Thanks for the tutorial. I've only had iron heads and never pulled one. > -----Original Message----- > From: Mercedes [mailto:mercedes-boun...@okiebenz.com] On Behalf Of > Curly McLain via Mercedes > Sent: Saturday, February 20, 2016 7:13 PM > To: Mercedes Discussion List <mercedes@okiebenz.com> > Cc: Curly McLain <126die...@gmail.com> > Subject: Re: [MBZ] Diesel Purge > > >Really? I had always heard the exact opposite > > > >> -----Original Message----- > >> From: Curly McLain via Mercedes > > > >... Iron head engines are more prone to cracking than the OM60x engines... > > Every iron head I have had off has been cracked. The 616 and 617 are much > improved over the 621. Alum or iron, they crack between the valves, > between a valve and the prechamber (3 places) Easy to see with no aid. Book > value is anything less than 10 mm crack can be reused. > > The alum heads crack less in these places, but the 14 head cracked into the > water jacket. Iron heads will eventually crack into the water jacket too. > Driving with a combination of Diesel Max's Method and my method will > reduce incidence of cracks. > > I have had 2 603 heads off. 50/50 first had no cracks, but blown head gasket > at the front of #1 could be from excess oil from the turbo seals. Second had > about a half dozen cracks. None are serious > enough not to use the head. There are 18 common crack places on a 6 > cyl. The worst was my Hawaii OM621 with 18 cracks, with only 12 normal > places to crack as it is a 4 zyl. A tired head will also crack outwards from the > valves or prechamber also. Driving a cold engine like you stole it is the cause. > That was someone else who caused the cracks. The head was in the trunk > when I bought the car. > It had cracked to the water jacket, hydrolocked, snapped the timing chain, > that cause the cam and cam bearings to break. It was a mess when I bought > it. So, Yes, Iron heads crack into the water jacket too. > > in 40 years, I replaced 2 OM 621 heads due to excessive cracks. The first was > not cracked through. The second was. I have never replaced a OM603 head, > with 6 that I have owned. The cracked OM603 came off a junkyard car last > weekend. I'm not afraid to put in on an engine, as the cracks are within spec. > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
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