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Hardened seats/valve recession?

Started by b5blue, December 12, 2015, 09:25:04 AM

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b5blue

 "Hardened valve seats" and "Valve recession" I do not see much chatter on this topic? After putting seven years of hard driving daily use and a few 1,000 mile road trip adventures on my 70 Charger the heads crapped out and it ran worse and worse degrading rapidly. Pulling the valve covers I found some bent push rods and pulling the heads revealed they were shot. The valve seats and guides were badly worn and being mid-divorce at the time the car was parked.
Doing research I found the thing about unleaded fuel and it's effect on valve seats and figured that may have been the root cause. The heads were closed chamber that had been ported very nicely, built during the cars drag racing days. After popping the keepers and removing the double spring sets the slop in the guides was really bad. I'd always kept fresh Kendall oil in all my engines and 440 got even more frequent changes during that time but looking back a new oil pump may have helped, it never gave any sign of starving for flow. (Pressure read a bit low on the dash at idle with the lumpy 509 cam but we checked with a mechanical gauge and found the dash gauge was reading lower.) Seeing all the chatter about the pros and cons of aluminum vs factory heads and knowing we have some darn good engine builders I just wonder how much this subject is addressed when running iron heads?     

BSB67

Not sure I follow the story very well.  Did you find the bent pushrods yesterday, or 10 years ago?  Are all the parts and pieces available and their operating orientations known?  The oil pump was not the problem and would not have helped.

What you describe does not sound like valve recession.  Got pictures?

500" NA, Eddy head, pump gas, exhaust manifold with 2 1/2 exhaust with tailpipes
4150 lbs with driver, 3.23 gear, stock converter
11.68 @ 120.2 mph

b5blue

  Sorry, the story was just how I found the subject of valve recession from unleaded fuel. The failures were long ago and of no matter now as the heads were donated to the racer who did the port work. (I've 346 heads now, a bit better but just induction hardened seats.)
  There is so much information on B/RB builds here but little if any mention about installing hard seats in heads I was just wondering if it's "a thing" at all?  :shruggy: Years ago I was just trying to sort out why the engine gave up on me at the worst possible time and recall that as a potential factor that could limit the life of the next build.

birdsandbees

I just mix my gas 90% unleaded premium pump to 10% 100LL AV gas. With 100LL having about 10 times the lead of the old leaded gasoline it seems to work just fine. If for some reason I ever have to tear down either of my engines then I'll have the valve seats done, but until then I love the smell of AV gas in the morning!  :icon_smile_big: Of course it helps having 500 gallons of the stuff in the yard, although anyone can drive out to the local airport with a few Jerry cans and they'll happily sell you some.
1970 'Bird RM23UOA170163
1969 'Bee WM21H9A230241
1969 Dart Swinger LM23P9B190885
1967 Plymouth Barracuda Formula S
1966 Plymouth Satellite HP2 - 9941 original miles
1964 Dodge 440 62422504487


Challenger340

200 ml of 2 stroke oil added per tank of today's unleaded fuels is sufficient to prevent valve seat recession with the older iron heads,
and NO.... it will NOT smoke like a 2 stroke.
Only wimps wear Bowties !