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Re-installing cylinder head, what gasket should I use?

Jonas Nordstrom

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Im going to remove a cylinder head to drill out some broken exhaust bolts.

What gasket is recommended when putting the head back?
And any tips on getting the block/cylinder head surfaces clean and smooth again?
(I wont pull the engine, so no milling etc.)

413 block.

Thanks

block.jpg
 
If the engine has never been apart, it probably has the .020 steel head gaskets. The common Fel Pro head gasket is almost double at .039. This drops the compression about a 1/4 of a point.
The steel head gaskets sealed because the engine was machined fresh and everything was new. I don't think I'd trust them after pulling a 55 year old head off. You are now faced with either having mismatched compression side to side or replace both gaskets.
 
Well, you'd obviously want to use another pretty much identical to the one on there now, eh?
Otherwise, you'd be messing with mismatched compression from one side of the engine to
the other - and might even get into messing with the intake, etc. sealing back up properly,
too.
See what's on there now and match it if at all possible.

As far as cleaning surfaces, if it was a healthy, good running engine before, take all appropriate
actions to prevent contamination of your oil passages and such and scuff the surfaces down well
with Scotchbrite or some such.
 
If all you're doing is removing a broken stud, then it's much easier to weld a nut to the broken stud and remove it with a wrench then it is to drill it out. Crank the welder up high and fill the nut with weld, the heat will also loosen the broken stud.

If you don't have a welder, a Harbor Freight flux core welder will only be about double, maybe triple what a gasket set and other misc items would be. Edit: I see you're in Europe, so prices are probably different.

That’s how I got this broken valve cover bolt out.

D688F8D6-DD2E-47A9-A13E-214DF75C6C74.jpeg View attachment 1005317
 
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I've been fortunate to live where rust isn't as big of a problem as it is elsewhere BUT I have dealt with bolts breaking off flush. The welded nut procedure has worked quite well twice so far.
 
Well, you'd obviously want to use another pretty much identical to the one on there now, eh?
Otherwise, you'd be messing with mismatched compression from one side of the engine to
the other - and might even get into messing with the intake, etc. sealing back up properly,
too.
If the engine has never been apart, it probably has the .020 steel head gaskets. The common Fel Pro head gasket is almost double at .039. This drops the compression about a 1/4 of a point.
The steel head gaskets sealed because the engine was machined fresh and everything was new. I don't think I'd trust them after pulling a 55 year old head off. You are now faced with either having mismatched compression side to side or replace both gaskets.

I have some gasket sticking out on one side and its def a steel gasket.
I did think about replacing both gaskets if I need to change gasket thickness.

Its quite narrow to reach but welding on a nut could be a possibility as the bolts broke pretty flush.
 
I would suggest taking them both off, it's not that much more work and you are most of the way there if you pull one head.
Check the heads for warp and twist.
If they are not really straight and flat then mill them.
If they are straight then clean everything really well and use a steel shim again.
If you mill them then use the fel pro gasket.
Even if it ran well, I would remove all the valves and studs.
Hand lap the valves, install new studs (one broke already) and put new valve seals in them.
Otherwise you potentially fix one half and then possibly have to do the whole job again in a few years.
 
And check your hangars on the exhaust system.
A broken hangar strap can cause extra stress at the manifold and contribute to breaking the studs.
Good luck with it.
 
Just see what gasket is in there when you remove the head and replace it with the same thickness. I’d use brake cleaner to Wipe clean the surfaces and use a new razor blade if there is sealer or crud that won’t come off. Use a shop vacuum while scraping to pick up anything that comes loose.

ScotchBrite will be removing material, not good on the head and block surface. BB mopars have 17 head bolts and don’t generally have head gasket leak problems so no need for surfacing them. I’d leave the other head alone if it doesnt have any problems. If you change head gasket thickness The change in compression will vary with you engine displacement. More compression Change for a smaller bore.
 
NO SCOTCHBRIGHT the little carbide particles are death and even harder to get clean than glass bleed
Mr gasket .o28 is as close as you can get
run a compression test you may need a valve job
how are those stem seals, timig chain
if oem you are way bast borrowed time
 
I would try to find a mopar .020 gasket.. theyre out there. Try some machine shops. ALSO, if using a steel shim,,, get the gasket spray (mopar). They weren't designed to go on dry.
 
When I checked Summit, the Mopar shim head gaskets are special order, and cost $171.99
The inexpensive Mr Gasket is also special order, but just $25.26 each.
They do have two different bore size, 0.027" thick Cometic MLS gaskets in stock at $88.41 each.

I don't know how easy or hard it is to get parts for a big block Mopar in the EU?
Part of my thinking on the Fel-Pro kit, is it should be easier to get, but also includes most of the other gaskets and seals the owner will likely need like the valve cover gaskets, valve stem seals, plus all the extra gaskets that may be needed later like water pump and housing, timing chain cover, oil pump and oil pan, front cover seal, rear main seal, and thermostat gasket.
 
The job list is growing by the hour...
If the car is otherwise fine, I'd just try to get the studs out without removing the head. The valves, seals etc might be ok for the next 10 years.
There are specialist mobile stud guys here in Australia, maybe you have similar? Only 2 weeks ago I had this same issue, the guy came out to my house and got the stud out for $80.
 
The job list is growing by the hour...
If the car is otherwise fine, I'd just try to get the studs out without removing the head. The valves, seals etc might be ok for the next 10 years.

This.
Thanks for the tips, I will try the welding.
The car has sat too long in the garage and needs to get out.
The 413 came with the car and runs great but I have shop-ready 1970 440 HP block also in the garage, waiting to become the new engine

For a smaller operation for the 413 I could change the stem seals as I found a cracked one, though I then need to find a good valve spring compressor tool?
 
common mistake "i'm going to remove a cylinder head" is different than "how to remove a stud'. Find a half reputable mobile welder? I wouldnt worry about the stem seals too much.
 
If it's just exhaust studs & all else is ok, I would consider pulling the motor/trans up-out clear to Drill & tap.....I hate pulling old stuborn heads with all the surface prep & big $$ gaskets cost...far less "critical" disturbance ...just saying......
 
That's only if the welded nut trick don't work out.
 
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