SuzukiSavage.com /cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Resurfacing the rocker arms /cgi-bin/YaBB.pl?num=1247078069 Message started by Oldfeller on 07/08/09 at 11:34:24

Title: Resurfacing the rocker arms Post by Oldfeller on 07/08/09 at 11:34:24 This is something I need to do, so that is why I am starting the brain picking session.   New rocker arms are expensive and the new ones will abrade just like the originals did.  We live in a ZDDP depleted world right now and that is not going to change any time soon.  So perhaps one of our solutions is to try a different material out on the tappet end of the rocker arms. To discuss this intelligently, we are going to need some welding experts (hopefully somebody with a hardness tester that they can get access to). I see that the cam lobes are fairly well understood by Lancer, so Lancer -- how hard are the cam lobes?  If you don't know off the top of your head, I bet your regrinding house does know and could answer that question next time you talk to them.   We need to have our tappet resurfacing method come out at least a few points softer than the cam lobes or we will be biting a cam lobe wear out issue in exchange for the rocker arm wear out issue. Next, resurfacing method to use.  We can weld up the tips with a hard surfacing rod (carefully picked of course) or we can grind off a flat and then gas braise on a little square of a better contact material. Both ideas have downsides -- I will let the experts discuss which is better because I am not a welding expert. ================ Lastly, at the end of the discussion we will hopefully have us a recovery method for our rocker arms that will yeild something with somewhat better durability than the stock rocker arms.

Title: Re: Resurfacing the rocker arms Post by verslagen1 on 07/08/09 at 11:58:22 Hard material wear better because in the process of hardening, the molecules are packed tighter together.  So instead of rubbing 2 sheets of sand paper together, you are rubbing 2 sheets of glass.  But if you have the proper lube, even sandpaper will glide on each other. In your case, we have lubrication failure.  And I think the materials for the cam and rocker are the same.  Many metals when rubbed together dry will gall.  But add lube and you're fine.  there are many treatments that will give the base metals a slicker surface in the absence of oil. If I were looking for additionall life of the cam and rockers, I would be looking at roller lifters.  If all I wanted was a little more insurance against oil failure, I'd be looking at a surface treatment.

Title: Re: Resurfacing the rocker arms Post by SV og LS on 07/08/09 at 12:39:04 647760617E7375777C23120 wrote: If I were looking for additionall life of the cam and rockers, I would be looking at roller lifters.  If all I wanted was a little more insurance against oil failure, I'd be looking at a surface treatment. I've heard nitriding works very well. Around here reground cams are usually nitrided which they say is a quickish and cheapish process.

Title: Re: Resurfacing the rocker arms Post by srinath on 07/08/09 at 13:37:59 Cams and rockers are hardened. Dunno to what rockwell on either ... but RC45 on the cams and RC30 on the lifters is what one VW mechanic used that I knew of. Cool. Srinath.

Title: Re: Resurfacing the rocker arms Post by Ed L. on 07/08/09 at 16:45:19 Heating the tips of the rocker arms and quenching them in oil will increase the carbon content of the wear surfaces on the arms. It would need to be done five or six times to get the carbon into the metal. Even then a penitration of only 1-2 millimeters would be achieved. After that a final heating to red with a oil quench will harden the metal. Placing it in a oven at 450-500 degrees for two or three hours toughens the metal and reduces brittleness. Don't know if this would work on the rocker arms, a lot depends on the type of steel they are made out of. Even if the tips are built up with welds some type of heat treatment would be needed to relieve the stress from the welding.

Title: Re: Resurfacing the rocker arms Post by LANCER on 07/08/09 at 18:45:00 05262E2C2F26262F384A0 wrote: This is something I need to do, so that is why I am starting the brain picking session.   New rocker arms are expensive and the new ones will abrade just like the originals did.  We live in a ZDDP depleted world right now and that is not going to change any time soon.  So perhaps one of our solutions is to try a different material out on the tappet end of the rocker arms. To discuss this intelligently, we are going to need some welding experts (hopefully somebody with a hardness tester that they can get access to). I see that the cam lobes are fairly well understood by Lancer, so Lancer -- how hard are the cam lobes?  If you don't know off the top of your head, I bet your regrinding house does know and could answer that question next time you talk to them.   We need to have our tappet resurfacing method come out at least a few points softer than the cam lobes or we will be biting a cam lobe wear out issue in exchange for the rocker arm wear out issue. Next, resurfacing method to use.  We can weld up the tips with a hard surfacing rod (carefully picked of course) or we can grind off a flat and then gas braise on a little square of a better contact material. Both ideas have downsides -- I will let the experts discuss which is better because I am not a welding expert. ================ Lastly, at the end of the discussion we will hopefully have us a recovery method for our rocker arms that will yeild something with somewhat better durability than the stock rocker arms. I will try to get some info tomorrow

Title: Re: Resurfacing the rocker arms Post by PTRider on 07/08/09 at 20:04:47 Ron Ayers has the rocker arms for $41. How much of a problem is excess wear of the cam contact surface of the rocker arms?  Are we sure that the entire oil system is in good working order supplying the correct flow of oil to the cam area?  Is the oil viscosity suited to the actual temperatures encountered?  How many miles are the rocker arms good for?  What oil is being used?...diesel engine oil or motorcycle oil, or automobile engine oil?  Automobile 10W-40 is crap oil.

Title: Re: Resurfacing the rocker arms Post by verslagen1 on 07/08/09 at 20:46:21 If repairing is what you want to do, then I'd get some loaners to compare dim's. Nitriding is the process I was trying to remember.  That's good chit.  Slicker than goose chit.  Get that crap on there and you can run it dry again. Concidering the effort, I'd get new.  maybe nitride 'em too.

Title: Re: Resurfacing the rocker arms Post by Oldfeller on 07/08/09 at 20:57:13 PTRider, we have two scenarios that we deal with as a list.   First is catastophic oil pressure failure which we like to do by simply running out of oil (extremely low oil level) and by pumping some froth instead of oil (very low oil level) and causing the oil pump not to work at all by misassembling the flange gear on the back of the clutch basket. All of these things are operator errors and certainly are our fault. Second, and much more gradual but also happening to all of us is a lack of ZDDP in modern car type oils which causes many of us to begin the gaulling process on the softer rocker arm material.   Once started, it progresses along slowly until we do a top end tear down and set ourselves up for a $90-100 set of replacement rocker arms.   This happens more frequently than you would think .... These new replacement arms will do the same thing again, BTW -- which is why I am looking for better/stronger build up material. So far we have our rocker arms being slightly softer than a pocket knife blade (you can score the rocker arms with the point of the pocket knife).  This falls in line with an RC30 rating as mentioned above.   It is also a deep blue/purple draw color on an oil quenched open flame anneal (for those who heat treat and draw their own steel). We have ad hock VW info that cams are case hardened to RC 45.  Lancer will get us some additional information. If we can find some welding rod that comes in at RC35-40 that would be a very nice resurfacing rod to use on these worn items.

Title: Re: Resurfacing the rocker arms Post by PTRider on 07/08/09 at 22:48:40 By the way, the 20W-50 oil I use has 0.1519% zinc, "Extra zinc anti-wear additives to protect flat-tappet cams from excessive wear," and is labeled, "recommended for use in all 4-cycle air-cooled or water-cooled motorcycle and ATV engines. Supreme 7000 Synthetic Racing Oil SAE 20W-50 can also used in those motorcycles that have a common sump for the engine and transmission." http://www.schaefferoil.com/datapdf/705.pdf This company's syn-blend 15W-40 and full syn 5W-40 have been in my Volvo turbo engine for probably 150k now (175k on the engine), and with the camshaft and a couple of rocker arms visible in the oil fill (no rollers, just rocker arms on the cams) there is no visible wear, just a shiny area on the cam lobes.  The engine runs smooth and peppy.  These oils don't list the zinc content on the spec sheet, but do say, "19. Exceptional Valve-Train Wear Protection," and, "Significantly Less Bearing, Ring, Piston, Cylinder and Valve-Train Wear."  This matches my experience. Case hardening the rocker arm faces might be good.  The type of case hardening depends on the composition of the steel used to make the rocker arms.  Not all steels are suitable for nitriding.

Title: Re: Resurfacing the rocker arms Post by SV og LS on 07/09/09 at 02:10:40 IF it was lack of ZDTP related problem, one of the zinc additives could help. That being said, I sold 2 bikes a while ago, one with 134000 kms and a Savage with 86000 kms, both ran with cheap mineral automotive 10W40. Neither had cam or valvetrain problems. I doubt it's a ZDTP problem as the actual zinc content hasn't changed that much as this recently linked Penrite oil company information (http://www.penriteoil.com/uk/nextpage.php?navlink=Zinc%20in%20Engine%20Oils) suggests.

Title: Re: Resurfacing the rocker arms Post by Oldfeller on 07/09/09 at 08:16:31 Surprise, your European oil standards were different than those in the US -- your article mentions this fact.    It also mentions the bad for your clutch friction modifiers that were added to replace the ZDTP action in the new auto motor oils.  It also mentions using diesel oils.  I find nothing to disagree with that is contained in this article. ======== "In effect, an engine oil that contains about 0.1% phosphorus or higher, will easily provide the required anti wear properties for older engines and in fact ones at around 0.07% will do the job very nicely.  As a rule of thumb, zinc content is about 10% higher than the phosphorus content but there are some variances occasioanally. Within these changes was the incorporation of friction modifiers.  The early ones were very active and did cause oil consumption in older engines.  These days, technology is well advanced and this no longer is the case. Now we have API SM – for the first time, the limit on phosphorus is from 0.06-0.08%.  There are industry concerns about the applicability of these oils in older engines.  However, the limit only applies to 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils (so called “ILSAC” grades, GF-4).  Any other grades are exempt from this. In the US though the same additive tends to get used all the way from 0W-20 to 20W-50 as as a result, the new low phosphorus SM/GF-4 packs find their way into older engines.  This is why many of the "beware of no zinc" papers and articles are coming from the US.

Title: Re: Resurfacing the rocker arms Post by mikestrikes on 07/09/09 at 11:35:52 WEBCAMS hard surface welds rocker arms !  ;)

Title: Re: Resurfacing the rocker arms Post by SV og LS on 07/09/09 at 12:11:33 7251595B585151584F3D0 wrote: Surprise, your European oil standards were different than those in the US -- your article mentions this fact.    It also mentions the bad for your clutch friction modifiers that were added to replace the ZDTP action in the new auto motor oils.  It also mentions using diesel oils.  I find nothing to disagree with that is contained in this article. ======== "In effect, an engine oil that contains about 0.1% phosphorus or higher, will easily provide the required anti wear properties for older engines and in fact ones at around 0.07% will do the job very nicely.  As a rule of thumb, zinc content is about 10% higher than the phosphorus content but there are some variances occasioanally. Within these changes was the incorporation of friction modifiers.  The early ones were very active and did cause oil consumption in older engines.  These days, technology is well advanced and this no longer is the case. Now we have API SM – for the first time, the limit on phosphorus is from 0.06-0.08%.  There are industry concerns about the applicability of these oils in older engines.  However, the limit only applies to 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils (so called “ILSAC” grades, GF-4).  Any other grades are exempt from this. In the US though the same additive tends to get used all the way from 0W-20 to 20W-50 as as a result, the new low phosphorus SM/GF-4 packs find their way into older engines.  This is why many of the "beware of no zinc" papers and articles are coming from the US. Savage cam problems have been there for longer than API SM oils. Mine never had a problem, other European Savage owners have had damaged camshafts using better oil than I did so it appears to be not just the oil rating. Zinc and phosphorous help but we cannot say that Savages never had cam problems until API SM and camshaft and rocker arm failures have just recently appeared.

Title: Re: Resurfacing the rocker arms Post by furious70 on 07/09/09 at 13:15:36 the zinc problem is not a myth, a lot of muscle car guys are having trouble, especially with solid cams.  I switched to valvoline's race only oil in my race car for that very reason.  That's not an appropriate oil for a wet clutch AFAIK however.

Title: Re: Resurfacing the rocker arms Post by LANCER on 07/09/09 at 15:39:46 According to Webcam, the hard surface cam lobes are at Rockwell #56-60 on the C-scale ... or C something like that...anyway, it was a C.

Title: Re: Resurfacing the rocker arms Post by PTRider on 07/09/09 at 19:08:20 2330372C2A30367275450 wrote: the zinc problem is not a myth, a lot of muscle car guys are having trouble, especially with solid cams.  I switched to valvoline's race only oil in my race car for that very reason.  That's not an appropriate oil for a wet clutch AFAIK however. Is it only on rebuilds with stiffer valve springs? ZDDP or ZDP or ZDTP (the zinc phosphate compounds) are not the only solutions, just the cheapest one.  Certain borate, antimony, and soluble molybdenum compounds do the job, especially when combined with ZDDP, but cost more. I use a 20W-50 race oil labeled for motorcycles with wet clutches (http://www.schaefferoil.com/datapdf/705.pdf). 69646B6660773732050 wrote: According to Webcam, the hard surface cam lobes are at Rockwell #56-60 on the C-scale ... or C something like that...anyway, it was a C. 56+ Rockwell C is good. http://en.wikipedia.org/wiki/Rockwell_scale

Title: Re: Resurfacing the rocker arms Post by justin_o_guy2 on 07/10/09 at 03:58:58 and soluble molybdenum Older Moto Guzzi's ( shaft drives)require this added to the rear drive. Owners buuy a container & it lasts forever. Of course, they dont change that oil every 3,000 miles, either. I wonder what amount would be good( if any) in the engine? Maybe its not okay with a wet clutch?

Title: Re: Resurfacing the rocker arms Post by Oldfeller on 07/10/09 at 06:14:06 Ok, this info from Lancer means that those with his hi lift cams (built up & reground by Webb) can use hard surface built up rocker arms with no annealing.  Those of us with stock cams will likely need to flame anneal (drawn) our built up and reground tappets to a light blue temper. Test for correct hardness would be you can just barely scratch it just a tiny tiny bit with your pocket knife's point, with about equal damage being done to your pocket knife tip. =============== Justin, Moly disulfide is a clutch killer -- leave it on the splines of your shaft drive where it belongs.  Only exception might be a tiny bit put on your cam journals to make sure they have some high pressure start up lube while the engine oil gallery fills up with oil on first start up.

Title: Re: Resurfacing the rocker arms Post by justin_o_guy2 on 07/10/09 at 06:32:22 Okay, I wont do that. So far so good with the Rotella-T 15/40.

Title: Re: Resurfacing the rocker arms Post by furious70 on 07/10/09 at 06:50:15 17100F5C0 wrote: [quote author=2330372C2A30367275450 link=1247078069/0#14 date=1247170536]the zinc problem is not a myth, a lot of muscle car guys are having trouble, especially with solid cams.  I switched to valvoline's race only oil in my race car for that very reason.  That's not an appropriate oil for a wet clutch AFAIK however. Is it only on rebuilds with stiffer valve springs? ZDDP or ZDP or ZDTP (the zinc phosphate compounds) are not the only solutions, just the cheapest one.  Certain borate, antimony, and soluble molybdenum compounds do the job, especially when combined with ZDDP, but cost more. I use a 20W-50 race oil labeled for motorcycles with wet clutches (http://www.schaefferoil.com/datapdf/705.pdf). 69646B6660773732050 wrote: According to Webcam, the hard surface cam lobes are at Rockwell #56-60 on the C-scale ... or C something like that...anyway, it was a C. 56+ Rockwell C is good. http://en.wikipedia.org/wiki/Rockwell_scale[/quote] At first it was race engines with high lift solids and the accompanying higher seat pressures, yes, but I've been reading more stories on a couple mopar boards of guys with the newer, more aggressive lobed .904 tappet hydraulics being wiped out too.  While bigger than OEM, the cams aren't 'big' really, nor are the spring setups for them.

Title: Re: Resurfacing the rocker arms Post by PTRider on 07/10/09 at 06:50:27 There are various forms of moly.  Powdered MoS2, molybdenum disulfide, does not belong in engine oil and certainly not in wet clutches.  It can work very well in grease and gear oil.  Other moly compounds work fine in engine oil and motorcycle clutches.  Molybdenum Trialkyldithiocarbamate, MoTDC, which is liquid, soluble, and invisible in oil, is one such compound; there are others--Molybdenum d(2 Ethylhexyl phosphorodithiolate), Organomolybdenum complex of organic esters, and more.

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