Forum

[papasmurf]

I was commenting about "normal" forged steel con-rods. I used a titanium alloy con-rod many years ago in a 250cc two stroke, but that cost an arm and a leg even back then.
I had no idea Enfield's had aluminium con rods, that seems like a recipe for disaster to me.

[Lennie]

Exactly my point at the beginning Papasmurf when I talked about fitting a Steel rod in place of the Alloy one.. and a roller big end while you are in there...

[Presto]

Just for the fun of it (!), you can get an idea of progressive fatigue damage in the case of a con-rod, with a given stroke. Say (in theory) a rod is designed to tolerate no more than 575 engine cycles at 11,000 rpm. The same con rod will be able equally well to tolerate a million cycles at 10,500 rpm, 30 million cycles at 10,000, and virtually infinite cycles at 9,500 rpm. On the other hand, just 200 cycles at 11,000 rpm may weaken the rod to such an extent that it’s life-expectancy will only be around another million cycles at 9,500 rpm (NOTE: at 9,500 rpm one million cycles will be completed by the engine in one hour forty-five minutes).

[Uganda Dave]

Don't think just because the rod is ally its bad, more likely because of wrong material type or poor quality production. They use ally rods in Top Fuel engines all the time, OK they let go every now and again, but its not normally the rod.

Looks like I have stired up some pretty interesting debate though, its interesting reading. Still don't know which model to go for though lol

[mauri]

Uganda Dave, finding unbiased information on enfield’s is like going to the library only to find that its filled to the roof with works of fiction.



yet you’ll have a hard time finding even a couple of pages of unbiased fact’s.



on a more serious note, a normally maintained 350 will out last a badly maintained 500.

and vice versa, its in the hands of the person maintaining it or abusing it.