Ian Vincent Posted November 12, 2009 Report Share Posted November 12, 2009 Earlier this evening I started stripping the head and this is what I found. I am going to have it dipped and see if it can be rescued but I suspect it will be a goner. My question though is what would have caused it? One of the first things I did when I acquired the car 3 years ago was to remove the rocker gear and squirt a healthy dose of redex through the plug holes to avoid corrosion and the bores are OK, so I don't think its corrosion. Also, the cast iron does seem very soft - is that normal for Triumphs? and lastly - does anyone know where I can get a new head from?! Rgds Ian Quote Link to post Share on other sites
Don Elliott Posted November 12, 2009 Report Share Posted November 12, 2009 Ian - The depth (or the height) of the recessed combustion chamber in the head was about 1/2" when new for 8.5 to 1 compression ratio. The photo seems to show that the recess is only about 1/8". Maybe someone tried to skim the head. By skim, we usually picture removing about 0.010" but this head looks like someone removed about 3/8". Maybe he was looking for 20 to 1 coompression ratio for a fast TR. What overall height do you measure ? BTW - I don't see what damage might have accidentally ocurred. Quote Link to post Share on other sites
RandallD Posted November 13, 2009 Report Share Posted November 13, 2009 Ian- Assuming the head has not be skimmed excessively as Don mentions, my guess is that you may be able to salvage it. It looks to me as though the engine had a leaking head gasket a long time ago, and while the engine sat, that cylinder had moisture and more corrosion than the others. Still, with some work to the combustion chambers you may find that all the ugliness can still be removed hopefully. I just had a head rebuilt with a similar problem - admittedly not quite as bad looking as that one. Cheers, Randy Quote Link to post Share on other sites
Ian Vincent Posted November 13, 2009 Author Report Share Posted November 13, 2009 Ian - The depth (or the height) of the recessed combustion chamber in the head was about 1/2" when new for 8.5 to 1 compression ratio. The photo seems to show that the recess is only about 1/8". Maybe someone tried to skim the head. By skim, we usually picture removing about 0.010" but this head looks like someone removed about 3/8". Maybe he was looking for 20 to 1 coompression ratio for a fast TR. What overall height do you measure ? BTW - I don't see what damage might have accidentally ocurred. Hi Don, As far as depth of combustion chamber is concerned, the photo is misleading; the chamber is still about 1/2" deep. The overall head depth is 84.52mm - I don't know how that compares to the original depth when they were new - is that information on Terri-Anne's site? Rgds Ian Quote Link to post Share on other sites
Mike Collins Posted November 13, 2009 Report Share Posted November 13, 2009 Could that pitting be caused by detonation, serious pre-ignition? That can cause rapid and severe damage. Quote Link to post Share on other sites
88V8 Posted November 13, 2009 Report Share Posted November 13, 2009 I'd go with Randy's thought. Corrosion, that's why it seems to be soft. The head might skim depending on the cr, and/or you could use a thicker gasket. If the combustion chamber needs much cleaning up then you might need to get the other three chambers opened up a bit to equalise their volume. Ivor Quote Link to post Share on other sites
david ferry Posted November 13, 2009 Report Share Posted November 13, 2009 Ian, It's now possible to buy new cast iron heads from the usual TR suppliers. This is in addition to the aluminium heads that have been aroud for a while. Whilst they are not inexpensive, this could be the way to go, unless you are lucky enough to be able to sort out your existing head, or if that's scrap as you suspect, if you are able to find an uncracked original casting. It's unfortunate that many original castings are now cracked. I had to go through quite a few to find a good one for my TR3. If I were doing this again, I would feel inclined to ignore the cost and buy a new one. Good luck Regards David Quote Link to post Share on other sites
Don Elliott Posted November 13, 2009 Report Share Posted November 13, 2009 TeriAnn wrote the following. See Paragraph 3. The unshaven head measures 3.33" - exactly the conversion from the 84.52 you reported. http://www.tjwakeman.net/TR/FAQ_heads.htm Quote Link to post Share on other sites
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