|
|
Post by phoebeisis on Oct 12, 2008 12:28:48 GMT -5
My opinion
1)Get a Megacycle cam-Webcam frequently makes 'cheaper" cams,and WB switched to WebCam-a sign that Webcam has been WalMarted into making cheaper parts.Webcams good stuff is probably just fine, but White Bros is very commercial now, and them switching cam supplier means they got it cheaper.Megacycle folks are nice to deal with also-you might actually get the owner or his wife on the phone.
2)Get the rocker arms with the hard welded followers from Megacycle-worth every penny. One of my cams ate the followers, and them ate itself- spewed shaving all over the motor/oil tank.screens etc.
3)I use the Megacycle cam with these specs- it is there second from "lowest power" cam. .5" lift-at on both I and E(stock is .39")
It has about 30 degrees more duration than stock at both I and E. Megacycle shows stock duration stock lift vs their cams duration lift.I think they measure duration at .050" or .040". You won't have to open the pockets of any aftermarket HC piston with this cam. I also used the Titanium topped aftermarket springs Megacycle sells-just as you plan to. I "think" Megacycle shows the stock cam to have about 240 degrees duration both I&E- my cam is about 270 degrees and change with the .050" lift.It works great and pulls hard (with my 90 mm 10.2/1 compression JE piston-started life as 11/1,I ground the crown to lower the compression so it wouldn't ping on 93 octane-it doesn't) from 4500 to 7000. No point in pulling hard over 7000 RPMs. A stock sized-87mm- piston would make peak power higher up with this cam-not good.
Good luck,
Charlie
PS I forget the actual Megacycle cam number, but the specs are as written.The two HP cams are strictly racing and will peak too high for a non racing motor.Racers kinda expect to break their motor from the over revving(much over 7000 RPMs for very long)- just part of the game,I guess.I know of folks who rev to over 8000 RPMS, but not for me.
PPS- I was wrong in saying WebCam replaced Megacycle as WB cam supplier. In the 70's 80's WB sold Webcams under their own-WB -label. The also sold Megacycle cams, but under Megacycles label. The hottest one had .585" lift- a monster.
In the late 80's Megacycles owner said he quit supplying WB because they were beating him up on the price too much.He couldn't make any $$ supplying WB. I interpret that to mean Webcam makes cheaper cams. Who knows who is better- I like the mom and pop touch Megacycle gives you,and I've had good luck with their cams/hardwelded rocker arms and vernier sprocket(which I didn't need but it was cool,so I bought it(I had more money than sense back then- now I have no money, tiny bit more sense -maybe)
I suspect that the Webcams are just fine; I just like Megacycle better-more choice also.
The cam I have- cam # 251-30 in late 80's-works perfectly and by seat of pants seens to peak just under 7000 RPMS with 90 mm 10.2/1 JE piston etc.It doesn't ping on 93 octane either.
I milled down( ground it down with a Sears polisher/grinder) the crown of the piston to take 11 grams off and drop the 11/1 JE to 10.2/1 so it would be less likely to ping. I didn't want a race gas only bike, or have to always use octane booster.
|
|
smoris
Junior Member
Posts: 31
|
Post by smoris on Oct 12, 2008 15:43:58 GMT -5
thanx phoebeisis. I think you have the 251-30 cam, that is the one i would like to. I am not racing my SR and i never run it over 6000-7000rpm, so i don't want those monster race cams in my engine  I have possibility to fuel up with 95 or 98 octane, so 1:11 won't be a problem I think. It seems I will have to use the hardface valverockers to, or don't I need them on a '93 SR with 55000km? greetz and thanx a lot already |
|
|
|
Post by phoebeisis on Oct 12, 2008 20:01:32 GMT -5
I think you have much better rocker arms with much harder faces. I'm not sure when the change was made, but you can pass on the hard welds-your follower is better..
The early ones-all in the USA,76-81, came with followers that had a very, very thin surface hardening (maybe a plating, but maybe just some surface treatment).Later Yamaha 500s got much better ones.We also got the earlier-inferior- oiling system. There were a couple of significant changes to the top end oiling that will make your cam/followers last longer. The top end oiling changes are more than the oil line rerouting that we do here in the USA- more,and better. There is some trickery that was done to the rocker arm spindles. I forget the specifics- but -later models,certainly your 1993, are better oiled with better rockerarms.
Luck,
Charlie
|
|
sven
Full Member
Posts: 166
|
Post by sven on Oct 13, 2008 11:45:36 GMT -5
The new Yamaha rocker arms (from '84 on) work very(!) well on the
megacycle cams, if and only if the cam will not run over the edge
of the rockers' sliding face.
Check this out with prussian blue or so before ruining your valvetrain.
Kind regards
Sven
|
|
rei97
New Member
Posts: 16
|
Post by rei97 on Oct 15, 2008 2:33:57 GMT -5
Hi, even the old crome-plated rockers work, if the cam is high polished and assembled with grease before. Otherwise the rough nitrit-needles or the lack of oil in the beginning will eat the rockers. btw: Do you use this? galerie.sr500.de/albums/userpics/10081/normal_NW-Rad.jpgRegards Rei97 |
|
smoris
Junior Member
Posts: 31
|
Post by smoris on Oct 15, 2008 10:01:18 GMT -5
Hi, even the old crome-plated rockers work, if the cam is high polished and assembled with grease before. Otherwise the rough nitrit-needles or the lack of oil in the beginning will eat the rockers. btw: Do you use this? galerie.sr500.de/albums/userpics/10081/normal_NW-Rad.jpgRegards Rei97 no I don't have that, do i need it to install the cam? or is the stock cam sprocket ok? |
|
|
|
Post by phoebeisis on Oct 15, 2008 15:59:32 GMT -5
Smoris- that is a vernier cam sprocket. It lets you adj your cam timing(advance/retard) for different preformance.
You don't need it; it is strictly a performance part for those going for optimal HP. If you aren't planning to dyno/adj sprocket/redyno etc you can pass on it.
You can also just grind you stock locating "hole" to open it up for adj. The made to order cam sprocket is a much better idea than that. Megacycle used to sell the vernier sprockets- probably still does.WB also did.
Charlie
|
|
pcnsd
Full Member
Posts: 113
|
Post by pcnsd on Oct 15, 2008 20:31:36 GMT -5
Get a Megacycle cam-Webcam frequently makes 'cheaper" cams,and WB switched to WebCam-a sign that Webcam has been WalMarted into making cheaper parts. I don't mean to be difficult, but to my knowledge WB has always used Web cams, including the cam I purchased for my TT from Tom White in 1977 when they operated out of an small industrial condo in Garden Grove, CA. That cam, a WB1/Web88a lasted a very long time before failing in 2006 of what I believe to be a oil induced fault (since oils are a touchy subject, I will try to stay away from it here). In that time it provided excellent service and a few hole shots too. The Web88a and Megacycle 25130 are substantially the same profile (and a good one too in my mind). I use Megacycles cams nowadays but primarily because they offer made from billet cams (I have learned better with old age). PC. |
|
smoris
Junior Member
Posts: 31
|
Post by smoris on Oct 16, 2008 1:34:15 GMT -5
I am surely going to buy MC because they offer cams from billet, and I don't want to tear down my engine, take out the cam, send it to the US and wait for the new one to come back So the 251-30 will it be |
|
|
|
Post by phoebeisis on Oct 16, 2008 7:54:42 GMT -5
pcnsd- might be right, my mermory could be tricking me. I bought a WB-2 from them in 1980-mail order.It also failed-but it probably failed secondary to the follower failing.
I "think(pretty sure) I remember that Megacycle also supplied cams to WB in . I'm pretty sure that the owner of Megacycle said he had to quit supplying WB because they just wanted them "too cheap".This conversation happened-on the phone- about 1990.
I'm sure about the conversation-but memory is tricky. Maybe he said he tried to supply WB, but they wanted to cut his profit to fine- not my memory of it, but....
It was a long time ago, but.
I'm about 100% sure that MC also supplied WB with cams-and the Vernier sprockets maybe??
I should have been more clear-that Web Cam was always a supplier, but MC was dropped because of cost.
Thanks-sorry for the error.
Charlie
PS-I will track down a WBros brochure I have somewhere( it is from 1980) to see if they show both suppliers. Thanks for the heads up. But you apparently kinda agree-Megacycle makes "better quality" cams that Webcams? You are almost certainly correct-WBros didn't switch-they dropped Megacycle but kept WebCam-a cheaper supplier.
|
|
|
|
Post by solo2racr on Oct 16, 2008 10:31:47 GMT -5
I use Megacycles cams nowadays but primarily because they offer made from billet cams (I have learned better with old age). PC. Hi there, Nope unfortunately what they refer to as "billet" cams in the particular case of the sr / xt camshaft is just new Yamaha cams that they charge you in case you can not supply them with a core. :-( kind regards Christian I thought they were ground on new billet too. There website says "Hardface on our billet" or "Hardface on your core". I'll try to remember to call them later today and get the straight poop. |
|
sven
Full Member
Posts: 166
|
Post by sven on Oct 16, 2008 10:44:59 GMT -5
... I don't want to tear down my engine, take out the cam, send it to the US and wait for the new one to come back Ever thought of buying a used cam in ebay? |
|
|
|
Post by hudriwudri on Oct 16, 2008 18:45:28 GMT -5
god in heaven  there is a lot of mystery stories goin on in this fred. Here are a few notices form memory i might be wrong but really dont think so. 1. megacycle sells new oem cams as billets that they will weld onto several reasons tell me that that is more than surely the case. 1.1. steelbilletcams would not wear right on the rockerpads especially if hardfaced 1.2. in order to correctly apply the hardfacing material you need basically some sort of cast cam surface 1.3. What for, using a billet cam if it is more pricey less durable and less easy to handle than hard surfacing especially considering the fact that the cams surface has excellent wearing characteristics with the rocker superior to steel billets(to my knowledge only yoshimura gets original cam blanks). 1.4. They offer of course pure billet cams but to my knowledge "only" to apllications where there are no blanks available anymore (G50, etc. or some other more or less exotic rare stuff) or where hardfacing might be of materialquestions not advicable. 1.5. Of course "billet" sounds better than "new oem blank" no??? ;D 2. One of the Web cam profile is as mentioned (pcnsd)really very similar to the mc 130 profile 3. i would not believe that web cam would buy camshafts from megacycle. if so what would be the cause they have excellent camgrinding equipment themselfs? 4. On needs as a matter of fact very well a adjustable camsprocket since if there was only a small adjustment error in clamping the cam to the camgrinder the whole cam gets in complete manner either retarded or advanced with the usual not wanted results. 5. I think there might be a slight misunderstanding of WB vs. WB. meaning Web cams versus White bros. as white bros as a motorcycling goods merchandiser basically had for quite a while Web cams supply them with cams for the SR/XT/TT range. But nevertheless Web cam should be not affiliated with them and their whichever way sort of quality. Especially considering the fact that to my knowledge their cams are of equally high quality as the megacycle cams, or any other good hard surfaced camshaft. 6. Fact is thoug that some of the megacycle profiles are quite more intriguing than the Webcam profiles. that is though matter of perhaps a different thread, since this might get for sure off topic. 7. I have a problem seeing any quality or race proven difference between megacylce and web cam besides a slight price difference. considering the fact both of them use highly possible the same surfacing material and both companies have good profiles i would not see a hint regarding less quality because of being cheaper?? 8. agreeing with scm why not buying a used scraped (since the weld onto it anyways) cams of ebay and sending that in thus avoiding the delay. kind regards. Christian |
|
|
|
Post by caferacercarl on Oct 19, 2008 1:27:12 GMT -5
A good engine reconditioning shop usually can weld/reprofile rocker arms, or send them by post to Waggott cams, 61 2 6628 3795 they are cheap and good, or, buy the genuine Yammy ones post 1985, they also have heaps of hardweld cam options for these engines, [ about 9], if you keep the lift at valve under 550 thou and under around 308 degrees totall duration and a split lobe centre of at least 4 degrees you shouldn't have piston to valve clearance issues on the overlap. [ most of these "old hat" cams are 108 /108 and 500 thou, 300 degrees and then just leave everyhting the same but just jack up the lift a bit/ duration/ therefore overlap, old small block chev stuff.
|
|
|
|
Post by oldygoldie25 on Feb 15, 2024 13:56:12 GMT -5
Hi yall,
I bought a Yoshimura cam. ST-1. Still working on my project. Engine has Wiseco piston, head porting, 3 angle valve job. R&D spring kit (Titanium retainers), bronze valve guides, Keihn FCR 40mm. Megacycle venier timing sprocket. My question has anybody ever installed a Yoshi cam?
|
|
I have possibility to fuel up with 95 or 98 octane, so 1:11 won't be a problem I think.
