Valve Clearance 1098cc A-Engine

[Paul McGuffin]

I have four different reference books for a Sprite/Midget 1098cc engine. As far as valve clearance goes, two of the books say .012” cold, one says hot and the original manual says, hot or cold. What is the opinion here on the forum?

 

[Paul McGuffin]

I set the valves this morning, cold. They were all at .015 to .018. I set them at .012. I have no idea what cam is in the engine 1098cc (10CG). I only banged my head three times on the hood.

 

[drooartz]

I probably have the same books you do as far as clearances, so I can't add anything as to the value. I've always done A and B series engines cold for checking valve clearances.

 

[dklawson]

Set them cold at 0.012".

In general, it's not the cam that determines when to "change" the clearance from .012", it is the rocker arm ratio. The nominal, stock, A-series rocker arm has a ratio close to 1.2:1. High-lift arms are often close to 1.5:1. For the 1.5 arms you would take 1.5/1.2 x .012" = 0.015" The added gap is to accommodate for thermal expansion.

 

[Paul McGuffin]

Well...it seem to run better before I tightened the gap down to .012”