Head rebuilding

[mluck]

I have a bare head ready for rebuilding...is it wise to put bigger valves in it...if so,I see inline has the parts but no valve seats,where do I get them...truly I no nothing about heads or what parts to get.

[ags290]

Your machine shop would supply the valve seats. You might be better off looking for a later model head, depending on your casting number, that already has the bigger valves and hardened valve seats.

[CZLN6]

Howdy M:

I'm guessing that you are rebuilding your '67 head. It would be better if you shared the casting code from the head. It is on top of the log behind the carb mount.

If it is on the '67 head, there are several other things I'd like to know to be able to offer good advice. What is the intended us of this engine? What other performance mods are you planning? What is your budget? What is your compression goal? What do you have planned for the exhaust? What is the condition of the valves and seats in the stock head?

Ags' advice to look for a '78 or later head is solid. The later head will have 1.75" intake valves, hardened valve seats, a larger carb hole of 1.75" and greater intake tract volume. It will need a mill cut of .050" to get the chambers to 52ccs, the same as your '67 head.

To answer your question without the needed info, bigger valves can help to increase flow but greatest benefit will need more compression, more carb and exhaust. Your '67 head did not have valve seat inserts because it was built to use leaded gas, which is rare these days. Check with your machinist for availability. Low miles, low rpm weekend cars get along just fine without them.

IF you're not in a hurry, get us the above info so we can help you to do it right.

Adios, David