Cracked Aluminum Head

[1975ToyotaCrown]

Does anyone know anything about cracked aluminum heads,
lets just say someone cooked an engine and I'm told the head was cracked.
Is it possible to repair them successfully this guy took the engine
to an engine re conditioner who rebuilt the engine and repaired the head
by using the overlapping stud method.
Now after the head was repaired should one be able to see where the repair
was because we can't see any sign of any repair.
http://i109.photobucket.com/albums/n...nEngine007.jpg

[Hurricane]

ive heard of the way of using studs, you sould be able to see where the stud is, unless they welded over it with alloy after they put the stud in?

the head needs to be cleanr to see the stud

[cambelt]

Look between the valves , that where they mainly crack ,
Dave

[Mr DOHC]

i was of the impression that they only use the studmethod forcast iron heads.

if they just drilled and then welded the crack then u probably wont be able to see it, why do u assume the crack is in the chamber, VL heads always crack alon the cam tunnel.

btw, those water galleries look fucked, they need to be fixed

[1975ToyotaCrown]

We had it pressure tested and its now as good as new.

[MS-75]

Keep an eye on it as M series heads that get cooked have tendency to go soft.

Sean

[1975ToyotaCrown]

Mr Dohc, Yes the photo isn't very clear but the hole bits for the water are the best I have ever seen when it comes to a 4MU engine. It sure pays to use a good quality red radiator coolant, all the edges are straight and no pitting and yes I hear you say but the engine overheated. That was because the bottom hose blew and the first thing I knew about it was when the light came on and the engine went clunk, clunk, clunkity, clunk.

[roadkill]

Hi,

i personally would recommend two ways of fixing said problem.

1) take head off, swallow pride and throw in bin. Buy new (reco 2nd hand woteva) head and install............... PROFIT

2) Take out complete engine and sell as is where is. Buy new more reliable (ie not 4M!) engine................. PROFIT

Whilst i know alot of the time it may not be cheap to get a new head or even a new engine, at least it'll be something that you can hopefully rely on. You've also gotta realise that quite often an engine will crack in a few places as basically the whole head will have endured those same circumstances and is really only a matter of time till they too open up.

My brothers 80 series diesel had about 8 cracks in it which weren't hard to see once we new what we were looking for. I would like to think that if someone were to fix the cracks that you wouldn't be able to them once completed but i've never had a close look at a repaired alloy head.

ben

[jeffro ra28]

he just said he had it pressure tested and it is fine

[1975ToyotaCrown]

Our local one and only engine guy said the head is all good but I'm thinking about when I'm just about to take the 335,000 klm original 4MU engine out of our 1979 Crown and fit the rebuilt engine that I take all the new valves and tappet stuff out of the repaired cracked head and have the 335,000 klm head reconditioned then fit to the rebuilt engine..