I need to replace the rear camshaft bushing in my block and was advised to NOT order the current bushings as supplied from vendors, as they are made of brass. I ordered a triple gear bushing instead, with the intention of machining a replacement from it. When I opened the package the bushing sure looked like brass to me, so I called the vendor and they tell me it's made of "z bronze".
Now, I'm familiar with most steels and alloys but I have to admit that this is a new one to me. A quick internet search turns up information on bronze plaques made of this material. It also says it "looks and feels" like real bronze...not too promising.
Exactly what is this stuff and will it make a decent bearing?
Z bronze is bearing bronze. They probably mean C932, it's the right stuff for the application.
Okay, thank you Eric. I'd never heard S.A.E. 660 referred to that way.
SAE 660 is NOT "Z-Bronze". If someone sells you 660 saying it's the same as Z-Bronze, you got screwed. (or shafted)
I hope to be brief and informative...
Before there were SAE standards that allowed everyone both the recipe and the post treating processes to make the SAME STUFF at different places...
Industrial America was stuck using the local guys 'homebrew' and a promise of a tensile rating consistency for this version of 'homebrew'...or...learn how to smelt yourself in a large pot, decide on your own smelt hold time, your own smelt kill time, and your own mixture of chemicals, and add to that your own post processing and annealing process to achieve exactly what you wanted in terms of mechanical properties for the most efficient use of your own cost. Done this way, the actual chemical properties were the result rather than the innovative driving force behind the alloy.
Ford did the figure it out yourself way as an in- house developed product and refused to divulge the 'how to' when SAE was accepting standards recommendations starting in 1922 (or the SAE committee may have decided that Z-Bronze was bunk...no one really knows). Sooooo....Z Bronze stayed this mythical magical Ford alloy that still was supposedly able to defy a 'metallography' approach to what it really was...and today we no longer have the actual post process that Ford used, but we do have the chemical properties from the Ford Trade School textbooks.
One vendor from mid-USA claims he has a smelter willing mix to the Trade School chemistry, and have some sort of post process heat treat to turn this new alloy into the equivalent of Z-Bronze...
Other vendors may be using SAE-660, or SAE-62 on the parts they have made so it is always best to ask, although other than the triple pins it seems from consensus on the forum that the supplied bronzes for other places are good enough...
My mistake, I read the link too quickly. Evidently the term is for a Ford proprietary bronze, which is fine. It just surprised me that I couldn't find it on line anywhere. I'll save this new triple gear bushing for my transmission and see if I can find an old one to use for a camshaft bushing.
"Got shafted".........good one!
George, the rear cam bushing can be easily made from a used triple gear bushing. That way you know its made of good alloy. If you don't have one, give me a holler and I'll send you one. Just give me the diameter of your rear cam journal and I can machine one for you if you like. Just wondering if Rodney Flournoy might have one laying around.
Richard, you know Rodney? He lives just down the road (well highway) from me in Likely and is the major push behind all the vintage/classic cars that visit Alturas......including some very nice model T's. My wife's family, local ranchers, have been acquaintances with the Flournoys since Hector was a pup.
I just got an email from Herm regarding a used bushing, and I think he may be able to help me.
Z bronze is very close to today's naval bronze. The big difference is that Z bronze had no lead. Hence it was hard on reamers. Naval has a tiny trace of lead to improve machinability.
George, I met Rodney when I sold him an original 1917 T touring car. Check it out next time you're there.
We have been over this so many times it makes me sick. I have researched Z bronze extensively. I have at least five different formulas for Z bronze including one from Ed Francis former materials supervisor for Ford Motor Company and the Ford apprentice School Manual. All five are slightly different. We have tested original Ford bushings, both used and NOS.Their formulation vary all over the place. It was not a precise science. So why all the worry and fuss today? C92300 is the closest thing we have today to Z Bronze. C92300 has slightly less lead than Z Bronze. Otherwise it is identical. It makes no sense to try to recreate Z bronze today because which formula are you going to use and C92300 is as close as you need to be. 660 bronze is a very good bearing material highly used in the auto industry. It has slightly more lead than Z bronze but very close in formulation. It is what we use for the rear cam bushing and anyone who tells you that it is a bad choice doesn't know what they are talking about. The problem with this forum is we have too many experts who only want to find fault and criticize. They never offer a solution to a problem. They only find fault with others. We have been using 660 bronze for rear cam bushings for years. We have never had a failure or complaint in all that time. In fact I have never seen a failed rear cam bushing no matter what material it was made of. Have you? The facts are C92300 is a very good material for transmission bushings and 660 bronze is just fine for the rear cam bushing and front spindle bolt bushings. If it isn't broke, don't try to fix it!
Glenn, thank you for that input. I've used 660 bearing bronze for many things over the years and always found it suitable. So, when the statement was made that it was a bad choice I got more than a little curious. I've used it for bearings in gears, shafts, stationary engines and at least one windmill, so I couldn't understand what was so demanding of a camshaft that runs at half crank shaft speed?? On top of that, Ford evidently used cast iron which is a good bearing material as long as it's lubricated. It won't stand grit though...grit will grind it up in a hurry.
Richard, the last time I saw Rodney he was still pretty involved with Pierce Arrows and I had no idea there was a T out there. I'll have to go "reintroduce" myself and get the grand tour!
Glen, I personally have no problem using 660 bronze for rear cam bushing. My concern was initially whether it was appropriate for the planetary gears in a Perfecto. A very big difference. Likewise, I have no problem using 923 bushings for the triple gears. I've used them without problems in at least a few transmissions. I do take issue with using 660 for the top spindle bushing, however. There is a lot of thrust on the top of the flange where it rides against the top fork. I would rather use a tougher bronze, such as phosphor bronze. Now just because I disagree with you on this, doesn't warrant your referring to me as someone who is an "expert" who only wants to find fault and criticize. There is plenty of room for legitimate disagreement without resorting to name calling.
One more thing, If you are getting sick from going over this so many times, why not just keep quiet.
Hi Richard, Sorry, my comments were not directed at you. But that narrows the field. Everyone is entitled to their opinion But some here are way to critical of others opinions. The forum is a place to share our opinions in hope that it may help another member. You can take or leave an opinion. But some only make it a place to prove how smart they are with there criticism of others opinions while never offering any constructive input. To answer your question, We have been using 660 bronze to repair the Ruckstell pin holes for at least 40 years with no problems while we have seen the original cast iron totally destroyed. I think 660 bronze is an improvement over the cast iron. I also think it is quite adequate for the Spindle bushings. Just an opinion. Please no attacks.