JamieDaugherty

Is anyone running 1mm oversize valves? I've been considering doing this over the winter. I've already got a full port job so I'm looking for the next step up. I'd really like to know if the results would be worth the money.

Thanks!

Jamie Daugherty

Rollingalong

This is a old topic I know , but going with oversized intake valves is the only way you can properly port the intake bowl area due to the low spot in the port right before the intake seat .

You could build it up with epoxy I guess but I'd not do that on a street bike

RCVTR

The data I have shows 2-3 HP gain at the top end for 1mm OS intake and 0.5mm OS exhaust valves. All of the HRC valves are gone so you are looking at custom valves. Stage 1 cams add about 5 hp and more torque everywhere.

JamieDaugherty

That's not much. I think I'll just hold off for now. Thanks!

Jamie Daugherty

mikstr

[quote]Stage 1 cams add about 5 hp and more torque everywhere.

Question for RCVTR: Do you see an extra 5 hp with cams alone? Can you use the cams alone (I currently have Microns and a DJ kit) or do you also need a full exhaust or hi-comp pistons? Finally, are you referring to Moriwaki cams or is it possible to get stock cams reground to get a similar result?

Sorry for all the questions but I am trying to learn about all of this and may look at trying the cams at a later date.

cheers
Mikstr

Rollingalong

[quote="mikstr";p="20129"]Maybe i can help .

Generally these engines responded like this back in the day . All numbers RWHP .

Slip-on and jet kit -108

Larger intake valves and bowl blend - stage I Moriwaki cams - 115

Moriwaki pistons and the Moriwaki carbs - 124

Stage II Moriwaki cams - 133-136

Running too much cam and RPM broke the cranks . HRC billets are long gone but these engines set on kill made up to 160 rwhp with ram air and HRC cranks , ignition and more .

1997 Superhawk cams

intake lift .394 - exhaust .394
intake duration @ .040 lift 245 degree's - exhaust 245 degree's

Moriwaki Stage I cams

intake lift .406 - exhaust .406
intake duration @ .040 lift 255 - ex 249

Moriwaki Stage II cams

IN lift .453 EX .413
duration @ .040 IN 271 - EX 256

For comparison purposes of sorts- Suzuki SV1000S

.386 IN- EX .354

IN 234 -229 EX duration @ .040

There's still yet a couple of low cost ways to cam these engine's up to gain performance fro 3500 to redline w/o use of oversize intake valves and porting while just using slip-on's for under 1000 bucks just depending on how one wants to go about it .

mikstr

Hello RollingAlong

I would be interested (likely next year) to do a cam swap but the Mori's cost @ $1K CAN which is a bit more than I would like to pay. I am running Microns and DJ kit at present (along with a lightened flywheel). In an earlier thread you had mentioned that it was possible/feasible to just replace the intake cams (as te exhaust are already pretty "hot" apparently). I would be interested in pickng up a set of used intake cams and having them re-ground. Any suggestions?

Also, I use the bike for sport-touring so I am not into revving it to the moon (very seldom rev it over 7K)

Your input would be greatly appreciated

cheers
Mikstr

Rollingalong

Just a quick post with nothing carved in stone but one way to do it would be to use JE pistons , stock exhaust cams " retimed via slotted sprockets " and either one of their custom grinds off their master lobe sheet or their shelf grind # 125 which is .435 lift - duration 261 @ .050 which approximates 256@ .040 .

You don't have to run the JE's if the lobe design features faster ramps and a better engine might be your stock pistons with the Web 125/109 grind .

.435 - 261 duration @.050 In - aprox 256 @ .040 lift
.425 - 260 duration " " aprox 255 @ .040 lift < for comparison

250.00 for the two intakes vs 500.00 for a set . i think a set would make a better engine and again , stock pistons could be used and compression could be picked up a little when straightening the head surface . If it's a low mile bike with excellent ring seal that might be the way to go while offsetting price of the full cam set .

Todays gas is so bad it pings when cleaning parts with it these days so carefull on compression .

Intake and exhaust centerlines will make or break the power . Recommendations would come after finalizing cam choice .

It's nice when an engine is built and the volumeric efficiency is increased and the main jets become able to be backed down to around stock

mikstr

thatnks again,

I was hoping to keep the stock pistons (even though teh bike has 50,000 miles now, I had it dynoed last summer and the results were good, the operator even commented how it was a strong running VTR) and simply slip the new cams on (thereby not requiring engine removal). Again, if I could decent results with just the intakes I would gladly try that.

I want to try to avoid the high compression route for two reasons, cost beign one (new pistons), the other being having to switch to more expensive high octane fuel (good ol' 87 is just fine with me).

In the end, I am not trying to build a rocket (would be cheaper to simply buy a used R1 or such), just getting a bit more "oomph", more smiles every time I whack open the throttle.

cheers
Mikstr

Rollingalong

What year bike do you have and what year exhaust cams are you planning on picking up ?

Reason i ask is there was another cam set more commonly used that i forgot to list . It's the one that i had said was plenty big but in context to using a "set of intakes only" from Web Cam .... not on the intake side .

.400 lift IN 249 duration @ 1mm

.435 lift EX 272 duration @ 1 mm

Way too much duration on that exhaust cam to be used on the intake for the stock compression .

mikstr

My bike is a 99 VTR Firestorm (Canadian version if that matters at all). All cams are stock.

cheers
Mikstr

shayne

G'day Rollingalong.

What are you achieving by slotting the cam sprockets?

If the head or cylinder hasn't been machined, then wouldn't the standard timing marks be correct?

Is there a gain to be made by advancing or retarding? I have 10:1 compression due to custom pistons.

Scooberhawk

If you don't mind, I think I'll jump in to reply that advancing the cam timing would move the power up into the higher rpms, while retarding the cam timing would add more low end power. My guess is he'll tell you to retard the timing to make more use of that power down low, where you say you use it most.

VTaRse

Just got these done:
1mm oversized inlets, flat faced valves, they'll go in over the next week, wonder what the difference will be, if any?

scottiemann

way to bring back the dead lol...

looks good, theres various more current threads on high compression/valve work/cams then this one, this is almost 10 years old

If you want to document your engine build and various changes youve had to make and are going to make to get this running in top shape, I suggest you start your own thread.

CruxGNZ

That's tony.mon from the vtr1000.org site. He knows his way around this forum. If he posted in this thread, I assume he had a reason behind it.

scottiemann

and I'm scottiemann from superhawkforum.com circa 2007 and I know my way around this forum... just offering friendly advice.

VTR1000F

And I'm VTR1000F. This site is all about me.

scottiemann

alright enough of the not so witty banter and back on subject

VTaRse, did you have your heads shaved for higher compression? because that gasket surface looks freshly milled

mikstr

I am running a two-piece crank with tremendous success if anyone wants pointers......

CruxGNZ

I guess that came across wrong. I wasn't saying it to be snotty. Just letting you know is all. I actually just noticed he has that information right under his username haha. Oh well.

And Steve, we all know this site is about you

RoadManiac

On gixxer.com

there's HUGE discussion about the size off the intake port, the veterans still believe the bigger the more air in the engine, but newer dyno graphs on different bikes shows that small intake ports will give improvement on near stock engines, venturi effect etc. example... S1000RR but on heavy modded engines i have no idea what is best

VTaRse

Yeah, I've been watching this and other threads re the oversize valves- I bought mine a couple of years ago but have only just got them fitted.

Or that should really be I got them fitted a couple of months back, but then had a crack in the crankcase, welded it several times but ended up having to fit "new" crankcases.
Today it was running for the first time, and it feels strong.
But then for the past two months I've been riding a cb600, so the Storm WILL feel strong in comparison.

However, I've not had power lifts of the front wheel accelerating in third and fourth before....

It'll have to go on the dyno once I've got the fuelling a little better.
At the moment it's running at 9:1 most of the time..... it runs surprisingly well considering

By the way, I didn't have the heads decked at all, but the engineering shop that cut the seats in cleaned them up free of charge while they were there.