MarkGolf 0 Posted August 19, 2004 Hi.. I'm in the process of pulling a 2.9 VR6 engine apart so I can fit a new bottom end as I put a piston through the original.. Now, I've got no mechanical experienc, but have pulled the complete conversion out of a corrado, and getting it ready to go in my golf... Today I pulled the rocker cover off, and chain cover.... Would like some tips... The chain look brand new, but guess it would o, the guides look pretty new too with VERY minor marks from where the chain runs along them.. So I guess they've been changed... The car had donr 107k with full VW service history.. Well, tomorrow I want to pull the head off, but today I couldn't budge any of the splines holding it onto the bottom end.. I know the order in which they are all meant to be undone, so no need to warn me on that.. Do they need to be undone with a gun?? Would a LONG bar do the trick? Im not made of money, but the new bottom end im getting has done 92k, so would a re-bore and new piston rings be recommended?? How much would this cost?? I have a mate who does machining and he says if I can get the bore size, he can do the rebore for me.. So, anyone know the bore size??? If i get him to do this, he'll do it for a crate of beer, so how much would fitting new piston rings cost if i simply take the bottom end to the place and say 'fit new piston rings' thanks, any other advice would be appreciated!! what things shud I replace? I'm replacing everything single gasket, new bolts here and there, waht else?? the chains and carriers look fine so far.. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted August 19, 2004 Hello mate, I recognise you from the VR6Golf.co.uk forum :D Your car looks fantastic on those wheels, are they RH Cup Raders? To do a 2.9 rebore you need a 2.8 block. Bore size for the 2.9 is 82.5mm I think. VW can supply you with new 2.9 pistons but they don't do 2.9 overbore pistons, hence starting over with a 2.8 lump. Once the head is off, check the bores for tolerance using vernier calipers. Any ovalisation (especially in bores 1 and 6) will mean a rebore. From Stealth, you're looking at about £1700 for a bottom end rebuild but get some quotes from a local engine builder and compare prices. To overbore the 2.9, you will need J&R pistons from the states to take the capacity out to 3.0. Yeah a big torque wrench will give you the necessary leverage for removing the head bolts. As for gaskets, use VW or Victor Rientz ones only. Good luck K Quote Share this post Link to post Share on other sites
MarkGolf 0 Posted August 19, 2004 Cheers! They are RH ZW1's, in the middle of polishing them, amoungst many other things I have begun which I wish I never! lol Ouch, they are big figures, can't stretch to that at the mo! As its a bottom end from an unknown place an I can't afford the £1700, what can I do on a smaller scale budget? Just get piston rings re-newed? Im going to get Hi flow heads to lighten and balance my flywheel as I quite like the price they offer ( hiflowheads.co.uk ) The gaskets will defo be from VW as I get disocunt, someone mentioned about going for a mk4 head gasket, but as Im going for a supercahrger, they said stick to the original.. All far too trying, but should be worth it in the end I hope!! Just want to get it in the car and running, then I'll go about doing the up-grades.. Thanks for your help :D Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted August 19, 2004 We are most definitely liking RH rims on here :lol: You can just renew the rings but I don't know how long they will last in worn bores, assuming yours are. They might not be, my 2.9's bores were within tolerance at 93K when I had the head done and the engine certainly isn't lacking 6000 miles later..... Check your Yellow pages for local engine builders. My local one charges something like £20 a bore and if you're prepared to lug the block around, you can save a lot of money in the long run. The MK4 steel head gasket is thinner than the 12V one, which increases the compression ratio, so that won't be suitable for supercharging, well, it will suffice but you'll have to drop the Vortech/Z-engineering's psi a bit. Go for a 3.0 build with 9:1 pistons and you can crank the boost up, the later Vortechs can deliver 24psi with an upgrade kit.....but we're getting back into major bucks again there :? Have heard of hiflow heads but not experienced their workmanship, they seem OK though. Cheers K Quote Share this post Link to post Share on other sites
Joe M 0 Posted August 19, 2004 The MK4 steel head gasket is thinner than the 12V one, which increases the compression ratio, so that won't be suitable for supercharging, Kev, I seen you mention in another thread that skimming the head would affect the timing. Wouldnt this thinner gasket have the same effect? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted August 19, 2004 I would imagine so. PhatVR6 is using a MK4 gasket on his so should be able to answer that for definite. Skimming the head wouldn't normally be a problem on a cambelt driven head as you can use a vernier cam wheel to restore the timing, but you can't fine tune the cam timing on a VR, so if the machine shop goes too mad with the skimming, you're stuffed. I just have an old fashioned aversion to skimming based on past experiences and what I say is never gospel :wink: Quote Share this post Link to post Share on other sites
Joe M 0 Posted August 19, 2004 I dont think it is a problem giving the vr head a slight skim. I know my cars had a rebuild and I think I seen skim mentioned in the receipt somewhere and it runs fine. If the heads ever off again though I reckon I better use the standard gasket just in case. Quote Share this post Link to post Share on other sites
MarkGolf 0 Posted August 20, 2004 Oh nice... Fingers crossed its fine then.. Got a local engineering place near me, and im fine about lugging the block around. My mate may even be able to do the piston rings which would be a result! How do you go about doing the piston rings out of interest? When looking at a bottom end, are there any obvously things to look for? Guess I'll stick with the OE gasket.. Quote Share this post Link to post Share on other sites
MarkGolf 0 Posted August 22, 2004 The bored look and are mint on the new bottom end, so result there.. Been told to replace the big end bearings and piston rings.. Piston rings around£70/80 for a set of 3, or the lot? Quote Share this post Link to post Share on other sites
yellowslc 0 Posted August 25, 2004 If you have any specific questions with regards to engine building.. cam timing etc.. feel free to send me a PM. I've done quite a few of these. FYI.. JE pistons + 268 cams + mk4 headgasket with a resurfaced cyl head = 99% chance of valve to piston interference. It's roughly 50% when using OEM pistons with the above combination. In hot climates, the mk4 HG is a waste of time as the ECU will retard timing. This shouldn't be an issue in the UK. Quote Share this post Link to post Share on other sites
