Right. I know some stuff about mechanics etc but I am keen to learn. There's a fair bit of talk on here about whether people prefer 8 valvers over 16 or visa versa.

Do 8 valve engine have any benefits over 16 valvers? I realise that 8 valvers are simpler and cheaper to build and maintain but are there any other advantages?

Cheers.

The valvers are very revy and 100bhp. The gear ratio is also shorter.

As above, and the powerband is lower down on the 8v obviously. That's about it.

Apart from the uprated stuff the valvers get like the ARB etc

I think he's talking about engines in general!

The diffrences are manily how the engines deliver the power. usually 16v have to be rev'd more to get the power out of them where as 8v have the power band is lower down the rev range.

Would an 8v pull away quicker than a 16v off the line?

Cheers guys. Yeah I did mean engines in general. Quite a surprise that 16 valvers have so much more power!

8v's generally have a little more low down torque,with 16v's having far more top end.

That's like for like,with a sports 16v - some 16v's are not designed for high rpm.

Anyway,the reason is because sports 16v's can 'breathe' more easily at high revs,but this isn't relevant at low revs - infact,the more 'control' 8v's have of air flow at low revs is what enables them to give a better mixture down there,and thus better torque - and low rev efficiency.

Many modern 16v engines are alot more smoothly mapped though, variable valve timing and what-not. The Renault Clio sport for example is well torquey right from bottom end.

Would an 8v pull away quicker than a 16v off the line?

i can only speak of the golf gti engines found in the mk1-2 golfs ect, imo there wasn't much difference low down tbh although the 8v felt smoother as it just pulled well right through the range, where as the 16v pulled well up till about 4k then it really kicked in and was off

some people say that the 16vs don't have much below 4k but they have, its just that it doesn't seem much compared to when it comes in to its power band.

this may not be true for all 16v vs 8v engines, but this is what i found in these engines and seens as they were put in the same car (although for me one was in a mk1 and one in a mk2) its seems a fair comparison really.

having driven a 8v GT and a 16v GTI

i noticed a difference, you rev the GTi harder. without realising it, they just go n go when the power kicks in.

normal driving, after about 5.5k the GT was pretty much out of steam and didnt pull as well as it did in the low RPM range.

GT's 8v's are more fun as town cars imo. low RPM torque means they feel fast.

The only comparable engines would be the 8v gti golf and 16v golf really. Both meant to be sporty, but the 16v did have a fair few more years development - so still not a fair comparison. Introduced in '86 whereas the 8v had been used since the first mk1.

^^ I ran both in the same car. And with the same type exhaust and fuel system.

MK2 Polo coupe with bike-carb'd 1.6 8v - and then same car,same exhaust from floor brace back,same crank,ignition,flywheel,gearbox and carbs but with drilled jets,16v head,block,pistons and rods.

16v is a little more tractable at low revs yet is still nearly as gutsy and no compromise for traffic. 8v had silly torque causing easy wheelspin at very low rpm,but its power curve never really climbed,it just stayed strong consistently until it tailed off quite early.

Now though,its far more progressive.. Climbs hard,and traction is now an issue at higher revs too. Consistently climbing though,it doesn't kick in at any point,just gets stronger and stronger like never before. With the 8v,even when pushing up to motorway speeds,gearchanges were worthy before 5k rpm. Now its just getting stronger there,and it'll go all the way to seven.

This progressive style is more my cup of tea,instead of the almost turbo diesel antics of the 8v.

I've put a few engines in this car,but despite a slight drop in typical economy,I'm now sure i'll never look back to 8v.

Sounds good. 8 valves aren't bad then :-)

My 1.3 SPI keeps up with my mates 1.2 16v Corsa and thats a pretty decent engine. 8 valves FTW lol.

if there was an 8v and 16v at the same power, id have the 8

16v all the time for me

16v all the time for me

i have a preference for extra vales too

its the sound lol

Biggest advantage of an 8 valve is cheap insurance!!!

Biggest advantage of an 8 valve is cheap insurance!!!

Cheaper*

Biggest advantage of an 8 valve is cheap insurance!!!

i'd rather pay more and have more power

Biggest advantage of an 8 valve is cheap insurance!!!

i'd rather pay more and have more power

sames, i also after driving toms valver and then getting back in my 1l today am dissapointed by it now :(

205 gti 1.9, its an 8v but has 130bhp, way better to drive then a 16v kr/abf, much more torque throughout

Edited 18 July, 200917 yr by xcore

205: 130bhp , 121lbs torque.

1.8 16v: 139 bhp , 124 lbs

So the kr JUST wins for torque haha

I think its harder to restrain yourself with a 16V. They just like being revved and kind of egg you on to rev them. Where as an 8V you can happily potter about and its just a dopey car but when you wanna have some fun you can.