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+--- Thread: Block spacer ugently required (/showthread.php?tid=7685)
Block spacer ugently required - Hugh Barnes - 01-07-2022
Does anyone on the forum have a block spacer they would be prepared to loan for an urgent engine rebuild please? None of our usual suppliers have one in stock. Currently, the pistons are coming out the top of the block by 20 thou.
As I say, this is urgent as the car needs to be at Moreton under its own steam...
Can anyone help? Obviously a sale/purchase or replacement at a later date would both be an option.
Thanks for any offers anyone can make..
HUgh
RE: Block spacer ugently required - dickie65 - 01-07-2022
Take 25 thou off the piston crowns in a lathe is a feasable option
I have taken 20 thou off the top of pistons in the past on a high reving engine.
I have also hand made a heavy duty block gasket from some thick gasket material which was about 30 thou compressed.
There is also the option of fitting two head gaskets ( not the best solution though as there is more chance of failure )
Where abouts in the world are you ??
RE: Block spacer ugently required - Hugh Barnes - 01-07-2022
We have considered the machining of the piston crowns, but are concerned that we would lose a week organising that if we went down that route.
Cambridgeshire/Hetfordshire border is the location. I will be at Beaulieu on Sunday if there was a possibility of collecting one there?
We are also considering a silicone base gasket and a low compression head as a 'get out of trouble' option
RE: Block spacer ugently required - Colin Wilks - 01-07-2022
Have you tried John Barlow? I know he had some a while ago.
RE: Block spacer ugently required - Hugh Barnes - 01-07-2022
Problem solved!! Thanks for all the contact that I have had off line and suggestions here. A spacer is on the way...
RE: Block spacer ugently required - Dennis Nicholas - 06-07-2022
I once had a head gasket go on my Bristol 405 and stupidly drove it home resulting in a bit of a furrow burned between 2 cylinders. I phoned the Bristol works to ask what the head minimum combustion could be and without even a pause the nice man at the other end gave me the correct figure which was higher than what I had measured after head skimmed. I told him this and he replied "oh that's all right just make a solid copper gasket from suitably thick copper. 1. what exelent acurate customer service that is so rare nowadays. 2. There is your answer to fix the situation and gasket can be used again in future after cleaning and annealing it (heat to just red and hang up to cool naturally).
I did make a new thick copper gasket and car ran well and I eventually sold it still ok. (the man on the phone was the chief engineer for Bristol cars)
Dennis
RE: Block spacer ugently required - Ian Williams - 06-07-2022
Be warned Solid copper gaskets on an A7 engine do not appear to be a good idea unless on a dry decked engine. Perhaps it was just me but I tried several times and could never get them to seal the water ways so always experienced seepage, I tried several gasket sprays and goops recommended by racers of bigger engined cars.. I think that the clamping forces at the low head torques we use may be insufficient. If anyone has had positive experience's on an Austin 7 engine I would be interested to learn from them.
PS Hugh, I have not found the block spacers hard to make from Aluminium sheet, it is probably within the capability's of most Austin seven owners
RE: Block spacer ugently required - Hugh Barnes - 06-07-2022
Yes Ian, you are probably right but in this particular case, we lacked the time...
RE: Block spacer ugently required - squeak - 07-07-2022
I recall on the old forum Hernandez racing posted about acid etching the gasket to provide an unetched margin around all perforations, thus increasing the sealing pressure from a given stud torque.
RE: Block spacer ugently required - JoeRowing - 07-07-2022
(07-07-2022, 01:11 PM)squeak Wrote: I recall on the old forum Hernandez racing posted about acid etching the gasket to provide an unetched margin around all perforations, thus increasing the sealing pressure from a given stud torque.
Not all of us run 30lbs of boost though!