1.6 8v to 1.8 8v conversion

Hi Guys,

Im looking to carry out the above conversion in the near future as my 1.6 is getting a bit tired. Im going to go with a 1.8 head and 2.0 bottom end.

What im wondering is how much of the 1.6 setup I can keep in terms of fuelling/metering and electrics/loom? (I have the older bullet type fuseboard)

Also wondering about which gearbox to use with the 2.0, the 1.6 or 1.8?

Any advice appreciated.

Cheers

Should be able to keep all your loom as you need to use all your sensors etc. I used a 1.8 metering head which seemed to work ok. the 2.0 is not a rev monster so i wouldnt use the 1.6 box, consider using 2.0 box.

Cheers mate, good to know.

Anybody know if the 1.6 metering setup will be ok for my conversion? Would save me a fair bit of hassle.

my mk1 was originally a 1.6 and was converted to a 1.8 they used the 1.6 box and metering head and it was fine.ran spot on so it should be ok on a 2.0 i would have thought

FriedRiz said

Cheers mate, good to know.

Anybody know if the 1.6 metering setup will be ok for my conversion? Would save me a fair bit of hassle.

the 1.8 gti engine is pretty much a straight swap for the 1.6. the 2.0 belly will need the 1.8 head on it along with a blanking plate over the breather on the block, which the wur will be fixed to and a spacer ring for the dizzy. you can keep all the 1.6 fuelling, igition and box if you wish. 2.0 will rev fine if you cam it, therefor warranting keeping the 1.6 box. i'm sure later 1.6 5 speeds had the same ratio's as the 1.8 boxes anway. easiest and cheepest is a 1.8 engine swap.

Thats some great info guys, cheers.

Glad I can keep my fuelling and metering setup, makes things more straight forward as this is my first attempt at anything outside general maintenance and servicing.

Was planning on a cam anyway so well worth it if it allows me to use my existing box.

Last couple of questions…..

Which 2.0 should I try to get, Audi bubble block, Mk3 Tallblock?
Any engine codes would be great.

Will I need to use a clutch to suit the 2.0 bottom end?

Cheers

the audi 3a (bubble block) blocks best mate as its the same height as the 1.8, afaik the 1.6 and 1.8 blocks are the same size, the other @l blocks are around 17mm taller.

you take the flywheel and clutch off the 3a and bin them, then fit the 1.8 flywheel, clutch and pressure plate, this then allows you to use your original g/box etc.

if your going to do it i'd definately get a cam in there as wooders says.

Chris

Great Stuff, cheers mate

So my shopping list:

1.8 8v head, flywheel, clutch, pressure plate
2.0 3a bottom end
Blanking plate
Dizzy spacer
Cam
4 branch manifold

Could anyone recommend a cam and manifold?

Kent GS1 cam maybe?

i'm running a piper 285 cam, which i've been told is about as lairy as you want to go in a road car.

it idles quite lumpy, but really comes into its own above 4k.

depends what you want really i suppose, lumpy idle doesn't bother me i just want maximum power at higher revs.

i got an ashley mild steel tubular manifold, they're roughly 140 quid delivered from ashley, i did toy with the idea of stainless steel one but couldn't justify the extra cost. if the mild steel ones weren't up to the job the forums would be packed full of "don't get one of them" posts.

ref the blanking plate and spacer ring, i have both from tsr, i would see if anyone on club gti also does them, as the spacer piece i got from tsr doesn't have a groove in it to mount a seal, as a result i'm now getting oil weeping from around the flange. i remember reading soemone on there did the rings with the groove and a seal.

just a bit of hindsight that i wish i'd done.

ref the head, i'm running a solid lifter head on mine so this requires the gaps between the cam lobes and the tappet bucket setting up to a certain tolerance by using different sized shims.

when i fitted my cam i had to replace about 5 of the shims to get the gaps right, the problem is some of the sizes are now like hens teeth and i ended up having order one from a dealership on the isle of wight!

so if you are shopping for a head (in hindsight again!) i would suggest you look for a hydro tappet head, the later mk1 gti's and some early mk2 k-jet's came with dx engine codes with hydro heads. (you don't want pb head as this is digifant came in later mk2 golf 8v's)


these auto adjust to whatever the gap is, so no shimming required, and will save you extra messing about trying to get the gaps right.

the 3a bottom end will have run a hydro head on it to begin with so the pump will be able to cope with another hydro head so no worries there.

obviously make sure you get the correct cam for the head as the solid and hydos are different.

anything else you want to know just ask mate, i got plenty of guidance so am happy to help.

Chris

Might opt for a milder cam and the ashley manifold would certainly do the job, couldnt justify the extra expense for a stainless either.

Good heads up on the spacer ring and head too, nice one.

Just planning at the moment and will start picking things up as they come available.

Thanks for your offer, I will give you a shout 'when' I get stuck!  


Cheers

wouldn't bother with the ashley manifold, but i would heat wrap the standard one. i'f you are going 2.0 then i'd personally go kent gs2 or piper 285, there is plenty enough low down torque to sacrifice for upper power.

wouldn't bother with the ashley manifold, but i would heat wrap the standard one.

Cheers wooders, why do you say that?

Whats the best product for heat wrapping?

Plenty to think about on the cam front.

gather as much info as you can on cams, before you make a choice. i've had tubular manifolds and for me the unless your running high revs, they are not worth it and the ashley has large primaries, which is good for race engines and such, but not much use for road going cars. the standard one is not too bad to be fair. just plain exhaust wrap. it'll aid the inlet manifold temperatures

Good points there mate, great to know. Thanks a lot

So does the 1.6 manifold match the 1.8?

We've just launched the Technical Section (link on left), in there you will find a lot of answers to the questions you are asking.

Magic, thanks Paul