Triumph・BSA・Norton 用パーツ·世界中へ発送·お問い合わせ:(657) 231-9003
Le Hangar 23
Shop/Category/Fig. 1 — CRANKSHAFT, PISTON AND TIMING GEARS/Compression ring
Compression ring
View clickable diagram
Details
Also known asE3959
DiagramFig. 1 — CRANKSHAFT, PISTON AND TIMING GEARS · ref 18
Subsystemengine bottom
Listed in parts books1963–1964

Compression ring

A compression piston ring, PN 70-3959 (alias E3959), listed in the crankshaft/piston/timing gear section of the parts book.

PN · 70-3959

This is a compression ring, catalog number 70-3959, also listed under the older E3959 designation. It shows up in the parts-book section covering the crankshaft, piston, and timing gears, which tells us it's a piston ring rather than anything from the top end's valve gear.

Read more

Beyond that, the catalog entry doesn't give us much more to go on - no material, size, or specific model callout comes through in our records. The listing spans catalog appearances from 1963 to 1964, but we can't tie it to a specific model or engine size from what's on file.

If you're chasing a ring for a rebuild, give the shop a call with your engine's details and we'll confirm this is the right one before you order.

Not listed anywhere

We've never carried this one. Tell us what you're after and we'll go looking — you'll get a price and photos before you commit to anything.

Sign in to request it
We need somewhere to send the price and the photographs.
Pin your bike to check this part fits.

Sorry if we got something wrong here. If you think this information isn't correct, .

Related parts
Oil control ring
PN 70-3387 · Usually replaced with this
BackorderView
PISTON COMPLETE, C.R. 7 : 1
PN CP141 · Goes with this
BackorderView
PISTON CIRCLIP T20/3TA
PN 70-1767 · Goes with this
BackorderView
Any questions about this part?

Ed is at the counter. Tell him what you're working on or what doesn't fit, and he'll take it from there with this part already on the bench.