HRC valve springs, advancing cam gear timing?

[DeepCmonkey]

G'day all just have to say i have been enjoying reading this forum for the last couple of weeks and decided to join yesterday.

I own a 2001 sp-1 in Australia, it has a full Yoshi exhaust system and a pc2.

So far i have read a lot about the bolt on bits to make it lighter and a fair bit about engine mods, but has anyone experimented with adjustable cam sprockets yet?

Also if i decide to do a ground up rebuild with say a 13mm lift cam what springs would be recommended? (HRC or HRC copies) if available.

Cheers.

[Darkest]

I cannot even begin to answer those questions for you, but welcome to the forum

[DeepCmonkey]

Love the bike....

[g-man]

Changing cam lift on a RC51 should only be done on a dedicated race motor and with a very clear understanding that if you use cast cams you will end up snapping a cam at some point. The same results are not uncommon if you raise the hard rev limit on the bike.

The best bang for your performance dollars is high compression pistons (if you are using JE keep in mind that they were originally HRC copies and require HRC heads to get to the rated compression figures), stage one cams, airbox, head/port work and finally doing everything you possible can to put the bike (and rider) on a diet. If you are going through this much, lightening the crank and rods is a must as well.

FWIW, adjustable cam sprockets are not required on the RC51 as the timing can be altered using a PowerCommander PCIIIr.

[Nemo]

Originally Posted by g-man

Changing cam lift on a RC51 should only be done on a dedicated race motor and with a very clear understanding that if you use cast cams you will end up snapping a cam at some point. The same results are not uncommon if you raise the hard rev limit on the bike.

The best bang for your performance dollars is high compression pistons (if you are using JE keep in mind that they were originally HRC copies and require HRC heads to get to the rated compression figures), stage one cams, airbox, head/port work and finally doing everything you possible can to put the bike (and rider) on a diet. If you are going through this much, lightening the crank and rods is a must as well.

FWIW, adjustable cam sprockets are not required on the RC51 as the timing can be altered using a PowerCommander PCIIIr.

I thought he was asking about cam timing,no?

[dstewart]

Originally Posted by g-man

Changing cam lift on a RC51 should only be done on a dedicated race motor and with a very clear understanding that if you use cast cams you will end up snapping a cam at some point. The same results are not uncommon if you raise the hard rev limit on the bike.

The best bang for your performance dollars is high compression pistons (if you are using JE keep in mind that they were originally HRC copies and require HRC heads to get to the rated compression figures), stage one cams, airbox, head/port work and finally doing everything you possible can to put the bike (and rider) on a diet. If you are going through this much, lightening the crank and rods is a must as well.

FWIW, adjustable cam sprockets are not required on the RC51 as the timing can be altered using a PowerCommander PCIIIr.

+1
But here are some of my notes,

Billet cams are necessary to avoid snapping.
HRC Springs are about as good as your going to get, make sure to get the HRC retainers and HRC seats as well.
13mm is as much as the HRC parts will allow and I would not expect it to do so for extended periods of time.
Careful with the cam timing and additional lift, check for piston to valve clearance.

[g-man]

Originally Posted by Nemo

I thought he was asking about cam timing,no?

True, but if you are already putting cams in the bike to change lift and/or duration the only other value degreeing the cams might have is to alter the timing of the spark in relation to valves opening and modifying the ignition timing is best handled with the PCIII.

[dstewart]

PC3r is the only device that can change the ignition timing on the RC51.

[PBMW]

Originally Posted by g-man

True, but if you are already putting cams in the bike to change lift and/or duration the only other value degreeing the cams might have is to alter the timing of the spark in relation to valves opening and modifying the ignition timing is best handled with the PCIII.

I must be completely confused.
Does the spark trigger come from Cam timming? I thought it was crank timing.

Originally Posted by dstewart

PC3r is the only device that can change the ignition timing on the RC51.

Absolutely. I have one on my RC.

[mighty max]

Which cam is the best? stage1 or 2??

Question: If i wanted to fix stage 2 cams, any parts to be changed also or redo?...etciston, gasket....????