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16v head on 8v bottom end???? answers

Posted: Fri Nov 02, 2007 2:14 pm
by htid-gordy
hello im just wondering whether the 16v head would fit on the 8v bottom end because i think it could be a pretty good mod :D but not sure whether to or not so has any1 got any answers or has anyone done it :?: :?: cherrs

Posted: Fri Nov 02, 2007 2:39 pm
by JarnoVWPolo6N
Looked for this recently, all oil and coolant channels seem to fit. But you will need to get other pistons too, since the 16v valves fall to deep, and under an angle in the cilinder, not changing pistons will probably make the valves hit the pistons :roll: :cry:

Also don't not what the compression-ratio will do, and don't forget to check whether the timing belt + pulley will "match" the crankshaft, if your pulley has to many or to few teeth on it, the engine won't run for long :roll: :cry:

Posted: Fri Nov 02, 2007 3:52 pm
by nickm
Ive been thinking of doing this mod too. Ive got a 1.4 8V. Im sure I heard from somewhere that it was a straight swap from the 1.6 16V to the 1.4 8V, aslong as you got the new head skimmed down to the correct compression ratios.

As an asside; does anyone know how easy it is to change the head gasket, as mine has gone :roll: ?

Posted: Fri Nov 02, 2007 5:04 pm
by JarnoVWPolo6N
nickm wrote:As an asside; does anyone know how easy it is to change the head gasket, as mine has gone :roll: ?
Not that hard really, but proper tools are needed, get yourself a Haynes manual is you aint the meachnic fo the year yet, saves you a lot of worries 8) :lol:

???

Posted: Fri Nov 02, 2007 10:49 pm
by htid-gordy
yeah it would be an awesome mod i think!! how would we know what the compression ration should be though and would the 16v pulley work or would you have to work it out. also cud u use the 16v pistons? cheers

Re: ???

Posted: Sat Nov 03, 2007 9:15 am
by JarnoVWPolo6N
htid-gordy wrote:yeah it would be an awesome mod i think!! how would we know what the compression ration should be though and would the 16v pulley work or would you have to work it out. also cud u use the 16v pistons? cheers
16v pistons could be used, but depending on which bottom end you'll be putting the head, you'll have to get your cilinders widened, or if they're already too wide, you will need to buy some oversided ones.

Compressionratio depends a bit on your engine's "original" ratio (with the 8v head on) with mk4's 8v's, it's all between 9,6:1 and 10:1. To gain a bit mroe performance I'd say go for 10,5:1 to 11:1 MAX! or else you'll fry your pistonrings and high rev's.

About thepulley, I have no idea, never had a 16v pulley in my right hand, while having an 8v one in the left hand to be able to examine both. That's the fun of a "project"->figuring stuff out along the way :wink:

newb

Posted: Sun Nov 04, 2007 10:45 pm
by htid-gordy
yer but uv gta rememba im a newb these sorta fings scare me i jus want sum power out of ma car!!! lol o well im sure its a project that will be approached in the future!!! and i wud be usuing the 8v bottom end if i was to do it!!! :twisted:

Re: newb

Posted: Mon Nov 05, 2007 2:43 pm
by JarnoVWPolo6N
htid-gordy wrote:yer but uv gta rememba im a newb these sorta fings scare me i jus want sum power out of ma car!!! lol o well im sure its a project that will be approached in the future!!! and i wud be usuing the 8v bottom end if i was to do it!!! :twisted:
Did my best to understand your spelling, but looks like you want some more power form your 8v, just putting on a 16v head want make much of a difference, the difference between a 1.4 8v 60BHP and a 1.4 16v 75 or 101BHP lies in many things/parts :wink:

Why not just up-grade your 8v block? (cam, header, headwork, fuelpressure etc.)

jarno

Posted: Mon Nov 05, 2007 10:51 pm
by htid-gordy
yer thats not a bad idea but how much do you reckon it would cost me? and what sorta power you gettin out of yours? becase yours is an 8 valve too isnt it? what sorta mods you done to your engine? and how do you post pictures of your car on the threads and il show you my car. its nuthin special but its alright for a 17 year old lad and going to improve!!! get back to me cheers. :lol: :lol:

Posted: Tue Nov 06, 2007 9:11 am
by JarnoVWPolo6N
all that info is in my topic, enough is done to the engine, but still needs assembly back, didn't cost me that much, cheaper then buying 16v head, pistons etc. etc. all to make 16v head fit ;)