661 Stroker

[Jimmy in NC]

What is the bearing size in a 661?

My smart ass wants to answer "round and big enough" but this thread is interesting and legitimate problem solving is occurring. Press on fellas.

 

[Mastermind]

What is the bearing size in a 661?

12x17x13

 

[srcarr52]

12x17x13

You may not need spacers if the 661 is designed to be constrained by the lower end bearing (more thrust clearance at the piston than on the crank journal, rod can go to the extremes without contacting the crank throws).

I would use the 394 bearing which is the correct size to stay centered in the 394 piston. The needles will hang a little out the edge of the rod. If the rod needs to be constrained up top, just make thrust wasters to go around the pin bearing and keep the rod centered. Use some brass, bore your ID and finish the OD, cut to correct thickness with a parting tool.

 

[Mastermind]

You may not need spacers if the 661 is designed to be constrained by the lower end bearing (more thrust clearance at the piston than on the crank journal, rod can go to the extremes without contacting the crank throws).

I would use the 394 bearing which is the correct size to stay centered in the 394 piston. The needles will hang a little out the edge of the rod. If the rod needs to be constrained up top, just make thrust wasters to go around the pin bearing and keep the rod centered. Use some brass, bore your ID and finish the OD, cut to correct thickness with a parting tool.

I can do that.

 

[srcarr52]

I can do that.

 

[Mastermind]

@Redfin

Should I start another thread, or is it ok to talk about other piston options here?

 

[Redfin]

Im good yappin here.

 

[Redfin]

BDC. Crown is just a touch below ex floor and primary trans.

 

[Mastermind]

Im good yappin here.

Cool. This is a nice project. May as well keep it together.

 

[Mastermind]

BDC. Crown is just a touch below ex floor and primary trans.View attachment 173517

You have plenty of skirt length to lower that floor too. So.....not a real issue.

 

[Redfin]

You may not need spacers if the 661 is designed to be constrained by the lower end bearing (more thrust clearance at the piston than on the crank journal, rod can go to the extremes without contacting the crank throws).

I would use the 394 bearing which is the correct size to stay centered in the 394 piston. The needles will hang a little out the edge of the rod. If the rod needs to be constrained up top, just make thrust wasters to go around the pin bearing and keep the rod centered. Use some brass, bore your ID and finish the OD, cut to correct thickness with a parting tool.

Big end is .072” pin end is .064”

 

[srcarr52]

Big end is .072” pin end is .064”

Going to need some washers then to keep the rod corralled.

 

[Redfin]

They'll need to get ground on so a pocket of exhaust isn't left on the top of the piston.

Can you explain this for me Shaun? Ive been rackin this around since you posted and I would think the scavenge would not leave anything sufficient on top the crown to be concerned with?

 

[srcarr52]

Can you explain this for me Shaun? Ive been rackin this around since you posted and I would think the scavenge would not leave anything sufficient on top the crown to be concerned with?

It would be fine till BDC and then there would be an open void that would be getting sucked into the stream above it, that air filling the void will be from the exhaust side of the cylinder which may still have exhaust.

 

[Redfin]

10-4

 

[srcarr52]

10-4

Did that really make sense? I’ve been drinking.

 

[Mastermind]

Did that really make sense? I’ve been drinking.

I always understand myself better when I've been drinking.

 

[Deets066]

Did that really make sense? I’ve been drinking.

I just started, I’ll let you know after a bit

 

[Hinerman]

Did that really make sense? I’ve been drinking.

No, try again when you've had a few more...

 

[Dub11]

I always understand myself better when I've been drinking.

But you don't drink..........