I understand your concerns Mark, the bearings should have a good supply of oil and will not suffer undue stress during the starting process as you will not be giving it any welly and loading the bearings. Doug said he will not be using any boost during the initial runs. this in turn will not stress the bearings.
My 7A engine and I think the S2 engine use 10/30 IIRC, a cheap supermarket version of that would be ok. GTX is too good to run in an engine I feel. The rings will bed themselves in very quickly. I had to rebuild a midget engine for someone who started the unrun engine on Mobil 1. It smoked like a dog and the rings never bedded in. The block had to be honed again and a new set of 73.5mm Cosworth Rings were required. The rings were about £100. A lot for a new Midget engine but maybe not for an Audi.
The initail start up and running in on an 'A' series engine is very important. The Audi engine is an old engine as well ( design and materials date to the early 80's.) this means to me that it needs a bit of care.
A friend has a Vincent Motorbike and he has made it up to date with fancy American pistons and a Nikasil lined bore. It did not need any running in but he has had compression problems because the rings skate over the liner. He went acros the USA with this bike and when he went to collect the bike from the docks in Bristol it wouldn't start easily, ( no compression). he'd used the bike for 3,000 miles in high temperatures but it was very cold at the docks ( in October last year.
Porsche 928's have nikasil lined bores and they go on for interstellar mileages.
more info here http://www.brisonaircraft.com/cylinders.htm
Sorry if I've added this to your shopping list now!
I hope this makes sense!
David
My 7A engine and I think the S2 engine use 10/30 IIRC, a cheap supermarket version of that would be ok. GTX is too good to run in an engine I feel. The rings will bed themselves in very quickly. I had to rebuild a midget engine for someone who started the unrun engine on Mobil 1. It smoked like a dog and the rings never bedded in. The block had to be honed again and a new set of 73.5mm Cosworth Rings were required. The rings were about £100. A lot for a new Midget engine but maybe not for an Audi.
The initail start up and running in on an 'A' series engine is very important. The Audi engine is an old engine as well ( design and materials date to the early 80's.) this means to me that it needs a bit of care.
A friend has a Vincent Motorbike and he has made it up to date with fancy American pistons and a Nikasil lined bore. It did not need any running in but he has had compression problems because the rings skate over the liner. He went acros the USA with this bike and when he went to collect the bike from the docks in Bristol it wouldn't start easily, ( no compression). he'd used the bike for 3,000 miles in high temperatures but it was very cold at the docks ( in October last year.
Porsche 928's have nikasil lined bores and they go on for interstellar mileages.
more info here http://www.brisonaircraft.com/cylinders.htm
Sorry if I've added this to your shopping list now!
I hope this makes sense!
David
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