Cummins Piston-to-Bore Clearance

Looking for information on the Piston-to-Bore clearance of the 5.9L Cummins. This is information that should be in the shop manual (if I had access to one). Need to know the clearance spec. and if there is more than one piston grade. Thx.

If available I'd also like to know the bore and piston diameter

tolerances.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

From my '99 factory service manual... Cylinder Bore Diamater (Max)..........102.116mm (4.0203 in.) Cylinder Bore our of round (Max) .....0.038mm (0.0015 in.)

Piston Skirt Diameter .........................101.864-101.896mm (4.0104-4.0117 in.)

Sorry, I couldn't find anything on Piston-to-Bore clearance.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Ed H. wrote:

Thanks for info !

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That's because they hid it :) (bore diameter-piston diameter/2=p-to-b clearance)

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Tom Lawrence wrote:

You could calculate the piston-to-bore clearance if the service manual has the bore size with tolerance (instead of the Max Dia.). Using the numbers above give an answer that I know isn't correct (.252mm max p-to-b).

As comparison, the current 6.4L ITEC Powerstroke runs 0.0441-0.0909mm piston-to-bore clearance.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You forgot to divide by two. That would then be 0.126mm max clearance.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Tom Lawrence wrote:

Typically, p-to-b clearance is described as the diametric clearance. For clarification, the Powerstroke clearance specs that I mentioned above are the diametric clearance.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I thing you are forgetting a few .00

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The nominal bore/stroke dimensions for the 5.9L are 102mm X 120mm (4.01574" X 4.7244").

Subtracting the piston diameter(s) from the nominal bore size gives a piston clearance tolerance of .104mm-.136mm

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.