OST-019: Collaboration

[oldeskewltoy]

oldeskewtoy Wrote:The clients head went off to Loynings this am.... the guides are being replaced,


With luck I'll see the head back end of the week, or the beginning of next.

Well.... The Supertech guides will not be used () the O/D of the guide is .4342"-.4344". The guide holes in some cases are as large as .4340". The size is mostly because this is an old used head, it has seen thousands of heat cycles.

Loynings feels that a 2 to 4 ten thousandths (.0002" -.0004") interference fit is not enough, they prefer at least a .001" interference fit. Sooo the Supertech guides are not large enough in diameter and so will not be used. Its a shame really....the aftermarket frequently only caters to standard parts... even when the factory offers std and O/S.

Replacing the Supertech guides will be a set of OEM guides that ARE O/S... they are .0019"(.05mm) larger O/D then the standard valve guide.

THIS is one reason I try NOT to replace valve guides... there is no way prior to removing the old guides to know if std or O/S is required.


So the head will likely be @ the shop for closer to 2 weeks so the parts can arrive from Toyota's Cincinnati depot