Hard Weld Build Up? - Hard Weld Cams Rocker Pads?

[madman]

I need to find out how to build up rocker pads and also cam shaft lobes with hard facing material? I wish to enlarge the cam rocker pad area on my gs 1100 cc based engines to allow a more aggresive cam profile. I seem to run out of cam rocker wipe pad area at around .360 lift but need to run around .420 or so. Also welding up (hardwelding) cams . What do you need to watch for in terms of warping the cam from too much heat and what type of hardfacing do you udse .? Also how thick can yopu apply it? Thanx Interesting Site, I am hacking away at my flow bench. Thanx Mike

[larrycavan]

I would call the following people and see if they'll share anything with you.

Web Cams [nice people]

Bob Carpenter [he's built hundreds of Suzukis]

Sid Pogue [Pogue Machine in Oklahoma City ]

[49-1183904562]

Madman,

I would not go down this path, if the cams are Steel then have them annealed then weld, grind and heat treat. If they are semi steel then spray weld grind and heat treat. In either case if you are worried about stability and long term effects have them cryogenically treated (this will stabilize the molecules) before hardened. You are not talking a lot in money I get Harley heads Cryo treated after welding up combustion chambers and runners for about $60 a pair. There are many places on the web that will do both of these services for the enthusiast racer.

Rick



Edited By 1960FL on 1236565979

[GordonE]

I have tried to get som info on this too. There is not much info on the net about it.
But I think that you have to first weld a buffer layer before laying the hardweld. The buffering material should be of NI base(50%->) this is used beacause its rather soft, so that the cast iron can contract without cracking. If you use a hard material, that material will not giva and a crack easily forms in the edge of the weld.
You should preheat to at least 300 Centigrades and let it cool very slowly after the weld is done. preferably 600C and 10degrees per hour... Sounds not easily doable for a diy:er...

With hardweld you can get a hardness of around 60HRC that I have read it should be.

The thicker layer you weld, the more hardeness you lose.

I have also seen some pictures of oxy welding of cams. It dosnt look easy.

Regards Gordon

[madman]

Thanx Guys. i actually have thought about making some Rockers from M300 aerospace steel. But the time involved?? I am trying a Low Buck Approach well because I am a Low Buck Man with a low buck Race Bike. I know what i could buy for loads of money but doing it myself has always been more fun for me. I want to thank everyone for there time. I am in the midsts of a few projects BUT they are almost all done. Another week and i will be finishing insulating and drywalling the walls in my new race shop and wiring it up for the new Flow Bench (still building it) and some other equipment. Thanx Mike

[don52]

If you are going to make rocker arms from scratch the cheapests way to hard face them is to have the wipping face chromed. Or you can start to spend bigger money and have a DLC "diamond like coating" done to them. It was developed for use in F1 engines and we used it on wrist pins and lifters in the IRL engines to keep the cams from scuffing and the pistons from siezing on the wrist pins. It is an amazing coating!

We used to reprofile the rockers on some OHC engines to get more lift and keep the lobe from running off the end of the pad. Something you want to avoid at all costs.

Welding, when we couldn't get blanks, worked very well if it wasnt a hollow cam. The hollow ones cracked about 50% of the time when we tried to straighten before grinding. So we pretty much quit doing them. This was on 4 cyl and v6 cams, on a short cam Like a vtwin you shouldnt have the warpage issues.

[madman]

HI DON
The Engines i play with are 4 cylinders Suzuki Motorcycle Engines. I try to keep them around 1425 cc. Also would like to get a LOT more Cam in it than currently running. I am hacking away at my Flow bench also. Just finished a new shop. LOTS of Contractor problems, Im still redoing all types of things that these craftsmen?? di for ridiculous amounts of money, Anyhow soon alls done, I oput in floor heating in my shop and i like it a LOT very nice, Thanx for youre time mike Waterloo Ontario Canada

[don52]

Ha, I am going through the same thing. We found a good deal on a building back in Sept and just got the permits to add 900 ft of office 2 weeks ago, I can't believe this city! We are in a comercial area and they don't even have 3phase power on my side of the street let alone to my building. The "city Planners" for this area should be hung! Ok I just took a deep breath.

I am not familiar with the valve train on that engine, does it use shaft rockers or are they on adjuster bosses? or bucket and shim? They are many ways to cheat them all, but for long term reilability least amount fo wiper friction, welding and keeping the base circle stock or if you have a fresh blank slightly larger will work the best. Post a picture of the valve train and I can give you some Ideas if you want.

We used to work with a great Cam guy but the Cup Crew found him and now you can hardly get him to answer the phone. The bummer is he built the business doing motorcycle cams.

[madman]

Don these engines use adjustable forked type shaft rockers. There are aftermarket heads available with under cam bucket shim setup and two valve head style but very expensive. I like to putter around myself with my engine stuff. I have a well equipped small shop and do almost all my own work, Just trying to finish a big press for taking cranks apart, I cant afford 54 grand for a bike head also I am thinking that my old bike may be a bit obsolete compared to the Busa Turbo Bikes out there. Example a guy i know 280 pounder rides a trubo Gixxer 1000 with a RC turbo setup and runs 181 mph in the quarter mile and mid eights EASY and he drives it to the track? Thanx