Click Here -> Please Consider Making a PayPal Contribution to the FordSix Forum!
2019 Contributors:
NJwpod, 1strodeo, mightynorseman, maxtrux, 6d7coupe, broncr, Phase3, 68Flareside240, bmbm40,
mustang6, WorldChampGramp, justintendo, BigBlue94, ags290, motorsickle1130, Rooster, ousooner919, ethanperry
rzcrisis, DoctorC, jamyers, Motorboy, fastpat, Silverback280, chad


<<< New Site Update >>>

Valve adjustment frequency and lead additive

Moderator: Mod Squad

peeeot
Registered User
Posts: 130
Joined: Thu Feb 07, 2008 5:07 pm

Valve adjustment frequency and lead additive

Post #1 by peeeot » Fri Aug 23, 2019 12:55 pm

On my 223, the valves need to be adjusted much more frequently than the 12k mile recommended interval. I am having to adjust them after a few thousand miles and finding that they are tight, not loose.

The only explanation I can come up with for this is valve recession into the head. The head is original so the valve seats are not hardened. I have never had issues running unleaded gas in other engines of this vintage, so this is a new scenario to me. Is lead additive/substitute an effective or necessary solution?

User avatar
Daves55Courier
Registered User
Posts: 181
Joined: Sun Feb 26, 2006 2:40 am
Location: Southern Illinois

Re: Valve adjustment frequency and lead additive

Post #2 by Daves55Courier » Sun Aug 25, 2019 12:38 am

Sounds like your valve seats are deteriorating, due to the use of unleaded fuel. I rebuilt my first engine in 1973 (a 1955 Ford 272 Y-Block) and was told I would need to get the heads re-seated with flame-hardened seats.
There could be a danger of ending up with bent push-rods if valve seats are not corrected, but at some point you end up with no valve seats at all, until you change to annealed seats.

There is a lead-substitute additive available at some chain auto parts stores. Maybe you can get by using it temporarily until heads are rebuilt, but I have no faith in that.

peeeot
Registered User
Posts: 130
Joined: Thu Feb 07, 2008 5:07 pm

Re: Valve adjustment frequency and lead additive

Post #3 by peeeot » Sun Sep 08, 2019 9:22 am

This is definitely valve recession. I pulled the engine and removed the cylinder head to find marked valve recession on all exhausts. Cylinders 3 and 4 are the worst; one of them is perhaps slightly below the combustion chamber surface.

I haven’t removed any valves yet but obviously there will be some parts needed to rectify this. I have heard that when switching to hardened valves/seats that only one of the two need by hardened—either the valves OR the seats. Is this correct?

Mdixon300f100
Registered User
Posts: 157
Joined: Wed May 02, 2018 6:43 am

Re: Valve adjustment frequency and lead additive

Post #4 by Mdixon300f100 » Sun Sep 08, 2019 11:19 am

peeeot wrote:This is definitely valve recession. I pulled the engine and removed the cylinder head to find marked valve recession on all exhausts. Cylinders 3 and 4 are the worst; one of them is perhaps slightly below the combustion chamber surface.

I haven’t removed any valves yet but obviously there will be some parts needed to rectify this. I have heard that when switching to hardened valves/seats that only one of the two need by hardened—either the valves OR the seats. Is this correct?


The head will have to be machined and a new hardened seat pressed it. It the valve is harder than the seat, well, you already have that problem...

Who is online

Users browsing this forum: No registered users and 2 guests