BANG!

What's the problem? Wouldn't be cream for long ;-)

Along the same lines of banging a white metal main with a sledge hammer ...........

I used to work for a very old fashioned garage who had been Vauxhall agents since before the war. Their cellar was a real mathom house of a dark hole and wondrous place for someone of my tastes, especially as the Old Man told me I could take home anything I fancied but throw the rest away.

Amongst the things I found - but he insisted on keeping "...as it might come in again sometime" - was a machine for making pistons bigger when they were worn.

Basically, it was a sturdy, bench mounted machine fabricated from 1" steel sheet with a rack of sleeves in all sorts of sizes. The plan was that you fitted a sleeve to the piston, allowing for up to 10 thou expansion. This you fitted to the machine and screwed a closely-fitting steel cover in place over the open end that was equipped with the back end of a shotgun.

A full load twelve bore cartridge was then divested of its shot (that's what made me look at it, there was lead shot everywhere!) wadded with newspaper, slipped into the breach and fired. The Old Man told me it was in constant use just after the war when replacement pistons were virtually impossible to get hold of and that it usually worked as intended, restoring the piston to its original diameter, but occasionally the surprised looking recipient of the blast up the jacksy would crack.

A quick hone and a wipe with the scraper to remove the bore ridge, a new set of rings (being cast iron, they were never in short supply apparently), a set of gaskets and back together for another 10,000 miles.

It still amazes me the way that engine technology has changed in my lifetime. When I started out in 1958, 10,000 miles was about what you'd expect before you needed to lift the lid. I have just bought a 20 year old Volvo 740 2.3 litre with 144,000 on the clock with the thought in my mind that it wasn't THAT high a mileage for a Volvo! Apro pos of which, I must sadly record the passing of the 760 estate, it boiled in Kent at the weekend and now needs a new radiator and a head gasket. As no-one keeps the radiators anymore (rare car with a gearbox oil cooler in the bottom of the rad) it's manufacturer's original at £400 plus another estimated £300 for the head gasket job.

Goodnight Irene :o((

I am now in the market for a decent Volvo 960 estate, normally aspirated 3 litre straight six with a black or grey interior (!) - no-one know for one, I suppose?

Regards,

Kim Siddorn,

Amen

The straight six was a pretty bullet-proof engine compared with the Renault-based V engine that followed it. It has a long history behind it...

There's an M reg 960 CD estate on ebay, but its done 178,000....

Peter

-- Peter & Rita Forbes snipped-for-privacy@easynet.co.uk Engine pages for preservation info:

in the 50s & 60s my father leased space in the back of his garage to a firm that had one of these machines, the process was called Koetherizing.

To this day, the individual, long deceased, is still remembered as "Shotgun" Goodwin. The system that replaced it was Micropeining, where a small cam driven hammer was used to pein the inside of the piston skirt in increase the diameter.

My father used to talk about the various methods of decreasing piston clearance prior to WWII, one I remember was a device like an inside out hose clip that could be fitted inside the piston and expanded to decrease the clearance. Of course the advent of solid skirts put a end to that..

Tom

Tom

as a poorboy mechanic we used to knurl pistons, then beat them thru the bore using a wood driver and hammer. this generally 'sized' them. after that, we installed the rings and put the engine together. it really was a bit tight, but they would run quietly for a fair time. as you say, tho, this was the fifties. sammmmm

There is a company in Cardiff called Serck, who will re-core radiators for about £70. I went there a few weeks ago to get my maxi radiators recored. Best bit was it was a two day service!!

Head gasket cant be more than a few pounds. All you need to do now is find someone that will skim it for you!

Adrenalin

as an experiment I knurled (medium size diamond pattern) the skirt of a (dead) 5hp Petter M piston. Bore 4.75 inches and I gained about 10 thou on the dia. ttfn Roland

The good thing about nurdling the piston is that the striations hold oil well.

The bad thing is it decreases the surface area.

I wonder if they balanced out?

Regards,

Kim Siddorn,

Thanks Peter, a kind thought - but I don't see me and a cream interior getting along all that well ;o))

Nice car though ..........

Regards,

Kim

A vacuum is drawn on the non-explosive side as well..

Tom

Speaking of Stirling engines, a large contract was just signed for a NZ firm to supply gas fired SE gas heaters/generators to the UK market..