924Board.org

[jamie924]

hi guys
am i right in thinking vw lt van pistons fron say a 1988 2 l model will fit the euro na block and rods what compression ratio will they give
also does anyone have any experiance of skimming them to reduce compression height how much metal can be taken off etc
has anyone used a 3mm odd spacer plate between the block and head to give the same result
i also heard of someone using vw rods was this to reduce or increase compression i wonder anyone know the affects and which rods
im aiming for a 7.7-7.8 comp ratio yes i know it will be a pig off boost and alot of work but the car i have a cheap source for pistons is near by i have a fully kitted workshop mill lathe tig etc and i dont work so i have all the time in the world and yep im a little mad to
also anyone know of a good uk cam supplier for a billet cam never liked regrinds
thanks

[bruce76-924]

Jamie,

Where in the Uk are you?

Bruce.
_________________
1976 924 LHD, full cage, semi tube chassis, 951 brakes, lightweight 951 body panels.
1.8t engine conversion with Holset turbo and 6 speed Audi gearbox.

[Rich H]

No idea about pistons and such, but piper sell a 924 billet cam IIRC.
_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[endwrench]

The pistons most here are using are the VW Type 1 . You would be looking at around 8.5:1 compression with a 931 head depending on the exact make of the piston.

Todd
_________________
'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....

[leadfoot]

It's 8.9:1 compression VW pistons type 1 (dak dak)
You need to get small end rod bushings from EBS or buy new h beam rods with 22mm end holes...
No I wouldn't skim them, or use decompression plates
Time to invest in some engine building software
PIPER CAMS in the UK
Stuart
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[jamie924]

hi
thanks for the info
i have had alot of sucess with decomp plates over the years with ford engines the cvh zetec and the bastard zvh conversion hence my lean towards them as im thinking of aprox 2 bar of boost at peak either from a t3/4 sierra cosworth turbo or a eaton m112 jag xjr charger both will produce this with an engine of 924 size
am i right in thinking the 931 head will give most of the compression drop as i have wipped the heads off the 3 motors i have and with a new set of rings they will be tip top and before head removal cyl leakage was minimal and compression was very good so i wonder if its worth just using a 931 head with a 3mm gasget type decomp plate (multishim copper) and see how she goes
by the time you have built an engine with forged pistons h beams and bearings its going to be up around a grand so im kind of erring on the try it and see method
it will be on ms1 extra with knock dual maps and boost retard so im hoping this will protect things a little bit before total melt down lol
thanks for the cam info i had forgotten piper did a 924 cam weather or not i will get much from it with forced induction remains to be seen but i suppose it would sell well on ebay if it doesnt make much difference
im in wiltshire bruce whish is quite a way from bradford but i do go to manchester alot if you need any bits im stripping off or anything machiening up id be happy to help as i can see the thought and logical understanding in what you have done and id love to see it develop into even more of a monster lol
also does anyone know of a company who make a 4-2-1 exhaust header / manifold for rhd cars as i can only seem to find left hand drive ones and altho we have a tig i hate making manifolds and the 924 has no space so it will be a pig specially with the steering columb on that side
thanks guys
jamie