Topic: Billet blocks....who will pay...pics added 9/7/09...10/24....2/10

[MJL]

If I can sell my CBR soon I'll definitely be interested in building a big block motor.

Now to go read the piston thread.


:edit:

After reading the piston thread and looking around at who has what to offer, I could easily spend all the CBR money in just the motor.

[MRieck]

If I can sell my CBR soon I'll definitely be interested in building a big block motor.

Now to go read the piston thread.


:edit:

After reading the piston thread and looking around at who has what to offer, I could easily spend all the CBR money in just the motor.

Yes....no problem

[Terry in Australia]

Hey Mike, pardon my ignorance mate, (I was born with a huge "Ignorance Quotient", according to my wife...........) but I'm still wondering what the benefits of a "milled from billet" cylinder block will be, compared to a bored out and re-sleeved OEM block? If it's just added "bling", I can't see the point? Cheers, Terry.

[MRieck]

Hey Mike, pardon my ignorance mate, (I was born with a huge "Ignorance Quotient", according to my wife...........) but I'm still wondering what the benefits of a "milled from billet" cylinder block will be, compared to a bored out and re-sleeved OEM block? If it's just added "bling", I can't see the point? Cheers, Terry.

I wouldn't use iron sleeves which would really improve heat dissipation.

[NitroHunter]

I'm still wondering what the benefits of a "milled from billet" cylinder block will be, compared to a bored out and re-sleeved OEM block? If it's just added "bling", I can't see the point?

When overboring a stock block for large sleeves, it's not uncommon to cut through the edge of the air gap between the sleeves. These areas are then commonly filled (from the exterior) with a high temp silicone to prevent oil leaks.
With so much material bored away, a weak area has been created between the new sleeves. Stock blocks have been know to crack or even split during sleeve installation. 
The aftermarket blocks are solid in these spots, so they're much stronger than stock, but now there's no air flow - and subsequently little heat dissipation between the sleeves.
My RC block is solid and has only 6 thick fins, as compared to about 10 on the Honda block. Much stronger, yes, but far from ideal.
Now look at the early oil cooled GSXR motors, you'll see a tremendous number of fins, as more fins = more surface area exposed to air flow = greater heat dissipation.
Good plan.
A billet piece, especially one without sleeves, could be machined to offer this, while providing the structural benefit of being much stronger between the bores.
And the 'bling' would be awsome! 

[Terry in Australia]

Okey Dokey, thanks for that, so if (when I bore out my OEM block this weekend) I cut into the air gap but weld up any holes to avoid oil leaks etc, and I carefully install the 73mm sleeves and nothing cracks, will my (now very light) 1060cc cylinder block survive, do you think?

Thanks for your explanation Nitro, I now think I understand why Mike prefers to go with the plated alloy bores rather than cast iron sleeves, without them I assume the billet block wouldn't be that much of an advantage, as you'd still have the heat dissipation problem due to no room for air gaps because of the cast iron sleeves taking up the extra room, like with my (soon to be) overbored OEM cylinder block, or your old RC "big block"? Cheers, Terry.

[NitroHunter]

Truthfully, I'm not sure that even with a billet block and plated bores there'd be room for air gap between 1-2 and 3-4. Our big bores just take up too much space. My big sleeves' top flanges touch each other and I don't know how thick of walls would be required for a plated aluminum bore. But any form of additional heat dissipation would be welcomed.
Welding up the cut through areas between bores could be a challenge, but would no doubt make things stronger.
I've had success installing sleeves by heating the block and freezing the sleeves prior to installation, they've just dropped in with no pressing. I haven't personally experienced the split block horror stories I heard from RC back in the day.
All that being said, there are a lot of very healthy big bores that have seen plenty of hard miles without issues. A billet block with plated bores just seems like a 'more better' approach. 

[mec]

for clarification

boring
welding
boring again

mec

[754]

I agree with Mec, bore to within 20 or 30 thou, weld from inside, then finish bore.

 Myself, I want sleeves.

..............................................................................

What should be mentioned.

Billet is at least 50% if not a lot more, stronger, than stock, diecast cylinder.

You can put more meat or fins where you want them with billet, and maybe less cutout at the camchain cavity, giving a more rigid, harder to crack assembly, that should result in a longer lasting leakfree cylinder, that may actually have round  bores..while running.

................................................................................

Can anyone produce evidence of a stock cylinder punched to 1080cc that actually had  any kind of  a good number of running hours on it?

[MRieck]

Truthfully, I'm not sure that even with a billet block and plated bores there'd be room for air gap between 1-2 and 3-4. Our big bores just take up too much space. My big sleeves' top flanges touch each other and I don't know how thick of walls would be required for a plated aluminum bore. But any form of additional heat dissipation would be welcomed.
Welding up the cut through areas between bores could be a challenge, but would no doubt make things stronger.
I've had success installing sleeves by heating the block and freezing the sleeves prior to installation, they've just dropped in with no pressing. I haven't personally experienced the split block horror stories I heard from RC back in the day.
All that being said, there are a lot of very healthy big bores that have seen plenty of hard miles without issues. A billet block with plated bores just seems like a 'more better' approach. 

Correct

[754]

You really have to see a stock cylinder (and hold it in your hands), bored to 1080, to see what you are up against.

After talking to the original builder/owner of the local 1080 motor, and looking closely at the original cylinder, with the huge sleeves, and what he did to try to keep it leakfree.. I know which way I would go.

Eventually that motor got a RC block.

The only way I could see the stock one holding up is maybe if it was really babied, and kept at low revs, which would be pointless.

[NitroHunter]

Those thin sleeves are scary.
BUT...
In 1979 I met a local a guy that had a 1080 bike, essentually a self built RC Cobra motor. Bored stock block, 12.5:1, Golden Rods, 327 cam, etc. It was a BAD FAST street bike. When I met him, he told me there were already more than 10,000 miles on it and he'd never had it apart.
No oil leaks, nothing. Regular tune-ups.
(So I had to have one - but I went 970)
He moved on several years later so I don't know long the motor lived after that.

Of course there was the RC Eng add featuring a 1200 Z-1 with 40,000 miles on it that would run 10.90's. The big lettering in the add stated "RC big bore kits live!"


 

[BLUE71TURBO]

Is it not true with plated bores ( like two stroke cylinders ) once the bore is scratched
the cylinder is junk?  The cost to have the cylinder bored and replated would cost
more than a new cylinder !  I believe sleeves is the way to go. Any problems in the
future you can just bore it out to the next size. You cant do that with a plated bore.     

[MRieck]

Is it not true with plated bores ( like two stroke cylinders ) once the bore is scratched
the cylinder is junk?  The cost to have the cylinder bored and replated would cost
more than a new cylinder !  I believe sleeves is the way to go. Any problems in the
future you can just bore it out to the next size. You cant do that with a plated bore.     

  http://www.mt-llc.com/Ordering/pricing.html The boring and plating isn't that expensive. Scratching and plating damage generally happens to 2 stroke engines secondary to seizure....that's my experience. Sleeves hold a lot of heat. When Yamaha went to the FJR1300 they used an all aluminum block.
  Boring an SOHC 750 out to handle 73mm pistons really weakens the block. The bores the sleeves sit in tend to get a wavy type of distortion. As mentioned...those sleeves get very thin too.
 the billet block would be stronger (like the old RC blocks) but would also dissipate heat better. The plated surface is very hard....the pistons skirts would wear out of spec before the bores.

[Retro Rocket]

What is this coating called Mike. I am looking for people that do this sort of work in Australia.  Do you have any cad drawings of these blocks? And are they still going to be built?  Just checking out my options..Thanks.

Mick

[fuzzybutt]

bmw has used nicasil lining in their cylinders for many years with no sleeves

[754]

Its not sleeve thinness that is a problem with 1080s. It is lack of support for the sleeve &inablity to keep gasket surface flat, and oil inside the motor.

I can see the advantages of the plated bore, but if they were sent undersize(require fitting), would it not then be difficult for some to find a shop with that honing equipment?..or do you send yours in to get them fit?

[Terry in Australia]

bmw has used nicasil lining in their cylinders for many years with no sleeves

That's true Fuzzy, my BMW K1100LT with Nikasil plated alloy bores has done a genuine 100,000 miles and was compression tested at it's last service and hasn't lost any compression pressure from new. Considering that most of us ol' farts will never do those kinds of miles on a CB750 in our lifetime, I'm sure that it's fair to say that one of Mike's proposed billet blocks should last forever. I do have to say though, that I'm talking about a purpose designed water cooled BMW engine, not an aftermarket add-on with the usual inherent compromises like the air gap/heat dissipation issue that an alloy block even with plated alloy bores will address, but still won't entirely dismiss.

With 9 or 10 bikes in my garage and a company car I'm lucky if I get time to ride all of my bikes once or twice a month, so I'm not at all fussed about boring my stock block out to take my beautiful 73mm MTC pistons. (Thanks again Rick!) Even a stock CB750 engine is far from "bullet proof", so if I want to really thrash one of my bikes as Frank suggests is the recommended method of big bore ownership, I'll instead do it on my Suzuki GS1000S, with it's virtually unbreakable engine. On the other hand, I won't be too frightened to open up my 1060cc SOHC engine powered road bike now and then when I think the road is clear of cops and Kangaroos............

As far as wavy sleeve bore distortion goes, well I guess I'll have to live with that, but as an aside, my 73mm sleeves are still thicker than my 836cc sleeves, and (so far) I haven't heard of too many "thin sleeve" horror stories originating from 836cc kits? Yeah yeah, I know, the combination of bigger heavier pistons with thin sleeves and a dramatically weakened "swiss cheese" cylinder block will virtually guarantee that I don't make it past my mailbox before the whole deal explodes in a ball of fire, but what the hell, it'll be fun while it lasts, ha ha!  

  

[BLUE71TURBO]

So what's going on with the big blocks?  Have any been produced yet?  Pictures?

[MRieck]

So what's going on with the big blocks?  Have any been produced yet?  Pictures?

Money needed.....I really need a few people to commit

[crazypj]

Nikasil was developed by Mahle sometime in the late 60's.
Porsche made it 'famous' in the 917 and later on in road engines.
 Personally I wouldn't have any issues with a block directly bored and coated (new coatings can be harder with better wear characteristics)
 No-one seems to have issues with modern monoblock motors and various trade name coatings.
 If it gets damaged you weld up bore damage, re-machine and re-plate.

PJ

[Retro Rocket]

Can we see what these will look like Mike, do you have any cad drawings or pics ?
I am very tempted......

Mick

[Big Jay]

We do over 100 big bore hayabusa blocks a year, and the nikisel is extremeny reliable, even when squeezing them hard.

Jay

[Retro Rocket]

Hi Mike, are you still looking into getting these made.?

Mick

[MRieck]

Hi Mike, are you still looking into getting these made.?

Mick

Yes Mick.....I'm saving cash up. Start up isn't cheap.