Briggs 17HP Twin Intek - Broken Rods

[Tinkerer200]

Alright, I am getting lost here. The original disagreement was on why we have steel and aluminum push rods in engines. I read what you posted from the service manual yes. You are right that they do have aluminum on the exhaust side of some Vanguards, possibly the ones coming from japan but that did not say anything on why different material push rods are used. Which was the original question in the first place. I can almost bet that those push rods are not the same aluminum ones that are found in other Vanguards and modern VTwins. The reason why we have steel in the exhaust side of the ones that are manufactured here are because the steel will NOT expand as much causing a change in lash. Aluminum is ok to use in the intake because the temps do not reach 1,200 plus degrees. Everyone should check the manual...always! But, it is not going to tell you why we use the different materials. If it does... show me... Please...

For many years my statement that aluminum push rods were used on valves involved in compression release was true. I also said I did not know what was done on Vanguard V twins made in the USA. You said aluminum push rods were not used on exhaust valves which was shown to be incorrect. I made NO statement as to why, you did that. There was no "Original disagreement" about "why" I made a simple statement, easy enough to understand.

Walt Conner