Nigel - can't remember saying that but I certainly went into great depth on all th relevant features. The fundamental problem is the port floor is way too high above the valves. The last thing you want on an inclined valve head with a decent amount of port downdraft is a long short radius like the 20v has. The port exhibits two very distinct flow regimes - at lower lift and higher lift. And at higher lift separation in the lowr port section completely disrupts the flow. NO, even though you're getting 400bhp from yours I can assure you the 20v doesn't develop anything like the flow a head with those valve sizes should/could.

G

I made a note that you managed to flow 137 CFM @ 10" through the head you prepped with 32mm valves fitted. Is that not good then?

Guy - I definitely remember you praising the basic head design - maybe it was just one or two aspects. However, I recall you saying you'd been pleasantly surprised by the stock flow figures (although you could clearly see room for improvement)

However, it looks like you've deleted the build thread from your forum, so I can't find your comments. I seem to recall a 14% improvement being mentioned, which is well over 50bhp on an engine like mine - worthwhile, I'd say. I also seem to recall you mentioning that the head you were given had been worked slightly, although nobody knew who had done it.

So - what's the answer for our 20VT head? (is there an answer?)

I would LOVE to be able to prop up my midrange, but I don't want to do it at the expense of loosing my top-end rush

What diameter inlet valve does the 20v have out of interest?

29.5mm I believe

In my personal opinion,regardless of who it upsets i wouldnt even entertain using anyone else other than Barbz for the head work.
Simple facts.
Tried and tested for years,hes a nice chap and personally i have seen gains of increased spool up on the same turbo,brilliant fuel economy,water and oil temps cooler and to reiterate hes a nice chap who will go way beyond the call of duty to ensure the engine you asked for is supplied to you.
In my case he even came upto Bristol to ensure things were going smoothly.

Guy i wouldnt recommend you to cut lawns.
Your arrogant beyond belief and are known throughout the trade for your attitude and prices.

Theres no need for it and im surprised you get any customers at all.

Does 'Barbz' use the forum ? Perhaps he could be good enough to come on and explain why what he does to these heads to get such good results.

Then everyone else would do the headwork and he would be out of a job.

you ain't seen nothing until you've seen Guy with a fly mo..... Expensive though!.....

No, he would have more work.
If you can explain your method and back up what you do with scientific facts the chances are people will not always understand in all cases, but logic and common sense always ring true in a persons mind. People who can't or won't explain in detail the why's and wherefores, in my experience either hold onto information in the stupid belif that no one else will ever know it (even if your wrong) or just don't know what there doing.

I read a lot about barbz on the forum, i'd be interested to hear about the 20v ports from the horses mouth.

Phone a freind ? :-)

Thats not how it works.
A winning formula is never disclosed.

Try asking Flea to reveal in depth all of his maps,graphs and data from the last 5 years so everyone can see how he does it.
Many have tried but only 1 succeeds.
Barbz is no different.

Totally agree with that last post from JBT

For some maybe, for me I'd like to know what I'm paying for. At least Guy has put a point across about a potential problem with the head, aren't you interested to know how it can be overcome or improved ?

Whoops, my mistake - that link goes to Begbies build.

Matty's is here
Link

@ Tricky, im sure if you go to Barbz for headwork and you were paying him to do it for you, im sure he would answer any questions you had about what he was doing or how he was doing it along with anything else, but also in private.

I'm sure your right, I was just hoping to provoke a decent discussion and maybe learn more about the 20v head.

Sorry but I know exactly what Barbz does and how Guy operates. I've know Barbs for longer then 99% of people on here and seen how he performs the work carried out. I am also customer of Guy Croft's, will be indebted to all the help he has give to me over the years above and beyond engines even down to checking my own technical drawings.

I know why people compare apples and oranges - they purely do not know the difference. I do know the difference, its not based on feeling or person friendship but on quantifiable operations, proceedures, principles and standards - area which I compare to knowledge learned from published works from an array of authors and not heresay on internet forums. This means I can judge peoples work to standards I am aware of - they same way you can judge a builders work when you know how things should be built on a house. Most on here do not know what they are looking at yet state an opinions based only on BHP numbers, its only a part of the story.

So I can say categorically that comparisons are pointless as I know both sides of this fruitless argument I can state simply that Barbs and Guy Croft are not in the same business. If you have a certain budget go one route, if want a race engine go the other route. But please everyone stop and consider to yourselves - 'what do I really know about subject xyz' to make a judgement. A difference exists for a reason, and there is nothing wrong with that reason.

A bit uncalled for John and not really professional for one trader to be slagging off another business / person.


Squish band.

Can't see Tricky doing that to be honest. Having seen what he has built in his own spare time at quite a cost, he wouldn't be going to Barbz for the head work. Rich, apologies if I'm putting words into your mouth here.

What we need, is one engine built by Barbz without headwork, then one with headwork and compare the results, via an engine dyno, rather than a RR as there would be too many variables. Another question you have to ask is, does Barbz have a flow bench? AFAIK he doesn't, so how do you know if one port is going to match the other port, then match each cylinder and have equal flow across all of it? You can't without a flow bench.

Like Rich said earlier, I've known Barbz for about 10 - 12 years or so and is always there for hands on advice and have nothing against the man either.

Begbie, im just saying it theoretically as Tricky was saying about Barbz coming on here and telling evryone how things are done and going back to the point that JBT made about Flea and the mapping.
Im not saying Tricky should get headwork done by Barbz.
What im saying is if he were to and wanted to ask some questions personally then im sure there would be no problems in hiding anything.

Capiche?

Someone must have a picture of a port/combustion chamber worked by Barbz?

I would like to see anyone copy a port just from a picture (it's impossible you can be sure) so there'd be no harm done to hard won experience but for me I'd be able to tell a head that had potentail to be good and no I'd not be copying it, 16 ports is more than enough hassle to work on.

Ta muchly

If there's no explanation when buying services and parts for engines my advice is to run a mile, so many make believe they know all about this vast topic (performance engines)but when it gets down to the nitty gritty they are soon show to be lacking.

This I'm not aiming at either Guy or Barbz as I know them both to be free sharing, it is a common trait in this trade though. I always look at it from the point of view that those that really do know there stuff have no concerns about sharing info, they are safe in the knowledge they could never cover all the variables in a simple explanation. Huge papers are written on tiny subjects.

Nik thanks that was kind of my point.

"Squish band."

As in 'the' or is that his forum name

I'd say that's a pretty good way of telling whether something is doing its job or not.

This forum often feels like that

I must be honest, I don't know Guy Croft from adam, but from what I've seen so far, I'm not really impressed.

Lets keep this thread on topic and not make it personal please otherwise it will be locked. There was some good information on this in the initial stages!

its a very crude way. area under the curve baby, thats the real test for road going cars with std ratio boxes