Molnar 360 rods

It's still the better plan to sell the rods, then buy rods more optimized for a stroker. Use the Molnar 6" long 2" journal AMC rod.

Rod ratio makes very little difference, but it is a good guideline to use a rod a minimum of 2" longer than the stroke. This guideline can be broken, but you better know what you are doing. The crank counterweights may require cam machining to clear the pistons, and that is getting to be pretty radical.

Going with the more optimum stroker rod gets you much better bearing availability, easier machining, and a better piston. Not all crank grinders will widen the cheeks for .940" width, but some will. The conventional "Detroit" crank will give you a 3.85" stroke widened for the .940" journal, the rods bolt in with the correct offset, and the CH works for 1.265-1.270 and a very nice package.

One other thing to mention is a good grinder will index the throws a bit for better material thickness from the rod corner rad to the oil drilling. Not paying attention to this has ruined a few cranks. Make sure your grinder knows what he is doing.

Edit - scratch all of the above. I see you are trying to use existing pistons. You are probably going to have to back off the stroke and make everything fit. Or sell the pistons and go with something more optimum. In the long run it will probably be cheaper unless you are doing the machine work yourself.

Edited by Ken_Parkman - Dec/02/2016 at 2:05pm

Steve, you didnt have my pistons lol center of pin to bottom of piston pin pad was far, my wisecos were way smaller and would have cleared by a ton

SKeown wrote:  I realize the design of a piston can pose clearance problems. I was referring to center line of crank journal to center line of the wristpin. Another thing, the counterweight sweep can differ from crank to crank and front to rear of a given crank. I do recall you got a bum set of pistons along the way.  SKeown

Yes, i did get a nice but wrong set of pistons from Lunati. You assured me about the valve reliefs re-cut to 18 degree is not a problem. I originally planned the this 360 stroker with 6"  rods and a de-stroked 401 crank cut back to a 390 stroke but having the 360 molnar rods got me to thinking about this new plan. If this plan doesn't work i will use the molnars in the current 360 build. Right now i have to swap out the water pump on my 73 J4500, seems the 73 360 had a one year only pump design and i put on one of my stashed away pumps from a '75' car, had the wrong casting.   Any way i'll go back to mock up the stroker parts after the water pump.

So are you doing a 360 or 401? I have a set of Carillo rods, that are AMC specific 360 rods. They've been sitting for awhile when I was going ot get my 360 build going. They've been magnafluxed as well as shot peened. There sitting in motor oil right now, so no rust can attack them. Would be willing to sell them.