SV 650 Big Bore kits?

Don't have a clue on this one, but personally I wouldn't risk it......if you're flat out (130mph) on a puplic road, then your asking for trouble. If I were you I'd spend £200 on the following

1. Rebuilding the forks,spring and oil to suit you.
2. Smaller front sproket (1 tooth less as on the naked)
3. R6 Throtle tube and matching grip of course.
4. Upgraded brake pads and fluid.
5. Do the retard removal thing.
6. Longer Dog Bones.
7. Ride, Ride and Ride some more...no substitute for experience.

I'm working on item 7 before trying any of the others.

Originally Posted by BigBaddad

Don't have a clue on this one, but personally I wouldn't risk it......if you're flat out (130mph) on a puplic road, then your asking for trouble. If I were you I'd spend £200 on the following

1. Rebuilding the forks,spring and oil to suit you.
2. Smaller front sproket (1 tooth less as on the naked)
3. R6 Throtle tube and matching grip of course.
4. Upgraded brake pads and fluid.
5. Do the retard removal thing.
6. Longer Dog Bones.
7. Ride, Ride and Ride some more...no substitute for experience.

I'm working on item 7 before trying any of the others.

Seconded. You can go alot faster by sorting the budget suspension, and riding alot. Even just doing the forks with an ohlins spring kit will work wonders

And fitting good tyres

And riding lots

Matt

Originally Posted by Knaapie

Mmmm, this creates perspectives. I thought it was only advisable to do with an "out of the crate" engine, like was done with yours. As r4ce_e3nd wrote, the 700cc kit price is 300 euros. Good or bad? But uhm, what are shells?? And running out of oil hasn't happened as far as I know. Although I did have a low level on 2 or 3 occasions, but filled it up as soon as I noticed.

But as I told you, if I want to have an engine improvement I'd rather come over to you and Steve. And bringing my own stuff in that case is not that polite... Besides, I would like to have other stuff done (f.e. lightening the crank, like you told me) to get a good, and more important for me a reliable result, which isn't going to be for free.

The kits over here are about £220. It doesnt matter if the engine is new or not to be honest. Shells are the liners that sit between the rod and the crank and will wear if the bike has been run low on oil. Just a low level wont cause any problems. TBH with the bore kit its worth looking at carillo rods as some stock rods can be weak. You put new shells in with these anyway.

Lightening and balancing the crank is well worth while for what your doing. They take about a kilo off which is massive!!.

BTW my failed shell was actually a twisted crankcase which was caused when the bearing was pressed into the case. Nothing to do with the engine being tuned..just pure bad luck!!! Also had an overheat but that was due to the head bolts stretching as they had been torqued a few times. Worth changing these for new ones everytime. In fact so far compared to a SS600 tuned motor mines been bloody good especially considering it has 18bhp more than stock in some places on the curve - a nice hooooge big fat mid range!!. Gawd i will miss this bike...the Superstock 600 feels flacid in comparison!!!

[northwind]

Originally Posted by SV650Racer

Lightening and balancing the crank is well worth while for what your doing. They take about a kilo off which is massive!!.

BTW my failed shell was actually a twisted crankcase which was caused when the bearing was pressed into the case. Nothing to do with the engine being tuned..just pure bad luck!!!

Ah, I'd wondered about that one, the original explanation didn't make an awful lot of sense tbh (though you guys would know better than someone who'd never seen the engine!) but the injected engines have a bit of a history of issues with the revised bearing setup, warps and cracks. Not much happens to SVs that hasn't happened before

With the crank lightening, I meant to ask you about that previously but I always forget. That's a lot to shed, are you taking it exclusively out of the crank and counterweights, or also the flywheel and maybe generator? Yours was total loss i think, are you counting that with it?

My big question is, was there any loss of usability from the lowered engine momentum... SHould spin up faster but also slow down faster, but that's just theory, doesn't mean anything in the real world.

Reason I ask is engine number 2's definately going to get its crank balanced when I get my act together and rebuild it (and maybe some other trickery) but I'm not sure of the pros and cons of going past that. With my main engine, I've always set the limits of tuning at pistons and upwards, so I've not always paid that much attention to what you can do with the bottom end (apart from blowing it up)

The kilo is just off the crank. Its taken off the large flat surfaces and then holes are also drilled to aid the balance. IMHO it picks up alot quicker as the SV can be lazy uner load, especially with the big bore. We also took most of the windings off the genny making it lighter but it still charges at full rate as i didnt like the hassle with total loss. When the SV with high comp is hot it wont turn over unless the battery has full charge. Making a re start a nightmare should the race get stopped and then restarted.

I didnt notice any difference in engine braking though, but then again using the slipper clutch and prefering not to use the engine to brake the bike i probaly wouldnt notice anyway.

It reduces the load the crank has so is better for it in the long run. Very worthwhile if you have the motor apart. Worth looking at the ports too..things you can do there make alot of difference as stock they are very restricted.

I was wondering, because you talk about low oil level, what has happend to your engine if you start losing (burning) engine oil. Because mine does... It has already 70000 km's on it so maybee a revision of the engine should be a good thing, but what has to be replaced/checked to prevent it losing oil? Do I look at a great cost or not? Can I do it myself? (I have experience in replacing cam's)

And sorry for going off-topic, but with the knowledge we have here running in this topic my problem should be explained in 5 minutes. Not?

Generally at that mileage pistons and rings would benefit the engine. Its normally the rings loose in the bore that cause oil useage. My father in laws FZR1000 used alot of oil (they tend to anyway!)..but with new pistons and rings it halved the amount it consumed.

Thanks for the repley.
Am I right to say that I also loose a bit of compression with the bad pistonrings? Or will it only the oilrings be damaged?

[northwind]

Originally Posted by SV650Racer

I didnt notice any difference in engine braking though, but then again using the slipper clutch

Best sentence ever

Yeah, a bit of head work's a no brainer if you've got them off, not as much as with some older engines I think- every SV head I've seen is pretty tidy, not too much in terms of casting and edging, but the exhaust ports look like there's plenty of space for improvement.

Thanks for the info on the crank lightening, I shall file it in the back of my brain. Have you guys done the work on standard bore engines at all? Lightened flywheels and cranks quite often lead to complaints about poor idle, difficulties pulling away from a stop without using a ton of clutch (since the crank and flywheel weight all acts as an energy store... Likewise on/off engine characteristics because of the faster spin-down times. Not all an issue at all on track of course, but I've not found a road perspective for this in the SV, so I wonder if you've any thoughts specific to this stuff (other than engine braking of course!)

[northwind]

Originally Posted by r4ce_e3nd

I was wondering, because you talk about low oil level, what has happend to your engine if you start losing (burning) engine oil. Because mine does... It has already 70000 km's on it so maybee a revision of the engine should be a good thing, but what has to be replaced/checked to prevent it losing oil? Do I look at a great cost or not? Can I do it myself? (I have experience in replacing cam's)

I'd also maybe be pointing a finger at the valve seals... 70000km isn't really big miles for the SV though, depends on use of course. How much oil are you actually burning? Any sign of smoke in the exhaust?

What might make economic sense for you, would be to find yourself a working top end- SV engines with wobbly big end bearings are dead easy to find, you can buy them very cheaply in otherwise good condition if you shop around and are patient. Then, just swap the heads, barrels and pistons entirely- replaces the 3 main culprits, bores rings and valves. It'd cost you a couple of sets of new gaskets too, and it's DIYable, though not exactly simple. You'd need to be careful of how it was stored though- the bores are cast iron, so if they're not well protected and water gets in it's game over.