22-05-2018, 08:47 PM
(This post was last modified: 22-05-2018, 08:59 PM by Andy Bennett.)
I have made a somewhat speculative purchase of a block and would appreciate some guidance on what my options are.
With my engine chewing a head gasket once a year (1000 miles) due to various breaks across the gasket caused i suspect by less than perfect surfaces on the block/head, and there being a lot of exhaust fumes from the tappet cover (with cord rings having been fitted by a previous owner to ‘cure it’) I have for some time been planning a top end upgrade/rebuild/repair.
Well, the opportunity has come to fruition. I have purchased a block with the following identification: 7521, 31 8 29. Now call me Sherlock, but I take it from this that it is a 1929 block.
My box is a 1933 model.
The block at first look appears basically sound. It needs some helicoils etc and some surface refinishing, but hopefully nothing too problematic from what I can see so far.
So to my questions:
The bore sizes are 2.235 to 2.237 inches. Is it safe to take it that this means that it has been bored to +30, rather than +40?
The block is ‘naked’ so no guides, valves, studs etc. I cannot see any significant changes from the 1929 to 1933 block design, so can I use this 1929 block on my 1933 engine? If so should I use the earlier flanged guide etc as on the pre 31 engines or can I just use the later plain guide etc in this block and so basically build it up as a 1933 spec block?
One of the water inlet manifold stud threads has suffered somewhat, as in below picture. Clearly this is going to be an area which suffers from corrosion. However, it also doesn’t take pressure. There doesn’t look like a great deal of material to take a helicoil and there is a decent amount of thread present, so recommendations appreciated, should I just use as is or attempt helicoil?
edit: there is more material than the close up image suggests, the shadow makes it look worse than it is.
Thanks all
Andy
With my engine chewing a head gasket once a year (1000 miles) due to various breaks across the gasket caused i suspect by less than perfect surfaces on the block/head, and there being a lot of exhaust fumes from the tappet cover (with cord rings having been fitted by a previous owner to ‘cure it’) I have for some time been planning a top end upgrade/rebuild/repair.
Well, the opportunity has come to fruition. I have purchased a block with the following identification: 7521, 31 8 29. Now call me Sherlock, but I take it from this that it is a 1929 block.
My box is a 1933 model.
The block at first look appears basically sound. It needs some helicoils etc and some surface refinishing, but hopefully nothing too problematic from what I can see so far.
So to my questions:
The bore sizes are 2.235 to 2.237 inches. Is it safe to take it that this means that it has been bored to +30, rather than +40?
The block is ‘naked’ so no guides, valves, studs etc. I cannot see any significant changes from the 1929 to 1933 block design, so can I use this 1929 block on my 1933 engine? If so should I use the earlier flanged guide etc as on the pre 31 engines or can I just use the later plain guide etc in this block and so basically build it up as a 1933 spec block?
One of the water inlet manifold stud threads has suffered somewhat, as in below picture. Clearly this is going to be an area which suffers from corrosion. However, it also doesn’t take pressure. There doesn’t look like a great deal of material to take a helicoil and there is a decent amount of thread present, so recommendations appreciated, should I just use as is or attempt helicoil?
edit: there is more material than the close up image suggests, the shadow makes it look worse than it is.
Thanks all
Andy
Enjoy yourself, it's later than you think!