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Discussion Starter · #21 ·
Mr Ring,
No, I do not. It went to France.
You're the second person to ask this in the last week.
I would have made more if I knew there was demand.
 

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Crumbs, this is something of a thread revival!!! But I am glad because I didn't see it first time round!

I love the attention to detail on this head, and the revised squish lips now mirrored on both sides of the combustion chamber.

I have a DVA ported VVC head intended for forced induction - I'd post the pictures here, but I don't have picture publication rights for this forum - but probably a similar strategy for the porting, but with a squish chamber left as per standard...

How is that modified head performing in France - have you had much feedback from the new owner? :)
 

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Mr Ring,
No, I do not. It went to France.
You're the second person to ask this in the last week.
I would have made more if I knew there was demand.
I have a feeling as the K turbo conversion is gaining in popularity you might find more people asking for headwork like this. I'm an admin on the K turbo owners forum on FB, I know of at least two other people who would be after similar headwork.

Not interested in making a few £££ at all?
 

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Discussion Starter · #24 ·
Dr Bell,
The squish jest were not mirrored - one was offset to create more near-TDC swirl.

I use Photobucket for my pictures and I like it.

Not much other than just afterwards. C'est la vie.



Mr Ring,
I only build heads for free, I don't build them for profit. Even that head was paid for with beer before it was cancelled.
That way I can take as long as I want with them - that's the trade off.

My day job is quite good, and most people wouldn't want to pay my hourly consultancy rates for cylinder head work, so it's more effective to make money on contracts.
 

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Dr Bell,
The squish jest were not mirrored - one was offset to create more near-TDC swirl.

I use Photobucket for my pictures and I like it.

Not much other than just afterwards. C'est la vie.
That's a shame we haven't heard more - it would be great to know whether your efforts paid off or not? Offset on one of the squish jets duly noted :)

Do you think that those squish jets would work well on a NASP engine as well - or do you see this as an "optimised for forced induction" design?
 

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Discussion Starter · #26 ·
Dr Bell,
It made over 270bhp, apparently, when tuned up and turbocharged in an Elise. The gearbox broke this summer, apparently.
To the best of my recollection it was on standard valve seats and guides and had a standard crank, but better pistons and rods, and blanked VVC units.
I'd like to think it was due to all that torque, and i'm probably at least half right.

I did a great deal of research (well funded company research, not garage research) back in the day on in-cylinder events and mixture preparation across a lot of engine types (SI and CI), placing squish lips amongst other things, and it is my opinion that these types of modifications would work well on the VVC engine in n/a form due to it's already fantastic 3D flow characteristics (tumble + swirl), but as I have no access to the kinds of equipment to establish such things it would only ever be an opinion.

I'm doing it to my own head certainly, but without the back-to-back testing of standard head and a jetted head, or more importantly for me, a modified head and a modified and jetted head I just can't be sure, and i'm not going to do it due to cost and aggravation.

My own head's jets would depend on what I do with the pistons - if they are quite domed with big valve pockets it will interfere with the swirl to the degree that there is no real point in having two - a deep single in the standard position to guide the squish towards the plug would probably be best.
With dished pistons (as that engine had) where there is a decent bowl at TDC the opposed and offset jets should really pay off. The other issue is that the higher volumetric efficiency of the turbo engine puts a lot of air in, which then gets compressed, which then becomes denser but more importantly more viscous, and so the extra forcing from the geometry should help drive more swirl.


Money (wife) permitting, my ideal spec would be higher compression pistons to go with it, probably enough to get 11.2:1, some h-beam rods, with that Piper exhaust cam and my higher port head with my inlet 'Megafold'.
But that's a story for another day...........
 

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Discussion Starter · #28 ·
Mr.111,
Your ignorance is entirely pardoned.
The inlet Megafold is my ongoing work on a longer tract inlet manifold with a slightly bigger plenum volume and an angled approach so the air enters the head at an angle to attempt to get the benefits of a higher centerlined port without as much work on the head.

Prototype 1 was given away, prototype 2 was aborted, and i'm now at prototype 3 stage.
 

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Sounds terribly interesting, many thanks!

Looking forward for the next thread then... As ever :)

Thanks again for sharing all this

Claude
 

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I did a great deal of research (well funded company research, not garage research) back in the day on in-cylinder events and mixture preparation across a lot of engine types (SI and CI), placing squish lips amongst other things, and it is my opinion that these types of modifications would work well on the VVC engine in n/a form due to it's already fantastic 3D flow characteristics (tumble + swirl), but as I have no access to the kinds of equipment to establish such things it would only ever be an opinion.

I'm doing it to my own head certainly, but without the back-to-back testing of standard head and a jetted head, or more importantly for me, a modified head and a modified and jetted head I just can't be sure, and i'm not going to do it due to cost and aggravation.
When one approaches this level of modification, objective testing is important, but also really rather expensive as you say! Probably not in the realms of us mere mortals sadly. But 270bhp is pretty impressive from a K-series! I'd have thought that block rigidity would start to become an important part of reliability at this level though?

Shame that there are not more 1.8T TCi-Tech engines about... ;)
 

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Discussion Starter · #31 ·
The rigidity of the block is inherent in the girdle type construction that these engines have - the bottom end is quite stiff in comparison to it's contemporaries, but the loose liners and open deck would be where the concern comes in.
I mentioned once before that a commercial block filler from someone like Moroso could be used carefully to build up a better base for the liners, but ideally a closed or partially closed deck would be the best solution to improve the mode behaviour of the upper block.

I've so far not seen anyone close a deck, although I believe the 1.4 engine had a variant, so the people running these high output engines, such as Mr Andrews customers for Lotii and Caterhams, must be okay as they are.

Although when we consider that the French fellow could have had über boost and gotten really good torque at normal engine speeds, but with large bending stresses from the direct forces, whereas an 8500rpm n/a engine will have relatively low pressure loads, but hugely higher inertial loads (increase with square of speed) and high resulting 2nd, 3rd, 4th order forces, it could be argued that they are really different problems.

Maybe both are okay.

Where is the extra bracing in the TCi-tech engines?
 

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The rigidity of the block is inherent in the girdle type construction that these engines have - the bottom end is quite stiff in comparison to it's contemporaries, but the loose liners and open deck would be where the concern comes in.
I mentioned once before that a commercial block filler from someone like Moroso could be used carefully to build up a better base for the liners, but ideally a closed or partially closed deck would be the best solution to improve the mode behaviour of the upper block.

I've so far not seen anyone close a deck, although I believe the 1.4 engine had a variant, so the people running these high output engines, such as Mr Andrews customers for Lotii and Caterhams, must be okay as they are.

Although when we consider that the French fellow could have had über boost and gotten really good torque at normal engine speeds, but with large bending stresses from the direct forces, whereas an 8500rpm n/a engine will have relatively low pressure loads, but hugely higher inertial loads (increase with square of speed) and high resulting 2nd, 3rd, 4th order forces, it could be argued that they are really different problems.

Maybe both are okay.

Where is the extra bracing in the TCi-tech engines?
It is interesting that the K-series evolved from having a closed block to an open block design. Is this a question of production expediency, or were there other design considerations at play? Yes, early 1.4 K-series "low port" engines had closed block designs, and 1.4 turbos have made massive power... including in the Land Speed record MG EX-F.

Some 1.8 litre engines were built by tuners I believe - back in the late 1990s - but I can't remember more about them.

Curious that the 2.0 litre Judd K-series touring car engines were also open block?

The Ricardo redesigned K-series, the TCi-Tech, uses very similar looking block castings to the K, but with additional webbing over its external surface. I have no idea as to the internal structure or material specifications though.

There are some pictures on this form showing comparative photos that are quite interesting. I presume that the webbing is there for block stiffness rather than any other function?
 

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Discussion Starter · #33 ·
The reasons for going with an open deck are usually for lightness and to allow a more uniform, or better quality thin wall casting.

Judd don't do things on a whim, but depending on what was the specification of the engines it maybe did not make economical sense to cast blocks that way, or modify them, or the rules wouldn't allow for a change that significant.

If they were using Cooper joints/Wills rings or similar for the liners that may have been enough.

Or maybe they were just fine due to the imposed redline and lightweight components that were likely used not putting particularly high side loads on the liners.



It's wholly possible that the TCI-tech engines are webbed for noise reasons - to prevent particular resonances - rather than for rigidity.
I don't know anyone, or anyone who knows anyone, who worked on it.

At Mazda we webbed a lot of things, and Volvo seem to web things that, after a period of reflection, don't make sense, so it's maybe done for drive-by noise emissions.

You should have heard the clatter off my top end when I fitted my lightened cam cover - you would swear the tappets were coming out to meet you.
A few grams of metal in the right place goes a long way.
When I changed back I thought I'd gone deaf.

I'll do it again though!
 

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I don't know anyone working there either - but perhaps some people who might know some people who did? This risks Chinese whispers (pun not intended! LOL) but I'll ask - and you may be right about the NVH rather than rigidity.

I really hope someone can get one of these engines and strip it down to compare with a K-series!

Respective pictures - K-series first:



TCi-Tech:

 

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Discussion Starter · #35 ·
For anyone who still remembers and cares, this cylinder head died last week.
It was killed in a big overreving incident in the classic 5th to 2nd shift. Everything in the engine died along with it and the exhaust and turbo were blown off, mildly reshaping the bulkhead.

There was small ceremony to mark it's passing in France consisting of people watching some blurry GoPro footage and laughing at the loud bang.
 
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