rayaapp2 Posted June 8, 2011 Share Posted June 8, 2011 S12, S-36, S82, S89R, and S49X. I find myself digging through wrecking yards for good rockers. I never find complete sets in good shape. So I take whats good and leave the rest. So now I have several sets worth of rockers, but no matches. Ive listed the casting codes from the ones I have. Why did Nissan make so many different ones. Im guessing that for the most part these codes are for weighting and pad height. I see a few where the rocker is actually a few mm longer like the valves or pivot point were moved in the head. Anyone have any better ideas of what these casting codes were for? Hopefully that will lead me on the hunt for the an optimal set or at least figuring out which ones to use where. Thanks Quote Link to comment Share on other sites More sharing options...
SKiddell Posted June 9, 2011 Share Posted June 9, 2011 (edited) Same here really I have not been able to find rhyme or reason behind the alpha numeric codes and have noticed significant differences not just at the main bearer pad but on the under side webbing (to the point of fouling on the spring retainer in the worse cases) and the offset at the lash pad end skewing the wipe pattern (on the cam lobe not the rocker pad) left or right by up to several mm. I have matched up a number of "codes" but they still seem to have these differences therefore the codes must mean someting else (batch, date, time ??) Alan (T) if your around, or any one else do you have any insight as to this coding, any info would be greatly appreciated. Edited June 9, 2011 by SKiddell Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted June 9, 2011 Share Posted June 9, 2011 I've got two full sets getting refaced at Delta. Another 11 are in the garage and a 'new' complete set on the way to the house. There is a slew of different markings. When I've got them all together I'll try to determine if there is any rhyme or reason. I suspect that several OEM suppliers were producing these rockers which would account for the random markings. Several people have mentioned the various offsets on this and other forums. It could be nothing more than poor molds. It may also have been done for specific engine (auto/industrial) that required the offset due to valvetrain design. With a wide cam lobe and pad the offset may not have been considered a critcal issue for Z production runs. That said, it seems reasonable to assume 0 offset would eliminate side loads reducing friction and wear in a performance oriented engine build if you've got enough rockers to build a matched set. Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 11, 2011 Share Posted June 11, 2011 Serious racers have known of these variances for decades. "Production Tolerance" is what it's called. Casting numbers identify assembly components as a last resort in field failure investigations. Before anybody mixes and matches rockers...MEASURE EVERYTHING. Do this, and you will find some very interesting variances which can affect the performance of the engine cylinder-to-cylinder. There is a reason some people degree each cam/rocker/valve assembly one time before going on to the next stage of assembly. Quote Link to comment Share on other sites More sharing options...
SKiddell Posted June 13, 2011 Share Posted June 13, 2011 Agreed Tony however like a lot of things there is little (useful) written about it so one has to discover it all over again. Before anybody mixes and matches rockers...MEASURE EVERYTHING. Do this' date=' and you will find some very interesting variances which can affect the performance of the engine cylinder-to-cylinder. There is a reason some people degree each cam/rocker/valve assembly one time before going on to the next stage of assembly. [/quote'] As an engneer its normal practice for me to work in "blue print" mode (much to the annoyance of others) and as such the variances are quantified however I can see your point, there will always be those that open the lid and throw it all in hoping for the best. My particular interest was in the rocker casting numbers Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted June 13, 2011 Author Share Posted June 13, 2011 Some of them dont fit my L series vary well at all. They do not sit correctly on the lash pads or at least anywhere near correctly. There are many small differences though. Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 14, 2011 Share Posted June 14, 2011 To distill it for those who may have missed it the first time around: "Casting numbers identify assembly components/sourcing as a last resort in field failure investigations." Quote Link to comment Share on other sites More sharing options...
datsun79z Posted June 14, 2011 Share Posted June 14, 2011 Brian Kostraba in Bend Oregon is now suppling us with brand new rockers. Compared to originals they represent a weight savings of approximately 20%. I believe they are balanced as well. I hope this helps you. Mike H Quote Link to comment Share on other sites More sharing options...
z240 Posted June 14, 2011 Share Posted June 14, 2011 Datsun79, some additional contact info for Brian would be much appreciated! I ran across his stuff the other day by accident, and it seems he is a source for custom lash pads as well. Can't for the life of me remember where I found him! Details, handle, something! please! Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 14, 2011 Share Posted June 14, 2011 Free time, curiosity and Google - http://www.hammondsplains.com/z/zworld/zenthusiasts/index.htm Contact at bottom but can't tell if it works. Quote Link to comment Share on other sites More sharing options...
datsun79z Posted June 14, 2011 Share Posted June 14, 2011 Brian Kostraba can be contacted on this forum. He goes by the name of Zcarbum. Brian handles an assortment of parts for Z cars. He is a pleasure to do business with. I hope this helps out. Mike H Quote Link to comment Share on other sites More sharing options...
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