Storm 0 Posted June 28, 2004 "We don't have 2.9s over here, but I've NEVER seen a 2.8 motor with ovaled bores, even super high mileage." I got the above quote from a US specialist. Makes for interesting reading. If a 2.9 on average gets ovalised bores at 100-110k and a 2.8 never does, then the 2.8 is going to drink alot less oil and last a helluva alot longer. What do you guys think? problematic bores is a big price to pay for 69cc. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted June 29, 2004 If a 2.9 on average gets ovalised bores at 100-110k and a 2.8 never does, then the 2.8 is going to drink alot less oil and last a helluva alot longer. What do you guys think? problematic bores is a big price to pay for 69cc. We put up with it. What can anyone do about it? Perhaps the bore wear is just down to the extra power output? Perhaps it's down to the comparison between the way Coupes and Hatchbacks get driven? Perhaps driver education is better in the US (thrashing it from cold is the big killer no doubt)? Who knows! Also, I'm no expert, but I think there's not really enough evidence to state that a 2.9 gets ovalised bores at "on average 100-110k". There's been a few cases of it, and it's not unheard of, but you look at how many cars are left with that and more miles on them that show no signficant problems. Quote Share this post Link to post Share on other sites
Rpmayne 0 Posted June 29, 2004 Can't see that the extra displacement gave an extra 12bhp on its own as mentioned on here before. Does the 2.8 run as hot as the 2.9 standard? Why would the thinner walls of the bore create more ovalisation unless its down to the heat warping them? Me no understand, except mines been rebored so I've only got about 75,000mls going by that before I need the next one. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted June 29, 2004 The extra displacement isn't the only difference to the 2.9 (and it's an extra 16 bhp IIRC - think the 2.8 is 174). Throttle body, inlet manifold and cams are different. Plus I believe the 2.9 has a 4-bar fuel reg as standard where the 2.8 has a 3.5 bar one. There may be other differences I've forgotten.. Quote Share this post Link to post Share on other sites
vr6storm 0 Posted June 29, 2004 The extra displacement isn't the only difference to the 2.9 (and it's an extra 16 bhp IIRC - think the 2.8 is 174). Throttle body, inlet manifold and cams are different. Plus I believe the 2.9 has a 4-bar fuel reg as standard where the 2.8 has a 3.5 bar one. There may be other differences I've forgotten.. Dr_Mat i think he's refering to the power figures for N.American spec VR's btw.......178bhp........tho not sure if an american pony is the same as one of our UK ponies??????????? Quote Share this post Link to post Share on other sites
dr_mat 0 Posted June 29, 2004 Ok, I wasn't sure anyway... I'm fairly sure US bhp is exactly equivalent to UK bhp, but I don't know of a reason for the difference.. Quote Share this post Link to post Share on other sites
Andi 2,147,483,647 Posted June 29, 2004 HP is the same, its a standard. But its the corrected values you get off a rolling road. UK (SAE) rolling roads work on a higher standard and are stricter. US (STD) one's are notoriously more generous. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted June 29, 2004 But surely they are quoting the manufacturers figures? Do VW use different figures from the same engine in the US? Quote Share this post Link to post Share on other sites
vr6storm 0 Posted June 29, 2004 But surely they are quoting the manufacturers figures? Do VW use different figures from the same engine in the US? AFAIK 178bhp is what VW(america) quote the SLC as being :wink: Quote Share this post Link to post Share on other sites
h100vw 0 Posted June 29, 2004 Is the Yank engine a 2.8 or a strangled 2.9? Gavin Quote Share this post Link to post Share on other sites
vr6storm 0 Posted June 29, 2004 Is the Yank engine a 2.8 or a strangled 2.9? Gavin AFAIK its the AAA-2.8 VR :wink: .........no doubt with some lovely emission controls tho :roll: Quote Share this post Link to post Share on other sites
Rpmayne 0 Posted June 29, 2004 The 2.8L is a 81.00mm bore and the 2.9L is a 82.00mm bore. I think on the Vortex forum they were saying any bigger than 83.00mm bore (3.0L) and ovalisation problems can really start. Not exactly thick cylinder walls to start with. Quote Share this post Link to post Share on other sites
dazzyvr6 0 Posted June 29, 2004 to take the 2.8 to 3.1 you need to overbore it but the 2.9 is ok from what i read Quote Share this post Link to post Share on other sites
Joe M 0 Posted June 29, 2004 The american slc makes slightly more power than the golf due to a less restrictive exaust and catalytic convertor. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 29, 2004 It's not just the 2.9 that suffers. The guys on vr6golf.co.uk seem to discuss smoking, plugs 1 and 6, rough running etc as often as we do. I think it's partially down to the manufacturing standards. Some engines were good, some were Friday afternoon jobs. Vince showed me a VR engine with back to front con-rods for example. And the remaining cause is simply driver neglect. Thrashing it from cold, rarely servicing it and filling it with cheap oil. That description would fit my Dad perfectly, but he only has his cars 2 years and doesn't care...... and that's half the problem. That early abuse makes itself apparent further down the line. Don't forget most C VR6s were owned by professionals or were company cars due to the ridiculous price tag! How many CC drivers do you know that treat their car as if it were their own? I don't know any....... Quote Share this post Link to post Share on other sites
Rpmayne 0 Posted June 29, 2004 Good point, that's why we all need to be enthuasts (or try and stay enthuastic) to put up with the problems older cars will have I suppose, especially performance cars. Must have been good jobs to get them as CC's. Quote Share this post Link to post Share on other sites
