52mm intake manifold on 1.8 16V?

[MackyM]

I've seen one for sale. Is it worth getting? What gains/problems might result?

[rowlers]

i've heard they give greater top end but loss of low end torque???

what sizes are available to fit the valver? is std 40mm?

[2l_16v]

the 16v came with either a 42mm or 50mm, as far as I am aware there is no 52mm.......

the 42mm has parallel runners and a larger plenum chamber, this give more lowe down torque and slightly weaker topend.

the 50mm has wider runners but they get narrow at the top near the plenum chamber, and the plenum chamber is about 2/3 the size of that on the 42mm one.

For everyday drivability the 42mm is better, if your racing, with lots of top end stuff the 50mm is better (in theory)

Ive tried both on my 2L 16v mk2 and honestly can say it didnt appear to make any difference to the drive...

[jims13]

macky fAIRLY SURE YOURS HAS the 50mm intake/plenum. pop round one night if you like and ill measure it for you

jim

[MackyM]

Thanks Jim. I have another question too: The guys at AP say my car is still smoking (after the head rebuild) because of oil caught in the exhaust system before the repair smoking away. The issue I have with this is would it smoke immediately upon start up on a cold day? How can the oil be burning off when the exhaust system is cold? (I get a big old puff of blue most mornings) Seems to me like something was missed - or am I mistaken?

[lch1]

dont want to sound nosey but who did your head work were the valve stem oil seals replaced what happened to your head was it new head job also oil can damage the catalitic converter if this is pushed in to it ,has it had an emmision test you may have worn oil rings on pistons which push down oil back into lump when engine is cold they may not seal but as it heats up they will expand and re-seal so no smoke only on start up
whilst engine is cold!!!
just a suggestion
hope its some help
lch1

[jims13]

a compression test would more than likely so any signs of any more wear. id say blue smoke is rings/bore wear , but tbh i would hav thought that ap would have diagnosed it before making you part with your hard earned.

what milage is the lump on???  and how much oil does he reckons in there?? do you have a cat?? didnt think you did.??

oh and i have the 50 and 42mm intakes and didnt notice a difference unitl i fitted my 4 branch. guess its all down to the breathing as they say.

jim

[MackyM]

Took it back to AP and they spent a morning testing it. They say there's no evidence of ring wear - at least not when the engine is warm. Mileage is 142K now, but Andy says it drives like 60K and probably has another 70K in it until a new lump is on the cards. He did say that there is an awful lot of oil in the exhaust system. As for whether I have a cat - I don't have a bloody clue 

To the previous poster - the head rebuild included new stem seals, new guides and all 16 valves reseated - pretty extensive in other words. I didn't understand how it could subsequently smoke cold, but your theory on the expanding rings might explain it. Regardless of how much oil is in the exhaust, how can it burn off cold??

[lch1]

me guess a buggered cat!!! full of oil and will smoke no matter what

[jims13]

can soon tell if you have a cat or not!!  

jim