what is involved in boring a motor

[tc862011]

i understand the oem version of breaking in a motor, i more or less was just relaying what i have read and wanted to see if someone had a different method

[Big Jay]

Yeah, personally I would never, repeat NEVER, bore out any engine for power. you're just asking for overheating and other issues when you do that. Only bore out an engine if it's too far gone to hone and you need to get the original clearances back. This was something I was taught in my high school auto shop class about 20 years ago, and since then I have seen (and laughed at) many, many, many people sitting on the side of the road due to their engine overheating and throwing rods because they tried to bore their engine past what it was designed for. Not to mention the fact that boring typically won't increase your displacement all that much, unless you put a stroker kit on it as well (at least for car engines). When I was a jet ski mechanic I did build/ machine down a 550 case to fit 650 cylinders and pistons. the thing ran like stink and didn't have any major mechanical issues. You could probably do something similar to these bikes if you wanted to but I sure wouldn't even think about boring it out; then again, my 550 as it sits gets me plenty fast enough (90+ highway) and is virtually bullet proof, so I wouldn't touch it.

Very bizarre post.

People have been boring out motors to make more power forever without any of the calamities you mention.

[Seana23]

hi babes.
Not sure if someone else has said this.....

How to bore a motor.......

....speak really really monotonously....


...sorry, couldnt resist that one...

Xxxx

[ozman]

Yeah, personally I would never, repeat NEVER, bore out any engine for power. you're just asking for overheating and other issues when you do that. Only bore out an engine if it's too far gone to hone and you need to get the original clearances back. This was something I was taught in my high school auto shop class about 20 years ago, and since then I have seen (and laughed at) many, many, many people sitting on the side of the road due to their engine overheating and throwing rods because they tried to bore their engine past what it was designed for. Not to mention the fact that boring typically won't increase your displacement all that much, unless you put a stroker kit on it as well (at least for car engines). When I was a jet ski mechanic I did build/ machine down a 550 case to fit 650 cylinders and pistons. the thing ran like stink and didn't have any major mechanical issues. You could probably do something similar to these bikes if you wanted to but I sure wouldn't even think about boring it out; then again, my 550 as it sits gets me plenty fast enough (90+ highway) and is virtually bullet proof, so I wouldn't touch it.

i always worked on the theory that the japanese only assembled motorcyles to make it easier to ship them over to us so we could then modify them to suit ourselves
boring is a great way to get extra power and provided the mods are done correctly seldom results in overheating etc

oz
ps ive never thrown a rod either !

[lonerider00]

Big Jay, Ozman, you guys go for it. I was only relaying my experience with car, semi-truck, Naval submarine, and small jet ski, boat, and motorcycle engines that I've been working on both professionally and privately, in racing, professional, and road going use since I was 12 years old. You might have different experiences, and I know a lot of people do it with decent results. I never would due to the reliability issues that it ultimately causes. There are other/better ways to increase power than to bore an engine.

[ozman]

you raced a submarine ?

[rapidray]

I never would due to the reliability issues that it ultimately causes. There are other/better ways to increase power than to bore an engine.

I build big GS motors & have NO reliability issues. If you bore an engine & have problems with reliability you are doing it wrong! You might not be as good a mechanic as you think you are. You would have to be doing something wrong to have issues just from boring. Zora Arkus Duntov, (ever heard of him?!!) once told the upper execs at Chevrolet that "Cylinder boring is an effective means of weight reduction!" when they argued with him about wanting to build bigger engines to get more horsepower. I build 1400+ cc GS morors that will go across the US reliably. I know what things need to be done to make that possible. Maybe you don't & are therefore not a fan of cylinder boring. Did you know that boring a GS 1150 block 3 mm over to a 1229 will run warmer than that same block bored, re-sleeved, & bored to 1327 will? It is the same with an 1100 block going to 1260 vs 1166. Be afraid all you want, there are literally HUNDREDS of engine builders in this country that know better. Don't take this personally, you just don't seem to have the experience to back up your fears.
Ray.