470 head repair ?

[nola mike]

trying to put my head back together (i had some rusted exhaust valves over the winter/bent pushrods). I put in 2 new valves. They are the same overall dimensions as the old ones, but I noticed that the keeper groove is slightly (2mm or so) lower on the stem than the old ones. The only consequence that I can think of is that the spring is a bit more compressed, but I can't imagine that that's a big deal. I'd still like some reassurance that I'm not going to blow anything up. Pics of old v. New valve, and one of the new one installed--you can see that there's a bit more stem exposed.

 

[nola mike]

Re: 470 head repair ?

 

[stonyloam]

Re: 470 head repair ?

Well, not knowing any better, it would seem that it would be best to have them all the same. That valve my use a different retainer lock than the stock 470. I'll bet your machinist can fix you up.

 

[Bt Doctur]

Re: 470 head repair ?

They should be Ford 460 truck head, The valves should all be the same . You wouldnt want the keepers to just pop off and drop the valve from not enough spring tension.
installed height 1.86, +,- 1/32

 

[nola mike]

Re: 470 head repair ?

The new valves are ford 460. They are the same height as the others, and the keeper grooves appear the same except that they're a touch lower on the stem. If anything, the spring tension on the new ones should be a bit more. We're no longer near civilization, and tomorrow's the day to put it together, so no go on the machinest. I guess we'll see...

 

[stonyloam]

Re: 470 head repair ?

I guess the only thing that I would worry about is the spring becoming fully compressed, so that it is no longer a spring, but a solid block of steel, don't need another bent pushrod :facepalm:. Good luck. Let us know how you make out.

 

[dn010]

Re: 470 head repair ?

Get them all the same; this is why they have specs. It will save you from future problems. - IMHO

 

[stonyloam]

Re: 470 head repair ?

Here is an interesting article on valve spring height: http://50mustangsuperfords.automotive.com/42529/24453-valvespring-installed-height/index.html You can get offset locks and retainers. Your machinist can probably find them. Good luck.

 

[nola mike]

Re: 470 head repair ?

Hadn't thought of the potential binding issue. Anywho, it looks like the tolerances on this head are huge. Maybe that's why the dimensions of the components are all over the map. I put it all back together, and cranked it by hand, no issues. Valve clearances are within spec with the new valves and pushrods. I have a bit of pitting on my gasket surface on the exhaust manifold, and wanted to get some high temp RTV for it (no time for the hour roundtrip to the store), so I didn't get a chance to finish it and fire it up. All that's left for next weekend are to put on the exhaust mani/riser, and carb. And then hopefully get on the water. I wonder what the chances are that this isn't the only problem keeping her from running...

 

[Jasen]

Re: 470 head repair ?

You have the incorrect valve installed in that head. If you used the original locks, those are wrong as well. That valve you posted there is too long.
There are five different lengths of 460 exhaust valves and they're not interchangeable: 4.983 in., 5.042 in., 5.198 in., 5.244 in. and 5.446 in. Put the wrong valve in and your geometry is off which can lead to catastrophic engine failure. Those aluminum 470 blocks ventilate with ease.
Valvetrain geometry and spring pressures are critical. There's a reason they list dimensions in .001" increments. You're playing with fire running it that way.
I know I'm a noob here, but I had a 470 (rebuilt it) and am a Ford master tech with 24 years in it...I've built a few engines. Just trying to help.

 

[nola mike]

Re: 470 head repair ?

well, I put the manual calipers on the old valve, and measured 4.992". New valve is 4.983" per specs (though it's installed and I didn't actually measure it). But I'm pretty sure that's the right length. The keeper grooves appear identical, and I haven't run across different retainers--if they do exist, please show me where. Also, they installed no problem. The only issue I can see now would be spring bind. It turned over fine by hand. Next week I'll turn it over and make sure I still have some play in the spring with the valve open. Again, my rocker-valve clearance was well within spec, so I think I'm ok at this point. Guess we'll find out...

 

[nola mike]

Re: 470 head repair ?

Well, the rumors of my engine's demise have been exaggerated. Finally got everything back together today in between rainstorms, and much to my surprise it started easily, there were no leaks, no horrific metal-on-metal sounds, or any other problems. At least on muffs, it ran great for about 15 minutes. The oil is a bit milky (hoping from the riser leak), but all else is well. Plan tomorrow to warm up again, change oil, retorque head bolts, change gear oil, go fishin'.

 

[nola mike]

Update: 470 head repair ?

Update: 470 head repair ?

Well, went about 25-30 miles this weekend, and much to my surprise, nothing blew up. Still a bit scared to keep it at WOT for any length of time, but I had it at 4300 rpm for a bit. Rest of the time was generally at 3-3500 rpm. No leaks, oil stayed clean, no overheats. Sounded great. Ready for the summer!