RedArrow Refurbishes d24t from a brown 740

[RedArrow]

D.2.4.T.

t for tractor

[RedArrow]

Hopefully I can test and adjust this wastegate!! IDK how but will be trying to figure out.
Eventually I`ll need to get a t3 rebuild kit for the gaskets and studs.

I need to temporarily reuse that large round gasket that is on the aluminum turbine housing. Hope that`s ok.
And deal with the Mercedesbenz wastegate seal that is cracked and I cant seem to find it online.

Also, finally, to decide what`s going on with the intake (how will it look, will it get coated or polished up a bit?) I have nonturbo intakes and one is polished pretty well but I`d like to keep this d24t stock for now and see how it runs.

d24t intake stays for now. I`ll try one more time to machine sand it into something more acceptable.

[RedArrow]

Who would spend time cleaning up a d24t manifold; or even worse, the miniature turbo of a usually less than ~100HP car?

The manifold gaskets have some paint on them from a previous cylinder head porting experiment but they are new and never been torqued onto an engine so i`ll use them on this d24t.

Talking about porting... wow look at these...

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I tested the wastegate valve and it opens very well but I couldnt set up the compressor with a gauge so I`m not exactly sure at what pressures it did but it seems to move easily and freely and appears to be not stuck at all. https://www.youtube.com/watch?v=DpEAvlqdq6E

[RedArrow]

Gaskets are up and exhaust stud threads cleaned&greased a little, bolt holes cleaned up, manifolds ready to be installed with their mating surfaces doublechecked and wiped clean with solvent.

nice progress

Factory torque value for the exh manifold nuts is 18ft/lbs only*
I did align the manifold well and did torqueing in 3 stages.

then,

at the very last stage with the very last nut (cyl 6, top),

something sounded like the wrench clicked `too early` and it did in a weird way...
well, it wasnt the torque wrench, the stud broke into the cylinder head.
((FYI, it broke about 0.6-1cm (= appr 1/2 inch) in, as measured from the cyl head outer surface.)

UGHH

Project abandoned now.



What`s the well-known, `working method`, your probably best stud extraction trick from d24 head experience?


Maybe you have a certain exact type of drill kit idea to use, a reverse stud remover kit that worked good or whatever, etc etc, IDK.
Also, do you know the exact length of these studs? Can someone let me know after measuring one if available?


Thank you.
I dont want to experiment and make the situation worse than what it already is, so I really appreciate the sharing of a well known, proven (worked before on d24) method
)
Thanks!
until then, here`s some pictures.


I put the intake up to show how it would look if that stud didnt break into the head.

I tilted the engine to have the hole filled with wd40 so the remains of the broken stud can soak overnight. Fingers crossed

[ngoma]

Situation not particular to D24. No reason to cause you to abandon your project.

1. Soak it with penetrant, try a left-hand drill bit. Sometimes the drill bit working in reverse will unscrew the stud remains.

2. Weld a nut to the remains of the stud and unscrew it with a wrench. Hundreds of examples of this on youtube.

3. (requires the most skill) Drill the stud exactly perpendicular and straight into the exact center in increasing sizes drill bits until you can scrape out the last remaining bits of thread left from the threads in the head. Almost impossible to get the drill straight and centered. If you damage the threads in the head, you can drill oversize and use a Time-sert or helicoil.

4. (not recommended) EZout or similar. Often these break off in the stud leaving you worse off than before.


#2 is probably your best bet, telling you now.

Good on you for using the proper (special Volvo) exhaust manifold heat/tension washers, cleaning the threads, and using anti-seize.

[RedArrow]

Originally Posted by ngoma

Situation not particular to D24. No reason to cause you to abandon your project.

Yeah. And thanks for starting with positivity and sending useful advice as an answer!

I was just referring to the fact that I had to suspend installing the manifolds, turbo, etc. My plan was to finish up today with everything but yesterday I saw no chance achieving that. The assembly got `abandoned` temporarily due to this broken stud. I was wondering back then if there was a specific well-known trick that`s particular about how to deal with the d24 when that happens (35-40years old Volvo studs, specific stud length, thickness of cyl walls whatever if there was a series of to-dos or not-to-dos).
I`m sure studs happen to break at almost every major brick rebuild too. To me the most annoying part was, as I said earlier, that the exhaust stud broke 1cm in and nothing was left `outside`.
There was good exercise on the broken ac bolt, a warming-up experiment for the day, and the testing of some of the tool kits I bought. Mostly, none worked. Only the good old method you circled as being the hardest and most complicated. :~)

Originally Posted by ngoma

1. Soak it with penetrant, try a left-hand drill bit. Sometimes the drill bit working in reverse will unscrew the stud remains.

Unfortunately none of the shops I went to have ever heard of a left hand drill bit. Weird. I loaded up on various sets of stud/bolt removal kits, several kinds and sizes of drill bits, punch kits etc, just to have them in case i ruin my other tools, ...so tomorrow there will be quite a lot of returned merchandise (of either low quality tools or/and unwanted spares) esp the HF are usually useless for a serious project.
About soaking. When I got the engine, it was sprayed all over, literally all over, daily, for almost a week every day. When the stud broke I tilted the engine and filled the hole with wd40 again and I think it constantly swam in wd40 at the drilling too and through the extraction. A left hand drill bit set, if quality, will be my next buy. I`m sure they often work wonders.

Originally Posted by ngoma

2. Weld a nut to the remains of the stud and unscrew it with a wrench. Hundreds of examples of this on youtube.

This would have been the best but the welder is tucked away and I can`t use it = IDK how to weld. Would def need a class before touching that equipment.

Originally Posted by ngoma

3. (requires the most skill) Drill the stud exactly perpendicular and straight into the exact center in increasing sizes drill bits until you can scrape out the last remaining bits of thread left from the threads in the head. Almost impossible to get the drill straight and centered.

I chose this method and it worked, through series of various attempts of using combinations of techniques and options, using whatever was available. YES, it WAS impossible to keep the hole perfectly aligned. I took my time and did my best OCD approach and lots of care but it still ended up being wrong in many ways, wrong angle and not even centered perfectly. I could have ruined all of the threads but ruined none which I think is good news. Thanks to the expensive and good quality drill bits and some common sense thinking which had luck on top of it all. I`m glad it all went quick (meaning it solved overnight. it didnt go quickly though and definitely not smoothly)

Originally Posted by ngoma

4. (not recommended) EZout or similar. Often these break off in the stud leaving you worse off than before

Yes I had good hopes on those but then gave up soon after. I bought sets and tried to get another broken-in bolt out at the ac bracket; and it failed. The technique sounds great but the quality of the products arent satisfactory.

I had a very nice hole punchstarted then drilled, up to the next sizes then the frkng extractor broke into the whole thing, exactly what the nightmare stories tell. The remover snapped and broke into a perfectly made and filled the by then already extended hole. To be continued next time but I`ll sleep on it a few times.
maybe a set of diamond marble grinder bits will cure the issue with lots of watercooling every 5seconds and tons of patience. My d24 motor can do well without the ac bracket for now, it`s the garage that needs ac these days.

Below are a few picts of the darn ac bracket bolt. The hole was well-drilled. And completely thru (I estimate the part left inside to be about only 1-1.2cm long).
It all felt promising at that point. I tried a method I saw online yest: hitting in a strong torx head bit and turning it out that way. It twisted bc bit was too soft then I came up with that smart brittle extractor that broke in. I now wish I hit in a large and stronger torx head instead, not the `easy-out` style thing.
Intake bolts were sooo ready but that had to wait.

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Luckily the threads were all preserved. No hitting was necessary except the punch and hammering in the long-necked torx bit. Out of many others that is the one that finally in the end took out the remains of stud.

Before drilling into the broken stud, I took out another stud, from another cylinder, using the two locking nuts method and took careful measurements.

It came handy today that I had 4 VW studs ordered several months ago for the downpipe of my d24t car but never actually replaced them. 1 of the remaining 3 I used at the EGR junction (I still have 2 more left but none of the exhaust studs have bad thread at all).

This day gave me a chance to have this d24t back together again relatively fast.

Level, stabilizer bar and the whole precision-approach, and quality new drills, were not enough, to avoid having a hole that`s badly aligned.

[RedArrow]

Getting there...

It is now time to

-reconnect the main oil tube and add the large oil filter
-reconnect the turbo oil banjo and flexpipe (lots of playing with the two copper washers)
-reinstall the intake and its other parts, the rubber connector pipe, clamps
-dont forget the metal coolant pipe that serves the oil cooler, and the two grommet bushings (I did, so repeat)
-drive in a new stud for the turbo unit where the egr mushroom (or a future blockoff plate) connects
-secure the turbine housing nuts all around without overtightening them
-add a new gasket using gasketmaker, for the sometimes leaky oil pipe and wait an hour for retorqueing that new orange `gasket`(old gasket is put aside since it a corner of it cracked off, it did not seal too well anymore)
-cut a new section of coolant hose for connecting the rear of the head to the long metal coolant pipe and find new ABA clamps (none of this two I managed to do today)
-align and tighten the two clamps on the red hose connecting turbo with intake manifold
-use new nuts on the downpipe studs And the studs/bolts that hold the two future exhaust manifold heat shields (they need major de-rusting and get painted, currently soaking in diesel fuel to get clean)
-...
-...

[RedArrow]

In the meantime, with all that assembly, why not have a starter painted?

And because I do not want to spend time making two blockoff plates for the EGR unit, I decided to use the egr mushroom again (from this engine I flexed it off so I`m using a spare I removed from the d24t car). Black paint is under progress for this useless egr thing. Dries until tomorrow.

By then, the BOSCH starter will be fully dried as well. I decided to not use the Remy starter I have because it is so big that I can barely see the nice Farm Green engine color because of it It started the long sat engine up well, now we give Bosch a chance too.

Plus, there is more room to do stuff/repairs/checkups/cleaning if I have a smaller starter on the motor. I prefer the Bosch, btw. And it is black in the center which I kept as is but repainted shiny metal flakey silver rim paint on the rest... plus added a clearcoat bc these motors do get dirty, I know that.


Yes, the valve cover nuts are new too. The ugliest part for now is the oil pan. )) not forgotten But I had a lot to do.



Then I took pictures and tucked the motor in the corner to finish the day...

If you made it reading this far, good. But the project is not near completion.