mikie Posted June 17, 2003 Posted June 17, 2003 Looking at the MG Cycle website, it looks like you can buy this kit (4 bearings and 8 washers) for about $30 instead of the $120 that the dealer quoted me, unless I'm missing something he said. No one here has tried this yet, eh?
al_roethlisberger Posted June 17, 2003 Posted June 17, 2003 Do you have the link to their "roller rocker" kit? I looked around but didn't see it on the website. al
jrt Posted June 18, 2003 Posted June 18, 2003 I saw a shim and bearing set to replace the spring, but not a bearing-supported rocker assembly. If I missed that, I'd be interested in where it is. I'll probably buy the shim/bearing replacement for the spring anyhow. Looks cool. Anyhoo, I have a couple extra rocker assemblies. I'm going to send one to my father-in-law and see if he can make one (uh, four) like the MGCycle pic. We'll see. Cheers, Jason
al_roethlisberger Posted June 18, 2003 Posted June 18, 2003 ...ah, but the photo posted shows a "roller rocker"... does MG-Cycle offer that as well? I couldn't find the photo that was posted on the MG-Cycle site. al
callison Posted June 18, 2003 Author Posted June 18, 2003 That's because they're under the section for the race bike. They are not available from MG Cycle and according to that page, they're loaners. I don't know where they originated from, but I bet Mike Rich would know. I think I've seen them somewhere as well, but I'll be danged if I can remember where.
al_roethlisberger Posted June 18, 2003 Posted June 18, 2003 ahh, then what exactly are we talking about in the photo then? al
Guest jeremy Posted June 18, 2003 Posted June 18, 2003 methinks they may be a Dr. John/Race Co. item. just my 2 cents
jrt Posted June 19, 2003 Posted June 19, 2003 Al, The lateral thust bearings (stock is just a spring and some washers) and bearings on the rocker spindle are ones that should be (relatively) easy to fit. The roller bearing on the rocker tip...now that would require some effort. Sorry to confuse ya'll- I snagged the photos here: http://www.mgcycle.com/racing.htm The other thing that I've seen recently is a windage tray (on that page and on guzzitech). Maybe that would be a solution to the oil pick-up under acceleration thread? Cheers, Jason
roberto Posted June 20, 2003 Posted June 20, 2003 Just a thought. Are the small US tappet clearances contributing to valve seat wear? BTW, my '88 Le Mans is only just starting to show signs of valve stem oil seal wear after over 120,000 miles (bit of blue smoke on startup). Have the valve/head materials changed significantly since then? Roberto.
Guest Jeff Kelland Posted June 20, 2003 Posted June 20, 2003 In response to jrt saying that roller tips won't help guide wear, I have to disagree. By removing the drag of the rocker arm tip across the top of the valve stem, side loading of the valve stem in the guide is eliminated resulting in less wear. Less frictiion at the tip and less friction in the guide = more hp too.
jrt Posted June 21, 2003 Posted June 21, 2003 I think you're right, Jeff. I thought about that after I submitted the post. But it can't be a whole lot- I was dinking around with my eldo this morning and the rockers come down reasonably straight. Jason
Guest Jeff Kelland Posted June 21, 2003 Posted June 21, 2003 I don't think there's a lot to be gained either, however the tech paper that I read (a long time ago) used a chevrolet 327 as an example, they measured the torque required to rotate the engine with the spark plugs removed. They did this with stock rockers and then with roller rockers, if my aging memory serves, I believe the differance was almost 12 lbsft of torque. Now thats 16 valves and we have only 4 but the rough math would indicate a gain of 3 lbsft for us. Not a lot in terms of performance but pretty significant in terms of wear condsidering where that friction loss is being gained. Time will tell if you guys start running this stuff. Jeff
jrt Posted June 22, 2003 Posted June 22, 2003 That's interesting- thanks for the info. There's a couple of books I need to read- I want to learn more about engine modifications and I want to learn more about suspension. As it stands, I know just enough to be dangerous. Like many, I picked up most of my skills and information from my dad (grew up on a farm) and young friends (we liked bikes/cars). We weren't rich, so it was always 'how can we make this thing go?' not 'how can we make it go correctly?' Makes me wonder how many bad habits I've picked up. Cheers, Jason
callison Posted June 28, 2003 Author Posted June 28, 2003 I talked to Mike Rich about those roller tipped rocker arms. They were a "weld up", not a production type of item and two of them failed in use with the expected disastrous results. There are no roller tipped rockers currently available for our bikes. Needle bearing rocker arms are available somewhere, although I don't know where at the moment and haven't looked for them.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now