which bottom end for 2.0l conversion and do i go for it?

[danny_p]

the 6A and 9A engines  feel freer revving,  but the ABF  develops more torqe through the revs ( grunt ) and will rev as high as the other 16vs

[Horney]

the 6A and 9A engines  feel freer revving,  but the ABF  develops more torqe through the revs ( grunt ) and will rev as high as the other 16vs

Can you explain why this is? Is it the head? As as far as I know the bottom ends are essentially the same and the ABF cams are similar to the KR ones I now have in my 9A.

Nick

[danny_p]

mixture of reasons,    the abf is a tall block  so has longer con rods,     this gives a better rod / stroke ratio.   lower thrust angels on the piston    this helps it to produce more torqe and also be a bit more efficent but at the expense of rotating mass.  hence the 6 and 9a feel revvyer.   in theory  the abf bottom end is acyualy beter suited to handeling high rpm tho.

theer are also differances in the head,   the abf head was desinged to have higer port velocities ect.     has smaller port than the kr but valve guides are shorter so less restiction also exhaust port has slightly diffrent desing to try remove flat spot   all this is aimed at grunt though the revs.   cam wise the abf has much diffrent cam it's got less overlap but more lift again desinged  to give grunt through the revs as well as power.  the KR head with more overlap and bigger port  can flow more at higher rpm  but suffers lots lower in the revs hence the ABF  develops simalar peack power  but through the revs gives more torqe

[rubjonny]

oh and cut the rib out of your bonnet for the abf as well cos its taller

wait till after yuou fit it before you do this though, you may find it fits fine!  I think its k-jet on abf that gives issues, the abf on std managment fitted to my mates has no clearance issues.

[xAx]

I assume all the coolant hoses fit or do you need these from a donor car too?

and what about the radiator?

[rubjonny]

depends what you're starting with really, if its a 1.6-1.8 then all the hoses will fit fine, top rad hose may need a bit of tweaking. Though if its a 1.6 you'll want to fit a GTI 8v rad & hoses, 1.6 rad is way too weedy.  Also MK3 bottom ends use a different lower thermostat elbow & hose, just bin them and fit a MK2 Golf 1.6+ elbow with a new stat.

[sharpie]

you'll probably find it's a decent idea to fit a bigger rad at the same time.

[danny_p]

defanatly,    would highly recomend useing a bigger rad than the GTI one as well,   running a  new GTI rad on mine and water temps get a bit higher than id like when giveing it some for any length of time.  chould potentialy cause issues in warmer weather,   so will be ftting tolado or passat rad soon. 

[sharpie]

abf hose kit going to hook straight up to that then danny? there's a cordoba 16v sitting near me that i could get the rad and fan set up from but the piping looks completely different, ie. hoses on the right, not the left.

(before you say get the whole engine etc... it doesn't have the keys)

[dTEA]

depends what you're starting with really, if its a 1.6-1.8 then all the hoses will fit fine, top rad hose may need a bit of tweaking. Though if its a 1.6 you'll want to fit a GTI 8v rad & hoses, 1.6 rad is way too weedy.  Also MK3 bottom ends use a different lower thermostat elbow & hose, just bin them and fit a MK2 Golf 1.6+ elbow with a new stat.

so the mk3 8v bottom end that i've found is useless then?  Its gotta be a ABF or 9A really to get it right?  Does this mean using the head on the donor block or as I was originally thinking, use my 16v head.  I also know my block is K-Jet, so does this mean swapping the management over or not...i've got lost somewhere in this :embarassed:

Cheers guys