Rebuilding an ea82

RSR 555 · Post by **RSR 555** » Sun Feb 24, 2013 9:50 pm

After you lap them, wipe them clean and have a look at the way they are lapping. It should be a constant clean face all the way around. If it's thin in one area and thick in another then your valve might be bent. If so, you take them to a head specialist and have them regrind them, then try lapping again.

steptoe · Post by **steptoe** » Sun Feb 24, 2013 9:52 pm

get 'em cut. Gees, u r taking me back to when I used the shop valve grinder to do all my heads, thought nought when we had a big clean up - out it went into a $730 pile of scrap metal few months ago - now think was a bad idea

jims · Post by **jims** » Sun Feb 24, 2013 11:41 pm

Can you replace the valve seats in these heads?

RSR 555 · Post by **RSR 555** » Sun Feb 24, 2013 11:57 pm

You shouldn't need to replace them, as they are very hard and never seen a set wear out. If they are gone, I would look for another set of heads, may end up costing a lot less.

jims · Post by **jims** » Mon Feb 25, 2013 12:12 am

Thanks Ron. The lapped surface on both the valve and the seat are uniform so I'm not sure what to do now?

RSR 555 · Post by **RSR 555** » Mon Feb 25, 2013 12:28 am

Ok. What sort of grinding paste you using? and does it have course and fine grit?

Subydoug · Post by **Subydoug** » Mon Feb 25, 2013 1:05 am

A tip my dad showed me when doing valves is to use bearing blue. Smear a little onto the valves sealing surface and slam the valve firmly into the seat. Gives a nice blue ring which shows exactly how the valve is seating. Takes a bit of practice to work it out. You can also tell if the valve is bent by spinning it in the seat. If its bent you will see the edge of a particular point move in and out...if that's clear..

Also, when lapping the valves, make sure your lifting the valve and rotating it 90 odd degrees every now and then.

Regards

Douglas

steptoe · Post by **steptoe** » Mon Feb 25, 2013 6:56 am

They are EA82 ,free spinners - be rare to have a bent valve ?

jims · Post by **jims** » Mon Feb 25, 2013 11:17 am

Thanks guys.

The compound I'm using is PowerPlus. It's designed specifically for valve lapping and has a course grit and a fine grit for finishing.

When I lapped them the first time I did two goes with the course grit and then finished them all with the fine grit. However, after I tested them and failed I lapped them again only using the course grit. I didn't think finishing them with the fine grit would that much of a difference?

Can I keep lapping them or am I at risk of ruining the valve or seat if I do?

steptoe · Post by **steptoe** » Mon Feb 25, 2013 6:22 pm

have a look at the thickness of the valves, between the angle and the face, some get thinner than others at about this age

RSR 555 · Post by **RSR 555** » Tue Feb 26, 2013 1:39 am

PowerPlus is pretty commonly used brand, so you should be ok, as long as you follow their instructions.

Personally I would have used 1 times course and 2 times fine. I'd give it another go with the fine and retest.

jims · Post by **jims** » Tue Feb 26, 2013 12:16 pm

Okay thanks Ron.

I can get some new valves for around $10 each from Auto One. Maybe I should give that a go?

RSR 555 · Post by **RSR 555** » Tue Feb 26, 2013 12:22 pm

Try lapping once (or twice) first with the fine grit, then if this doesn't work, then look at new valves but I'd take the heads down to your local head specialist and ask them first before shelling out good money.

BTW, my name is Paul, not sure where Ron comes from?

jims · Post by **jims** » Tue Feb 26, 2013 2:30 pm

Argh, sorry Paul! I was thinking of someone else. Sorry about that.

I will try the fine lapping and see how I go. Will let you know. Thanks for all the advice. I appreciate it.

James

RSR 555 · Post by **RSR 555** » Tue Feb 26, 2013 3:26 pm

No worries at all James, I've been called a lot worse over the years. Lucky I have think skin

Yea mate, lap them again and let us know how it turns out.

jims · Post by **jims** » Tue Feb 26, 2013 8:54 pm

Success!

I lapped a couple of times with the fine grit but I also cleaned out a lot of scale that had built up below the seat. I think primarily what was happening was bits of dirt were breaking away and fouling the space between the valve and the seat (heads haven't been professionally cleaned).

So now I want to go through the other head and clean it up like I have done this one. Only problem is I have already installed it with a new gasket. I guess I can't reuse this new head gasket after unbolting the head and cleaning it further can I?

Subydoug · Post by **Subydoug** » Tue Feb 26, 2013 10:12 pm

Highly recommend sandblasting the heads, makes them sexy

.

For future endeavours though I quite like this mantra. Prior preparation prevents piss poor performance

Regards

Doug

RSR 555 · Post by **RSR 555** » Wed Feb 27, 2013 2:05 am

Awesome news James

I too like the finish on sandblasted heads (and block for that matter) but really have to make sure you really, really wash them out well, as that fine little grit gets into every little hole.

I also recommend you change the welch plugs, as these rot out badly.

steptoe · Post by **steptoe** » Wed Feb 27, 2013 6:57 am

some heads - OK, one pair of heads from an EA I had came with factory staked welch plugs of the non ferrous kind - was no need to knock out and renew

Was a surprise!

jims · Post by **jims** » Wed Feb 27, 2013 8:21 pm

Made some more progress today.

I installed the valve springs and retainers on the right head and installed that with a new gasket.

Feel like I'm finally starting to get there:

In the end I decided not to remove the other head and clean it further. I'm confident the valves are lapped well so they will just have to cope with any bits of gunk left over.

Next I will order some new valve lifters and continue on.