the Official 16v thread

[Preen59]

You can see that the exhaust side is basically exiting at a 90deg angle, but then if you open it up too much, you lose a lot of bottom end... stuck either way really. The sharp-cornered lip just off the valve seat can be smoothed right over within reason, but it's quite hard when the head isn't in two pieces like the one above!! I can't speak from experience - never done one myself, just had the process explained to me to just a big expense (!) - but they say it's a very hard head to work on, which is easy to see with the cross section pics.

Other problem is that the exhaust valve is too big in relation to the intake valve (according to theory anyway), which is why you go up 2mm to 34mm on the intake, but only up .5mm to 28.5mm on the exhaust when going to bigger valves

Yeah bonk made that comment about the exhaust, but from what i understand he's done what he can to improve that within reason. He's removed all the lips etc and once the seats are cut he'll finish it off properly.

What comp ratio did you run with your ibiza?

I'm thinking 11:1 for mine, but i'd like to get some input from people who have used the same engine.

[Valver.]

You can see that the exhaust side is basically exiting at a 90deg angle, but then if you open it up too much, you lose a lot of bottom end... stuck either way really. The sharp-cornered lip just off the valve seat can be smoothed right over within reason, but it's quite hard when the head isn't in two pieces like the one above!! I can't speak from experience - never done one myself, just had the process explained to me to justify a big expense (!) - but they say it's a very hard head to work on, which is easy to see with the cross section pics.

Other problem is that the exhaust valve is too big in relation to the intake valve (according to theory anyway), which is why you go up 2mm to 34mm on the intake, but only up .5mm to 28.5mm on the exhaust when going to bigger valves

[Valver.]

By the way Stu, here's my head, Ports mostly finished. Awaiting the seats getting cut and the throat opened up for the bigger valves.

What do you think?

Looks good - anything's an improvement

Here is a 9a head we cut in half. Look at the angle of the exhaust valve in relation to the port, and also the ridge protruding into the intake port (one of the first ports of call with head work... no pun intended!)





My Dbilas head using an early ADL (European 1.8 16v Ibiza with Digifant) casting with narrow ridged intake port:



Chambers polished up to prevent carbon build up:



Intake ports left coarse for good mix-up

[Preen59]

Yep, that's exactly what I meant

Hehe, great minds think alike.

[Valver.]

He's saying a tired, standard 16v engine might be worse than a fresh, worked 8v...

Yep, that's exactly what I meant

[Preen59]

awesome!!!

it wouldnt cost more if you did all the work yourself

He's saying a tired, standard 16v engine might be worse than a fresh, worked 8v... Why not just bash a set of rings and maybe pistons depending on wear in a 16v?

[GoLfMan]

A hot, well setup 1.8/2.0 8v could definitely challenge a higher mileage, standard 9a 16v IMO, yes It's all a bit subjective still, though!!

EDIT: But tuning the 8v to do so would cost more than a reasonable 16v swap...

awesome!!!

it wouldnt cost more if you did all the work yourself

[Preen59]

By the way Stu, here's my head, Ports mostly finished. Awaiting the seats getting cut and the throat opened up for the bigger valves.













What do you think?

[Preen59]

Agree that pic is pants probably for a cortina lol

I am getting some prices together.

Awesome. I'm in.

Aslong as you can find an actual pic of the right set. I'm thinking the set shown is for a Honda maybe?

[evorobin]

This isn't actually a manifold for any VW that I know of.

I have built a MK1 16V using one of their manifold, that was in 1996 and I don't think the price has gone up since then!!

They don't look like a Supersprint but do the job for less money.

Gavin

Agree that pic is pants probably for a cortina lol

I am getting some prices together.

[Preen59]

Not intended to be a blunt post, but if people are to learn from this thread, let's a least be a bit realistic about how much power is reasonably achievable on all but a massive budget

And even so, 16vs are nice to drive for their torque figures, which can be boosted up nicely in the mid-range with tuning... far more important in a road car with sensible gearing and speed limits.

Thanks for keeping it real, Stu.

By the way, what HP and torque @ what RPMS did your tall block in that seat have, if i wouldn't by prying to ask?

[h100vw]

http://www.ashleyexhausts.co.uk/prod...cts_id=1411382



Anyone else fancy 16v header group purchase?

This isn't actually a manifold for any VW that I know of.

I have built a MK1 16V using one of their manifold, that was in 1996 and I don't think the price has gone up since then!!

They don't look like a Supersprint but do the job for less money.

Gavin

[Valver.]

so basically are you saying a hot 8v can achieve nearly the same amount of HP for less dollars?

A hot, well setup 1.8/2.0 8v could definitely challenge a higher mileage, standard 9a 16v IMO, yes It's all a bit subjective still, though!!

EDIT: But tuning the 8v to do so would cost more than a reasonable 16v swap...

[GoLfMan]

so basically are you saying a hot 8v can achieve nearly the same amount of HP for less dollars?

[Valver.]

you will get that from a STD 1.8 KR valver,

155-160 for a std 2.0 would be ball park, i think Dom is on the right track

You'd be surprised if you put an old, unrebuilt 9a with KR or ABF cams on an engine dyno. Not only are the cams alone not worth a 20bhp+ increase (you don't get that in peak figures moving from PL/9a cams to Schrick 260s), an engine with a quarter of a million kms already won't make its standard output.

Fair enough a lot of the UK cars "have" blaring hp figures, but no one has used a proper engine dyno, and I'm sure if someone was to put a genuine, fresh 160/170/180hp engine in their car, they'd be very surprised.

A 172hp Clio has miles more grunt than some of the VW 16vs I've driven claiming similar outputs - same, too, with the 168hp B16A Honda, which has far less torque. I'd be more inclined to believe a 15 millio dollar factory dyno than "Vince @ Stealth" with regard to how much power my engine had

Not intended to be a blunt post, but if people are to learn from this thread, let's a least be a bit realistic about how much power is reasonably achievable on all but a massive budget

And even so, 16vs are nice to drive for their torque figures, which can be boosted up nicely in the mid-range with tuning... far more important in a road car with sensible gearing and speed limits.