The Ford Barn

31 RPU · 11-02-2013, 06:34 PM

Just got a set of new aluminum pistons for my engine rebuild from Brattons. These pistons don't have a slit at all in the skirt. How much clearance do you allow in the cylinder walls for these pistons? Is it the same as the pistons with the slit? There are no dumb questions...right?

Thanks

Tom Wesenberg · 11-02-2013, 08:03 PM

Pistons with the slit can be fit a little tighter. Usually the new pistons have a clearance recommendation with them. Off hand I'd think about .0025 to .0035" would be OK, but wait for Dave or Herm to answer.

J and M Machine · 11-06-2013, 09:01 PM

Correct: on the pistons they do recommend .002-.003" as i contacted them in Taiwan and a few weeks later i received a response.

31 RPU · 11-07-2013, 05:22 AM

Ok, another question. The wrist pins can be pushed in with my thumb. It this ok? I thought they were supposed to be a tight fit?

dave in australia · 11-07-2013, 06:47 AM

Quote:

Originally Posted by 31 RPU

Ok, another question. The wrist pins can be pushed in with my thumb. It this ok? I thought they were supposed to be a tight fit?

They will need c clips at each end. A full floating gudgeon should move in and out with finger pressure.

31 RPU · 11-07-2013, 08:07 AM

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Not sure if I stated that correctly. The wrist pins slide into the piston easily. I thought they should be tight??

They have snap rings with the set. I have already fitted the connecting rod bushings to the wrist pin.

J and M Machine · 11-07-2013, 08:09 AM

You stated it correctly.
They should be easy enough to slide through but not loose enough to fall out.

11-02-2013, 06:34 PM	#1
31 RPU Senior Member Join Date: May 2010 Posts: 182	New pistons Just got a set of new aluminum pistons for my engine rebuild from Brattons. These pistons don't have a slit at all in the skirt. How much clearance do you allow in the cylinder walls for these pistons? Is it the same as the pistons with the slit? There are no dumb questions...right? Thanks

11-02-2013, 08:03 PM	#2
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: New pistons Pistons with the slit can be fit a little tighter. Usually the new pistons have a clearance recommendation with them. Off hand I'd think about .0025 to .0035" would be OK, but wait for Dave or Herm to answer.

11-06-2013, 09:01 PM	#3
J and M Machine Senior Member Join Date: Oct 2010 Location: 40 Mt.Vickery Rd. Southborough,MA 508-460-0733 Posts: 352	Re: New pistons Correct: on the pistons they do recommend .002-.003" as i contacted them in Taiwan and a few weeks later i received a response.

11-07-2013, 05:22 AM	#4
31 RPU Senior Member Join Date: May 2010 Posts: 182	Re: New pistons Ok, another question. The wrist pins can be pushed in with my thumb. It this ok? I thought they were supposed to be a tight fit?

11-07-2013, 08:07 AM	#6
31 RPU Senior Member Join Date: May 2010 Posts: 182	Re: New pistons Sponsored Links (Register now to hide all advertisements) Not sure if I stated that correctly. The wrist pins slide into the piston easily. I thought they should be tight?? They have snap rings with the set. I have already fitted the connecting rod bushings to the wrist pin.

11-07-2013, 08:09 AM	#7
J and M Machine Senior Member Join Date: Oct 2010 Location: 40 Mt.Vickery Rd. Southborough,MA 508-460-0733 Posts: 352	Re: New pistons You stated it correctly. They should be easy enough to slide through but not loose enough to fall out.