Hi all! my engine is at the machine shop to have two valve seats installed and the machinist said he was not sure how deep he could machine to receive a new seat without getting into the water jacket.He is very experienced at valve jobs but has not worked on a t engine before. I checked Snyder's and they have seats that measure 1.213 ID. 1.269 OD. and 0.216 thick.I know now that he will be safe with these valve seats. anyone know how close to the water jacket it will be after the cut is made for the new seat? thanks Ken
You will not get into a jacket that high in the block, the ones that snyder's or lang's sell work fine.
Shouldn't your engine machine shop be able to get the appropriate valve seat from their suppliers ??
Not wanting to take business from our suppliers, but valve seats are just valve seats.
Big chev vlaves also help to fix small discrepancies in the seat area and you'll notice the difference in the breathing too.
Can someone tell me exactly how valve seats are removed and inserted? I have done valve jobs on my Ts, 8n tractor and flat head jeep, but never had to replace a seat.
SSGrant,
There are many different ways to remove a valve seat. I've welded a bead around the inside surface and seats just fell out.
For more then you ever wanted to know about valve seats see:
http://www.enginebuildermag.com/Item/1946/valve_seat_installation_procedures.asp x
Of course valve seats are not original on a Model t engine. If they are there they were added by someone other then Ford.
Jim
Thank you Jim for the info and link.
Scott
SSGrant,
I have seen a three pronged tool that has a small point at each "finger". The tool is expanded so that the points dig in at the bottom edge of the seat insert, whereupon the insert is pulled out.
Installation in a factory is accomplished by feeding the inserts down a tube with a jacket around it, through which liquid nitrogen is circulated. On a smaller scale, dipping them in a vessel of liquid nitrogen before insertion works just as well, and having them sit on dry ice for a bit before insertion works too.
Keep in mind that the temperature of the exhaust valve typically increases by about 100 degrees when inserts are used. This is because there is now an extra "barrier" to the heat transfer between the valve and the block, or head if OHV. So it becomes more important to pick a more heat resistant valve material.
FWIW,
Roar