the largest diameter piston you can get for intake flow. Then adjust the crank length to push the CC to the class limit. If you're going all out...thats the plan.

The rod ratio for 12,000 reliable HP with a decent power band should be about 1.7 to 1.8:1. So if you're getting custom rods made, you need to make the decision on the stroke first, then the rod, then the compression height follows.

A shorter rod is going to make power lower in the RPM range. So what you dont want is a short rod. big low end torque, bottom end tied to a top end that wants to sing with the angels.

On the dirt bike side, Honda has been shortening the rod on the 450 to make it grunt as an example. I really eny you on this project. This kind of stuff is where the joy is born.

IMHO, JE, CP are interchangeable. Cant make a mistake. Both are excellent pieces. Ive just got more experience with the JE stuff.

Thank you for this info. Where do I get the formula to figure out the rod ratio? I'm sure Dennis will want as much mid to upper usable power as I can supply him and keep the motor together.

As far as rods go I have been looking at Falicon knife edge oval rods
http://www.faliconcranks.com/1pc.html

And Carrillo rods but which one? They have many options and styles of rods. I can do some of the high performance mods to the rods here in my shop easy enough.
Need a strong rod but not to heavy of a style. Lots of options.
http://cp-carrillo.com/Tech/RodTech/tabid/76/Default.aspx#hpo

Also whats your guys take on 16mm wrist pins? I may try to get some used rods from another model of bike if they spec out to my needs and many of the used Carrillo rods that I have seen use 16mm pins.

Thanks for the help guys, Jim

Posted: Mon Jun 09, 2014 8:11 am

JJam wrote:

Seamus wrote:

Well, deciding the bore size is barrel dependent. You want the largest diameter piston you can get for intake flow. Then adjust the crank length to push the CC to the class limit. If you're going all out...thats the plan.

The rod ratio for 12,000 reliable HP with a decent power band should be about 1.7 to 1.8:1. So if you're getting custom rods made, you need to make the decision on the stroke first, then the rod, then the compression height follows.

A shorter rod is going to make power lower in the RPM range. So what you dont want is a short rod. big low end torque, bottom end tied to a top end that wants to sing with the angels.

On the dirt bike side, Honda has been shortening the rod on the 450 to make it grunt as an example. I really eny you on this project. This kind of stuff is where the joy is born.

IMHO, JE, CP are interchangeable. Cant make a mistake. Both are excellent pieces. Ive just got more experience with the JE stuff.

Thank you for this info. Where do I get the formula to figure out the rod ratio? I'm sure Dennis will want as much mid to upper usable power as I can supply him and keep the motor together.

As far as rods go I have been looking at Falicon knife edge oval rods
http://www.faliconcranks.com/1pc.html

And Carrillo rods but which one? They have many options and styles of rods. I can do some of the high performance mods to the rods here in my shop easy enough.
Need a strong rod but not to heavy of a style. Lots of options.
http://cp-carrillo.com/Tech/RodTech/tabid/76/Default.aspx#hpo

Also whats your guys take on 16mm wrist pins? I may try to get some used rods from another model of bike if they spec out to my needs and many of the used Carrillo rods that I have seen use 16mm pins.

Thanks for the help guys, Jim

Simply take the desired stroke and multiply it by your desired rod ratio.

So say you're looking for a total displacement under 913cc right? So you'd be at 72X56mm to get 912. With the 56mm stroke, to get a 1.8 rod ratio, would need a rod thats only 100.8mm long. So lets say you end up with a 100mm long connecting rod, you'd take the 100 and divide it by the stroke of 56 and you get 1.7857. Perfect. But if you found something that was slightly shorter and you ended up at 1.72, it'd make slightly more power off the corner and be fine to 12000 rpm.

The rod length controls the piston speed (feet per second down or up the bore) at a specific RPM. Not to mention the dwell at TDC is longer. The piston doesn't know what the RPM is, all it cares about is FPS, stop, go the other way. The slower that transition is, the easier it is on everything else.

If you're having a crank de-stroked, you can use a slightly narrower rod and just have them grind the bottom journal with a larger fillet which is stronger anyway.

Honestly, the HP of this thing will still be limited by the head, even with one of Captains high HP monster heads. I think you'd still be fairly optimistic if you were looking at 140 hp which can be done with almost every 750 4 cylinder produced. If I found a 750 rod from a modern bike that had a 16mm wrist pin and was about the correct length, I wouldn't hesitate. You're not running nitrous or a turbo on the thing. Besides, an after-market pin for a more modern engine in 16mm is probably going to be stronger than the 17mm OEM pin in the 1100 rods.

As far as an after-market rod goes, I think the tapered H Beam Carillo is plenty, or the Knife Edge Failcon, are both valid choices. You could probably get a 17mm pin that weighed less than a 16mm pin that was as strong (probably stronger) because of the larger diameter.

Posted: Mon Jun 09, 2014 1:24 pm

JJam wrote:

Seamus wrote:

Well, deciding the bore size is barrel dependent. You want the largest diameter piston you can get for intake flow. Then adjust the crank length to push the CC to the class limit. If you're going all out...thats the plan.

The rod ratio for 12,000 reliable HP with a decent power band should be about 1.7 to 1.8:1. So if you're getting custom rods made, you need to make the decision on the stroke first, then the rod, then the compression height follows.

A shorter rod is going to make power lower in the RPM range. So what you dont want is a short rod. big low end torque, bottom end tied to a top end that wants to sing with the angels.

On the dirt bike side, Honda has been shortening the rod on the 450 to make it grunt as an example. I really eny you on this project. This kind of stuff is where the joy is born.

IMHO, JE, CP are interchangeable. Cant make a mistake. Both are excellent pieces. Ive just got more experience with the JE stuff.

Thank you for this info. Where do I get the formula to figure out the rod ratio? I'm sure Dennis will want as much mid to upper usable power as I can supply him and keep the motor together.

As far as rods go I have been looking at Falicon knife edge oval rods
http://www.faliconcranks.com/1pc.html

And Carrillo rods but which one? They have many options and styles of rods. I can do some of the high performance mods to the rods here in my shop easy enough.
Need a strong rod but not to heavy of a style. Lots of options.
http://cp-carrillo.com/Tech/RodTech/tabid/76/Default.aspx#hpo

Also whats your guys take on 16mm wrist pins? I may try to get some used rods from another model of bike if they spec out to my needs and many of the used Carrillo rods that I have seen use 16mm pins.

Thanks for the help guys, Jim

Why not Crower rods? Start reading at page 214 of the catalog, it gives the "C to C" of the various rods of various engines ....

http://www.crower.com/connecting-rods-catalog

They run about $750 a set for billet .....

Posted: Mon Jun 09, 2014 1:47 pm

They will also do Titanium..........price might be a concern though.

Captain

Posted: Mon Jun 09, 2014 1:53 pm

Captain wrote:

They will also do Titanium..........price might be a concern though.

Captain

Yes, they start at $2300 for custom lengths I believe .....

Posted: Mon Jun 09, 2014 3:58 pm

Captain wrote:

They will also do Titanium..........price might be a concern though.

Captain

Titanium...........I would love to hang out at your shop. What a trip! My brother made a titanium speedo mount for his CBX from extra laying around his work Wink

. You could pick up a bulldozer with tbe dam thing!

Posted: Mon Jun 09, 2014 4:37 pm

Shawn, the class limit is 931cc for any size of carbs. Any cc over that up to 1020cc max limit has to run a maximum 29mm carbs.

Maybe I'm wrong but it would seem that a 930cc bike with carbs that can flow what the head can do, would be a faster bike? Am I totally wrong here because it would be a whole lot less money to build a 1020cc motor but whats the fun it that??

Brent has said that the cylinders he's sending me have 70mm bores. So I'm assuming I will need to bore them to clean up?? Won't know until I have them.

So if I went with 70.5mm bores and 59.6mm stroke I end up with 930.24cc's and a bore to stroke ratio of 1.183:1 and to get the 1.8 rod ratio I need aprox. 107mm rod length. Is that correct?????

I'm looking at two sets of Carrillo rods here local to me but the guy won't measure them so I have to go meet him and do it myself. At $100.00 per rod I'm willing to drive and see what they are.

Brent Ti rod are way out of my league I can only dream of that kind of stuff. Your head is more then I can afford but its the best there is so I need it to go kill some Kat's out there. Very Happy

Thanks for the Crower link Darren. I forgot about that brand.

Cya, Jim

Posted: Mon Jun 09, 2014 5:28 pm

JJam wrote:

Your head is more then I can afford but its the best there is so I need it to go kill some Kat's out there. Very Happy

Cya, Jim

This made me laugh - I'm SOOOOooooooooooooo tired of getting pulled by the Katana on the straights... My 1020cc CB-F dragging me around isn't quite fast enough to draft him either. When he comes by I can't stay close enough to get a tow; he keeps pulling away.

I checked the results for Saturday at Road America - he won. Don't know about Sunday yet.

Posted: Mon Jun 09, 2014 10:21 pm

I believe the stock 750 rods are 113mm, removing 2.4mm from the stroke needs rods that are 1.2 mm longer.

It was posted that a CBX won Sunday at Road America, cbxworld site. I guess the Kat was having a nap.

Posted: Mon Jun 09, 2014 11:08 pm

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

Posted: Tue Jun 10, 2014 2:22 am

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

Youre not wrong, but the rod angle matters. The longer the rod is, the shorter your compression height is going to be. Doing it with your method can work, but you still will end up in the 1.7-1.8 range. unless youve got a really disparate set of parts youre combinging. You can have both short compression height and the correct rod angle.

If the rules say 930cc can run any carb, thats where you want to be. You dont want to be 930.24. Trust me on this. Ive been torn down after winning ( I was legal, which really pissed them off Laughing

) and second place will lose their shit over a .24cc. I think your math went awry somewhere because I get 930.7 on 70.5x59.6. 59.5 gets you to 929ccs. Maybe a typo for ya. But with all that said...

A 59.5 mm stroke with a 1.8ish ratio, a 105-108mm rod is what you're looking for. But if you find rods that are 100-113mm on the shelf that you can grind your crank for and match the pins, thats a no brainer. 100mm gets you to 1.68, and 113 is a whopping 1.9. Both are in the window.

Like I said earlier, you really need to have the head and the cylinders in hand before you start grinding cranks and rods. You want the biggest bore you can run. It'll flow better. Then settle on the stroke. Then the rods, then you can have the pistons made up.

Its a plan, from top to bottom, end to end. If you're making custom parts, make the parts you want, not ones that will simply fit. But if you stumble over some stuff that not only fits, but is inside your plan....

beerchug

Posted: Tue Jun 10, 2014 2:43 am

JJAM

As I said I have a set of RSC rods I would be willing to take far more advantageous offers for.

They are brand spanking new.

David

Posted: Tue Jun 10, 2014 3:49 am

AHRMA's class limits are 1025cc carb restricted for the Honda's, 931cc unrestricted carbs.

AHRMA Handbook link
Page 54 for Vintage Superbike

CB1100F Joined: Jun 18, 2006 Posts: 2529 Location: UK

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?

Posted: Tue Jun 10, 2014 5:17 am

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

Posted: Tue Jun 10, 2014 5:30 am

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