The Details of my new RACE motor. F'n SWEET

Posted: Thu Apr 19, 2012 5:03 pm

Ok, I'm feeling pretty lucky!

Lots of you know that I just bought a bunch of 900 stuff to get to the Honey pot.

So far everything is just as the seller Tim said it was and I have all the papers to prove it.

The Honey pot is a modified 900 motor. It has MTC forged 1100 rods, 985 or 1003 High comp pistons, (I haven't got the head off yet) the pistons and rod bearings have 167 miles on them, I can see nothing but hone marks at all points in the cylinders with my bore scope Very Happy

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The crank was lightened, balanced and fluted by ARP or Falcon I'm not 100% sure which company did the lightening and which did the regrind on the journals? I need to read the paper work more. It has MTC cylinder studs with a step built into them to stop the studs from screwing into the cases too far, Manley Oversize SS intake valves and std. size SS ex. valves, OMT valve springs, OMT heavy duty cam and primary chains. OMT oil pressure spring. The tranny gears have all been undercut, so it will shift and lock together better. OMT heavy duty clutch. Not sure what that all consists of yet? MTC tool steel rod pins and teflon buttons. V&H 14042 cam that wasw done by megacycle from what I can tell. It has 167 miles on it as well. The bottom of the sleeves were wrapped with copper on the outsides?? Maybe as heat sinks? Not sure why they did that.

My plans for the engine are to donate it to the first person that reads this thread.

Yah right. Sorry just kidding

My plans are to split the cases and and replace the bottom half with a good case as the bottom half was ruined in Tim's nasty crash. He is very lucky to be alive!! I will do all of the mods that we now know about. Oil screen, shift mod, clutch mod, Captain's guides and tensioner, MY OMT ported head with the Manley bigger valves, VM33 carbs will feed it and my race exhaust will let it flow.

Tim got 96rwhp with a cleaned up head, (nothing special) OMT street exhaust (very choked IMO) and VM29 carbs.

Anybody got any Ideas what she will produce with my OMT head, better header and larger and better carbs??? I'm hoping for the 105hp mark?? We will see. Now I will build two race bikes. One with a short stroke motor and one with this motor. Pretty sweet because I also scored a similar built VF-F 750 Intercepter motor with all the same goodies in it this year. I won't know what bike to ride??? Shocked

Heres the cams.

Heavy duty OMT chains. And slotted gears.

Cylinder studs. Cool

Wrist pins and buttons.

MTC 1100 rods

Cam specs. Cam number 140-42

Soooo How'd I do???? Alls I know is I need to heal up so I can mess with motors and building me a chassis. All in due time and I'm sure that I will hire a rider to show what this old pig can do. I will ride it also. But I want to see what it can do with a PRO on it.
I'm soo F'n excited!!

Sorry but I just had too tease you guys with it. Cool

JJAM

Posted: Thu Apr 19, 2012 6:48 pm

F'n Sweet!!

Posted: Thu Apr 19, 2012 7:55 pm

Some nice stuff in there Cool

Posted: Fri Apr 20, 2012 4:29 am

I wouldn't use only one bottom case, the cases are machined together in pairs, meaning they are matched sets.

Posted: Fri Apr 20, 2012 4:42 am

Well that sucks, because the top case is already bored to fit the sleeves. I can do this in my shop but it would be nice to just use what is there with the studs already lock tightend into them. I don't like to disturb that stuff if I don't have to.

Can anybody else 2nd what AMC has warned about? If so I will scrap the whole case set.

Thanks, Jim

Posted: Fri Apr 20, 2012 5:15 am

Let see if I can explain this. The mains are sized to the tenth of a thousanth. There is .0003" difference in an "A" to "B" and you want to just change out one half? You interchange conrod caps too?

This is right down there with the dumbest thing even possible to do. You related to that guy that beat on 1100 pistons till they broke?

The only thing constant is the bore. There is no relation up and down or back and forth only all the holes line up as a set.

As to welding a leak. I have this excellent welder that can weld pop cans together and the heat of fixing a leak warped the mains out of line. I have welded the bottom radius onto the motor mounts but the oil soaks into the rest of it making heli arc effective impossible.

Posted: Fri Apr 20, 2012 5:39 am

Thank You AMC for bringing it to my attention. I would have found the errors of my ways as soon as I went to check the journals.

Posted: Fri Apr 20, 2012 5:18 pm

This was why when I was racing I bought gobs of junk 750's. I had no use for the internals,just the crankcases. By searching I could also find the heavy duty donut ones and all my dragbikes were solid engine mounts.

Hawk Joined: May 02, 2011 Posts: 421 Location: Toronto

I got so excited when I read the whole thread... Then I read the fine print.

This is going to be sweet. Nice to see photos. Is this one going on the gloss black beast? Or is that another one?

k.

Posted: Fri Apr 20, 2012 9:19 pm

Ghost no this motor will go in one of my track bikes. I was only going to have one CB and one VF track bikes. But now I will have two CB-F racers. One with my short stroke and the other with this motor.

The bike I told you about and my OCD problem, LOL is the complete bike I had to buy to get this motor. I should have just cleaned the carbs and adjusted the valves, BUT that wouldn't be JJAM style. Someone is going to get a pretty decent 81 CB900F when I finish it in a week. It will be glossy black like your bike because of your bike. I normally don't like black but it looks good without the stock decals.

Thanks Jim, lunch is over back to work.

Posted: Fri Apr 20, 2012 9:46 pm

Looks like it will be a strong engine when you get it together should be heaps of fun, i would love a set of rods like that! (peace of mind)

Posted: Sat Apr 21, 2012 3:38 am

AMC49 wrote:

I wouldn't use only one bottom case, the cases are machined together in pairs, meaning they are matched sets.

sonicrete wrote:

Let see if I can explain this. The mains are sized to the tenth of a thousanth. There is .0003" difference in an "A" to "B" and you want to just change out one half? You interchange conrod caps too?

This is right down there with the dumbest thing even possible to do. You related to that guy that beat on 1100 pistons till they broke?

The only thing constant is the bore. There is no relation up and down or back and forth only all the holes line up as a set.

As to welding a leak. I have this excellent welder that can weld pop cans together and the heat of fixing a leak warped the mains out of line. I have welded the bottom radius onto the motor mounts but the oil soaks into the rest of it making heli arc effective impossible.

I'm just reading this thread and I was going to say you're kidding, right? I think you're must just be excited and not thinking... kind of understandable.

Any precision bearing mount that is split in the middle to install is bored as a set. You can't just split them up and mix and match them without doing some very meticulous measuring and matching and in the case of plain main bearings, boring.... if an adequate assortment of replacement bearing shells and sizes were available, you might be able to do it using much thicker bearing shells after an overbore, but they are not.

No, the way to do this is start with an unmolested good set of cases and merely bore for the sleeves to fit (we even opened up my 900 cases with hand tools, just like porting), which is easy and cheap compared fixing those cases or compared to coming up with those parts. That is a very nice pile of unobtanium parts. Wink

Those cams look more like Crane or Andrews, might even have been made by some small custom market guys down here that I can't remember the name of. Vintage Megacycle cams used CWC cores that had wider lobes, and no markings on the ends.. I've had a couple of sets of them. Megacycle also stamps their cams on the flange.

Posted: Sat Apr 21, 2012 4:18 pm

Yes, I was just thinking about the tranny bearings and never even considered the crank bearings when I was writing this. It will be done the right way. I have no plans of messing these parts up.

Thanks for giving a rats ass though. I need all the help I can get somedays. Shocked

Jim

Posted: Sat Apr 21, 2012 11:56 pm

Make sure to keep the revs down. Those MTC conrods were really fucking heavy and would knock the bearings out. They fell out of favor quickly back in the day.

Posted: Sun Apr 22, 2012 12:30 am

Wow, they look close to the Carrillos from the little you can tell from the picture. Maybe the H isn't hollowed out as deeply or something...?

Posted: Sun Apr 22, 2012 12:33 am

I will show pictures when I take it apart.

Maybe I can lighten them on my mill? Would it ruin the temper of the metal? I have scales and everything to make them the same weight.

Thanks Jim

Posted: Sun Apr 22, 2012 12:52 am

Meh, that would require a study in what they are and where they can stand reduction. Probably better to get different ones if it's a big issue. I can't imagine them being heavier than the stock ones.

Posted: Sun Apr 22, 2012 12:54 am

Wow, triple post. what happened... Rolling Eyes

Posted: Sun Apr 22, 2012 12:55 am

Meh, that would require a study in what they are and where they can stand reduction. Probably better to get different ones if it's a big issue. I can't imagine them being heavier than the stock ones. My Carrillo 1100 rods are considerably lighter than stock 900 pistons. I can send you weights when I'm at home.

CB1100F Joined: Feb 17, 2009 Posts: 2105 Location: Oz

JJam wrote:

Yes, I was just thinking about the tranny bearings and never even considered the crank bearings when I was writing this. It will be done the right way. I have no plans of messing these parts up.

Thanks for giving a rats ass though. I need all the help I can get somedays. Shocked

Jim

Nothing to it Jim, you can do it or it wouldn't cost much to get done.

Posted: Sun Apr 22, 2012 4:31 am

Thanks for the encouragement Don, I have a 3" block of aluminum that I mount heads on and put it on my tilting table. It allows me to get the seats and guides in the right position when I need to, on my mill. It looks like I can use the same set up to bore the cases.

My problem is that I'm so busy with members stuff that I never have time to work on my stuff. I need to change that though. I need to twist a grip soon with Melchiro.

Peace, Jim

Posted: Sun Apr 22, 2012 5:07 am

You guys remember I went with this engine when they were first new not come in late. The 900 rods were weak,the 1100 not come out yet.

This was the Ken Tipton era of MTC and he made aluminum and those steel rods. The aluminum ones John Sands used in his nitro Honda. Something about Ken making rods for some air compressor and the length of the forging could be used to make Honda rods.

Anyway back then the aluminum rods would live and the steel ones would beat the crank right out. Then again everything beat the crank out of the Honda. Just keep the revs to 10K.

Posted: Sun Apr 22, 2012 5:20 am

[/quote]

You all want another killer mod to making more power............................For free......................Machine some windows in the crank case between #1 & #2 cyl and again between #3 & #4
These windows start just above the main bearing "block" and finish at the same height as or to match the piston skirt at BDC. You even have to cut part of the cylinder liner away.
What does this do, I can see you asking.................................Well it cuts down on the pumping losses that occur from the underside of the piston travel and allows air that is displaced to more more easily move between adjacent cylinders. Remember that as one piston is ascending it's neighbour is descending so the air wants to swap places and can only do so in the OEM cases through small holes at the bottom of the case.

Think about it carefully and I'm sure you will get it.

Sorry I have no pictures of it but it is worth it believe me.

Captain

CB1100F Joined: Feb 17, 2009 Posts: 2105 Location: Oz

Yeah, that's a common mod and is actually standard fare these days on the modern IL4's. Not bothered for my street bike.

Posted: Sun Apr 22, 2012 5:45 am

Yes on all late bikes.

The mains do not seal off the chambers are combined probably not large enough to pass enough air so need to be larger.

Posted: Sun Apr 22, 2012 6:21 am

Captain wrote:

You all want another killer mod to making more power............................For free......................Machine some windows in the crank case between #1 & #2 cyl and again between #3 & #4
These windows start just above the main bearing "block" and finish at the same height as or to match the piston skirt at BDC. You even have to cut part of the cylinder liner away.
What does this do, I can see you asking.................................Well it cuts down on the pumping losses that occur from the underside of the piston travel and allows air that is displaced to more more easily move between adjacent cylinders. Remember that as one piston is ascending it's neighbour is descending so the air wants to swap places and can only do so in the OEM cases through small holes at the bottom of the case.

Think about carefully and I'm sure you will get it.

Sorry I have no pictures of it but it is worth it believe me.

Captain[/quote]

Thank You Brent for offering that up. I don't mess with anything new so I would not have known. I'm glad your back!! Very Happy

I HAVE LOTS TO LEARN, and I'm having fun. Jim

Posted: Sun Apr 22, 2012 8:46 am

Yeah, that makes total sense. Much appreciated.

Here's the data I said I'd get for you.

I have a 900 rod here weighs 387.5 grams sans bearing shells. YMMV

A Carrillo 1100 rod is 337 grams according to the box.

New bearing shells are about 26 grams a pair.

What do the MTC rods weigh without bearings?

Posted: Sun Apr 22, 2012 9:51 am

DonR wrote:

Yeah, that's a common mod and is actually standard fare these days on the modern IL4's. Not bothered for my street bike.

Well it wasn't 20 years ago when I first did it and none of the manufactures had or did anything like it. Nothing was even manufactured like it.
These tricks are just ways to try and bring them out'a the dark ages and make them perform better than they ever did in their day.
All these tricks add up in the end and you get some serious performance compared to what they were in the begining. And that's what makes it fun.

I would even do it to a street bike no question because it is so very effective........................... after all it is just a couple of holes

Captain

Posted: Sun Apr 22, 2012 10:56 am

Awesome trick, so simple yet . . .

. . it's good to see you back around Brent.

Posted: Sun Apr 22, 2012 11:03 am

Awesome trick, so simple yet . . .

. . it's good to see you back around Brent.