Need to rebuild the head

**Tim Smith** · 12-24-2010, 03:57 PM

It sounds like you don't have a mechanic yet. You know, if you want to do it yourself, you can just get a head, head gasket, intake/exhaust/rocker gaskets, some studs for the manifolds and then just do it yourself. Our hosts have all the parts.

It's not a difficult job but if you have never turned a wrench you might need some guidance. Do you know anyone in the ROAV club? Maybe someone there will help out over a six pack. It can be done in a couple of hours.

**Sputnicker** · 12-25-2010, 01:14 AM

Stuck valves are kind of unusual and are usually caused by damage in the form of bent valves or corrosion from moisture intrusion. Both can be serious and an indication of damage elsewhere. A worn out valve doesn't stick. If you want to do as much of the work as possible, here's what I recommend:

1) Remove the head per Green Bible
2) Remove all the valves, springs and keepers and keep track of where they came from. You'll need a valve spring compressor for this step. Try to determine what caused the valves to stick.
3) Inspect the tops of the pistons and the cylinder bores for damage, rust or excessive wear. If you have any of the above, you may be looking at more than a head rebuild.
4) Check the head gasket for damage and evidence of leakage (water, oil and/or hot gases).
5) It will probably be obvious why the valves were stuck at this point. In most cases the head will still be rebuildable, but now you will need a good machine shop. They can probably look at your parts and tell you exactly what you need. Here's the process they normally follow:
6) Vat the head to remove all the carbon and other crud. Freeze/core plugs should be removed first.
7) Look for obvious cracks and other damage. Magnaflux to look for non-obvious cracks.
8) Check the surface for flatness and machine if necessary (it will likely need machining)
9) Remove old valve guides and replace
10) Grind valve seats (or replace if badly worn or cracked). Note: A 1982 5MB engine should already have hardened seats compatible with unleaded.
11) Grind/replace valves depending on wear/damage
12) Lap valves to ensure a good seal (some folks skip this step, but I highly recommend it and it's easy to do yourself)
13) The rest is reassembly. You can pay the machine shop to do it, or save some money and do it yourself. Make sure you install quality valve stem seals and if you have any doubt about the springs, replace them (especially if there are any signs of overheating). I'd recommend the composite head gasket. Also, get a straightedge and feeler gauge and check the block for flatness - particularly if you find evidence of head gasket leaking or overheating. Reassemble per the Green Bible.

I don't live in your area, so I can't recommend a good machine shop. If you don't get a response from someone on this forum then call around to some reputable mechanics and ask for a recommendation. There is nothing special about a Land Rover head and any good machinist can do everything that's required.

If you get stuck along the way, post some pictures of broken or suspicious parts and you will get lots of help from this forum.

**cetesse** · 12-25-2010, 10:45 AM

Let's just say its been a journey.

It all started last February with the double snow/ blizzard. Ran out of gas and was forced to use the gas at the bottom of an old underground tank. It probably had water & other gunk in it. Performance, sluggish, hard to start was the result. On the way (finally after the storm) to get new gas, in retrospect it felt like not all cylinders were firing, I think at the time I thought it was just the bad gas but perhaps more. Also, the gear shifter broke on that journey. 2 months later after stripping down the inside, replacing the gear shifter as well as replacing the main shaft lock nut. It wouldn't start.

Next, I drained the tank. Still no gas. Removed and replaced the gas tank (originally was going to have it cleaned but it developed a rust hole in the process). Replaced the the gas line at this point as well all the way back plus an electric fuel pump. Rebuilt the Weber 34ICH carb as well as replaced the main jet (which was clogged).

Still wouldn't start. Replaced the distributor cap, spark plugs, wires, points, and coil. Get good spark. But no compression both via finger feel as well as with a screw in compression tester.

Removed the head cover. Out of the 8 valves, only 4 were moving when we handcranked -- and only one cylinder had both in & outlet moving.

Hence the head removal.

Here are some pictures. Sorry iPhone = not the greatest quality.

http://gallery.me.com/christopheretesse#100322&bgcolor=black&view=grid

Chris

**JimCT** · 12-25-2010, 11:08 AM

Marvel Mystery Oil

MMO does help keep valves from sticking with less than perfect gas. Have freed up sticking valves in our flat head 6 boat engine with MMO

**Sputnicker** · 12-25-2010, 12:59 PM

Can't really tell much from the pictures. A picture of the under-side of the head might help. What is that round mark on top of the #3 piston (a hole?)? When you got the head off were there still some valves stuck open? Any bent pushrods? Any burnt valves? Any signs of leaking head gaskets? Are the cam followers moving freely in their bores?

I can't think of a scenario where bad gas alone could lead to stuck valves. The springs that hold them closed are strong and it would take some serious friction to overcome that spring tension and hold the valves open. Bad gas doesn't create that kind of friction. And if valves are stuck closed you would have broken or bent some pushrods.

I've never seen a broken camshaft and don't think it's likely, but that's another possibility if only a few valves are operating close to the front of the engine. You can check that easily by seeing if the cam followers are going up and down when the crankshaft is turning. Put some down force on a pushrod so the follower rides on the cam.

**cetesse** · 12-25-2010, 02:38 PM

One bent pushrod, another not bent but needs to be replaced.

Cylinders 1 and 4 go up and the same time 2 & 3 go down as I hand crank the engine. No holes in the top of the cylinder head.

I did notice that the front of the head gasket was forward and off the head it self by a few millimeters when we removed the head cover.

Some of the valves are still stuck open with the head removed.

**cetesse** · 12-25-2010, 03:14 PM

Further update. The pushrods also move as expected.

I've added some higher resolution photos here:

http://gallery.me.com/christopheretesse#100327&bgcolor=black&view=grid

**Sputnicker** · 12-26-2010, 12:32 PM

Good pictures. Looks like moisture is the culprit, based on a lot of rust in all the intake ports and combustion chambers. I'm guessing it happened during storage and over time the rust caused the valve stems ro seize in the guides. Blown head gaskets and cracked blocks can also cause rust, but it's usually isolated to one or two cylinders. If the cylinder bores look okay, I'd suggest trying to rebuild the head with new valves and new pushrods. You could also buy a rebuilt head.

**Firemanshort** · 12-26-2010, 04:24 PM

I am in Sterling. I have used M and D machine shop in Purcellville for some recent machine work. The main mechanic is an old Willy's fanatic.

What is your time frame for repair? I might be able to swing out to Leesburg for a look-see if you like. I have done a head or two on a 2.25.

**cetesse** · 12-26-2010, 08:43 PM

Hi Firemanshort,
Looking to restart the rebuild this week. I'm around tomorrow and Tuesday at home, then I will likely send the head to Cincinnati with my father and he will rebuild it. Give me a call at 202-549-7070 if you are around Leesburg in the next couple of days and want to stop by.
Chris

**Firemanshort** · 12-27-2010, 05:06 PM

The North Eastern Snow Storm has other plans for me. I am stuck in Maine tomorrow. Then its an all day drive home.

**albersj51** · 02-12-2011, 01:26 AM

thought id piggy back on this thread...I'm restoring my SIIA that's got the 7:1 head and id like to go to an 8:1. I can get one that needs rebuilding for a couple hundred $$ in which case I'd take it up to 9:1. Any thoughts on what I can expect to pay for something like that? I ask because I can pick a rebuilt 8.25:1 for $600. From an economic perspective am I better off with the already rebuilt one or will doing the rebuild save me some money? Also would the extra .75:1 compression make much of a difference?

Thanks,
Jason

**cetesse** · 08-27-2011, 12:25 PM

Head is on -- she lives!

Well, 8 months later she is back on the road - picture of the cleaned up engine bay attached.

We did everything ourselves except for the final timing, and used Loudoun RoVa in Northern Virginia to help out there (simply ran out of time).

It was quite worth the drive home, especially at 45 MPH downhill

, with the line of traffic behind during rush hour on Friday afternoon.

Now do I paint her knowing the body is pretty rough or ??

So the sum total of the last 2 years is now:
new battery new clutch slave cylinder new starter new ignitor new starter relay new tires fixed fuse and got electronics to work drained and refilled both differentials replaced rear right reflector replaced fuel sender and got fuel gauge to work fully drained and replaced transmission and t-case fluid replaced main shaft nut replaced shifter shaft, ball, hi-lo ball, numerous screws on floor replaced 4 plugs and 5 wires rebuilt fuel pump (both new manual as well as new electric pump) replaced all driving and signaling lights banged out right hand side fender replaced fuel line from tank to manual pump added electric fuel pump rebuilt weber 34 ich carb added rear mud flaps replaced fuel tank and all lines DUCELLIER distributor, added Pertronix ep-142 electronic ignition with Flame Thrower coil (40511) replaced pump jet on carb with 76407055 (note the 55) Installed Pertronix EP-142 and Flame Thrower Distributor Installed new pump jet on Weber 34ICH carb Found that 4 out of 8 valves were stuck open or closed removed the head and had it rebuilt re-installed head BAFFLE PLATE ROCKERS 2.25 AND 2.5 PETROL - ERC9278 -
5/16 INCH SPRING WASHER. - WM600051L - BOLT FOR ROCKER BRACKET 2.25 PETROL - 525500 - LOCATING BOLT ROCKER SHAFT 2.5D NA 2.5DT 2.5 PET. AND 2.25 SUFFIX C ON - ETC4460 - £1.41 2 £2.82 AIR INTAKE HOSE PETROL 2.25 LITRE AND 2.6 LITRE. - 517903 -
Re did timing Oil Change Testing directionals New heater control valve Various new hoses Greased the spindles

Originally posted by cetesse

Let's just say its been a journey.

It all started last February with the double snow/ blizzard. Ran out of gas and was forced to use the gas at the bottom of an old underground tank. It probably had water & other gunk in it. Performance, sluggish, hard to start was the result. On the way (finally after the storm) to get new gas, in retrospect it felt like not all cylinders were firing, I think at the time I thought it was just the bad gas but perhaps more. Also, the gear shifter broke on that journey. 2 months later after stripping down the inside, replacing the gear shifter as well as replacing the main shaft lock nut. It wouldn't start.

Next, I drained the tank. Still no gas. Removed and replaced the gas tank (originally was going to have it cleaned but it developed a rust hole in the process). Replaced the the gas line at this point as well all the way back plus an electric fuel pump. Rebuilt the Weber 34ICH carb as well as replaced the main jet (which was clogged).

Still wouldn't start. Replaced the distributor cap, spark plugs, wires, points, and coil. Get good spark. But no compression both via finger feel as well as with a screw in compression tester.

Removed the head cover. Out of the 8 valves, only 4 were moving when we handcranked -- and only one cylinder had both in & outlet moving.

Hence the head removal.

Here are some pictures. Sorry iPhone = not the greatest quality.

http://gallery.me.com/christopheretesse#100322&bgcolor=black&view=grid

Chris

Attached Files

Need to rebuild the head

Need to rebuild the head

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