I just realized that I posted this on the 2017 forum!
I'm building an engine and just discovered that none of my spare connecting rods are the same.
I have a mixture of connecting rods....heavy, medium and light. There are four of the heavy rods, so at least that's a "set". Is there anything really "wrong" with using them? This engine will be in a regular T, not a speedster. I'll be doing the babbiting myself and will match the rods by weight.
If you use the older rods I would use aluminum Pistons. If you use the original cast Pistons I think it would be OK too. From what I have read Ford went to lighter rods and lighter cast iron Pistons to improve performance. I think the key thing to do is to match rods and Pistons no matter which type that's used.
Don't be afraid of the early rods. They were used on almost 4 million engines. They were discontinued in 1920.
See your post on the 2017 forum.
One of my cars had mismatched rods. Actually 3 different kinds when I bought it. Later I did some work on the engine and replaced them all with the lighter rods. It seemed to run OK at least I didn't notice any unusual vibrations with the mismatched rods.
The tooling I have to Babbitt rods is only a good fit with the light rods. This is probably the reason that both Langs and Antique Engine will only accept light rods as cores.
I have always believed or suspected the other reason is the Babbitt layer was a lot thicker and each rod took twice as much Babbitt.
What is the difference between the light and heavy rods. Can anyone post a picture of the different ones I have a lot of rods and would like to identify what I have.
I took a picture of two rods , one light one heavy.
The light rod on left weighs about 365 g and is about 0.84” just before the flare on the rod.
The heavy rod on the right is 429g and 1.02” just above the flare.
I use either set as long as they are matched
Dont be affraid the heavy rods run just fine just harder to get new babbit in them