Can the cylinder head be removed while the engine is in the car?

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guzzit3
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Can the cylinder head be removed while the engine is in the car?

Post by guzzit3 »

It looks like I need to take the cylinder head off a 1984 excel

A few quick questions before I start:
Are there any special tools or parts required? Do I need something to hold in the liners? Has anyone managed to remove the head with the engine in the car? If so what was the trickiest part?

Also the exhaust manifold seems pretty tricky to remove when the engine is in the car, what is the easiest way to do this? Is it best to take all 12 nuts off between the manifold and the cylinder head or could I leave these on and undo the 2 bolts between the exhaust and manifold instead?

Finally apart from replacing the head gasket, are there any other good jobs to do while the head is off? Thanks

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Hawaiis0
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Re: Can the cylinder head be removed while the engine is in the car?

Post by Hawaiis0 »

It will be far easier to do with the engine out. You could spend 3 days or more trying to do the manifold
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Re: Can the cylinder head be removed while the engine is in the car?

Post by Pete Boole »

Yep - getting the exhaust manifold off while in the car is almost impossible :roll:. I'll second the vote to remove the engine/box to work on it. It may seem improbable but it will probably won't take any longer and you'll not want to put a lump hammer through the exhaust manifold!!

Worth measuring the valve clearances before you dismantle unless you're going to work on the valves. Liner clamps needed when you've got the head off - do not rotate the crank without them in place. I am currently the custodian of the "club clamps"!

Pete

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rbgosling
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Re: Can the cylinder head be removed while the engine is in the car?

Post by rbgosling »

I've done it. Twice, in fairly quick succession. PITA, but do-able. I might well have left the exhaust manifold attached to the head and disconnected it at the next connection, I can't remember for sure to be honest. It is almost certain (unless it's been done already) that the exhaust manifold studs and nuts will have rusted into small stumps, so while you've got it off, replace the studs with stainless and the nuts with brass. You only need liner clamps if there is any chance you will rotate the engine while the head is off. Only other special tools you'll need are a decent torque wrench to re-tighten the head nuts, and a Torx driver bit for some of the cam carrier bolts. Some strong bar magnets to hold the tappets in place when you lift the cam carriers off are a good idea too. And you should use the opportunity to check the valve clearances, so you'll probably need to get some different size valve shims, but you'll only know what size you need when you measure the existing clearances and then measure the shims in there at the moment.

Check the valves, at the least give them a re-grind, but new valves may be required, the seating surface can get badly pitted. To do this you'll need a valve spring compressor.

If you are feeling rich, it's not a bad idea to get the head checked over professionally, and given a slight skim to refresh the bottom face.

With the engine in the car it is SO much easier to get some dirt in there, so be EXTRA careful on that!

And it should go without saying that you should replace the timing belt while you're in there.
"Farmer" Richard

1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)

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Re: Can the cylinder head be removed while the engine is in the car?

Post by bash »

I agree with richard. Undo the exhaust to manifold, take off the offside engine mount and undo the nearside, push the engine as far over to the offside as it will go and jack it up too and there should be enough room to get the head off with the exhaust manifold attached. Make sure the battery is off and undo all the usual pipes etc. If you take the cam carriers off watch for the shims falling out and dont be rough putting the carrier bolts back its easy to strip the threads in the head but if you do they are easy to helicoil at home.
Bash
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Re: Can the cylinder head be removed while the engine is in the car?

Post by DavidOliver »

While an engine out is not a difficult job, the full engine is quite light, and to answer your question, yes you can lift the head without removing the engine.
As commented, leave the exhaust manifold attached to the head, mainly later to undo with good access the many tight manifold to head bolts.
The liner clamps simply stop the piston ring to cylinder friction from de-seating the liner should you turn the engine. All you need are some large washers and short lengths of (copper) pipe on the head studs to clamp individually each cylinder. The ¨Pucker¨clamps allow piston removal, you will not be doing that.
While at it, check the front crank seal for leaks, easy to fix with a cambelt change as you have to pull the crank pulley.
Also cam carrier oil seals. Also the funny little L hose between head and thermostat, and the hose between inlet manifold and water pump. This hose has different diameters end to end and therefore is not a Halfords fix.
Once off, check the head for Core plugs front and rear, they rust from the inside to out, do not warn you and cost nothing to change.
How about a run of braided fuel hose for Carburretors to replace the old Teflon ones. Full fuel line replacement is recommended by some.
You will need special minimum thickness adhesive for the cam carrier to head joint. Measure existing valve clearances before dismantling, and maintain the position in the head of all components for rebuilding.

That´s enough for today as the F1 is about to start.

Dave the cog.

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Re: Can the cylinder head be removed while the engine is in the car?

Post by guzzit3 »

Thanks for the replies, that's a huge help. The exhaust/manifold bolts were pretty tricky, I managed to do it in the end, I don't have an engine hoist so this really was my only option if I'm do get this done is a reasonable amount of time.

A new timing belt has been ordered, along with Loctite 515 and a valve shims as some of the clearances were on the large size.

I'll have a look at doing some of those other things like replacing core plugs and the fuel lines to the carbs while I'm waiting on the parts to arrive, and check the condition of hoses, etc. as it's easier to do it now rather than have to take it all apart again later on.

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Re: Can the cylinder head be removed while the engine is in the car?

Post by rbgosling »

Should have mentioned, but not too late... check the state of the timing belt idler while the belt is off. Does it spin freely and smoothly? Is the surface contacting the belt in good condition (a rusty surface can wear the belt)?
"Farmer" Richard

1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)

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Re: Can the cylinder head be removed while the engine is in the car?

Post by Tanz »

There used to be a link in the Technical articles on removing the head with the engine in place but doesn't work now
viewtopic.php?f=8&t=3930
However, I did print it out many years ago so could scan it for future use.
Cheers, Phil
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Re: Can the cylinder head be removed while the engine is in the car?

Post by DavidOliver »

Not sure that Loctite 515 is the correct goo for the cam carrier to head joint.
Common practice is to assemble the cam carrier complete without joint seal and measure valve gaps.
The Lotus Workshop Manual refers to Loctite 504 and when assembled dry allow for 0.0015 inches on shim thickness for final assembly with Loctite 504.
I believe that during Angus days the Forum had a box of shims available to members.

Dave the cog.

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Re: Can the cylinder head be removed while the engine is in the car?

Post by rbgosling »

DavidOliver wrote:
Wed Jul 07, 2021 11:57
Not sure that Loctite 515 is the correct goo for the cam carrier to head joint.
Common practice is to assemble the cam carrier complete without joint seal and measure valve gaps.
The Lotus Workshop Manual refers to Loctite 504 and when assembled dry allow for 0.0015 inches on shim thickness for final assembly with Loctite 504.
I believe that during Angus days the Forum had a box of shims available to members.

Dave the cog.
Loctite 504 is No Longer Available. The advice I found was to use Loctite 518, so that's what I did in my engine rebuild. 515 may work just as well too, for all I know. 518 squishes down rather thinner than 504, so you don't need to add so much allowance for the goo thickness. Some trial and error is called for.
"Farmer" Richard

1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)

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Re: Can the cylinder head be removed while the engine is in the car?

Post by Tanz »

I got my shims from QED Motorsport. They were very helpful and gave good advice. Regarding Loctite between the cam housings and the head, they said they didn't use Loctite. Just use high temperature sealant that you can get from Halfords spread thin and evenly. I did the valve clearances in 2009ish and it worked perfectly and is still working. Might be time to check them again.
Cheers, Phil
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Re: Can the cylinder head be removed while the engine is in the car?

Post by Esprit2 »

It's important to know the final film thickness of the sealant you use. For Loctite 515 & 518, it's 0.0005" / 0.0127mm. What is the film thickness for the "high temperature sealant that you can get from Halfords"? If you don't know, I'd advise against using it.

For the optimum service life, shim to the top of the clearance ranges MINUS the film thickness during DRY trial assemblies. Then add the sealant during final assembly and the sealant film will 'float' the cam carrier up that last little bit to give a final clearance that is at the top of the range.

Intake . = 0.005-0.007", shim dry to 0.0065" / 0.165mm
Exhaust = 0.010-0.012", shim dry to 0.0115" / 0.292mm
The final result film will be very close to 0.007 & 0.012" (the top of the ranges).

Apply only a very thin film of sealant! It's going to squeeze down to almost nothing, and any excess will ooze out of the joint. It's easy to wipe off any that squeezes 'out'. But for every bit you see on the outside, you can bet there's a similar amount on the inside where it's not supposed to be.

Don't just squeeze on a bead of goo down the center of the mounting flange, and simply hope it goes where it's supposed to go when the cam carrier is bolted down. Use a flux brush to 'pain't a thin film only where it's supposed to be, and full width on the flange. Then blot it with a paper shop towel. Lay the towel over the 'painted' surface, and pat it lightly. Don't rub, you'll take off too much sealant. Just lightly pat the towel to ensure full contact, then peal it off. The remaining film will be very thin, but that's all that is required. Loctite 515 & 518 are a bright red gel, and the remaining film will barely be pink. That's all you want, 'cuz more just goes where it's not supposed to be.

Regards,
Tim Engel

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Re: Can the cylinder head be removed while the engine is in the car?

Post by Tanz »

Here's a link to the 'how to' I mentioned above. Thanks to Chris for providing the link .

http://www.ngate.plus.com/Benani_archiv ... asket.html
Cheers, Phil
Never take life seriously, nobody gets out alive anyway!

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