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Discussion Starter #1
ok, have the oppurtunity to buy some moriwaki stage 1 cams. I've never done cams on a bike before, anyone have any experiences with this and what kind of gains and/or issues that could come up? will reliability be severly degraded? is this only recommended for bikes with big bore kits or BIG engine mods? how is the powerband affected?my bike is equipped with turnone snorkel/airbox, pc III, Ethos design exhaust
, and scotts ignition coil stick conversion.

Also is there any difference between the moriwaki rear suspension linkage and the Dan Kyle ones? seem like Dan's are a lot cheaper but i have not heard of any differences between the two.

Thanks for the help guys.
 

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The Stage 1 cams have a bit more lift and duration than the OEM cams, and are milder than the Stage 2 cams.
You would see a bit more power mostly at the upper RPM range.
They should work well with aftermarket full exhaust and airbox.
Reliability should be ok since your bike will still have the OEM hard rev limit and not the higher rev limit of the HRC ECU.
I don't have the exact specs on the Moriwaki cams (lift/duration) since these cams were discontinued and are hard to find.

I have seen photos of the Moriwaki link and it matches the Kyle link, who copied the dimensions from the Moriwaki link.
The HRC link has the same dimensions as the Moriwaki link, but requires an eyelet lower shock mount vs the clevis mount the OEM and aftermarket shocks use.

From what I understand, you'll need to change out the springs, seats, and possibly the retainers to use the cams.
The springs are a different wind that allows the buckets to travel farther down the bore for the extra cam lift without binding. The seats also work with the springs in this as well.
The retainers are there for less reciprocating weight at the higher lifts and also fit the different inner and outer diameters of the inner and outer springs.

The bad news is that these HRC parts (springs, seats, retainers) have been discontinued.
I ordered my set last year just before they discontinued them.
Try contacting Rising Sun Cycle to see if they still have a set of springs, seats, and retainers.
Here are the HRC part numbers and prices from last year.

14750-NL6-000 HRC Double Valve Spring $11.10 ea. (qty 8 req'd)
14775-NL6-000 HRC Valve Spring Seat Outer $24.60 ea. (qty 8 req'd)
14776-NL6-000 HRC Valve Spring Seat Inner $32.70 ea. (qty 8 req'd)

I obtained a special set of titanium retainers so, I didn't price or order the HRC aluminum items.

If you decide not to use the cams, I may be interested in them.
 

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Discussion Starter #4
Awesome thanks for the info guys.

subsailor, i think i'm going to give them a try. i will ask the seller if he has any extra sets, or if i decide not to do it i will let you know right away. From what i've read in other threads on speedzilla is moriwaki makes some springs and im sure retainers and seats as well. question is are they available anywhere. I may contact simon percival on this as well and see if he can locate anything for me. I'm sure i will have more questions on this for you so expect to see some Pm's if thats ok. I don't know anyone else running different cams. i will keep you updated and let you know what info i pick up.

Ben, do you have pics and prices? can i find them on your site? you know i'd be happy to buy from you if they are the same.
 

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Discussion Starter #7
they are listed as SP1. Well, so far this is what i've found. According to mick hone, moriwaki distributor, the stage 1 cams use all the stock parts. The lift is the same but duration is changed. A few people on speedzilla have stated the same. i guess i could see this as being true seeing that the lift is unchanged. what do you think subsailor?
 

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I don't see why the cams would be different between SP1 and SP2, at least in fitment.
If I had to guess (and I've found this with some other items on RC51s), the fitment and catalog information wasn't updated when the items were made. So when the first RC51s rolled around the world in 1999/2000/2001 and the aftermarket started producing parts, they were for the SP1... around, say, 2002/2003 the wind was being let out of the sails and the aftermarket may have slowed production of some parts, and never updated catalogs/fitment guides, so they may still just say SP1. But that can also be a long-shot. :)

For the rear link, this link should work. If not, they are avail in silver and black, $235 plus shipping (figure $8 to $10 if going in the US).

And PM sent on something related... :)
 

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Discussion Starter #9
thanks Ben, PM sent
 

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Discussion Starter #11
Yeah, that would make sense.
 

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they are listed as SP1. Well, so far this is what i've found. According to mick hone, moriwaki distributor, the stage 1 cams use all the stock parts. The lift is the same but duration is changed. A few people on speedzilla have stated the same. i guess i could see this as being true seeing that the lift is unchanged. what do you think subsailor?
I would think that if the lift is unchanged, nothing would have to be done with the valve train.
It depends on how aggressive the cam profile is.
Even with the same lift, if the opening and closing of the cam profile is aggressive enough, it could still accelerate the valve train past the point of control by the stock valve train at high RPMs.
However, I doubt the stage 1 cams are that much more aggressive than the OEM cams are, only differing in duration.
So they should be good to install with no modifications given this information.
 

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Discussion Starter #13
ok thats what the distributor also said. Thanks for the confirmation. still waiting to see if hes got multiple sets, will let you know as soon as he gets back to me.
 

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Discussion Starter #14
ok bought the camshafts, they were his only ones. Am in contact with the distributor about more sets, he is going to contact Moriwaki direct and see what they can do for us. will keep everyone updated.
 

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Discussion Starter #16
Yeah, i'm not to worried with the Stage ones, if they were stage 2s i'd be concerned and probably wouldn't have bought them.
 

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Discussion Starter #18
ok, i don't anyone to get their hopes up. I doubt Moriwaki has any left, but i'm following up and trying to get people working on this. Maybe if there is enough interest shown Moriwaki will do something. I will keep on it and update you guys as i find out more.
 

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billet cams are best though on 130+ hp bikes FWIW stage 2 and some others broke at high RPMs
Besides the torsional flex from higher lift cams, there was some conjecture that a contributing factor was the removal of the quieting gears on the cams.
The removal allowed additional harmonics to be induced that lead to premature failure.
I have yet to see additional info to confirm/deny this, but on the surface I could possibly see where it might be true.

For such a great engine design, I have no idea why Honda when with cast cams over billet or other designs.
I can only figure that there was no reason to spend the money on an already expensive bike (back then) when the OEM cams were perfectly reliable.

Too bad that cam makers didn't offer aftermarket billet cams.
They pump out cams and valve train parts for most of the 4-stroke off-road bikes/ATVs, so I would seem easy to make sets for the RC51.
 

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Discussion Starter #20
Subsailor, wasn't there a forum member on speedzilla offering billet cams for sale awhile back?
 
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