Hi folks

We broke the heads down on our FE 360 this past weekend. I've attached a couple of pics of our hot-tank (worked great for the record!). My question is regarding valves. The valves on these heads are in pretty good shape and measure 0.3710 and 0.3690. New they measure 0.3716. Our machine shop originally planned on installing new valve guides boring them to fit our existing valves. Based on the fact that oversized valves are available, I'm wondering if it would be and option for us to buy new oversized valves and have the shop bore our existing guides to match the required tolerance? The oversized valves are 0.3866.

Any thoughts on this?

 

Production rebuilders usually do one of two things. Ream the guides to an oversize and install all new valves or put in undersize ID valve guides and then regrind all of the valve stems. Either way works you just need to have a pilot to fit the new size guide.

 

If the valves aren't nearly like new the right way to do it is to simply put new valves in the new guides. valves aren't that expensive. be sure they install the hard seats.

 

Definitely put in a hardened seat. On an FE I never go by the book on what seat to install. I always use one that's shallower because it is very easy to take away the whole step on the short side of the exhaust port and this puts that side of the seat sitting out in the air. A lot of Chrysler heads are similar.

 

I'd go that route if were me ... assuming the seat / sealing surfaces are good. You're talking 6 to 16 ten thousandths. You'll be using new seals, and this route leaves some room for heated valve stems and oil. Nothing wrong there either, would be my backup plan if the need arose.

 

Proper clearance is .0001-.0002 . a couple more for exhaust.

There's no way the valves are all worn within .0001 of each other so getting proper clearance would be impossible. it's new valves or lots of STP .

 

Did you mean to use all those zeros there?

The difference between 0.3710" and 0.3690" is all of 0.002".

 

I have reamed the guides and bought oversize valve stems. I have torn down engines from commercial rebuilders and found that they do this. The dilemma is often shops do not have the reamer on hand to oversize the guides but they DO have the reamer for standard so they install new guides and ream, a machinist makes more $$ this way any way; it is not the best interest of the business to invest in additional (not entirely necessary) tooling in order to save the customer money. New guides and new valves and make it standard is ordinary practice locally, however the last engine I did I reamed the original guides to accept oversize valve stems. has ran well for 10 years. Either way is the right way, and using you existing valves, what I do in that event is I mix and match and get the snuggest fit to the guide, it takes more time but it is atleast one step above a hack job. putting the most worn valve in the most worn guide will just drink oil, and one can mix less worn valves to most worn holes in an effort to nurse it along a few more miles. Sadly in my neck of the woods a lot of these older "classic" vehicles might get driven 2-5 times an entire year, a parade, a car show, and they park in the garage the rest of the time. I tell these folks why buy all brand new parts for something you absolutely refuse to drive? and most of the time everyone wakes up and realizes that a valve job for $200-500 and up will never recoup cost in a car that sees 50-75 miles a year. When you engine will potentially take 1000 years to see 50k miles, I don't think thousands of dollars of machine work and parts is that necessary--- Meaning "Right" or "IT WILL WORK" are the 2 dynamics.