Small crack between valves. 2.1 dj

Post by **Ciaoflyer** » 25 Jun 2017, 18:03

Striped my heads today and one of them has a little crack, is this a problem?

Post by **DoubleOSeven** » 25 Jun 2017, 18:35

I wouldn't put that head in my engine.

An expert welder could fix them but it'll be higher than the cost of a new head and they'd need to do large volumes to make it cost efficient for themselves.

Door Stops I'm afraid. When you rebuild get a temperature gauge fitted so you can keep an eye on your engine.

Heads only crack because of an issue with the engine, running too hot being the obvious.

Post by **Oldiebut goodie** » 25 Jun 2017, 19:30

Normal cracks, nothing to worry about. Common to diesel and petrol engines. Worry only if very large or the valve seat is cracked. I would have no qualms at using that head ( if I had one of those funny engines).

Website · Post by **CovKid** » 25 Jun 2017, 19:40

Have to agree. You'd be hard pushed NOT to find cracks between valves. Common. Generally they don't get worse and you should be able to use it without issues. In fairness to DoubleOSeven, no one likes to see cracks like that in heads, but its not the end of the world.

Post by **itchyfeet** » 25 Jun 2017, 19:43

Small cracks can be. no problem but on the other hand they can over time keep cracking into the water channels.

It's your call, a new head is not cheap all old heads have cracks.

It really boils down to your budget, if you can afford a new head then do it but if you cant then fit that one and it will probably be ok for some time.

Post by **Ciaoflyer** » 25 Jun 2017, 20:04

Great many thanks, been suggested I should grind it with a Dremel?

Post by **Oldiebut goodie** » 25 Jun 2017, 20:12

Why? That would only make it bigger.

Post by **itchyfeet** » 25 Jun 2017, 20:13

Ciaoflyer wrote:Great many thanks, been suggested I should grind it with a Dremel?

yeh don't do that
leave it or buy a new one

Post by **Ciaoflyer** » 25 Jun 2017, 20:13

They said that it is a high hot spot and should be ground flat

Post by **itchyfeet** » 25 Jun 2017, 20:26

Ciaoflyer wrote:They said that it is a high hot spot and should be ground flat

Serious engine builders will grind down the high material between seats ( on new heads) to make it flow better and stop cracks but this crack is already there and I assume you are not building a high performace engine with an old head.

Post by **Ciaoflyer** » 25 Jun 2017, 20:38

No, you are right not a high performance just standard. In terms of head cleaning an I right in thinking they don't require skimming? What is the best way to clean? Sorry guys but I am a newbie at this.

Post by **itchyfeet** » 25 Jun 2017, 21:10

WBH heads seal on the recessed area so skimming the water jacket seal area is pointless.

you can use an old barrel with fine grinding paste to clean up the recessed surface.

Post by **bigherb** » 25 Jun 2017, 22:58

Looks a bit big to me, the maximum width of the crack for reuse is 0.5mm

Post by **Ciaoflyer** » 26 Jun 2017, 18:31

If I go down new cylinder head route, what about other side which is in much better condition (think it has already been replaced.). Can I just rebuild this, new guides etc? Also, advice on where to buy head, The Engine Shop?

Post by **itchyfeet** » 26 Jun 2017, 19:22

New heads are AMC and the valves are cheese so buy a bare head from brickwerks and if your valves are in good condition you can reuse them.

Personally I'd refit it because I don't do high milage and I'd rather spend 100 quid on a gasket set later if it goes than 350 on a new head now, your call, depends upon your budget and use.

I have had a head crack right through and it was still drivable.

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