[Big D]

Hi all,

I’ve continued working on stripping this engine block over the last week. A couple of the valves came out relatively easily, but most haven’t been easy to get out and appear to be rusted into place in the top of the valve guides. One valve was broken at the head, and at least one was bent and most looked pretty rough. Almost all the valves were in the down position, so even when I got the valve spring keeper out, I couldn’t get the spring off the valve. Access to the top of the guide on most of the valves was only possible through the ports, and it isn’t easy to get penetrant into the top of the guide from the port.

The valve pushrods, apart from two or three of them, were also stuck in their guides, so I couldn’t get the camshaft out either. With the pushrods stuck and the valves stuck, I had to scratch my head for a while about how to progress things. In the end, and considering the condition of the old valves and the cost of new valves, I decided to cut the valve springs, cut the keeper end of the valve off, and work penetrant into the valve guide (from the underside), while tapping on the cut end of the valve with a drift to see if I could loosen them up.

Most of the valves were pretty rough, and I’d already decided I would be replacing these along with the springs so it just made sense to do it this way. This has been relatively successful and I have 7 valves out now. The other 5 valves are proving to be a challenge. I can tell by the sound when tapping on the cut end that the valve and guide are now one so I will need to come up with another strategy to get these last ones out.

I have tried applying some heat around the guides from the ports but it is little hard to apply evenly from there. I may yet look at somehow cutting off the top of the valve. This will give me good access to the guide so I can get penetrant in there. Failing that, as a last resort I may just punch out the guides with what is left of the valve stem in them. The guides are removed by punching down out of the block (with the piston side up), so I would still need to have taken the top of the valve off to do this though. These guides will need replacing anyway, so that could be a quick way to deal with the problem valves. Most of the valve guides had some corrosion in them so I will probably just replace the lot.

Once I had cut the keeper ends of the valves off, I was able to turn the block over and get some penetrant into the pushrods, and start tapping away on these. After a bit of work of penetrant, the pushrods were free enough to be able to fully tap down so I could get the camshaft out. A bit more penetrant later and out came all the pushrods.

The pushrods are pretty rough even after a soaking in solvent and with replacements costing $20 each, it just makes sense to replace these as well. I’ll also check out the pushrod guides after the block is cleaned up to see if any need replacing.

The camshaft has cleaned up nicely. It has a bit of pitting in a few places but the lobes are clear. The crankshaft from the M8 block is the best one I have so I will be using that. It has a bit of pitting here and there but overall is pretty good.

Now that I have some of the valves out, I can see that most of the valve seats are in pretty good shape. A couple have some deep pitting but overall these look better than the other block I was working on. Hopefully my engine reconditioner can work his magic on these seats.

I’ve removed the broken manifold studs. I still need to retap a couple of these, along with drilling and tapping the extra holes for the studs to hold the bigger M8 manifold.

I’ve attached a picture of the various shims used in these engines. They are easily bent when trying to clean them.

That’s about it for today. If anyone has any other bright ideas about the valves, I’m all ears!