Engine blew up with a bolt coming loss from CCT. Great fun wheel lock up @70...awesome!!!!


Now for the fun bit.


Removed engine, stripped it down, did measurements and found that I am still within service spec if I renew shells at bottom end.
Big question I have now is. Pistons.


Slight side wall wear on all pistons, barrels need a honing but shall I enlargen bore, IF SO, what size shall I go.


1, CBR1100 XX pistons 79 mm.
2, CBR1000F original size 77mm.
3, any other options besides replacing for new barrel or 2nd hand.


If option 1, means I will need to resize jets. If this is viable has anyone done this before. I will make a video on this if need be. you all have a video of mine shown on your pages already.
if option 2, I would much prefer to open up the heart of this beast. frame and bike can handle it. BUT!!! I want wise words of comfort.
option 3 sounds horrible............


Please advise. Where is the best place to obtain a decent price for parts. David stores offer shell prices of £185 for crank shell renewals. I need this cheaper. Piston rings depends on pistons IE option 1 or 2 as per above.


Please advise and pre-emptive advise would be awesome.


thank guys.....

 

The most cost effective method would be to find a replacement engine.

Where do you live, we can help find an engine or the parts you need to buy to repair your old one.

 

I hear what you are saying but it is better the devil you know than the devil you don't. atleast I know the engine will be sounds and new...

 

Do you have substantiated info for going 2mm over and using Blackbird pistons? A quick search on Yahoo (who uses Yahoo????) only brought up a thread CBRF from a year ago where someone "thought" you could use them.... It's more than just bore. Wrist pin size, wrist pin height, dome size/valve clearance, etc.

 

I gotta agree on that. There may be a good reason the replacement engine is being sold out of a bike, ie bad tranny. It too may have wall loss and money not well spent.

I agree with Conrice on, there is more than piston dia. involved with changing out pistons. It may work or it may blow the top off the popper.

Anyway, going over a little may require opening the jets. Its a good idea to go bigger in stock configuration as all factory bikes run lean from the assembly line for emission purposes.

Not to sound cheap but, if its within spec, I'd rebuild what I have.
I rebuilt a Chevy engine I had. It had 100,000 miles on it and was 1/2 out of spec. I figured I could rebuild it and get another 100,000 mi before going over on the bore. The rest of the car didn't make it that far. lol

 

I did something similar. I found an Isuzu on the side of the road with a sign on it that said $400. I peaked in the window and saw the engine sitting in pieces in the back. The tranny was propped up by a 2x4 underneath the car.

Beyond using a simple automotive hone, hatching by hand, new thrust bearing, and mains/rods of course, I threw it back together as I found it.


That thing ran great, but the rest of the car didn't make it as long as I hoped... I still regret crushing that thing (but it needed a fuel pump and all new suspension which would have been about 3x as much money as I had into the entire car)...




Back on topic - while you have it apart, maybe give the head a small port job and get a regrind cam on it. That's relatively cheap, and it'll be a nice bang-for-your-buck in the performance department instead of bigger pistons.

I'm not sure how much extra hp a 2mm-over would give you by itself. Besides, you could lose a ton of compression, or have the piston and valves become in intimate contact. There are rules of thumb for valve pocket size, but I sincerely doubt you'll find all of the measurements you need (to make it the devil-you-know) without ordering everything and measuring yourself, which is a huge financial gamble considering the value of the motorcycle we're talking about. The guy-on-the-phone at Weisco is only going to be able to give you so many measurements for the Blackbird.

If there's substantiated information out there that you can trust (and there might be considering people drag race blackbirds), then by all means, have at it. I'd be following it every step of the way should you post it on the forum.

 

I really like the replies that I am getting.


Upon some further checking, it is possible to raise the roof on the head to allow piston - valve clearance by adding a thicker gasket, but would need to do a plastercien test for gap clearance.`
That being said I still need to check deck height of the pistons but I fear one thing, I am not entirely sure about the +2 mm rebore, this might result in a too thin of a wall for piston and barrel.


From what I have measured, it is not recommended to take this route. Hence from a previous post from a member of the CBR forum has suggested regrind the cam shaft.
However I had also thought about believe it or not, nikasel the barrel to close the tolerance. BMW I believe were the first to do this and langcourt do re-nikasel barrels.
I will make enquires about if they can do this to this version of barrel. This would be a major improvement on coating and performance. As long as the process is done right nothing will go wrong. Langcourt are the best to advise and if they agree this can be done I will opt for this route I think. Unless someone else has other views.


I will double check the tolerance on those blackbird pistons but I think the barrel will be too thin. Sad I know.


All I ask is for ideas of way to improve this engine as a project seeing the guy has decided to scrap it as it will cost too much for him. Hence now mine and I am tempted to do more for it.

 

Nothing wrong with going nikasil, just double check that your piston rings will be compatible.

That's what my engine's walls are coated with.

 

can I ask, have you noticed any performance boost having nikasel slapped on your walls.? Should this be the case what piston rings have or are you using.


I have made enquiries about oversizing pistons and it turns out that yes 79 will fit the bike but the pistons used are custom made from wiesco and JE pistons. I need to find out who is making them and for how much.


Now I have more to think about, Nikasel with 79mm pistons. More expensis. GREAT!!! ;( hahaha ...
To find out more about this 79Kit, I google cbr1000F big bore kit and nice a number of pages to trawl through. Shame its all in $.. major cost to import items...;( :P


All I need is a best place to buy the lower end shells for the engine. Id rather go else where if Honda is to expensive, which I think it is. but Its just me thought.

 

I have a wiseco big bore kit (2mm over) and have upped my main jets to 140's, not had any problems except for front wheel lifting quite often under power in first gear.