The time is approaching for my engine rebuild on my Mk2 gti 8 valve with 186k. Over the last six months I have been assembling parts for the rebuild including a 'Man in the shed' ported head with Kent cam, ported VW inlet and exhaust manifolds, a DX code 1.8 litre bottom end fully rebuilt sourced from Big Boys Toys. I am now unsure if I should go ahead using the standard 1.8 litre bottom end (DX Code albeit from a Mk1 1.8) or to go down the route of sourcing a low mileage, good condition 2 litre bottom end from something like a Passat or Mk3 Golf?? I have read a few posts on here about the 2 litre conversion, but what are the main pluses and minuses of any conversion (e.g fuel economy, reliability, insurance etc) Would I be better off sticking with the reconditioned 1.8 litre bottom end. I am not after massive power, but a useful increase to 125-130 BHP would be nice. Have been told that the head and Kent GSH2 Cam and ported VW manifolds should give me 10-13 BHP, so on a standard digi that's about 122 to 125 BHP? I have read from posts on here that the 2 litre bottom end would give closer to 145BHP and big torque? Any advice? Cheers Alpenweiss2
i rebuilt a 2l block for mine, along with the same head setup you're going to use. it wasn't too bad, but you need to box clever with the dvla and insurance i think. i've not set mine up properly yet, but it's got a fair bit more power and torque. not a lot, but it's definitely an improvement.
It all depends on variables such as the quality of the headwork/port matching, what size exhaust system you use etc etc as to the power output My old digi 8v only gave its true potential with a Big Valve head. Stock valves had it feeling pretty strangled... With an 1800 id say anything up to 130BHP is realistic & 135-140 from the 2L. The 2L is much more torquey though... Another point of note is that a 2L block will chew up a stock 1800 clutch with the extra torque in no time at all. My car did just that with a LuK clutch... A Sachs 16v pressure plate with 8v friction disc is a decent upgrade
i.a.n.b has a 2.0 bottom end on his mk2, his made 135bhp at stealth racing after a mapping session His car is lovely to drive, it pulls a lot harder than my standard PB. Spec wise it uses the 2E bottom end, hotgolf lightened flywheel, vagobonds p&p head with enlarged valves (im unsure of the valve sizes though), raceland 4 branch manifold, cam (neither of us know the duration but its fairly mild) and the stealth remap He did get advised by stealth that a vernier pulley would free up a few more ponies and allow the timing to be made absolutely spot on
if you are going to all the trouble of ported head, cams, ported manifolds etc then I would get a 2.0 bottom end. Can be had for pennies and worth it whilst it is all out
Id say 135BHP for a 2L with BVH is surprisingly low! My old 2L 8v made 155BHP/153lbs/ft on Stealths RR back in the day with very similar spec... Hotter cam & vernier pulley definitely required along with a 2.5" exhaust system...Schrick 276 ftw
