360 crank in a 318?

[68fury]

A local club member has started a bit of a debate about putting a 360 crank in a 318 due to having a good 318 motor, a good 360 crank & rods, and wants to get the most out of this on a tight budget.

We're all pretty sure we've heard of 350" 318s using the 360 crank turned down, but nobody knows what pistons were used, which rods, or what. Theres rumours of using 318 pistons with a little machined off the combustion face, using Ch**y pistons or all manner of other things we thought we heard.

Anyone know if this is feasable or just stupid talkin'

Thanks

[michaelmopar]

I know that the small main journal is the same from a 273 to a 340 and the 360 is a larger small main journal. It's a 2.5 vs a 2.81. so with some work i guess it is possible, but why i would ask the guy who did it. all the extra work to get a smaller bore and less cu.in than a stock 360. go with the 360 would be my choice or stroke the 318 the right way to a 390 then you would have something. just my input. good luck

[68fury]

well, everybody suggested just buying another 360 (he bought one but the block is damaged, but the rods, crank, etc are all good). This has progressed a little farther than "what is a good idea?" to "is this even possible?" I think he mainly wants to feel like the cash he spent on the 360 wasn't all wasted.

[Rust collector]

Yes it is possible, and I like the idea, if you put it in a truck...(or low rpm)
I don´t know the details about pistons and all the little stuff, but it has been done.
Mopar performance sell 360 stroke cranks for 273-340 engines..

[diego-ted]

I did it, used Fed. Mog pistions lc371P, had to machine the skirt so as not to hit the counter weight on the crank.
diego

[Rust collector]

How does it work?

[68fury]

Hi Diego-Ted, thanks for that, I guess those are the service replacement 318 pistons (without looking it up) and you used the 360 rods?

What with the 318 pistons sitting right down the bore at TDC anyway we thought they'd probably be about zero deck with the 360 rods/crank.

Did the motor work out OK? What kind of spec did you build it to? Sorry for all the questions but I get really into project ideas like this.

[DartGT66]

Typical 318 pistons sit about .090" below the deck at TDC. So, with a 360 stroke of 3.58 compared to the stock 3.31, so the pistons will come about 0.135" higher and the result is a positive deck height. You have to calculate what it means CR wise and check the valve to piston clearance + the skirt clearance, and adjust the CR by milling the pistons as needed and possibly clearance the chamber for the piston.

[68fury]

allowing for gasket thickness and using the 360 heads looks like it might fly without too much work?