Powroll Motor Performance - Since 1964  

 

 

For a limited time

 

 

 

 

 

Powroll

13840 Commercial Lp

Crooked River, OR

97760

 

Mail:

PO Box 920

Redmond OR  97756

 

Phone

541-923-1290

 

Fax

541-923-5637

 

Email

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Powroll - 4 Stroke Performance

 

Bore Kit Installation

This information is designed for use with Powroll products only.  Attempting to use this data with any other manufacturer's product can result in engine damage.

 

BORE KIT INSTRUCTION BOOKLET POWROLL PISTON CLEARANCES POWROLL RING GAP

 

Powroll now offers Boring Services

piston

PISTON CLEARANCE

All Clearance numbers are in decimal inches. 

For high compression or race applications, or if your model is not listed, please call for correct specs  541-923-1290.

KIT # CL   KIT # CL   KIT # CL   KIT # CL
00005N 0.0015   00185TA 0.0015   00272FHC .0025-.003   00311 0.0025
00006R 0.0015   00240 0.002   00274 0.002   00311T 0.0025
00019 0.002   00246F 0.0025   00277 0.0015   00314 .002-.003
00036N 0.0015   00247S 0.0025   00282 0.0025   00315 0.002
00071 0.002   00253 0.0025   00283 0.002   00316 0.0015
00075X .0015-.002   00254 0.003   00288 0.003   00317 0.002
00097 0.002   00255 0.002   00290 0.0025   00317HC 0.0025
00102V 0.003   00266 0.002   00298 0.002   00318 0.002
00105 0.002   00267 .0025-.003   00299 0.0015   00319 0.002
00110 0.002   00268 0.003   00302S 0.002   00320 0.002
00146 0.004   00270 .002-.0025   00305 0.002      
00147N 0.0015   00270E .002-.0025   00307 0.002      
00156N .002-.0025   00271 0.002   00308 0.002      
00182N 0.002   00272F .0025-.003   00309 0.002      

 

RING GAP

Some Powroll piston rings are purposely oversize to enable re-ringing of cylinders which have worn within certain acceptable limits. Because of this, ring ends must usually be filed down before installation.

More end gap is OK.  Not enough end gap can cause engine damage.

Follow the graph below to determine correct end gap:

Piston Diameter in Inches

Piston Diameter in Millimeters

Minimum End Gap

1.731" to 1.968"

44mm to 50mm

.004"

1.969" to 2.675"

50.25mm to 68mm

.007"

2.676" to 3.120"

68.10mm to 79.25mm

.010"

3.121" to 4.000"

79.35mm to 102mm

.013"

 

 

Powroll Motor Performance

13840 Commercial Lp  Crooked River, OR  97760     Phone (541) 923-1290    Fax  (541) 923-5637

Copyright © 2007 Powroll Inc.  All rights reserved.  All photos and text are the intellectual property of Powroll and cannot be reproduced without permission.

Descriptions and pricing are subject to change without notice.