VVC head

[PACR]

Noticed a VVC head for sale in CCC - complete for £285.

 

Those with uprated 1.8k engines - is the VVC head worth paying the extra £285 or so pounds over the standard one (given that I already have a standard one)? How much extra is the kit required to do away with the VVC stuff and are the cams needed special (ie more expensive, different shape?) for the VVC to normal conversion?

 

What's the going rate for an ordinary 1.8k Head?

 

Thinking about throttle bodies, ecu and headwork for project next winter... Stick to Supersport cams (already have factory SS conversion) and hyd. tappets, orig pistons and liners, bigger valves, ported, prob new exhaust. Wide torque band, peak power about 7000, possible 170 bhp? Sound possible / reasonable? Is it worth getting a VVC head to a: benefit from better ports, bigger valves b: not totally bugger up my origonal head c: be able to use the car whilst putting together the top end?

 

Piers

 

 

 

 

 

 

Edited by - PACR on 22 Jan 2001 12:02:24

[murph7355]

I'm reliably informed that the VVC makes a much better start point, but whether you can ultimately get more power with it I'm not so sure. I suspect any differences there are will only really be felt with large power (220bhp+).

 

I don't believe the gubbins needed to de-VVC is particularly pricey and the cams to use are the same as for the non-VVC big valve conversions (check out Dave Andrews' site for the definitive info on all this - URL has been given elsewhere on this forum very recently).

 

Going rate for a stock head from a head fettling shop is about 100 quid +VAT in my experience. I guess this should be considered the abs.max. for one of these!

 

170bhp's fairly straightforward from a 1.8 with the spec you note (you wouldn't necessarily *need* a new exhaust I think). I wouldn't use Supersport cams personally as there are other alternatives that may better suit your needs or give more flexibility later. Best bet is to talk to someone who knows more than me though (I have my cats number if you like :) ) - again look to Dave Andrews' site or talk to Warren at Piper.

 

As you note, starting with a second head will allow you to do the manually intensive stuff whilst still using your car as it is. This is a very good idea (take it from me!). You can then always sell your old head or keep it for further fettling practice (not that I did either - had to have mine done for me to prevent being left with a few hundred quids worth of aluminium filings).

 

 

C7 AJM

[Peter Carmichael]

The VVC is the head of choice for big power. It starts with bigger valves (still tiddlers by many people's standards and two piece valves which won't stand big big revs). The port line is higher by a couple of mm which means that the charge gets a cleaner shot into the cylinder with a more open short turn. Importantly, there is no waterway cast into the bifurcation on the inlet side (the inlet side never gets that hot). This means that a lot more shaping can be done to improve the inlet ports without risking breakthrough into waterways.

 

The inlet cam is different, with larger end journals. They used to only be available machined from billet, but I think Piper got some cast blanks made up so the price may have come down.

 

I cannot remember the list price for the blanking kit (it is more expensive than I expected) and the cam/cams will be extra cost. This may add 500UKP on top of the 285UKP to your project, but you could stage your upgrade and not get much in the way of extra head work at this stage. A hydraulic VVC head conversion would be good for a flexible 180 bhp. The pistons will be getting marginal though.

[murph7355]

Listen to PC :)

 

URL for Dave's page is here. It has *all* the info you'll need...

 

C7 AJM

[PACR]

Checked out Daves excellent and easy to comprehend site...

 

Seems the VVC head needs lots more cash thrown at it than I thought.

 

I was trying to determine if it was really necessary for a mildish tune (compared to Peters, Mikes and the R500...) of under 100 bhp per litre. I think, from what I've read about others peoples engines, there is an area of tuning the k-series (about 100 bhp per litre) where you have to make the step to forged pistons, mechanical followers, new rods etc and that the ordinary head is OK to this point but the VVC conversion is required after it.

 

As I can't afford to spend vast sums on a better bottom end I think I'll have a hunt round for a cheap standard head and try my hand at porting....

 

As an aside - the VHPD engine uses (or used) the throttle bodies from the Rover V6. Are there any engines that might be found in the scrap yard that use throttle bodies suitable for a K series. And (bit of a strange one this) as my standard induction system uses a 'throttle body', albeit a short plastic one, could 4 of these (or slightly smaller so they fit along side each other be used to make a lightweight, cheap, high performance induction system?

 

Piers

 

 

Edited by - PACR on 22 Jan 2001 20:33:37

[Luke Beaumont]

Last years Piper catalogue shows the basic conversion kit at about £700, but speaking to Warren at Autosport (he even tried to sell me a VVC head smile.gif) they have, as Peter suggests, got blanks now so it's dropped to about £500. Surprised me to learn that the VVC valve sizes aren't too far off maximum for a K head.

[Peter Carmichael]

My valves are 32.5 and 27.3.

 

Up from (??) 31.5 and 27.2 I believe.

 

The conversion kit price covers a blanking kit and a pair of cams with whatever profile, IIRC.

[Mike Bees]

PACR - the level of tune you're looking for is achievable with an unmolested VVC head, i.e. no porting work required. If you're going to do your own porting then maybe a non-VVC head will be a cheaper place to start, but it'll be a lot more work and may require a couple of hundred quids worth of new valves (Dave Andrews has done some really effective conversions of the standard head by putting larger valves in the standard (but fettled) inserts). If you're going to pay someone to do the porting then it may be cheaper (and leave more potential for future upgrades) to start with a VVC head.

 

Mike

[Luke Beaumont]

Interesting to know, Peter.

 

Something I just want to share with everyone however - sourced myself a 1.8 VVC engine today - incredibly it was the first scrapyard I rang. Well chuffed smile.gif

 

Luke

[Rob Walker]

PARC,

 

The standard head ported with oversized valves and suitable cams will get you over 200BHP from either a 1.6 or 1.8 . At 180 BHP and 7800rpm you start to push your luck with engine strength. First requirement Forged pistons. The VVC head fully ported with oversized valves will take you well over 200bhp and possibly up to 250bhp. Over 200bhp and 8000rpm strengthening the bottom end, steel rods, crank and stronger liners are recomended. Sadly the expense doen`t stop there,increased capacity injectors, fuel pump, drysump, clutch etc etc ect.,