2.0 8v into mk2 1.8 8v

[tosh]

just purchased a solid g reg mk2 1.8 8v with a dead motor . have sourced a 2.0 8v motor not 100% sure that they fit .
any advice welcome . also looking for rollcage for same car

[marcus123]

how much have you got to spend on the engine mate?

i dont rate the 2 litre 8 valve, its pants!

[golfvr6]

A 2.0L will fit in no probs, will give a substantial improvement on the 1.8L lump.

[richy]

An extra 200cc (even with 8v) will be an improvement.

[tinman]

From the conversation i had last night, the improvement may not be in the place you want it.

a 2ltre conversion will increase your power, but under normal circumstances, wont increase your acceleration. your benefit is top end.

it seems that because you are not changing the bore size, only the length of the travel of the piston; the pistol has further to travel. the increased volume size of the cylinder gives you the extra power, but the extra distance that each stroke now takes saps the engine of its ability to accelerate as quickly as an engine that has a short stroke.

so, a 1.8 8v will accelerate faster or at least hold it own on a 2litre, but the 2litre will take you to a higher speed and it will be stronger at accelerating at higher speeds.

But, you still wont catch a 16v on the 0-60, however, you may eventually reach its top speed.

Tin

[golfvr6]

Not strictly true there mate.
A 2.0L will have lots more low down torque than a 1.8, so will be much better to drive.
If its has the same bore but longer stroke(which i doubt , probably larger bore and stroke) then the engine will produce even more torque.
The 2.0L will also produce a better top end.
Bigger is better  

[tinman]

hey, i dont disagree, i'm just saying that the performance may not be exactly what you'd expect.

i'm trying to figure out how you bore out a 1.8 block further than 1mm oversize as there is a load of oil bits at the bottom of the block you will interfere with. apparently.

Tin

[tinman]

also, i'm rather assuming that the 2litre block and 1.8block are identical, as everyone talks about putting a "2litre bottom end" on the 1.8 block to get 2 litres.

that to me sounds like the bottom bit of the sump and casing and all the bits that attached your main crankshaft, and big end bearings. therefore the 2litre is acheived by a longer stroke and not bigger bore.

again, this isn't my expertise. i only understand a fraction of what my 16v went through on its engine rebuild.

tin

[SoundillusioN]

correct me if i'm wrong but isn't the dubs 1.8 a bored out 1.6.  if so, surly a 2.0 is just a longer stroke, any more boring would break it!

[tinman]

i thought i read that somewhere as well.

casting my mind back a few years, the 16v brigade were always upset VW didnt put the 2litre 16v block in the late mk2 16vs. having said that, no-one could really understand why the 2litre 16v Corrado didn't perform much better than the 1.8 16v unit, and was certainly no quicker than the Mk2 1.8 16v GTI.

which rather adds to my theory that 2litre conversion doesnt give you the monster you are looking for in terms of acceleration, but does give top end.

also, my engine (ahem) is rebored out to its maximum (so the reboring people told me), which i am told is 82mm (1mm oversize). there is no VW part for a 1mm oversize. only .25mm and .5mm. the piston head are made specially (arm and leg time) by another German company.

i'll try and find the displacement figures for the 2litres tomorrow.

Tin