I finished polishing the connecting rods for my 1965 GT with a 289. I was just wondering if any of you experts could tell me if they are done well enough.
P.S. Does anyone have some plans to build a connecting rod balancing tool?
What exactly is the reason for polishing the beams on those rods?
Do you plan to run the engine at sustained speeds of 7000RPM for hours?
As far as I am aware, about the only benefit of removing the casting flash from the rods is to eliminate stress risers, and polishing the beams is only useful if you're trying to extract every last "nth" of power out of an engine; you really wouldn't see any increase in power by doing this until you reached the far upper limits of the RPM band, and even then, only minimal gains.
Considering these rods are the weaker, standard rods, it's unlikely that if you went to that RPM level they would live that long anyway . . . so, I'm just curious as to why you decided to go through the work you did . . .
By the way, I'm not aware of any plans to build your own do-it-yourself connecting rod balancer . . .
nice job polishing the rods, now take them out and have them shot peened to increase the strength further. stonecold, polishing the rods is a good idea even on a street engine, though not required. anything you can do to eliminate stress risers is good.
as for balancing, you dont need a fancy tool for that, just some common sense. you need a way to weight the big ends, and the small ends, as well as the whole rod. a small digital scale that measures weight in grams will do nicely. you also need something to support the end you are not weighing so you can get an accurate end weight. start with weighing each rod and find the lightest one, that will be your standard. then weigh each big end, then each small end, again the lightest one will be the standard. normally the lightest rod will also be lightest at both ends, but there are the occasional exception. then grind the weight pads at each end of the rod until each rod weighs the same plus or minus 5 grams or less, meaning all big ends, all small ends, and total rod weight, as the rest of the rods. now you have a balanced set of rods. pistons are even easier to balance. weight each one and make them all the same weight by taking a small amount of material from the bottom of the pin boss.
once you have done this, you need to take the rods, pistons, a bearing shell, a ring set, the balancer and flywheel/flexplate you are going to use and have the crank balanced. remember that you changed the weight of the rods and pistons, so the balance of the crank is going to be off a bit.
Ford stock rods are pretty damn strong. Stronger than the blocks. But fwiw when you sling a rod, 90% or more of the time it's the rods bolt breaking, not the rod
just upgrading from the stock rod bolts to the arps are fine for a healthy street engine. if you were going racing, i would suggest upgrading to 11/32 rod bolts, but no larger with stock rods as there is not enough meat to allow for 3/8 bolts.