Hello All
Recently I started rebuilding my D8 15A. Found out one head is cracked but repairable. Decided to source a replacement head instead of repairing and Tillys supplied a suitable head. I left it with the head specialists to fit the valves to the head and they asked me for new valves as the old valves don't fit the new head. After they sent through some photos it was revealed that the valve guides in the replacement head take a smaller diameter valve stem. Does anyone know what this head could be from? As far as I can tell even the D8H uses the same valves as the 15A. I haven't inspected the new head to see if anything else is different. Looking at the photos they sent through there are clearly differences in the casting but as near as I can tell the bolt hole pattern is the same. I asked them for casting numbers but they sent through some stamped numbers instead so the replacement head may be aftermarket. Numbers on the replacement head are E14118 and 398138.

Thanks

Phil
 

Ream the smaller guides to fit the old valves. I assume the old ones are serviceable?

Need the actual casting number for identification. As stated ream or change guides if valves are good.

Could it be a spacer plate head? If so you will have other problems with directors.

Wombat

can you change the guides to suit the valves you do have. i assume apart from stem diameter they fit.

Hello All
Thanks for the replies.Yes the valves are good but the guides can't simply be reamed out to suit the valves as the guides are missing the flange at the bottom to locate the bushing that the rotocaps sit on. My concern is that this is off a much later machine and as Wombat mentioned it will have other issues.

I am getting them to lap the valves on the other head and once they are done I will pick them up and inspect them for casting numbers. They are about an hours drive from where I live.

So I finally get the heads back last week. I went over them today and other than the valve guides and a few minor differences in the casting I cant' see any difference in the two heads. The head gasket fits both, the directors appear the same and are in the same holes. I think I will need to remove a valve guide and measure it up to make sure the bore is the same and then get some new guides.

Quick question though, Wombat mentioned if the head is off a spacer plate engine that there would be problems with the directors but I can't understand how this would be a problem provided the holes in the head match wouldn't the cooling properties be the same or even improved? My understanding of a spacer plate engine is that there were no differences in the head but the block had a spacer to prevent liner damage.

A spacer plate head has no provision for the directors and uses a different head gasket to get the water sealing at those holes. I have converted an early head for a spacer plate motor by pressing rings into the director holes to make them smaller and the had the head and rings machined/faced off. To my knowledge a Spacer plate head will not fit an early motor.

Wombat

Thank you very much Wombat.With that information I am confidant that the head will fit as the old head gasket matches the head perfectly and it has the directors.

I have a bucket full of new valves here that I think will fit your engine if interested.
0428717065.