same one, just close up

 

next one

 

.

 

I roadraced motorcycles for 10 years - both supersport and superbike. My first superbike motor, a cbr600f3, got a top to bottom build and blueprint by my mechanic w/me assisting. I learned alot from him about prepping a full race motor. That bike had a falicon knife edge crank in it and regularly saw sustained 14,000+ rpm (and 128whp from 640cc). That winter we took the motor apart and it was absolutely pristine. As i see it, the type of work darkhorse is doing is the proper way to build a race motor... if you want it to last. Wish I had the money to do it... and race it!

 

heres the other end of the girdle

 

And the ohter end of that same last cap. Notice how it is at a different height.

 

Here are two more pics, and then ill stop, this shows one of the cap feet, on only one of them.

 

here is the opposite corner of the same surface.

 

The more you post...the longer we have to wait for pictures of this thing assembled!

 

Alright, I want to clarify some things here. I love building motors, I love doing machine work, I just love what I do. I am not claiming to know it all, nor am I telling anyone here that they are wrong. I am just telling you a little about what I have found so far. It isn't the begin all and end all of this field by any stretch of the imagination. I do not doubt that some of you have these engine doing great things.

The way I was taught, and the way that I do things is obviously much different than alot of others who run these motors. We build high end race and specialty motors. And that requires doing much more than is usually required by normal standards. But that is the way I do it. In my judgement, a twisted block, warped head, crooked line bore, or twisted rod to name a few will not cut it for a motor that I put my name on and stand behind (And its not just this particular engine) Thats not to say that a motor that possesses those qualities will not run, but will it really RUN!!!? Have I had motors fail, of course! There is no guarantee on any of this stuff. But the failures are not due to inferior building work or overlooked area of the assembly, it is almost always caused by the nut behind the wheel doing something beyond the capability of the unit.

Bottom line is, this is the method I use to do an engine, it is the way I feel comfortable and confident. I will do things that you all may consider useless or redundant, but I have taken the time to find out and learn. There are plenty of times where I am taking too much time to reach a conclusion, but I am not building engines solely to make money, I do it because I enjoy it. So if you want it done more quickly, done more cheaply, and done with more flash, take it to someone else. I am not out here soliciting motor jobs from any of you, I just thought I would share some info. This has turned into a pissing contest on who is right and who is wrong, that was not the idea.

 

darkhorse,

Dont fret the small stuff. Your contribution is greatly appreciated. Please continue as the work progresses. Thanks!

 

Thanks for the information Darkhorse, we needed more tech. write ups like this.

 

You should definitely line hone the mains when you rebuild a block, particularly when you replace the main bolts with studs.

Same goes for the big end of rods (resizing) if you change out the rod bolts.

 

I am not trying to turn this into a pissing contest and I don't think I contradicted myself.

What I was trying to point out is that spending money and time to polish the inside of the block, whether it adds strength or not is a waste of time in my opinion. I haven't seen a block failure yet that would have been saved by this polishing. Splitting cylinder walls isn't going to be saved from that. This is the ONLY block failure I have ever seen.

I also don't want any kind of pissing contest. Your pictures and information are both great, especially the pictures.

David Buschur
www.buschurracing.com

 

The interior of the block was not polished in an attempt to keep it from failing as much as just trying to clean it up. THere are a lot of sharp edges and rough casting flash that I just cleaned up. It may add some strentght to the walls. But not to the point that it would keep it from failing. I just went through the block in an attempt to eliminate possible stress risers. There is a fair amount of reinforcing ribs in the casting, and just smoothing them out and radiusing the corners may help a bit. But if any of these motors were to expereince a catastrophic failure from something loke a rod coming apart, or a crank breaking, it would most likely rip through the iron block whether it was polished or not. I realize that that measure would not save the block in an event of that magnitude. I just know that the castings and wall thicknesses of many of these japanese blocks are thin and flexible for the most part, and we just take measures to try and help them out a little bit. Like I had mentioned in earlier posts, after going through the block, I found almost all of the dimensions to be askew from what they should be, so I went through and corrected them all. Splitting hairs? maybe, but in an attempt to mkae it as perfect as possible, I would do these types of things. This motor is going to probably get beaten to death, and I would hate to have had a failure due to something that was overlooked on my end.