Porsche Enthusiasts Club Forum

wanted 1, 16v 4.5litre piston , condition not important, as long as its still in one piece, need it to take sizes, etc to get pistons made , need one to give accralite asap, , doing a liner conversion , doing 2 blocks , as accralite have min order of 12 pistons , so getting 2 sets made , 12:1 comp large piston pockets , , if any is interested , or can help with one piston get in touch thanks derek
01555-841000

Hi Derek

WOW ...12:1 ... thats a LOT of compression, how are you going to avoid detonation ? because the standard ignition system would burn holes straight through the pistons with that compression....

Umm just had another thought.....didnt I read somewhere that our blocks did not have enough strength or wall depth for a liner job ???

All the best Brett

brett you make me laugh, 12;1 comp is not that high for normaly aspirated engine , my escort cosworth engine i build is 12.5;1 comp with 2bar boost makes 820bhp , @8000 rpm , granted it only does 1 hour running before sump is off and shells inspected not hard on big end shells but seams to be hard on main bearings ,, now i have thick walled line taking it out from 100mm to 104 with room to go to 106mm, i have looked at the block and its dead easy, only when you know what to do , this is just the same as porsche 928.com do already not rocket science, until you look at what your about to do , .,i remember when charlie shaw had his escort cosworth up at crail drag strip with nitros , he done 2 runs still didnt break 11.5, then on the 3rd run it back fired and sprayed all sorts under the bonnet burst in to flames , then the nitros bottle exploded just after he got out , car was finnished , and he nearly was as well , , so lets recap , ,,,so you think 12;1 is high, ;;;When you spray your nitros in and the engine sucks it up , your compression will go from 8;1 to 20;1 and strech the alloy cylinder walls , the head bolts will struggle to keep the head attached to the rest of the engine , the tops of the cast pistons will melt the spark plugs tips will melt , and just whatch out you you dont go up with a a big poof

job has been sorted , borrowed piston of paul anderson , as it turns out accralite were going to get the job , just before christmas , and they got bought over by omega pistons , and they dont do the compression hieght for 928and they said they didnt have a forging, arias that have made them in the past put the price up by 50%, so cp pistons have the job , they work with je , pistons in the states , , money has been paid dye has been cast, as they say ,, so now hard on with engine block and get it linered, 16 liners sitting ready to fit , crank has been toughrided, steel rods,20/20 steel fly wheel, ap triple plate clutch , out of my escort cosworh , fits straight on , : :

Hi

Wow thats a weird idea....

So you think that running Nitrous increases compression ??? by 12 points...

Well my engine is 10.5:1 so that would give me 22.5:1 ......

All the best Brett