Doing the heads on an EA81

Silverbullet · Post by **Silverbullet** » Sat Apr 30, 2011 1:12 pm

This is kind of a continuation of this thread:
showthread.php?t=19407

Have a quick look through and you will understand why I need to take the head(s) off

Started dismantling the top of the engine (again), got he manifold off in half an hour, the exhaust nuts came out without argument and the two bolts for the rocker arm assembly were equally compliant. So far the pushrods look ok, but I wouldn't be able to tell for sure without a dial indicator.

I was just preparing to remove the head bolts/nuts and ran into my first problem; the book shows a diagram of the sequence you are supposed to loosen/tighten the bolts and shows nine. My head appears to only have seven nuts/bolts holding it on. Where the book shows two down by the exhaust manifold studs I just have two rounded bits of aluminium where they should go but are blocked off

. A bit tricky to explain without pics, I might get one later.

So this would completely throw out the sequence of loosening and tightening wouldn't it? or do I follow the book up to those two bolts (the book says they are number 2 and 3 or 8 and 9 I think)

Also is there any problems to leaving the valve springs etc exposed? I can't put the rocker cover back on without the rocker arm assembly in place.

Cheers!

Post by **TOONGA** » Sat Apr 30, 2011 2:18 pm

Two of the bolts you took out for the rocker arms are part of the total of 9 on the engine. (bolts 4 and 5 in the gregorys manual 06.1 - Engine part 2 page 50 of the book)

just undo the rest following the pattern, I take it you are going to have them machined (faced) before they go back on so it shouldn't be a problem.

Are you doing a complete rebuild or just looking at the heads at this point?

if you are worried about the valve springs coat them in a light oil (singer or somthing similar) then put the covers over them

TOONGA

Silverbullet · Post by **Silverbullet** » Sat Apr 30, 2011 3:49 pm

Yeah I thought about it some more, looked at the book again and those two at the bottom are 1 and 2, so I just started from 3 and 4 and followed the sequence from there.

Every nut cracked easily enough, and they all came undone without any broken studs. Of course the head was sealed tight after the nuts were off so I tapped it with a rubber mallet and off she popped! This was all way too easy, and the further I get into it the more I think there's a big nasty surprise waiting for me somewhere

A neat trick to find if the valves are bent is to turn the head upside down and fill the area where the valves are with fuel and let it sit for 1/2 and hour so that's what I'm doing now. if theres no leaks then there's no bent valves. I was thinking that if the piston smashed into the valve while it was jammed open it might have pushed that valve out of the head slightly, since the intake valve on the spring side looks a little different to the others. So with whats left of the day and tomorrow I'll start taking the head apart cleaning as I go. Then if I see nothing amiss (bad news) it'll go back together and off to the cylinder head shop on Monday hopefully.

Yeah TOONGA I'm just getting the head rebuilt not the whole engine at this point...but if the piston is broken or something I guess it's a whole engine rebuild or new engine:???: Question, can you get just one of the heads rebuilt or do you have to do both of them? since one side would have more compression would equal unbalanced load on the crankshaft etc.

Not bad for an afternoons work, but like I say it was all too easy, there's a big nasty surprise coming I know it

Cheers

spike · Post by **spike** » Sat Apr 30, 2011 5:51 pm

Silverbullet wrote: if theres no leaks then there's no bent valves.

not a bad idea, EXCEPT!! valves can leak due to over things, usually seats and such and even with a bent valve it could still seal

best bet is just to pop them out and run them along a bench edge, like using a rolling pin you souldnt be able to see any light coming from underneath
there is a way to straighten valves, but it uses a lathe and ive never been confident enough to do it but have seen it done a couple of times

littlewhiteute · Post by **littlewhiteute** » Sat Apr 30, 2011 7:32 pm

Bent valves do not seal due to non concentric seating and not square to the seat. They bend just above the valve head.

If the stems are different heights, you have a bent valve.

And you don't need 1/2 hour with fuel or kerosene as a test fluid.

RSR 555 · Post by **RSR 555** » Sat Apr 30, 2011 11:47 pm

I'd recommend you take the heads to a cylinder head specialist and get them to clean/wash the heads, then vacuum test the inlet and exhaust ports, this will guarantee if the valves are sealing or not. If the heads aren't holding vacumm, just get them to reseat them for you (best time to get new valve stem seals fitted too) and then face the heads at the same time.. then you just need to buy a Regrind Kit (which will include valve stem seals) from your local parts place. I'd also remove your head studs and using a flat stone, clean the block reday for install. I'd also recommend you use some Hylomar spray on the head gaskets prior to fitting.

Silverbullet · Post by **Silverbullet** » Sun May 01, 2011 1:42 pm

Thanks for the suggestions. I was thinking about taking them apart myself but then I'd have to get some tools that we don't have and time that I don't have right now. Probably will just take them as they are to the head shop. Was going to get them faced as well as ask them what was wrong with the intake valve on that cylinder that got the rag in it, just wanted to know what happened to it

I thought they would do the regrind as part of the service? with stem seals and seats etc.
As for removing studs and cleaning the block, how would I remove the studs? yeah they are threaded in but how do you get a grip on them to unscrew them?
For re-installing the heads I was thinking about getting a pro to do it. However much I've learned from taking this apart I'm not sure about putting something as important as the heads back on myself. Might cost an arm and a leg though...

Did some more today as well, decided we are going to get both heads rebuilt just to be sure. Was taking the passenger side head off today and it's a bit more reluctant to come off than the other side; I was tapping it with the mallet again and the head was stuck on better than the other side. Eventually the seal broke but now it slides half way off the studs and gets caught up on one stud, can't move it any further. I'm thinking I may have bent that stud slightly causing it to bind in the head

I didn't hit it that hard but I guess it doesn't take much.

Tip: don't hit your head with a mallet

*Edit* got the head off, the stud wasn't bent, it was corroded and rust had built up around it and was jamming on the head. Will probably need a new stud anyway.

steptoe · Post by **steptoe** » Sun May 01, 2011 10:38 pm

was going to say ...but your edit has it !

Believe me...leave those head studs in. Get a piece of dressed all round DAR, pine 38 x 19 mm about 50mm long and wrap various grade wet and dry and that tough brown metal sanding paper to clean up the block face. Stuff rags in orrifices to prevent crap entering block and sump. Bit a WD40, CRC556 to help you along the way. Run a head nut up and down threads on studs to clean them up.

Before you spend time on this, turn motor over to see that all pistons travel in and out nicely and no free play. Bit of back and forth on the crank bolt to watch pistons please.....

To remove valve springs crudely is to use big open end spanner or socket that fits over valve, head with valves down on timber to protect and give short sharp whack against spring retainer usually shocks the connection apart, retainers fly everywhere and valve coms oute

steptoe · Post by **steptoe** » Sun May 01, 2011 10:45 pm

You are cutting your teeth on an old piece of technology, nice and basic, not a cutting piece of technology worth half your dads house. Keep goin' with job yourself with us guiding if need be. Prepsol is good to clean things before fitting head gasket. Got a torque wrench ?

Been noticing your meticulous detail on pull apart, you are going well. You managed the last weekend of five days under the bonnet, must be shorter than me and defo more flexible or resistant to under bonnet hours. I don't think you can stuff up a heads on EA81.

steptoe · Post by **steptoe** » Sun May 01, 2011 10:48 pm

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steptoe · Post by **steptoe** » Sun May 01, 2011 10:48 pm

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steptoe · Post by **steptoe** » Sun May 01, 2011 10:49 pm

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steptoe · Post by **steptoe** » Sun May 01, 2011 10:51 pm

The shots above (sorry to use up three posts there) is the tool I use to get at the headbolts of EA81's once rocker shafts are in, engine at op temp for their retension.
It is 11/16", headbolts are 17mm, but it all works

Oh, yeah, might help to play your vid to the headshop guys to show them what you are chasing

Valve stem seals only on inlets? on EA81

RSR 555 · Post by **RSR 555** » Sun May 01, 2011 11:03 pm

Silverbullet wrote:Thanks for the suggestions. I was thinking about taking them apart myself but then I'd have to get some tools that we don't have and time that I don't have right now. Probably will just take them as they are to the head shop. Was going to get them faced as well as ask them what was wrong with the intake valve on that cylinder that got the rag in it, just wanted to know what happened to it

No probs and it's always good to try yourself, if you feel confident. Also you can save yourself some coin too.. just follow the instructions in the WSM/FSM or you can always ask on here

Silverbullet wrote:I thought they would do the regrind as part of the service? with stem seals and seats etc.

Yes they will if you ask for a full service. I'd recommend a full service but it depends on your pocket

I'd buy a VRK and take the valve seals with you to the head shop or you'll be paying for them twice.

Silverbullet wrote:As for removing studs and cleaning the block, how would I remove the studs? yeah they are threaded in but how do you get a grip on them to unscrew them?

I'd grab 2 nuts and lock them together (using 2 spanners) on the end of the stud, then using a spanner on the nut closest to the block, start undoing.

Silverbullet wrote:For re-installing the heads I was thinking about getting a pro to do it. However much I've learned from taking this apart I'm not sure about putting something as important as the heads back on myself. Might cost an arm and a leg though...

Give it a go.. you can always ask here if you get to a spot that you don't feel confident with.

Silverbullet wrote:Tip: don't hit your head with a mallet

Very good tip.. should we dare ask why you suggested this??

Silverbullet · Post by **Silverbullet** » Mon May 02, 2011 6:20 pm

Phew a few things to reply to here haha

Ok so steptoe first;
Good ideas with the wet/dry and leaving the studs in, would have to be very careful though not to get any sanding crud in the cylinders?
Yeah good to get to know engines on old technology first, we were saying what if we were doing this on dad's car? (L series) he shook his head and says "wouldn't even think about it"

And never mind about me removing valves and things, the whole heads as they were went off today. Apparently they're going to clean them up, pressure test, dismantle, inspection, report to us and quote before they do anything big. Won't be seeing the heads again for at least two weeks

Interesting spanner, how is it of benefit? And yes we have a torque wrench.

Turning the engine over with the ratchet and watching the pistons, from what I can tell with the naked eye all of them come up flush with the block and putting a straight edge up to them confirms, but a worrying sign: the cylinder that got the rag in it, the piston comes up a fraction of a mm higher than the others

would explain the higher compression? but I don't understand how an obstruction in the cylinder could make the piston/rod longer? Would I be able to see any signs if I took the sump off?
Oh and I'm 6ft by the way

RSR, Hearing that the cylinder head guys are going to have to quote us, sounds like it could cost a crapload

Might have to put the heads back on myself, what with the price of all the gaskets I need not gonna have much left for mechanic costs. Plus will learn how to do it as well, will probably find it's not as hard as it seems

Yep found how to remove studs, should have googled it before I asked

I tried but they won't budge, and I don't want to force anything by a whole lot I never know what might break or bend properly this time.

As for hitting heads with a mallet, the book said you can do it (soft faced hammer) to break the gasket seal and I'm sure I've seen it done somewhere else, but it seems not such a good idea (especially with studs)
Dad said he's heard of someone undoing all the nuts and then threading them back on a few turns (not tight at all) putting a chain or something wrapped around the engine and then cranking it with the plugs in, compression breaking the seal. Wasn't to sure what could happen with this so didn't try it.

I think that's everything haha

Cheers!

steptoe · Post by **steptoe** » Mon May 02, 2011 6:58 pm

spanner gets in on the head bolts that rocker shaft gets in the way of. that piston worries me.you have both heads off and no explain of noise then? if heads are checked to be ok, suggests noise is in deeper.... can always wipe cylinders out after sanding of block, have used a heft rubber mallet on these heads myself. there is a nifty stud removing tool, packaged by Stanley to remove studs and works best with block still in car - but I'd work around studs myself, from past experiences

Silverbullet · Post by **Silverbullet** » Mon May 02, 2011 7:34 pm

steptoe wrote:spanner gets in on the head bolts that rocker shaft gets in the way of. that piston worries me.you have both heads off and no explain of noise then? if heads are checked to be ok, suggests noise is in deeper.... can always wipe cylinders out after sanding of block, have used a heft rubber mallet on these heads myself. there is a nifty stud removing tool, packaged by Stanley to remove studs and works best with block still in car - but I'd work around studs myself, from past experiences

Ah I see, I had troubles with the spanner touching the rocker shaft, just used a socket instead. There's no noise when you turn it over by hand, could the noise be the piston banging into the head? it only comes out by a fraction but it would be enough. If it is, the car is getting another engine for sure. Already talking about where we're going to find one that works for cheap.

sven '2' · Post by **sven '2'** » Mon May 02, 2011 9:24 pm

Silverbullet wrote:Already talking about where we're going to find one that works for cheap.

If it is a cheap engine, cannot beat U-Pull-It.

For something for a few more dollars but a known(ish) history - try Rising Sun or Subawreck.

Or buy another MY for the motor only and you get a shooting car (= parts car)

steptoe · Post by **steptoe** » Mon May 02, 2011 11:14 pm

any marks on the piston concerned? Too late to check the valves. If you hold crank by tool and hand try push or tap the piston to see if is...um....broken? You do have to suspect if something is out enough for you to see by eye

steptoe · Post by **steptoe** » Mon May 02, 2011 11:17 pm

what harm in cranking engine over with rags ready for oil spitting to see if noise continues?