Cylinder head corrosion, time for new head or should it be ok?

**Howieau** · 03-06-2007, 07:14 PM

I got my head back from the machinist recently, when he ran into a few things that might create a problem he notified me straight away to get them sorted. Ie, exhaust valves had thinned out and needed replacing, a valve stem was bent etc. He never mentioned anything about the corrosion in the water galleries, but from what I hear it can cause sealing issues with the head gasket.

Has anybody ever/seen a similar problem? Do you think my head is still good to go ahead with for my rebuild, or should I try and get a new head

Cheers.

**Starfire** · 03-06-2007, 08:17 PM

What is that? A 3S?

It's not the worst I've seen but far from the best. As long as the machining is good it shouldnt prove too much of an issue.

The other things could indicate that the head has seen better days. An important thing your machinist should check is hardness and flatness of the head. If it is too soft or warped it should be rejected.

**Aust162** · 03-06-2007, 08:24 PM

You can get it welded up by the machine shop. They add weld then grind it back. I had some welding done on my 3s motor too. Pretty common thing i was told.

ed · 03-06-2007, 09:59 PM

ive got a great article somewhere on why its a BAD idea to weld heads

meanwhile, i think that head will work ok. as mentioned certainly not the worst around. aint the best either, but i reckon its a oer

**Howieau** · 04-06-2007, 06:14 PM

http://www.ruststoponline.com/electr...rotection.html

Anybody every tried anything like this before?
An electronic rust preventer, supposedly stops the spreading of rust? Would that be worth looking into for my situation as a safeguard, or is it my corrosion something complete different to what the rust prevent refers to?

**Screamn_Sleeka** · 04-06-2007, 06:19 PM

Id say prevention is to little too late, the corrosion has gone too far and will be over lapping the head gasket, wetting it constantly, ie weakening it. Was the head taken off because of a blown head gasket?

Is it a 3s? just get a new head? they are always on ebay reco'ed.

**Crazyracer** · 04-06-2007, 07:51 PM

The corrosion doesn't look that bad. I reckon the head should be OK to use. Its been machined and there's plenty of non-corroded material around the water passages to be enough to seal properly.

Its always going to be a problem with an iron block / alloy head combination as the alloy acts as a sacrificial anode for the iron. You don't want it getting any worse though, so make sure you run some corrosion inhibitor in the correct concentration in the coolant. Don't skimp on the inhibitor though. If you mix it too diluted (or too strong) it can actually promote corrosion rather than inhibit it.