swapping cams over to get more hp ?

[VBRYANT]

I belive I read it on the American sv fourm but wondering. A is it true or B is it total bill has any one ever herd of this it was something like repacing the inlet cams with another set of exhaust exhaust cams ?

[Pricey12]

It can be done, yes. I'm sure someone more technically minded will be along in a bit to elaborate.

Is it worth it for a couple of extra horses? Probably not.

[VBRYANT]

Any more extra horses for me is fun more than worth it lol I like to tinker mine is a curvy just want to make some more go go power lol any help how to do this would be good

[maviczap]

It can be done, yes. I'm sure someone more technically minded will be along in a bit to elaborate.

Is it worth it for a couple of extra horses? Probably not.

Pointy cams into a curvy engine is a well known improvement in HP for little or no big outlay.

Here's the how to

http://www.bayarearidersforum.com/forums/showthread.php?t=154847

Some have swapped curvy cams into a pointy, but I forget which ones & the HP gains are relatively small compared to the above.

[VBRYANT]

You sir are a legend for this I think I will do this and up my jets and aifiter up grade im off to a dyno this weekend with my bike as standard to see what im startimg with

[maviczap]

I know :rave:

I've still got to do mine.

Let us know how you get on

[johnnyrod]

It's an easy job, cams cost about £150, and that's all you need. Check the clearances but I will lay money they'll be identical to your current set-up. No jetting changes needed unless you have filter/can etc. that you haven't compensated for. What do you get... top end power!
www.johnnyrod.co.uk/dynoruns.jpg (http://www.johnnyrod.co.uk/dynoruns.jpg)
From stock to noisy can to cam swap.

[VBRYANT]

Well once cams are done I will be upgrading filter and jets my idea is more air more fuel = more bang haha I alredy have a can on and iridium plugs dont no if the plugs make much difference on that dyno ? Is the green the stock one ?

[Bias]

I know that given the money the ideal swap is ......
Pointy inlet to Curvy Inlet
then curvy Inlet to Curvy exhaust

Now come the idiot questions :confused:

Seeing as second hand pointy cams are as rare as rocking horse doo-dah what sort of gains would you likely get by having Curvy inlet cams on both the inlet and exhaust ? On a Curvy that is.

As the Pointy inlet cam is only 0.6mm (?) higher than the stock Curvy inlet, are most of the HP gains from the Curvy cam swap because of the 2mm increase in the height of the exhaust cam ?

Im just thinking of a cheap and easy way of getting a few more HP from the SV and if this works I'll give it a go

Cheers guys and gals :thumbsup:

[VBRYANT]

I know that given the money the ideal swap is ......
Pointy inlet to Curvy Inlet
then curvy Inlet to Curvy exhaust

Now come the idiot questions :confused:

Seeing as second hand pointy cams are as rare as rocking horse doo-dah what sort of gains would you likely get by having Curvy inlet cams on both the inlet and exhaust ? On a Curvy that is.

As the Pointy inlet cam is only 0.6mm (?) higher than the stock Curvy inlet, are most of the HP gains from the Curvy cam swap because of the 2mm increase in the height of the exhaust cam ?

Im just thinking of a cheap and easy way of getting a few more HP from the SV and if this works I'll give it a go

Cheers guys and gals :thumbsup:
I like yout thinking on this thats the main thing cheap extra hp

[Pricey12]

I'm not sure about this fixation with trying to squeeze every extra ounce of performance out of the SV engine. I've gone down the full exhaust, filter and jetting route and yes my bike may be slightly quicker than stock, but if it is it's only marginal. Perhaps the cam swap is better bang for your buck. Ultimately though, if you want more power get a different bike. Just my two cents.

[maviczap]

None of those you've done will do much for HP increase

[Pricey12]

None of those you've done will do much for HP increase

Maybe not, but as with the cam swap they're popular mods. My point is that no matter what you do, the SV is never going to make more than 80 odd BHP. At the end of the day, people always want to tinker, that's half the fun of owning an SV I guess.

[carelesschucca]

I'm with Pricey on this. the gains are negligible you want more power look at other bikes.

[Bibio]

your not going to feel a gain of 5bhp from a v-twin and even if you do where is that gain going to be in the rev range. enjoy the bike for what it is and if you feel the need for speed then move up onto a larger bike. believe this or not but your better spending the money on the suspension as this lets you ride faster round corners.

[maviczap]

I'm with Pricey on this. the gains are negligible you want more power look at other bikes.

Aye, but that's more money than a cam swap, which was the OP's original question.

[Bunkle]

I bought my curvy already sorted with a pointy cam swap carried out, carbs have been jetted up and K and N Filter fitted. Its running a full M4 exhaust system too.
Once I get the poxy ignition sorted I'll be taking it on a Dyno run and will report back.

[johnnyrod]

So did no-one look at the dyno trace I posted? For sure the SV will never be a missile but the cam swap is cheap and makes a big difference to top end with no losses lower down. Can/filter makes only small differences and when you add the set-up costs it's poor VFM. I'm not sure how much the cam swap would yield with stock filter/pipe but the OP isn't going that route anyway.

As said somewhere, on the road the SV is quick enough, on the track you're going to get eaten by faster bikes. I've found that at medium-speed tracks like Cadwell, the extra power of the new cams is enough to bridge the gap to the IL4s and just about keep them at bay.

[maviczap]

Yes, I've read it a few times & I'm sold on the cam swap as the best bang for bucks option.

I just need to pull my finger out & do it

[Bunkle]

I can't find your Dyno post johnnyrod, do you have a link to it?

[Bias]

The Dyno chart is on the bottom of the page that jonnyrods signature links to. Theres lots of good info there

[Bunkle]

Cheers for that, makes interesting reading.
I'll be looking at the ignition advance option next.
Looking forward to getting a dyno run done and seeing what increase there is with my set up.

[VBRYANT]

A quick one for today did a dyno run on my bike came out with 75 hp so thats good going to get some cams swap them blah blah blah see what we end up with after hoping to hit the 80 mark some how

[Pricey12]

75 BHP as standard?

[VBRYANT]

As standard as it is yes all it has is irdium plugs and exhaust

[Pricey12]

That's a very healthy starting point then. I would have expected it to be lower.

[VBRYANT]

Yeah I was surprised myself bike has 37k on it aswell

[johnnyrod]

If it's a dynojet dyno then it could read basically anything. What you're looking for is the differences, speed of throttle response, and air/fuel data. I'm sure the main difference between mine as "stock" and after dyno set-up with the pipe etc. was a knackered chain and a different dyno with better correction factors.

I wrote that page ages ago but I haven't changed the bike a lot since then. I've got a new pair of cylinder heads off a race bike but not had time to get the dyno set-up done as it definitely ran leaner at the top. I blew this year's budget on them but would really like to get linear fork springs or maybe even the GSXR front end route as the brakes I think are showing their age, though the front end as is has never caused a problem.