EGR HELP

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Oct 8, 2013 | 11:45 PM

Gypcmechanic

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EGR HELP

I posted on another site but only got a little info. I'm not a ford guy but have always liked the F-100 so I picked one up very cheaply with 2 burnt exhaust valves in the 360. So luckily the same day I found a dude a few blocks away with a very sexy set of rebuilt 390 heads. I'm pretty sure the EGR valve was the cause. What can I do to eliminate the EGR valve? I am keeping the stock intake manifold. I haven't pulled it apart yet but is there a way to block off the riser plate? Any advice, experience, pictures, tribal knowledge is greatly appreciated!

Oct 9, 2013 | 06:26 AM

fmc400

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From: Austin, TX

Quote:

Originally Posted by Gypcmechanic

I'm pretty sure the EGR valve was the cause.

It most certainly would not have been the cause. I suspect you have little quantitative evidence actually supporting this claim.

Quote:

Originally Posted by Gypcmechanic

What can I do to eliminate the EGR valve?

Don't. Please search for "EGR ping."

Oct 9, 2013 | 07:28 AM

Gypcmechanic

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If it's not, then why woukd both rear cylinders have burnt valves which happen to be where the exhaust comes from for the egr. And how can diluting the fuel air mixture be good for a clean flame front and positive burning of that mixture. The new heads I have , have hardened seats better valves and guides than were available in 1973. So if you eliminate it along with the correct timing and. Better fuel how can it be a bad thing?

Oct 9, 2013 | 08:50 AM

mikeo0o0o0

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From: Stanley, VA

Quote:

Originally Posted by Gypcmechanic

then why would both rear cylinders have burnt valves which happen to be where the exhaust comes from for the egr.

Actually, that's incorrect. The exhaust crossover, where the EGR valve pulls the exhaust from, flows from cylinders #2 on the passenger side and #7 on the drivers side. The rear cylinders are #4 and #8.

Oct 9, 2013 | 08:57 AM

mikeo0o0o0

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From: Stanley, VA

Quote:

Originally Posted by Gypcmechanic

how can diluting the fuel air mixture be good for a clean flame front and positive burning of that mixture.

The whole purpose of the Exhaust Gas Recirculation (EGR) system is to lower peak combustion temperatures to reduce nitrous oxides emissions which are formed during high combustion temperatures.
In my mind, if anything, lower peak temperatures would reduce chances of burnt valves. In reality though the main reason for burnt valves in these engines is the lack of tetra ethyl lead in modern unleaded fuels. Tetra ethyl lead not only increased octane but was also an excellent high temp and extreme pressure lubricant for the valve train.

Eliminating the EGR system won't have any appreciable effect on valve life but unless you recurve the distributor advance curve and rejet the carb it will have an effect on the drivability.

Oct 9, 2013 | 04:41 PM

Roger Carter

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From: Corbett, Oregon

Back in the before times, way before unleaded gas was available...

Burnt valves in FE's were not uncommon in the years gone by. Usually it was cylinders 7 & 8 that burnt. Mainly saw this problem on cars (and some trucks) that used the stock manifolds and stock type single exhaust. I always figured the center dump driver side exhaust manifold, with the cross over pipe, tended to "block off" #7 and #8 exhaust flow.

Roger Carter