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+--- Thread: Riser Plate for Block (/showthread.php?tid=6198)
Riser Plate for Block - Jamie - 03-06-2021
I have now assembled my engine to find that as a result of the block being skimmed over the years, the pistons stand a smidgen proud and strike the head without the gasket in place. Allowing for flex in the crankshaft when in use, I am concerned that the pistons will still hit the head when the engine is in use.
It is a long shot, but does anyone have a block shim spare which they would be willing to sell?
Regards,
Jamie.
RE: Riser Plate for Block - Colin Wilks - 03-06-2021
John Barlow had some a couple of years ago.
RE: Riser Plate for Block - Ruairidh Dunford - 03-06-2021
I bought a number from David Cochrane earlier this year.
RE: Riser Plate for Block - Steve Jones - 03-06-2021
I have one from David Cochrane as well. Solved the same problem for me.
Steve
RE: Riser Plate for Block - Jamie - 03-06-2021
I could try John Barlow: thank you. Thank you for the suggestion of David Cochrane, but they are out of stock on David's website, sadly.
Jamie
RE: Riser Plate for Block - Ruairidh Dunford - 03-06-2021
Maybe I bought the last of the stock - email me on dunford1@aol.com if John cannot supply you.
RE: Riser Plate for Block - Jamie - 03-06-2021
Thank you, Ruairidh.
I have e-mailed John. I shall let you know what he says.
Kind regards,
Jamie.
RE: Riser Plate for Block - Chris KC - 03-06-2021
How much of a smidgeon Jamie?
RE: Riser Plate for Block - Jamie - 03-06-2021
Chris: it is a little less than the thickness of the head gasket as the pistons clear the head with the gasket in place, but I shall measure the protrusion in the morning.
RE: Riser Plate for Block - Chris KC - 04-06-2021
Just my personal view Jamie, but rather than have pistons protrude from the block I'd have their crowns skimmed, there's easily scope to remove 10 or 20 thou from a "Seven Workshop" piston. On a 3-bearing engine I'd run them flush with the block, on a 2-bearing I'd allow another 10 or 20 thou for crank whip (e.g. if you miss a gear at speed).
An alloy shim plate is a neat solution, but if unavailable I have in the past doubled-up paper gaskets to get a bit more thickness. It didn't leak any worse than any other arrangement I've tried. Typical paper gaskets compress to around 15 thou thickness in use.
On my 3-bearing engines (with Reliant con rods) I use rather more substantial spacers i.e. 1/8" or so. These are hand-made from sheet aluminium, I think it would be tricky in anything less than 1mm thickness. Keep in mind when inserting spacers you need to watch out for pistons hitting the deck at bottom of stroke too.