I couldn't get that to work so I have posted the link instead - hope that's ok.

http://s977.photobucket.com/albums/ae255/group5lancia/?action=view&current=Plenum1.jpg

Looks like you made that in CATIA V5 etc.....

Fixed it for you. Very nice looking inlet manifold. How much did this cost to get made?

B its a CAD drawing

Not cheap I'm afraid - £750 was the final quote which is cheaper than my exhaust manifold - but it was the first one so copies might be cheaper. However, as the head would not flow what I wanted without the proper inlet, what choice did I have but to do it properly?

The curve in the runners is to suit my installation. These could be made straight or curve the other way, and injectors could also be relocated.

Literally hot off the press and will be installed next week, so pictures (photos) to follow.

Any pics of the real thing?

As I said above, it has just been finished and will be fitted next week, so I will get some 'real' pics up a.s.a.p.

that looks like a brilliant bit of kit there!

cant wait to see the real thing!!

I know it is, still a very nice looking manifold

The design was inspired by this LC2 setup

Nice work. I love the Lancia LC2's (infact anything with Martini livery.... )

That's a pretty drawing, must be to fit the coupe engine bay? Your running a coupe or a lancia?

I'm suprised to see the cross section is as much as it is. You must of ground a lot out of the cylinder head entrance or maybe the manifold runners taper down smaller near the head? Have you a throttle in mind to use? Sorry for the questions, just a favourite subject of mine.

Nik

I have 36.7mm inlet valves, giving a valve area of 2116mm^2. The inlet ports are 27mm diameter at the narrowest point, giving an area of 1145mm^2. This size was chosen to match the peak RPM the engine will be run at whilst keeping good gas speed at lower RPM. From the narrowest point to the head face the ports increase in area to finally match the inlet runner area.

Peak flow is 182cfm @ 10" of water (287cfm @25", 304cfm @ 28") with the valves in. This is an improvement of 143.5% over the standard head, with measurable flow improvements from 2.5mm lift. I haven't yet measured flow with the manifold on but EAP says all will be fine with an actual total engine flow of 646cfm @ 8000 rpm @ 29psi boost or 574cfm @ 8000 rpm @ 21psi boost.

The engine is fitted in a Lancia, but the runners could be re-designed and the throttle body position modified to suit a Coupe I am sure.

Yeah, of course you have

Not sure if there was a hint of disbelief in the previous post, but here is the comparison from the flowbench

A pretty graph isn't going to win me over I'm afraid, you'll have to do better than that.

The big valves is interesting, any chance you might explain how you went about fitting these?

That is your choice, of course. I don't have anything to prove here - I'm just trying to help those who asked, including the OP, about dealing with the flow restrictions of the various standard inlet arrangements.

As for fitting the valves, you can get in touch with Automotive Machine Services who did the work. I have sent you a PM with contact details. All I can say is it wasn't a big job - new seats required of course and also for the exhaust valves which are 32mm. The 36.7mm valve is only 1.15mm bigger in radius after all..... oh, and I forgot to mention the bores are 86mm

2mm over bore?..... Isn't that ALOT?
Mines just been bored to 84.5mm, which makes it now a massive 2.02 cc engine.....

Nick

I agree. I have 85mm bores in the 8 valve engine and I thought that was on the limit. But the 86mm was specified and machined by 'the man' and he also supplied the CP pistons. I know it's not the only '2.1' block he has done - so who am I to argue? Block is Fiat Croma which might make a difference...

I can't help but think that the respected Guy Croft who has put a fair part of his lifes energies into the Fiat twincam might have a decent handle on how to extract CFM from our cylinder head. He has afterall done many of them to all levels of performance. I know him to not be a bull shitter in any way and have not the slightest doubt that he has done everything he could to get the most. Below he talks about just this subject and you might do well to read it. Whoever is telling you those figures is having you on. To do it with a pinch point of 27 mm is fantasy. As you'll likely know Gregs car is no slouch with a power level that is amazing, all on a standard valve size.

http://guy-croft.com/viewtopic.php?f=13&t=80&hilit=greg

The simple fact is the standard valve size on a decently worked cylinder head can supply enough air to maintain 100% ve at incredible rpm, peak potential VE happens lower still.

86 mm bore is asking for trouble too, at the level I think your shooting for you'll be needing all the rigidity you can get, those rings will be struggling as it is.

Is your manifold (inlet) to be exactly the same as the drawing? Looks to me that the air flow at the transition into the cylinder head is going to be nosediving into the port floor.

Pictures would go a long way to proving what you talk about, I'm happy for you to push boundaries (I like to be this way too)but sometimes some things just aren't worth the expense or effort but I'm sure there's plenty who would like to SEE what you've been up to.

Nik

There is, I think you will agree, a huge difference between the head on an 8 valve twink and the 16 valve engine. The only true similarity is that they will fit on the same block.....

In this case, GC supplied and bored the block and provided the pistons - all his spec, not mine. If you think it's asking for trouble, kindly argue the point with GC, not me.

GC also supplied the head fully prepped and assembled by his own hands with his own inlet valves, springs etc (flows shown on the lower trace). GC has not fitted the larger valves nor been involved in the additional machining and porting. GC has said on his website that the Lancia/Fiat head can flow as much if not more than any other production based 16V head, possibly with one or two exceptions. Take a look here... http://guy-croft.com/viewtopic.php?f=9&t=98

I have 13.8% more valve area, so 160cfm x 113.8%=182cfm - exactly what we have achieved.......

Though they are pleasing (to me) I don't think the figures that have been achieved are that extraordinary compared with what GC has produced from the XE and other heads. Neither are the port sizes in the least extreme for an engine running to 8000 rpm. And as for the valve size, as I am sure you won't need telling, what a larger valve allows is better breathing at all lifts and all RPM - not just peak RPM. This is what makes for good torque - as again I am sure you know. With the standard valve there is a mis-match between the valve size and the throat - the throat is too large for optimum performance with the standard valve as I am sure you and GC are aware of. This has been verified by several other independent experts - but I won't name drop. Rather than add metal to the throat we decided to enlarge the valve to match the throat. Simples. The preferred port size to match the valves is somewhat larger, but as we are looking for peak power at somewhat less than 8350rpm we have kept the size down to 27mm.

As for the manifold, I assure you that the angle of the inlet runners is perfectly inline with the angle of the port looking directly at the back of the valve.

As for proof of anything - well, as I said earlier - I am here to offer some answers to the OP and a possible alternative for those looking for a solution to the inlet dilemma. Prooving will be done on the race track. It's the only place that matters.

That's interesting to hear the source of your engine, not at all what I'd expect of Guy. You'll have to keep us updated on results.

I am suprised at the throat size though, some 6/7% away from becoming a burden on lower rpm torque imo.

I guess it depends on what RPM you are talking about - so what number are you working to?

New pics - and a comparison (angle wise) with the Kappa manifold - which has a straight shot to the back of the inlet valves.



Glossy!

And matching cam cover....

I look at the minimum cross section as being more to do with the bowl and valve size rather than rpm. The length of runner has more influence on rpm imo.

Your manifold certainly looks glossy, I like a bare alloy myself but each to their own. Maybe when I've finished them I can offer you an upgrade on what you already have. Aimed at a very similar rpm to yours and certainly not going to restrictive, if your running by then (it'll be a while yet) a bolt on test would be interesting for you I'm sure. Are you running the power steering pump in the integrale position? A taster of what the air will see on it's way into the cylinder http://i3.photobucket.com/albums/y85/1NRO/inletmanifolds016.jpg the rings are to be pressed and dressed onto the runners once the plate is welded to the runners. There's to be an injector mounted in the lower plenum above the bell mouth and a diffuser system between the two.

Have you a particular throttle size in mind to use?

Yours has very short runner lengths - why is that?

It looks pretty solid and bomb proof though - what is the finished weight?

CL comes in at 175 mm

Forsure it's heavy duty, I don't know the weight as it's not finished yet but the attatchment for the or brace is there so no worries on that front.

What size throttle are you intending if I might ask? Also are you running the integrale power steering pump?

What cam duration and timing is the 175mm tuned to work with, and at what RPM?

I don't have power steering on the race car. I have three TBs and will be selecting the best option on the engine dyno.

Depends on who might buy one and the nature of the engine they have/are building. There's a number to choose from and custom also.

No power steering! What's the car?

I thought maybe you'd have a theoretical dia TB, in such a carefully simulated engine.