GSXR cams

[Eternal49]

I found this thread in the FAQ section, about installing bigger GSXR cams in Kats.

http://katriders.com/vb/showthread.php?t=75466

I was wondering If Im suppose to put the GSXR Ex cam where the Katana Ex cam went, or am I suppose to put the GSXR Ex cam where the Katana In cam went?

Also has anyone done this before?

Thanks,

[Trackerrrr]

EX and IN stand for EXhaust and INtake, and no you can't swap them for each other . Exhaust for exhaust, intake for intake.
The GSXR cam swap has been done by a few ppl here, not a hard upgrade to do.

[VifferJim]

I found this thread in the FAQ section, about installing bigger GSXR cams in Kats.

http://katriders.com/vb/showthread.php?t=75466

I was wondering If Im suppose to put the GSXR Ex cam where the Katana Ex cam went, or am I suppose to put the GSXR Ex cam where the Katana In cam went?

Also has anyone done this before?

Thanks,

At first I was thinking, "Huh? Why would someone think that you should do something like that??" Then I read Chris's thread and I think you're hung up here:

"Take the cam caps off put the IN and EX GSXR cams were the EX and IN Katana cams went."

But, take a look at the lob height comparo in that thread... It reads like putting the EX Gixxer Cam in place of the Kat IN would yeild a shorter lobe height... I'm pretty sure you don't want that.

It seems you go IN to IN; and EX to EX. But, don't follow me - I never did this mod. Wait until someone who's actually done the swap comments...

[Eternal49]

EX and IN stand for EXhaust and INtake, and no you can't swap them for each other . Exhaust for exhaust, intake for intake.
The GSXR cam swap has been done by a few ppl here, not a hard upgrade to do.

Yes, I had done a cam swap in a car before that required you too swap the intake came with an exhaust cam and off the timing a few degrees.

At first I was thinking, "Huh? Why would someone think that you should do something like that??" Then I read Chris's thread and I think you're hung up here:

"Take the cam caps off put the IN and EX GSXR cams were the EX and IN Katana cams went."

But, take a look at the lob height comparo in that thread... It reads like putting the EX Gixxer Cam in place of the Kat IN would yeild a shorter lob height... I'm pretty sure you don't want that.

It seems you go IN to IN; and EX to EX. But, don't follow me - I never did this mod. Wait until someone who's actually done the swap comments...

That is exactly what confused me.

Thanks for the input guys, hopefully someone who has done the mod can chime in soon, im also curious on a estimated power gain from this swap.

[tmk7c9]

I haven't done it on a Kat, but I HAVE done it on a Bandit 1200....so there should be some similarities.

First off, it's usually recommended that you swap intake cams, but not exhaust cams. The intake cam typically gives reasonable gains on the upper 1/3 of the RPM range with virtually no effect on the rest of the power curve (added power, with no downside). swapping the exhaust cam will give even better gains up top, but at the expense of midrange power. Basically it moves the entire curve to the right a few hundred RPM. Replacing the exhaust cam becomes a compromise of midrange vs topend power.

I swapped both cams on my bandit, but I also installed a 1216 JE big bore kit at the same time, so I can't really comment on power gains due to just the cams.

If I remember right, the 1990 GSXR 750s had the largest cams (I think).

Again, this is what applied to my bandit 1200. I'm not sure if the same holds true for the kat, but I'd imagine many of the same principles apply.

[Eternal49]

I haven't done it on a Kat, but I HAVE done it on a Bandit 1200....so there should be some similarities.

First off, it's usually recommended that you swap intake cams, but not exhaust cams. The intake cam typically gives reasonable gains on the upper 1/3 of the RPM range with virtually no effect on the rest of the power curve (added power, with no downside). swapping the exhaust cam will give even better gains up top, but at the expense of midrange power. Basically it moves the entire curve to the right a few hundred RPM. Replacing the exhaust cam becomes a compromise of midrange vs topend power.

I swapped both cams on my bandit, but I also installed a 1216 JE big bore kit at the same time, so I can't really comment on power gains due to just the cams.

If I remember right, the 1990 GSXR 750s had the largest cams (I think).

Again, this is what applied to my bandit 1200. I'm not sure if the same holds true for the kat, but I'd imagine many of the same principles apply.

How did you find out about the exhaust cam?

[tmk7c9]

How did you find out about the exhaust cam?

most of my info came from Fast Larry's Bandit FAQ

http://www.portablepct.com/fastlarry/banditfaq.htm

It looks like he's changed the portion about the GSXR cams though....he used to have several paragraphs of info about it, but now it's down to just a few sentences.

Also, there were forum members on Bandit Alley that discussed the mods also. You may still be able to find some of the old threads if you head over there.

[VifferJim]

I haven't done it on a Kat, but I HAVE done it on a Bandit 1200....so there should be some similarities.

First off, it's usually recommended that you swap intake cams, but not exhaust cams. The intake cam typically gives reasonable gains on the upper 1/3 of the RPM range with virtually no effect on the rest of the power curve (added power, with no downside). swapping the exhaust cam will give even better gains up top, but at the expense of midrange power. Basically it moves the entire curve to the right a few hundred RPM. Replacing the exhaust cam becomes a compromise of midrange vs topend power.

I swapped both cams on my bandit, but I also installed a 1216 JE big bore kit at the same time, so I can't really comment on power gains due to just the cams.

If I remember right, the 1990 GSXR 750s had the largest cams (I think).

Again, this is what applied to my bandit 1200. I'm not sure if the same holds true for the kat, but I'd imagine many of the same principles apply.

This is consistent with the advice I got when I was thinking about swapping out cams (and from Chris Frank, too - he's the guy who wrote that thread you referred to initially).

[Eternal49]

Ok, I ended up getting in touch with the guy who wrote the article. Katana intake cam is directly swapped with GSXR intake cam, and obviously the same goes with the exhaust cams.

Also, will the valves have to be readjusted after the cam swap? Are they to be readjusted to factory Katana specs?

[Trackerrrr]

You will have to readjust valves back to Kat specs.

[loudnlow7484]

I swapped in the GSXR cams this winter. It's as simple as can be..... you're just replacing one part with the other, in the exact same position and everything. I've only had it running for about 10 minutes since then, though, then I noticed that carb #2 was dumping fuel nonstop into the engine, so I pulled them and haven't put them back yet.

Make sure you use a torque wrench, unless you've got a carefully calibrated hand. Those cam caps take nearly no torque at all when you reassemble. (8ft-lb IIRC)

[Trackerrrr]

I swapped in the GSXR cams this winter. It's as simple as can be..... you're just replacing one part with the other, in the exact same position and everything. I've only had it running for about 10 minutes since then, though, then I noticed that carb #2 was dumping fuel nonstop into the engine, so I pulled them and haven't put them back yet.

Make sure you use a torque wrench, unless you've got a carefully calibrated hand. Those cam caps take nearly no torque at all when you reassemble. (8ft-lb IIRC)

And trying to helicoil a stripped hole is a pain after you gorilla the bolt.

[overboost07]

I swapped in the GSXR cams this winter. It's as simple as can be..... you're just replacing one part with the other, in the exact same position and everything. I've only had it running for about 10 minutes since then, though, then I noticed that carb #2 was dumping fuel nonstop into the engine, so I pulled them and haven't put them back yet.

Make sure you use a torque wrench, unless you've got a carefully calibrated hand. Those cam caps take nearly no torque at all when you reassemble. (8ft-lb IIRC)

i thought i read somewhere that you had to split the case to replace the cams?

[Wolfe_UK]

i thought i read somewhere that you had to split the case to replace the cams?

Nah just pop the cam cover off the head

[loudnlow7484]

i thought i read somewhere that you had to split the case to replace the cams?

Whaaaat?!?!

Nope, no pushrods in the kat engine. The cams are sitting directly under the valve cover.