One of the weak spots on the Spitfire seems to be the head gasket. This is based on my own experiences (I am doing this job for the 4th time now) and online boards. All anecdotal in the scheme of things, but it happens enough that I thought perhaps having a basic style write up would help some newcomer have a smaller heart attack.
Here we are at the end of basic disassembly
Symptoms
Your headgasket goes in between the cylinder head and the block. This means it is not only containing the extreme pressures and temperatures inside the cylinders, but also sealing water and oil passageways between the block and head which are also under pressure.
What all this means is that a failure can lead to some combination of things mixing or leaking. You might have oil in the coolant and coolant in your oil (can lead to foamy/frothy brown liquid states) or you can have cylinders leaking into each other - or coolant leaking into a cylinder or cylinders.. The most common scenario for me has been losing the compression seal between cylinders 3 & 4. 1 & 2 are also very close together, but I have not run into that. When it gets bad the car may have white steam coming out the tail pipe.
This specific instance has manifested itself as starting and idling normally but then just stumbling a lot under throttle, sometimes at random. Luckily the head and block are both iron, so they have the same coefficient of expansion and are pretty tolerant of overheating. That is the good news. There were cars back in the day with iron blocks and aluminum heads that did not fare as well.
You can do a compression test ahead of time which may or may not catch it. A leakdown test is usually better here - you pump in compressed air and then see how long it takes to lose cylinder pressure. That is, if you don't have coolant in your oil / oil in your coolant. If you have mixed fluids you should hope it was the gasket because the other alternatives are worse. (cracked block/head etc.)
Repair Tips
* Bag and tag parts from each subsection. It seems so easy coming apart but later when you put it all back it will be overwhelming. I like ziplock bags personally.
* Try to note any special conditions - like there are 3 bolts but the longer one goes on the left or the top RH one is a stud.
* Try to re-install bolts into components when you can to maintain orientation and location. (just loose but enough to stay put)
* Take lots and lots and lots of pictures to record hose positions, wiring details and so on.
* Make sure you have ordered all of the gaskets you will need ahead of time. Most will be included in a head gasket kit, but measure twice.
Rough Steps:
Disassemble the various bits connected to the head. Anything with a bunch of nuts or bolts should be done in a criss-cross pattern or alternating in such a way as to avoid localized stress. Then remove the head , clean & check everything and re-assemble it.
Tools: You can take most of the car apart with a pair of screwdrivers (1 flat, 1 phillips) and 3 wrenches - 7/16", 1/2" and 9/16". Bring a couple kinds, and some extensions etc. but those sizes will cover most of your tasks.
Steps:
* Disconnect the battery
* Remove Rocker cover (2 x 1/2" nuts)
* Remove Rocker shaft (4 x 9/16" nuts)
* Drain the radiator
* Drain the engine block (plug is toward the rear of the block on the manifold side)
* Disconnect the coolant lines to the radiator (screwdriver)
* Remove the Head nuts / stud (front right is a stud) also 9/16"
* "" Water pump housing (3 x 1/2")
* Re-connect the battery and turn the engine over to help break the old headgasket seal. Since the valves are all closed but the head studs aren't holding head down, the pressure of the cylinders can break the seal pretty easily sometimes. I've had good luck with this approach.
* Disconnect the battery again
* Remove the intake and exhaust manifolds. The order and extent will differ based on what is on the car. (9/16" nuts mostly. Small 'wings" on top, 2 big "wings" on the bottom)
* Remove the water pump housing and pipe (which generally won't come out until the exhaust manifold is either loose or gone
* Remove the radiator (4 x 1/2" nuts and bolts)
* Remove the spark plugs
* Hit the head with a plastic or dead-blow hammer a few times, upwards if possible to loosen it up. The opening up front where the water pump housing was is pretty handy for this. Use gasket scrapers and a plastic hammer to work around the head where it meets the block until it comes loose.
* Carefully lift off the head (it's heavy!)
Triage
In the middle of things, you may have found other issues or noticed other broken things. This most recent time I noticed my radiator mount had broken (again!) Net net, you may need to order more parts to finish the job.
Cleanup / Prep
I like the clean off the head's mating surface with a brass brush either on a drill or by hand.
I clean off the block with a razor and either gasoline or brake cleaner. (wear gloves, pls) Stains are ok, what you don't want to do is have any scratches in the deck. It should be level and smooth so that it will make a good seal with the new gasket. If you use a brush, do your best to make sure you are not losing bristles into the block or cylinders. This is why sandpaper or scotchbrite are usually out - you don't want the media getting into the engine. I leave the oil in the sump until the end, and then I drain it - hoping that it catches and carries any particles. If things look really dirty I will drop the sump and scrub it out.
Some folks insist you should always replace the head studs. In the past I have re-used the old studs and the head gasket seal has lasted roughly 10 years, figure 20,000-30,000 miles or so. This time around I am replacing the head studs and using brand new ARP fasteners. Follow ARPs instructions for installing the new studs.
You can remove the old ones by putting 2 nuts on to an old stud (to jam them together) and then using a pair of wrenches to remove them. They may be very tight. Use a thread chaser with some oil to clean the threads and then use ARPs assembly lube to install the new studs finger tight.
First half pics:
Different distributors can have different orientations. On the Lucas D12 (modified for use here; it's an early 70's TR6 distributor) lead #1 is the bottom one in the pic. The Distributor spins CCW, so you can see it go 1-3-4-2 in order. If we need to find TDC for cyl #1, we need to know where the distributor will be pointing. You can also see the 10 nuts for the head here. They should come off slowly, in an alternating pattern as if you were putting the head on. There is a lot of pressure on it from the studs.
The water hose hookups are a little crazy, so I took a pic. The water outlet that goes straight goes to the heater valve (for the car's interior heat) and the one going out at 90 degrees to that runs up into the intake manifold. You can see one of the small "wings" holding down the rearmost bit of the intake manifold and header.
A 9/16" combo wrench I sacrificed to make removing the exhaust manifold easier. I've had this for easily 30 years now. It can be tough getting up in there, depending on the car and what has been fitted. Grinding down that side made things easier.
I bought this spigot that goes in the hole you use to drain the block. It's pretty handy. When this work is done I will flush the whole system out as best I can. It's been sitting, and it was kind of gross when I drained it. Not unusual for head gasket damage.
Since the carbs had to come off, I took a pic of the control shafts. They aren't actually attached, they just sit there. I also marked the choke location with a sharpie, although it's pretty easy to set up. The front bar is the choke, the rear (upper in pic) is the throttle bar. The throttle springs are those coils on the end. it confuses everyone because the throttle cable bracket still has the mounts for the old-style return springs.
And there we are; the head is off. Next up we need to clean off both surfaces (head and block) to get them ready for the new gasket. I also am replacing the head studs this time around. The only bummer is the 2 long ones in the rear that locate the hook to hoist the engine won't be in the kit. That soot on the pistons is normal from idling.
Finishing up the disassembly phase. Pushrods are in order, held in a piece of cardboard. They should go back to their same locations. (as should lifters if you remove them for any reason like, oh idk, cleaning) I wanted to take the carb/shield/intake all together but it was too hard. The heatshield is very sharp on the bottom so it both makes the work slow and difficult, and then also cuts you. You can see the baggies of fasteners with their local assemblies in the tray. I write some detail about the parts in the bag with a sharpie.
To remove the old head studs, simply put 2 of the old nuts back on. Then use a pair of 9/16 box or open wrenches to push them against each other while you turn the whole thing (both wrenches together) CCW. For tough studs you may need to put the bottom nut all the way to the end of the threads for support. The idea is the nuts are pressing against each other to give you the grip to turn the stud. The distributor side was very easy; the hardest ones were near the exhaust ports by cyl 2 & 3. They are not (or should not) be put in tight. The ARP instructions actually specify "finger tight" - in caps. The shiny stuff is motor oil I put in the cylinders to protect them from rusting while the work is going on.
Out with the old studs. The rusty one was near the exhaust ports.
Now we can clean up the block. The triangular holes are water ports, the little round ones are for oil and the rest of the round ones are the holes the studs go into. I have put towels over the lifters to keep debris from dropping down there. They are sitting on the camshaft.
We want to get anything that is on the surface of the block off of there - any glue from the old gasket, any soot buildup from a leaky headgasket, etc. We are not worried about stains or coloration - just flatness. There should be no scratches you can catch a fingernail on. I generally use a brass brush to help clean things up since brass is too soft to scratch iron but will get old residue off of there. You can use brake cleaner on a rag to clean up. Most sites recommend just using a razor to scrape the block and sometimes nothing is better for getting old gasket material and stuff off. Nothing wrong with that. I just worry about putting scratches in it. There is also some residual crud in the sealing rings (those cutouts around the cylinders) that will need to get removed carefully. I would wind up putting a brass brush on an electric drill for some of this.
Here is the head after a little clean up. More to go, but we're nearly there. The smaller valves are exhaust and the big valves are the intake. The vertical lines are residual machining marks from when the the head was shaved.
Final cleanup/prep & stud install
Cleaned up and now we can check it for flatness. I don't have a mechanics rule, but I have the next best thing - a luthier's. It was expensive and certified flat and all that. Using the numbers from FelPro, you should allow for as many thousandths as you have cylinders (so .004" here is the limit) and never more than .002 across the block or head. My feeler gauge set goes down to .0015" (like thin paper). So away we go.
Checking the head
Checking the block. I could get a .0015 under in a few places but not a .002. So the skim job we did decades ago is still good. Move the rule around so you are not just checking on one side or the other. Look for problems and all that good stuff. Find them before they find you.
OK, so now we are ready for the new studs.
The studs come with their own special assembly lube. The instructions say to install the studs finger tight, and to make sure all the threads are in good shape so the studs and other hardware don't bind. Binding could mess up our torque settings.
Our head studs are 3/8"-24 UNF, as are our rocker shaft studs and manifold studs. Oil up the tap (motor oil is fine) and make sure it is oriented properly. It may be tough to turn, just go slow. My threads were pretty gunked up. Tooling steel is stronger than your cast block so do not "re-thread" it. Make sure it is in there properly before you get started.
A 1/4" drum brake wrench fits well enough to speed up the job.
Here is our 3/8-24 UNF die to clean up the other studs (rocker shaft & manifold studs). A tap & die set is a great thing to have around. In the past I have not paid this much attention to the fasteners and perhaps that is one of the reasons I've done this 4 times over the past 39 years. Although to be fair, the first time I blew the head gasket the engine was all original.
And there are the fancy new studs. Thanks to the cleaned up threads and the assembly lube, I was able to put them all the way in with just my fingers. The shorter threaded section goes into the block; the longer threaded section sticks up through the head. ARP includes a hex-key fitting on top to make them easier to remove in the future. Right now I can easily take them out with my fingers. The key idea here is that if you have friction when assembling the fasteners, whatever torque is going into overcoming that friction is torque you are not getting into the fastener, so your final torque will be lower than it should be.
Here is the Payen gasket set. The scuttlebutt is that the quality has slipped on these headgaskets (I don't know either way, just reporting) so I also ordered a kit from Fel Pro based on a friend's recommendation. I'll probably go with the Fel Pro for the head gasket at least. That's the one I don't want to re-visit. They are probably all made in the same factory, things being what they are. (update - lol, see below!)
The plan is re-assemble things, set the valve clearances and drain the 2 year old gas out of it and finally change the oil which is a mix of brake cleaner, coolant, oil and whatnot at this point. If it's really awful I will pull the sump off and scrub it out. We'll see. I have a gasket here just in case.
Then I will let it sit 24 hours to cure the gasket sealant, and then finally start it up. Hopefully!
Once it is running I will flush the cooling system and then change the oil again.
I will re-check the head torque and valve clearances after 500 miles or so.* (see below)
August 3rd Update
I opened up both packages of gaskets and while they both do in fact say they are made by Payen, the Fel Pro is using a different material for theirs. Perhaps they have a white label spec of their own? I don't know. And here I thought i was just being snarky...
I could not find a material that tied out to the markings on the Payen brand gasket.
I cleaned up the block and head with a razor and a drill with a brass brush attachment. They look pretty good. I wish I could skim them both just for piece of mind, but not this time around.
The Fel Pro gasket with a pretty clear 'Payen' stamp up top.
Close up showing the material labelling (see above for mfr specs)
Here is the Payen brand head gasket. Clearly a different material.
The manifold side is all clean, and I chased all the studs with a 3/8-24 UNF tap. I also bought new nuts and washers for the manifolds. They spin on easily by hand now. Triumph only calls for 25 ft lbs on these which is not very tight. I'll use a crows foot on my torque wrench (and adjust the spec of course) to get into tight spots. In prior years I just over-tightened them I think. I am not proud.
The business side of the head is all clean and ready to go.
* I have read a lot of online forums looking for 'expert' advice around this operations to see if I am missing anything. The CV at this point appears to be:
Change the old oil before starting the engine (duh)
Use pure water in the cooling system initially
Drain out the water and put in real coolant once you are sure it is not leaking.
Run the car for 50-100mi and then change the oil again and re-torque the head.
I also usually run the starter for 30-60 seconds with the coil disconnected to get oil pressure up before trying to start the engine. Just an old habit that couldn't hurt.
Draining the old oil to get debris etc out is just common sense.
Using pure water is to avoid contamination of coolant and oil if there is a leak.
Re-torquing the head is critical and the more knowledgable people seem to do it sooner than I was planning. You have to remove the rocker shaft, and then back the head nuts off about 1/4 turn and then re-torque them. It is important that the torque measurement is part of a smooth turn, not any binding from dirt or whatever. Do the nuts in the same order you installed them in that nice criss cross pattern. ARP recommends tightening them all down in 3 steps initially, 1/3 each time so with a total torque of 45 ft/lbs, so you do 15 all around, then 30, and finally 45. When you re-do them, follow that as much as you need to. I will note my own process when I get there.
Additionally I am going to install an alternate radiator for now, (getting the original fixed) and planning on flushing the block to make sure I don't have some contaminated mix of junk in there.
Our alternate radiator, an aluminum copy of the Vitesse? unit. I forget. The trick as I have been taught is to use the top hose from an MGB which is longer than the Spitfire hose. I may need to adjust that fan guard as well. I recall that hitting last time I tried this. On the plus side, I know it's clean inside and it is full width.
August 13th Update
I put the engine back together on the 12th and let it sit overnight before starting it on the 13th. I tried to make the AL radiator work but it has too many issues. The one I could not overcome is the incorrect spigot angle on the top. It is well below the thermostat housing and not at enough of an angle to have a clean hose run. I tried both the Spitfire hose (too short) and the MGB hose (too long here, and the height difference led it to collapse) It is also much tighter against the alternator than I would like.
There was a little drama getting the engine assembled but nothing too bad.
I used a brass brush on a drill and carful use of towels to prevent crud from getting into passageways etc. Now we are ready to go.
In the race preparation manual they actually polish the combustion chamber; I just cleaned mine up. Maybe in the future when I re-build it I will take the time.
Cleaned off the water pump housing face.
There is our new gasket, I hope it's happy.
The head in its final state.
I pulled out the lifters one at a time and washed them off, finally filling them with new oil. I also looked at the Cam surfaces.
You can pull the lifters out with a finger, they are not held in by anything. Just viscosity. Do one at a time and then replace it so you don't get them out of order. It's a good idea to make sure you don't have any debris in them or any meaningful wear on the cam lobes. You can also see the distributor drive gear here (in the middle)
When you tighten the head down, you need to torque the nuts in a pattern and do 3 rounds of tightening. Since the final value is 45 ft lbs, this means get them all up to 15, then all up to 30 and then finish them all. Same pattern each time. Each 3/8" stud will apply about 8,000lbs of force when you are done, so the 10 studs together are applying 80,000lbs of force. That is why being slow and careful matters.
Here is the head stud torquing pattern from the shop manual.
I had to bail on the ARP nuts because they were 12 point and I don't own any 12pt sockets. The manifold gasket (silver) goes on dry.
I got a thin layer of gasket sealer on the water pump mount and let it set.
I used a thin layer on the pump housing and used it to hold the gasket in place and let it set. Maybe 15-20 min until it was sticky enough that things didn't move around much. The water pump housing needs to go on before you can tighten down the exhaust manifold since the pipe runs behind it.
When putting the manifold on, be sure to get all of the studs and nuts started before tightening them down. They only need about 25 ft lbs of torque. It is a challenge getting to the nuts behind the exhaust manifold. A crowsfoot wrench can be a lifesaver here. You will need to adjust the torque spec since torque your wrench probably just got longer.
You have 4 short wings up top and the 2 long wings go behind the exhaust manifold. Make sure they are on a good angle to press against both manifolds. You want to tighten these as if you were putting on the head, nice and even in a pattern so you don't get air leaks or exhaust leaks. If you have idle problems you probably have an air leak. You can find them by spraying carb cleaner on the manifold. Some folks like to use propane (don't light it, just shoot the gas out and listen) you'll hear the idle change when you find the leak
You will hear an exhaust leak. All your noise should come out the tailpipes. The front of the car should be whirring noises and tappets clicking.
I like to install the front carb first, then add the choke shaft and the rear carb. The lower bolts are a little tricky, just be patient. Once the carbs are on, I check all of the fuel line clamps and the water hose clamps. I only leave them loose in case they are in the way of a fastener. Normally I follow the "do it now" school of auto mechanics - never tell yourself you will come back to some task - always do it now. It is too easy to get distracted or just forget something. And that can be dangerous.
Once I had the radiator and fan belt in, I sent the valve clearances, dumped fresh oil over the rockers and lifters and installed the rocker cover. I drained the old oil (which looked fine, no coolant in it and no metal on the drain plug) and re-filled the car with new 20W-50 racing oil with zinc and a new filter.
I installed brand new, gapped spark plugs. Due to the higher compression I use slightly cooler plugs; a 6 rather than a 7. (BP6ES in NGK; BP5xx would be stock) I use a Lucas sport coil but still use the stock spark plug gap. The Champion part would be an N9YC. (N12YC for stock low compression)
I disconnected the coil HT lead and connected the battery. I cranked the engine over for about 30-45 seconds to get some oil moving through it. Then I re-connected the HT lead, pulled out the choke and turned the engine over. It started in about 15 seconds on some old gas (best practice is drain it or mix it 3:1 with good gas. I was impatient & impulsive). I have to sort out the radiator and put that first 50-100 miles on it now but it's a good start!
Folks on the Spitfire boards are advising that 100mi is not enough; the factory called for re-tightening 1,000mi. I am still gathering info but it sounds like the nuts get loosened in sequence and re-tightened. How loose, and how do they get re-tightened? I am asking questions to see what the CV is.
It's running great at the moment, it needs a working radiator (the Al unit doesn't fit, my stock one has a broken bracket and my spare has a pinhole leak at the bottom!) and to have the timing, carbs & idle etc. checked. But then we can go put that 1,000 miles on. I will change the oil fairly early on, knowing that there was some old oil in the oil cooler and probably some gunk somewhere that will come loose once we drive around.
Update: 8.30.23
I have installed the replacement full-width radiator (from Moss) and it fits perfectly and is working great. I have tuned the engine up (plugs, points gap, timing) filled it with new gas (93 octane) and have put around 50-75 miles on it so far. The engine temp is fine (maybe a bit low) and it is running great. The only hitch is it sprung a leak in the water pump housing gasket so I have to go back in there.
After surveying the good folks over at The Triumph Experience boards, I am going to:
* wait to hit 500 miles to re-torque the head (I will probably check it again at 1,000)
* I will back each nut off 1/4 turn with an old fashioned beam-style torque wrench to check removal torque.
* I will re-torque the nuts one at a time following the same pattern as the installation.
* This will all be done with the engine cold. (the Spitfire Manual does not provide hot engine specs. The assumption is valves are set and other items are adjusted cold unless they specify)
* I will change the oil at the same time I do this work.
September 3, 2023
Got the water pump housing removed, cleaned up and re-fitted with a new gasket and a big more permatex this time. I let it sit overnight to cure, then I put some 10-40 in the carb pistons and re-filled it with clean 50:50 coolant. It is running fine but I have a small leak on the bottom radiator hose. Otherwise we're good. Going to try some other hoses I have here, it should not be this hard to stop leaks in hoses. Could be the angle is off. If I don't run out of time today I should have it on the road for real by tonight.
September 12th
I played with the hoses a few days back but didn't have time to shakedown the car. But I did today. I rant the temp up 3/4 of the way sitting in the driveway and had no leaks, so then I took it for a quick 5 mile jaunt and it ran like a champ. I think it is a car again.
Next up is changing the oil and filter, and then putting the rest of my first 1,000 miles on it so I can re-torque the head. So far, so good!
No leaks up top at full pressure
And no leaks along the bottom. I had a tough time getting the lower 2 radiator hoses situated properly. Tt was strange, but I finally got them sorted. I like to keep the engine area clean to make it easier to see things like leaks and find them. The radiator is the new Moss full-width model. It fits nicely and works great.
September 23rd
Well the car was running great, until it wasn't. The headgasket blew out with less than 100 miles on the clock. I got flatbedded home and checked my compression. With the plugs out, 1 & 2 had zero, and 3 & 4 had 100psi. I purchased an endoscope attachment for my iPhone ($30) to see inside the cylinders. I could see a ring of metal inside of #1 that I initially thought must be a valve seat. But it turned out to be the fire ring from the head gasket.
Luckily I was near our middle school so I pulled into the parking lot and left the car there.
That evening I went back to get it flatbedded.
And here is our headgasket, the barrier between 1 & 2 is gone, and a good size section of the fire ring in cyl #1 is also gone. For some reason the leak seems to have gone towards the indexing hole in the block (there is one by #1 and one by #4) let over from when it was made. I'm not sure why this would attract the hot gasses.
A close up of the damage by the indexing hole. Some of the EU Spitfire folks insist (based on modern gasket failures) that these holes must be filled in. The old racing trick iwth high compression engines was to cut down an early model valve guide to put in here. Then you mill the block so it's flat.
Net net, I have a copper racing headgasket on the way here that I'll be fitting which hopefully will last. In the meantime I need to measure the fire ring cutouts to make sure they are deep enough. They should be .030" deep.
References:
Arp Studs for Spitfire 1500: https://tech.arp-bolts.com/instructions/206-4203.pdf
Fel Pro site - checking block/head flatness: https://www.felpro.com/technical/field-test-garage/checking-cylinder-head-surface-finish-flatness.html
Fel Pro notes on acceptable Flatness: https://www.felpro.com/technical/tecblogs/surface-finish.html
Valvoline 20W-50 Racing oil with Zinc: https://shop.valvolineglobal.com/products/vr1-racing-motor-oil-sae-20w-50?
The good folks of the Triumph Experience boards, special shout-out to Mr Carter Shore! https://www.triumphexp.com/forum/spitfire-and-gt6-forum.8/what-to-do-with-holes-in-the-block.1990035/
Heat Ranges for Spark Plugs: https://www.ngk.com/what-is-a-spark-plugs-heat-range-2#:~:text=*When%20a%20spark%20plug%20is,keeps%20the%20firing%20tip%20hotter
Adjusting a torque wrench for changes in length: https://www.terex.com/docs/librariesprovider7/tech-tips/techtip_53.pdf
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