tr3 Shortened Pistons

[David James]

Anybody had any experience fitting and running a wet liner engine on pistons with non standard shortened skirts?

In an attempt to make up a useable set of pistons I have come across a new 86mm piston that looks to be shortened where the 2^nd oil ring would be. Effectively 20mm shorter. See photograph, 2^nd piston from r.h.s.

Facing off some broken pistons at this point would form a set but would they work ok?

Thanks in advance. David

[Motorsport Mickey]

They may work ok but long term you may experience problems.

 

The length of the skirt is developed in conjunction with the balance of the piston, we are not just talking weight but also the turning motion point where the gudgeon pin is placed. By removing the bottom of the skirt the 20mm shortening has increased the angular contact of the piston the same affect as having an increased bore clearance. That may lead to increased bore or piston wear and some clattery noises before you decide that you need to change them.

 

Mick Richards

[Rodbr]

Hi david,

FWIW heres a 1954 service bullitin

Sports/6/B December 1954 Pistons extensively used in rally work cracking crowns. The piston design was modified to add webbing at the crown. The new piston was folded into production with engine TS4882E.