aki 0 Posted June 18, 2006 hi guys just a quickie, ive been on the vortex and it seems that the suggestion is to use a mk4 vr6 headgasket to raise my compression ratio abit has anybody tried this and is it true? if its gonna raise the comp a bit its got to be worth a go! cheers for any help andy Quote Share this post Link to post Share on other sites
Chris VR6nos 0 Posted June 19, 2006 Well this is a vague question. For an accurate andswer to what you are trying to do don't you think we should have a bit more to go on mate? I've not measured the difference between the gaskets but the thinner the higher the C/R will be but not by much and if you would even notice but what are you trying to do? Oh and you will raise your compression by changing to a K&N air filter! Just thought i'd chuck that one in to see what people would say, but anyone understanding engines will understand the reasons for this! Those that argue obviously don't :roll: Chris Quote Share this post Link to post Share on other sites
dr_mat 0 Posted June 19, 2006 Go on - I'll bite - explain how a K+N alters compression ratio! :) Or are you talking about "compression" - i.e. in-cylinder measured pressure in psi? Quote Share this post Link to post Share on other sites
Crasher 3 Posted June 19, 2006 Chris, there are some automotive legends that refuse to go away arn't there. It reminds me of the air-cooled one about changing rod length alone increasing your CC or that fitting an externally breathing reed valve into your servo pipe (on a car with a lambda sensor) will improve your fuel consumption, no product name mentioned. Quote Share this post Link to post Share on other sites
Chris VR6nos 0 Posted June 19, 2006 dr_mat, good one, you're on it, the C/R can't change without phisical measurements changing but cylinder filling will be greater with a freere flowing air filter, the more air in there getting squashed the higher the pressures will obviously be. Not that it'll make much difference really though. Crasher, "changing rod length alone increasing your CC or that fitting an externally breathing reed valve into your servo pipe" Well i've never heard that one before, the crank and cylinders dimentions change CC and rod length does effect things but the main idea for rod length is to effect rod angularity ie. thrust ratios nad creating torque from long cranks but not much else. That Reed valve, i don't give it thought room, what a crock. Chris Quote Share this post Link to post Share on other sites
aki 0 Posted June 20, 2006 hi, ok ive polished and ported a spare vr6 head,matched and polished the inlet and exhaust manifolds and ive got a pair of 264 kent cams to go in! as ive got to take my old head off to fit my "new" one i wondered if it was worth fitting a mk4 vr6 head gasket as ive seen on vw vortex that a few people are suggesting fitting one as it may increase compression a bit.sorry compression ratio.which hopefully might liberate an extra horse! possibly even two! i realise that it will only increase the compression ratio marginally,but as they say "every little helps" as ive got to fit a head gasket of some sort! i may as well raise my compression even if its marginal. as im not planning on force inducing my engine it wont hurt to raise my c.r.a bit if possible! so is the mk4 gskt thinner? and will it fit on a 2.9 vr6 circa 1993 cheers andy Quote Share this post Link to post Share on other sites
Chris VR6nos 0 Posted June 21, 2006 Well yeah go for it but it should be easy enough to find out the thickness's of the gaskets from a parts supplier. Chris Quote Share this post Link to post Share on other sites
ntonar 0 Posted June 21, 2006 The mk4 gasket will bump it up the CR about a 1/2 point. Not only that but the gasket is better quality and will last longer. I am in the process of putting one on now. Quote Share this post Link to post Share on other sites
Henny 0 Posted June 21, 2006 you seriously reckon that fitting a later, standard VAG VR6 gasket will knock the compression ratio up by 1/2 a point? :| If the standard Corrado gasket were a 6 layer gasket and the new one was a space age material 3 layer, then you'd maybe lose, what, 0.5mm of height when it's clamped down with the head bolts? Compression wise that's gonna make as much difference as farting into the inlet... Hell, Once the standard gasket is compressed, about the only way you're gonna lessen the distance from the head to the block is to not use a gasket, but I don't think that'd do your compression much good! :lol: Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 21, 2006 The coated stainless gaskets for the MK4 12V are 1mm thick, so quite a bit thinner than the regular fibrous Victor Reinz ones. We (as in Vince and I) do know that 2 MK4 gaskets stacked drops the 12V CR to 9.6:1, so I would imagine as a rough guesstimate that 1 Gasket would increase CR to 10.2:1? 0.2 won't really give you a lot but as ntonar says, it's a vastly superior gasket. VW have changed to coated steel gaskets on pretty much all their engines in recent years. Quote Share this post Link to post Share on other sites
ntonar 0 Posted June 21, 2006 The mk4 gasket should bump up the CR from 10:1 to 10.5:1 FYI (at least for a 2.8l US vr6) Quote Share this post Link to post Share on other sites
aki 0 Posted June 26, 2006 cheers guys got to be worth a go then eh! wonder if itl make any noticable difference,but if its a better gasket it could prevant any future problems, worth a punt.... :) andy Quote Share this post Link to post Share on other sites
Chris VR6nos 0 Posted June 26, 2006 Interesting, i'd like to see how close the VAG map runs the engine's fuelling on full throttle as 0.5 C/R point will effect this a fair bit i'd have thought, no good putting things at rise without looking into it. Chris Quote Share this post Link to post Share on other sites
ntonar 0 Posted June 30, 2006 I am finishing my head gasket job this weekend. I will let you know how things go and how the car runs. Quote Share this post Link to post Share on other sites
