repairing cast iron?

[autocol]

a friend of mine drives a 64 EH Holden ute as his daily. the other day he said he was leaking oil, and wasn't sure what the thing was the was spewing it out. so i got him to bring it round and it was the oil pressure sender.

too easy, i thought, sent him down to the parts shop, from which he returned with the wrong part, sent him back, and he eventually got the right part. thinking there was NOTHING you could possibly fuck up when replacing an oil pressure sender, i left him to it and went off wanking or something...

anyway, fuck it up he did, and ROYALLY! the sender screwed into the block in a boss that's cast into the side just above the sump. he did it up too tight and broke the boss in two pieces off the block! i'm not certain but i don't think the area cracked any further...

what i'm wondering is: will anyone be able to repair this? i don't think it's a particularly stressed area of the motor, it just holds the pressure sender and that's it. can the cast iron be brazed in or something? or are we screwed, and do i have to waste my weekend (and one of my motors) getting him back on the road?

thanks, please save me!

col.

[du$ty]

to weld cast iron..you have to pre heat the metal then have the right stick tag it in..then tap it in.then let it cool slow...reheat its a pain.but i heard they make special rods to weld it without doing that .i think they are expensive as far as welding rods go.i believe you dont have to heat it up to repair it anymore.but a good welding shop should fix you up ok.

[Meester P]

Well to weld it will cause a LOT of work as you have to get it clean and free of oil,ie a strip down,it might be possible to do it with a chemical metal such as DEVCON, or some other type of two part epoxy. Either way it must be very clean to get it to stick.
I wouldn't like to guarantee a repair like this without welding cos if it lets go you will lose all oil pressure, is ther any way to screw a length of pipe into what is left?? if there is you could make up a fitting to take the sender weld it to the pipe and screw it in,kind of like a remote sender.
john

[Petejoe]

If this isn't a critical area, cast iron can be braised rather easily. The braise will hold the oil pressure fine, just be sure to use multiple passes and make sure its good and clean.

[autocol]

so by the sounds of things i may not be totally screwed, and may in fact get to work on my OWN CAR this weekend! that'd be a first in a while!

i'll look into it, but if it can't be repaired as such that screw-in "unit" sounds like a good plan...

wish me luck!

[lucky_1974]

Stick welder with nickel rod works for me.

[dixiedog]

[ QUOTE ]
Stick welder with nickel rod works for me.

[/ QUOTE ]

That is the only method we found for a well head repair- preheat cast iron and use nickel rod. If it's ductile iron you can use nickel rod without preheating, as in attaching steel flange rings to ductile iron pipe, pressure tested to 150psi and still in use.

[manyolcars]

Tap the hole deeper, insert nipple, coupler and sending unit

[286merc]

Im guessing here that the hardest part is going to be getting a perfectly clean crack to work with.

One thing that should work as long as the pressure is low is to silver solder.
So how are you going to clean out the crack and prepare it for filling? Even welding will require you to try and V groove the area and cracks have a habit of spreading if they arent drilled at both ends. So now you have to figure what to do with all the metal filings; one solution is to surround the area with a few magnets but you still need to flush the engine oil passage and drop the pan.

For soldering you can clean with tinners acid which is a diluted hydrochloric. Also can use muriatic or another form of hydrochloric.

I repair cast iron with a Henrob/Dillon mini torch and nickel rod; it keeps preheating requirements to a minimum.

Maybe Devcon or JB Weld is the better way to go in your case!

[autocol]

[ QUOTE ]
Maybe Devcon or JB Weld is the better way to go in your case!


[/ QUOTE ]

HMMM!!!

i've got some JB weld in a drawer downstairs! you *may* be onto something 286!

the most heartening thing i suppose is that the cracks started and finished in the boss. there are no more cracks to speak of, because the cracking area cracked right off! i hear what you're saying about drilling the ends of the crack to disperse the stress because i'm a drummer and did exactly that to a cymbal i hit too hard and cracked, and it stops the crack from propogating any further.

the fact that the damaged area does NOTHING but hold the oil pressure sender in place makes me think that perhaps a liberal use of JB-weld might be a suitable fix!

thanks for suggesting that, and thanks for all the suggestions guys, i'll investigate some more...

(further suggestions welcome!)

[metalshapes]

Isn't REPCO Australian?
They had a product to repair cast iron.
You drill into the crack, tap it, and screw a tapered cast iron plug in it.
How do I know? I used to work for the only guy in Holland that held the licence.

[autocol]

metalshapes, repco is a great australian company... in fact, you'll find that the only australian team ever to win a formula 1 world championship was... REPCO-Brabham.

unfortunately, the shape of my crack doesn't exactly suit the type of repair you suggest. i'll try to get some photos of it and post to better explain the problem.

[metalshapes]

that would be the Brabham BT19, right? 1966?
one of the story's I have heard about Jack Brabham is that he started his racing on dirt ovals, and when he'd get excited, he would fall back into his old dirt track sideways powerslide style of driving ( instead of the more neat road track 4 wheel drift) and he would set up his Formula 1 car so he could drive it both ways.
The fact that he used a Olds block with heads he designed with Repco for that championship winning car makes him one hell of a Hot Rodder in my book...

[autocol]

cripes! i can't name the MODEL he was driving! sounds like you've done your homework, metalshapes!

okay, i just had luke over with the 'bits' that came off the block, and took some photos.

first up, here's the location. still oily and everything, but you can see that the cracks don't head INTO the block, which is good.

http://www.ltdesign.org/uncletoff/HAMB/luke1.jpg

next up, the two pieces that need to find their way back there...

http://www.ltdesign.org/uncletoff/HAMB/luke2.jpg

basically, looking at this i DO think that i should be able to JB weld this up, but for now there's a couple of things i'm concerned about. firstly, when holding the pieces together the grains of the metal don't seem to QUITE want to line up. i think when it broke they deformed somewhat and the pieces don't quite line up properly when pressed together. secondly, i don't want any leaks once this is done! what would be your strategy of preparing the bits, and applying the JBweld, to ensure that A) everything lines up and B) doesn't leak?

and finally, just for the fun of it, a shot of luke in front of the disabled car, imbibing in our national drink (Victoria Bitter). also in shot is his girlfriends car (a mazda 121 metro) which is the unfortunate recipient of his questionable driving while the EH ute is out of action. http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

http://www.ltdesign.org/uncletoff/HAMB/luke3.jpg

[Deyomatic]

Which engine is that? Is it a Chevrolet engine or some Holden model? From your pic, it looks like you can just run the tap in there a bit further and it might be ok, presuming nothing hits it on the inside. The reason I'm wondering which engine it is, is because on say a SBC, there are a couple of places that you can put a sender. If you could seal this hole up completely, could you use different hole?

Remember also, this thing is probably going to be seeing like 40 psi or so of oil.

[autocol]

it's a 186 cube holden "red" straight six... so named because the blocks were painted red out of the factory. obviously, a previous owner of the car thought a cute shade of mauve more appropriate.

to be honest, i be reluctant to bore another hole in this block for fear of weakening it. i imagine the sender was mounted in a strengthened boss so that the wall of the block wasn't weakened where it was installed...

good idea, though...

[lowsquire]

If the sender has a taper thread,youre in trubble,as the outward force as you screw it in will likely be too much for jb weld to hold against...maybe.
Is there enough meat to tap into whats still there?
tapping into the gallery in another spot would be my choice,and just fill the hole up with the jb. weld. the block wall will be strong enough as long as you can identify the oil gallery and drill straight into it.

[autocol]

shit... i guess i'm in trouble! http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

perhaps for now the JB weld and a considerable amount of loctite will solve the problem at least temporarily. right now, i don't have the time, and he doesn't have the money... the motor will get swapped out for something better not too far down the track.

i just don't like my chances of drilling a hole and tapping it without pulling the engine, which is what i'm trying to avoid in the first place... http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

i think i'll JB weld it together, loctite the sender in, take the sump off and clear out all the shit that gets in there, and hope for the best!

thanks for all your help guys...

[Deyomatic]

What if you JB welded the sender in? Drain the oil, clean off the area really good with a wire brush and some brake cleaner. Set the sender in there and goop it on.

Would it be possible to build up the hole with JB weld and tap the JB for the sender?

Are you positive there are no other existing holes that you could tap into? Both my SBC and my Y block have 2 holes, (I think the Y does).

[53choptop]

my $.02 cents, if you can find it use DEVON, it is JB WELD on steeroids.

I have been running my 350 SBC with a sizeable crack along the side of the block for a little less than a year now with No problems, the block crakced when I didn't use antifreeze last winter. Hell I hadn't even rememberd until someone mentioned it on the thread.......

[286merc]

To quote a past infamous US president "I feel your pain".

So how about this. Take the sender and thread it into so a nut, hunk of pipe or whatever being careful you get the proper reach into the block if that is important.

Then gob the whole thing to the block with JB or that Devcon I mentioned yesterday. I dont know if it is available Down Under but here is the link.

http://www.devcon.com/maintenance.cfm

One of the guys here used Devcon to patch a cracked flathead block and it worked great.

BTW, having spent considerable time down there and experiencing both the national drink and the drivers, who needs an oil gauge anyway?