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Thread: TR4A Head off for broken manifold stud - What else to do ?

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    TR4A Head off for broken manifold stud - What else to do ?

    During a removal of the TR4A exhaust manifold the lower rear stud twisted off in the head.
    I drilled the stud out but the easy out just smeared the and nothing came out but shavings.
    All of the other studs came out with some lots of WD40 and double nutting.

    From the PO this car had a history of blowing out the manifold gasket every 30k-40k miles right next to the broken stud. I am in the middle of the first pass at a mechanical restoration of this vehicle which has not run since 84. The vehicle has 144k miles total and had a lower engine overhaul around 85k miles.
    The had a broken valve spring around 50k miles other then that no other mods since new in 67.
    This has original valve seats and valves (not modern hardened for unleaded ops).

    I have removed the head and handed it over to a machinist who is evaluating the broken stud.
    I have not looked at the cam shaft
    After the stud issue is resolved we plan fo fit check of the manifolds (without gasket) to see if we need to do some "adjusting" of the rear manifold port.
    I plan to replace the manifold gasket with the Moss uprated gasket (695-070).

    Questions:
    1) Has anyone else had this blowout problem ... what was resolution ?
    2) Any recommendations on other upgrades to head while I have it out.
    Valves, seats, guides, etc.
    3) Are any of the Moss upgrades parts worth the effort (tappets, roller rockers, etc)
    4) I see alot of discussion on 3/8 vs 5/16 valves/guides.
    I will continue to monitor those threads...

    The plan for the car is normal driving with this car and might be a partial daily driver.
    However I would like to NOT revisit the head again after everything is together.
    Attached Images Attached Images
    1947 Willys CJ2A
    1967 TR4A IRS (CTC77927LO) Current Project

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    Jedi Warrior BlueMax's Avatar
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    Re: TR4A Head off for broken manifold stud - What else to do ?

    Stud can be EDM which would save the threads. After that I would have the machine shop skim the manifold surface on cylinder head. I would also have the exhaust manifold done as well. As far as performance up grades go as far as your pocket book can handle and enjoy the car.

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    Re: TR4A Head off for broken manifold stud - What else to do ?

    Also I have purchased new exh manifold studs.
    The exh manifold has been blasted and HT powder coated - looks great.

    What would be the minimum to do before putting it all back together ?

    Thanks!
    1947 Willys CJ2A
    1967 TR4A IRS (CTC77927LO) Current Project

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    Luke Skywalker KVH's Avatar
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    Re: TR4A Head off for broken manifold stud - What else to do ?

    Awesome we've got another Tucson TR4 owner. There are a number of us here in Tucson, and 6s, too, and lots of 3s. You'll find great advice here from a great number of folks who have had everything bad happen to their cars, at least once, and who can guide you any problem or issue. I rebuilt my overdrive on this Forum. Rebuilt my engine. Disassembled my horn relay box. Replaced the axles on my IRS model. Rebuilt my entire front end. Replaced two dashes and two interiors. Two clutches and one broken clutch fork pin. Fixed the upper shift housing on the tranny. Replaced coils springs and shocks. So much more. One guy here in Tucson is a real inspiration to do things right; he carries spare distributors and fuel pumps wherever he goes, and knows more about TRs than you could imagine. I swing by his house to admire his garage and epoxy floor from time to time. I could list names from California to Belgium, to Australia, but good you're here. Post your problems. We'll give you all the advice you can stand, and maybe a laugh or two.

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    Yoda Geo Hahn's Avatar
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    Re: TR4A Head off for broken manifold stud - What else to do ?

    I had hardened seats added to both my TRs when I had the heads off for other reasons. Also did new springs, guides and valves because (like you) wanted to drive and not be back in there for some time. I did nothing with the cam or rockers.

    On one car I went with long manifold nuts, on the other I used brass. No idea which will be less of a problem in the long run (possibly both are fine) though the longer ones are a bit easier to get a wrench on for those ones under the manifold.

    As for what else - were you able to do a compression check or read oil pressure prior to the tear-down? I ask as you're about a third of the way into the work needed to replace pistons. liners & con rod bearings.

    It's never a problem knowing where to start - but it can be a problem knowing where to stop.

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    Re: TR4A Head off for broken manifold stud - What else to do ?

    KVH,
    Thanks for the Hello...

    I have met several guys at work that are into cars (Pantera's, TR's, MG's, etc) and are members of the local club.
    This TR4a kinda fell in my lap(cost to transport from Cupertino) and I would have never bought but I have always wanted one and so here we go. This car is in great shape from the body perspective. The boot lid has some rust that needs work and the battery area was redone. The engine is is relatively good shape but I just want to get it in good mechanical shape and drive it a bit before starting on the cosmetic stuff.

    This broken stud is the first Oops on the car... I am trying to be rather careful as I know that some things are fragile.

    Again at this point the head is at the machinist shop awaiting broken stud diagnosis and what ever upgrades I want to do before reassembly. All suggestions will be considered.

    I live near River/Swan and the car is stored near Alvernon/FtLowell.
    Give me a shout if you want to meet up sometime.

    Thanks again !
    1947 Willys CJ2A
    1967 TR4A IRS (CTC77927LO) Current Project

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    Yoda Geo Hahn's Avatar
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    Re: TR4A Head off for broken manifold stud - What else to do ?

    Not sure if your schedule permits, but Tucson British car owners meet for coffee every week. Tuesday mornings from 7:30 to about 9:30 at the Starbucks on the NE corner of Grant & Swan. Some come early. Some come late. Some don't even drink coffee.

    We're there rain or shine every Tuesday for the past 8 years (except the one time it fell on Christmas day and even then a few showed up).

    Stop by if you can and meet a few of the other local enthusiasts (including a TR3A owner who also has a vintage Jeep & is a BCF member).

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    Jedi Knight
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    Re: TR4A Head off for broken manifold stud - What else to do ?

    Regarding the blown head gasket----I have had that happen to me --once. It happened about 10,000 miles after I redid the head. Figured out that the head gasket was installed upside down. The gasket appears symmetrical so can fit either way--BUT the side of the gasket that is solid and does NOT have the folded over seam goes against the block. The block side has the larger water ports that will deminish the gasket if the folded seam is made available to the water. Putting the seam against the head better protects the gasket. This was especially true for me at the rear of the number 4 cylinder.
    I would guess that many people install the gasket opposite of the way I described with no bad effects.
    It would help if you knew where the old gaskets failed.
    Charley

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    Re: TR4A Head off for broken manifold stud - What else to do ?

    Charlyf,
    It was the exh manifold gasket that blew out every 30-40k miles...
    It blew out toward the car bulkhead from the rearmost cylinder of the engine...
    The stud that just twisted off was the lower rear stud... right where the gasket kept failing.
    Guessing that the rear port of the exh manifold is not flat on the head...
    1947 Willys CJ2A
    1967 TR4A IRS (CTC77927LO) Current Project

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    Re: TR4A Head off for broken manifold stud - What else to do ?

    re> Tuesday mornings from 7:30 to about 9:30 at the Starbucks
    Will do..
    1947 Willys CJ2A
    1967 TR4A IRS (CTC77927LO) Current Project

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    Re: TR4A Head off for broken manifold stud - What else to do ?

    Do whatever it takes to repair the threads in the head. With care, you may still be able to save the original threads; if not I would start by installing a Helicoil (or similar) insert. If that fails (I've never had one fail but others say they have), then try one of the larger solid inserts.

    If the shop doesn't skim the sealing surface of the head (which requires removing all of the studs and the two locating pins), then you can do the equivalent yourself with care and a fine tooth flat "machinists" file. I almost always find that the surface is pulled up around the stud holes. Do the same for the manifold. Actually, from the amount of damage I see in your photo, I'd ask the shop to skim the head even if they don't think it is necessary.

    When you reinstall the manifolds, be sure to leave loose the connections between them until after everything is fully clamped down. I actually just leave the connections permanently loose, as that extra heat to the intake manifold can't be helping performance in warm weather. Also make certain the intake fits over the locating pins before you start tightening the nuts. Pulling it into place with the nuts can turn up a burr inside the hole that keeps the manifold from fitting snugly against the head.

    On the front & rear studs (the ones without the bridge pieces), I find it works better to add a heavy "setup" flat washer between the manifold and lock washer. Obviously, replace the lock washers every time as the heat causes them to lose their spring. And recheck them for tightness from time to time, weekly at first until they stay tight then less often. For my money, the tall steel nuts work best. Use some anti-seize on the studs (I like the copper kind).

    There are special extra-thick (and heat resistant) gaskets available, but I've never had to use them.
    Randall
    56 TR3 TS13571L once and future daily driver
    71 Stag LE1473L waiting engine rebuild
    71-72-73 Stag LE2013LBW waiting OD gearbox rebuild

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    Re: TR4A Head off for broken manifold stud - What else to do ?

    In the same vein -- when reinstalling the manifold you may need to place the bridge pieces over the two lower middle studs before the manifold is fully home against the head.

    On mine anyway, I find that if the manifold is all the way on there is no longer room to get those big bridge pieces between the end of the stud and the body of the manifold.

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    Re: TR4A Head off for broken manifold stud - What else to do ?

    Thanks all.
    Manifold stud hole was repaired.
    Had hardened exhaust valve seats done at the same time...
    I have a new question on the wear pattern on the tappets and not sure if is is normal.
    Will post a new thread on this.
    1947 Willys CJ2A
    1967 TR4A IRS (CTC77927LO) Current Project

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    Re: TR4A Head off for broken manifold stud - What else to do ?

    As above, resurface all cylinder head and manifold contact surfaces, check valves, guides, valve seats etc.etc.
    Another simple low cost job would be to matchport the manifolds to the head.

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