Hard Exhaust Seats on a 390
#1
I know this has been discussed before.  First of all I am freshening a 390 that was built back in about 1980.  I was only driven about 200 miles and has been parked since about 1986.  I am now in the process of installing new valve springs and valve seals on the cylinder heads.  I am using springs Comp suggested for their hydraulic flat tappet cam I am installing.

Here is the issue I have come across.  When the these heads were rebuilt back in 1980 hardened exhaust were not installed.  Of course back then pump gas still had some lead in it so the valve seats look just fine.  Are hardened exhaust seats really needed for a car that might only see a few hundred miles per year?  I get conflicting information on this.  Some say Ford's castings are a harder alloy so it's not as critical as GM castings.  Any information is appreciated.
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#2
Hi Mike,

My Mustang heads do not have hardened seats installed for 2 reasons.  The guy who machined the heads didn't want to take the chance of ruining the HIPO heads.  He said if during the process he hit an air pocket in the casting the heads would be no good.  Second, he  indicated if hardened seats were absolutely necessary with today's gas he said he would have a line down the street for business. So I took his advise and did not have hardened seats installed.

So for what it is worth I am on year 5 with my Mustang and drive it only on the weekends during nice weather and have not had any issues.

Mike
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#3
Thanks for the information.  Your Fairlane turned out nice on a reasonably budget so I am trying to do the same and not spend on items that won't offer any benefit for an occasional fair weather driver.  The valve tips on the exhaust valves are worn for some odd reason.  But I can get new stock size replacements that are finished and ready to install for a reasonable price from a place called Alex's Parts.  My plan was thoroughly clean the heads, replace those exhaust valves, and install new Viton valve seals and the springs the Comp Cam's tech recommended.  I've tinkered with valve springs enough to be able to set them up at the correct heights and loads.  I was stuck grappling with the exhaust seats, leave as is or have hardened seats installed.  Plus, Redline makes a lead substitute that gets good reviews and the mixture is only 1 oz. per 10 gallons of unleaded fuel.

I need to post a few pictures of this project.  It's a 1956 Ford F100 pickup.  Yeah, an old fat fendered Ford.  It was a frame off restoration in the early 1980's.  Body, paint, frame, suspension, brakes, motor, trans, and drivetrain were complete in about 1983.  It was driven a little around town, maybe 200 miles at most, for a few years.  Since then, it has been sitting in a garage (that was rarely opened) for 33 years, never moved, never started.  I had to buy tires and wheels to move it.  The old right rear tire was stuck to the garage floor.  It's slowly cleaning up and looking a lot better.  But, I'm surprised how dirty it can get even in a pretty much sealed environment.  The original chrome from 1956 is not bad, but the chrome from the early 1980's is terrible.
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#4
Mike,

Sounds like a neat project.  I like the old fat fender Ford trucks.  Please post some pics...I am very curious to check it out.

Mike
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#5
Yeah it is a nice project.  I've been working on it a little over a month now.  I nice change from a small car plus there as there is lot of room to get to anything.  I like that everything seems to be much more simple too (I guess I'm getting old).  There are now a lot of reproduction parts for it and the so far the quality of them seems better than those for Mustang reproduction parts.  Only draw back I've come across so far it that parts for big block Ford motors are more expensive and not as easy to get as for small block Ford motors.


I took the Mach 1 out for a ride a couple of days ago.  When I opened the hood I forgot how little room there was.  I wondered how I ever got the entire car assembled.
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#6
Oh yes, big block Ford parts are a whole new price catalog.  At least it be something you can compare the performance to your Mach 1 to. If my memory serves my right your Mach 1 has a 351, correct?   Unfortunately, I just put my cars up for the winter.  We had our first snow and they put the nasty salt on the roads.  That's when I stop driving them.
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#7
Brief update on this 1956 F100 since it's been a while.  The motor is freshened, complete and installed.  Ended up having to get the cylinder heads rebuilt.  Exhaust valves were still original Ford from about 1963 and the tips were flaking apart.  I did get hard exhaust seats installed in the process.  I still need to get a set of adjustable rocker arms.  For this motor I'll probably go with a low cost import set from Pro Comp.  I don't like the import idea.  But, valve spring pressures are not high and anything U.S. made for an FE motor is at least $1000.  At least Pro Comp offers a set that is stainless steel instead of aluminum.  Everything is seeming to snowball into more than I expected.

With about 40 hours of tinkering I got the hood to open and close after replacing the hinges, all the body mounts, and completely unbolting all the sheet metal on the front end.  The hood still has a twist in it and will eventually need to be replaced.  But for now it works.  I installed the correct fender support/alignment rods in the process.

A couple weekends ago I was simply going to wire the alternator after converting from a generator.  After all the truck had a new wiring harness installed and it's been garage stored since then, so, this should be an easy win.  I quickly discovered the main 10 ga. wire from the starter solenoid that fed power to the entire truck was crispy and flaking apart.  This led to the entire under dash harness being crispy, flaking apart, and partially burned.  For those familiar with vehicles this old, you're aware the only fuse they had back then was for lights and built into the headlight switch.  Everything else was wired direct without fuses.  So, what started as wiring an alternator has turned into an entire new harness.  The best value I found for what I need was a Painless 28 circuit universal kit that Summit Racing had on sale.  At least, everything will now be on separate fused circuits with a modern fuse box.

After wiring, the next time consuming task is repairing the front inner fender wells.  At one time this truck had a tilt front end so the front inner fenders had to be cut leaving one section bolted to the cab and the other section attached to the tilt front end.  I'd like to replace them, but the cost is high, new repro or used.  So my plan is to bolt them back together using a strip of 18 ga. sheet metal to fill any gaps.  I guess they could be welded together, but then they would probably warp, need body work and repainting, and a spray can won't work well for them as they are rather large.

It might not sound like much, but, it's taken quite an effort to get it this far.  I still need to upload some pictures.
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#8
Sounds like you're having a real time with it. Don't give up, It''l be a fun truck when it's done. 

JTS
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#9
I'll keep pushing forward.  The wiring harness came in.  Looks nice I think because it's new and has a nice fuse box.  It's actually an OEM General Motors fuse box.  I would like to see a complete schematic along with the 130 page instruction book it comes with.  The instructions are simple to follow, but, I guess I'm getting old.  Even with glasses I need a magnifying glass to read the labels printed on the wires.
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