Pinto Car Club of America

I have a few questions involving valve work I may have done to my 73's 2.0 head.


If I have the seats replace with hardened ones (so I can make this "daily driver" worthy), is it mandatory that I replace the exhaust valves as well, or can they be re-ground?


If I do have them re-ground, is that going to destroy any hardening of the valve material to the point that I should just replace them to avoid doing so shortly down the road?


If I don't have the valve job done, is it safe to run the car on leaded gasoline? I have seen a post by Pintony that if the car was previously run on leaded gasoline, then that would have hardened the seats enough to safely run the car on unleaded gasoline, is this really true?

Pintony knows more about Pintos than any man alive! If he says its so, bank on it. He's the man!!!! Just my 2 cents worth.

I overhauled my 1972 2.0L cylinder head one year ago and went ahead and had all 4 exhaust seats replaced with the stellite hardened ones primarily because the #2 & #3 cyl. had burned exhaust valves and that caused the seats to get burned too.

Pay close attention to the valves guide wear and mainly the "taper" the the valve stems get from wear in the guides over time.

I ended up replacing all 8 valve guides and valves because the stem wear taper was too much. New cam shaft bearings, of course new stem seals and be sure all valves stems are ground to the same length. All 8 valve tips measured 1.690 from the spring seating surface to the stem tip and when all put together I came within .005 of factory lift specs ( .400 ). Be sure the valve stems are not too long as this will reduce valve lift considerably. The shorter they are the more lift, but you have to be careful not to grind the tips too much or you can weaken the hardened tip. While your at it be sure and check all 8 springs for correct seat pressure and they are compressed to the proper length when installed.

Valve train geometry on these 2.0L heads is different than most because of the cam followers/rocker arms position relative
to the cam shaft center line.   Even a stock head with stock cam needs to be measured carefully to get it right.

I also have a 1971 2.0L with a no longer made Crower 284 deg. so called 3/4 race cam that really made all that fun, but when your poking the valves open .060 more than stock, all clearances on all of it has to be measured and verified so stuff isn't hitting something it shouldn't.

Here is real good info that I followed to ensure success.
VALVE TRAIN GEOMETRY      This is the part of the Pinto engine that seems to stump so many people,  including so called "experts",  who are either unaware of the problems  or fail to set things up properly. The main issue is as follows - the length  of the valve stem affects the valve lift and also the point at which valves  start to open and close. It is due to the complex geometry of the finger  follower system that Ford designed to open the valves with. The longer the  valve the less lift you get - and in many cases you will find performance  cams that have not been set up properly give even less lift than a standard  cam. Not surprisingly this reduces power greatly and often negates the entire  point of buying the performance parts in the first place. 
  For each additional 1mm in valve length you can lose up to 0.5mm in valve  lift. Most "performance" valves are at least 2mm too long. 
  The "effective" length of the valve stem is not just an issue with the valve  itself. The deeper the valve seats are cut into the head the more the valve  stem protrudes of course. Also the diameter of the "base circle" of the camshaft  lobes changes the cam geometry - so cams which have the same profile but  on different base circle diameters will not work the same. Finally there  are various makes of follower available and the shape of these can differ  too leading to further changes in lift and timing.
So setting up the Pinto valve train properly is a matter of carefully matching  valve lengths to the particular cam and fingers being used. It can take a  lot of work to do right and that costs money so many people don't bother  or don't know it even needs doing. Get it wrong and you can kiss 10% or more  of the potential power goodbye.
Copyright David Baker  and Puma Race Engineering