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Re: Head work..
#247500
12/12/2006 18:03
12/12/2006 18:03
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Joined: Dec 2005
Posts: 1,576
Glasgow,Near Florence..If only...
paul
My life on the forum
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My life on the forum
Joined: Dec 2005
Posts: 1,576
Glasgow,Near Florence..If only...
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Quote:
Have to disagree, we have never needed to use one to get the results we need. 
get to work you ,you don`t have time to get involved in bickering on here   ...................I and the rest of the coupe owners who you have re worked the head in their car, know you have done a great job on it............people seem to forget you worked for a good few years at EVO,and got plenty of experience working with fairly heavily tuned Integrales,and `early on` coupe tuning etc etc,therefor not just from `pottering about` guessing the work needing on coupes,I reckon,good understanding of what a specific engine requires, is just as,if not more, important than anything else.......I`m sure you have trialed plenty of things with head work on coupes and found what does, and what does NOT work,thats what R&D is all about...............
I can`t think of a better way of finding out what does and does not work on a specific engine...........
Guy Croft is a excellent, and very, very ,reputable person in this field...........and given most engines, would leave Barbz guessing what to do,but given the time and experience Barbz has on the coupe engine.....I`d highly recommend him above anyone else
was Paul S,now just paul...Member since Oct 2000,Coupe may be FATALLY injured - :(oh no it's not 
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Re: Head work..
#247501
12/12/2006 18:09
12/12/2006 18:09
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Joined: Dec 2005
Posts: 2,588
Essex
Rog20VT
I need some sleep
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I need some sleep
Joined: Dec 2005
Posts: 2,588
Essex
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Quote:
Quote:
not really sure how someone can consider themselves a performance engine builder without one
Have to disagree, we have never needed to use one to get the results we need.
i was referring to machine shops that carry out the work with big claims.
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Re: Head work..
#247502
12/12/2006 18:22
12/12/2006 18:22
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Joined: Dec 2005
Posts: 1,576
Glasgow,Near Florence..If only...
paul
My life on the forum
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My life on the forum
Joined: Dec 2005
Posts: 1,576
Glasgow,Near Florence..If only...
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yep agreed Rog, and their are plenty of them  . the hard bit, is finding a place, we know, can do what is required to get the best gains,I`d rather use someone who has, over the years displayed a great knowledge of our engines and showed that in practice, and not just theory, the work done gives the gains claimed....................and we have plenty of examples of that on here.........in my book,word of mouth, is far far more valuable than any flashy pamphlet
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Re: Head work..
#247503
12/12/2006 18:24
12/12/2006 18:24
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Anonymous
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Anonymous
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Quote:
Quote:
not really sure how someone can consider themselves a performance engine builder without one
Have to disagree, we have never needed to use one to get the results we need.
Im getting confused now  what was that Saracen lark all about Barbz?
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Re: Head work..
#247504
12/12/2006 18:27
12/12/2006 18:27
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Anonymous
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Anonymous
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Kevan, your getting confused because you've gone off topic mate. Now! Where did i put my sandwich. 
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Re: Head work..
#247505
12/12/2006 18:32
12/12/2006 18:32
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Anonymous
Unregistered
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Anonymous
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Barbz, thought u werent allowed to use the internet. Your missus was telling me the other night! Back on topic : Results are the main thing. If you have had headwork done and you get the results you are looking for from that headwork then whos to say it wasnt done right? Or a flowbench wasnt used. Fleas results show that *with headwork* great things can be achieved. Whether or not a flowbench was used is irrelevant. Ross
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Re: Head work..
#247506
12/12/2006 18:49
12/12/2006 18:49
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Joined: Dec 2005
Posts: 5,405
Castle Combe
Flea
Forum is my life
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Forum is my life
Joined: Dec 2005
Posts: 5,405
Castle Combe
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I have to agree with what has been said here in that if you know what works on a particular engine then there really isn't a need or requirement to incur the extra expense of a flow bench or cnc machine. It's not an easy mix because too little will strangle the top end and too much will kill the bottom end so you have to know what works on any given particular engine. Nyssa has already demonstrated that the standard head struggles beyond 400bhp and I have to say my old setup was incapable of flowing much more despite turning the boost up. That said it's an interesting topic and I would like to see more technical stuff if it was available. From memory the only person on here who has fitted a flowed head is sedicirich to his racing Tipo. If you are out there Rich, can you tell us how much the VE increased by and what sort of gains you managed over the standard head? I wish I had more time and money for this lark but I'm already well over quota on my coupé as is
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Re: Head work..
#247507
12/12/2006 18:50
12/12/2006 18:50
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Anonymous
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Anonymous
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Quote:
Barbz, thought u werent allowed to use the internet. Your missus was telling me the other night!
Back on topic :
Results are the main thing. If you have had headwork done and you get the results you are looking for from that headwork then whos to say it wasnt done right? Or a flowbench wasnt used.
Fleas results show that *with headwork* great things can be achieved. Whether or not a flowbench was used is irrelevant.
Ross
What I want to know is what the hell was done to your head to get your low down torque figures 
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Re: Head work..
#247508
12/12/2006 18:56
12/12/2006 18:56
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Anonymous
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Anonymous
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Lol. I'd like to know too.
Thinkin about it logically, I have a gt28r, which is smaller than most of the high power heros run on here.
I have a Torqueitalia straight induction pipe which helps with spool up.
I HAD an evo 6 intercooler with a greatly reduced boost route (not by choice, lost some of the piping when the car was off the road).
Then there is the headwork that Barbz has supplied along with a lightened and balanced flywheel and a 3" *custom made* downpipe and straight through exhaust.
As far as i can see its the headwork, the turbo and the custom exhaust. People who have seen the downpipe always remark its some piece of work, and as we all know the bigger downpipe helps with spool up no end.
Thats my thoughts on it anyways.
Ross
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Re: Head work..
#247509
12/12/2006 20:16
12/12/2006 20:16
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Joined: Dec 2005
Posts: 132
Markus
On a journey
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On a journey
Joined: Dec 2005
Posts: 132
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For what my input is worth.. .........from my experiences of the head work I have had developed for my car 1) The first head I have had fitted to my car was the same spec as nigels and fleas head. This is basically a normal head with ported inlet and exhaust ports, 3 angle seats etc etc...At the time I was running the gt28r and other usual mods 3" exhaust, staright run etc etc. The low down torque was phenomanol!!I had full boost at approx 3000 rpm and when driving off boost it was like a fast n/a car. It certainly felt quicker off boost than my 2.0T spark spider i have!! the car would pull smoothly all the way to the redline. The same spec head is now being used on nigels and fleas cars and both are producing in the excess of 370bhp and fleas is 400bhp at the wheels which is really saying something!! Even nigels car is producing a heck of alot of power considering he doesnt run any aquamist and has a supersprint exhaust!!So does the head work make any difference??  2. My current setup.....Is basically the same spec head with slightly more re-fined port, and big inlet valves  This head is almost the same as Paul S' head and Mavrics first head where he achieved 500bhp @ 1.4 bar!! Also with that setup he has been the first coupe ever to break into the 11s 1/4 mile. I currently run the gt28rs/r turbo on my setup and I get FULL boost @ 3200 . Bags and bags of low down torque and pulls with more power towards the redline. I run approx 1.2 bar at 6500rpm and by 7000rpm I have it set to 1 bar of boost. In the mid range I run 1.7 bar between 3200-5000rpm. Even though my car is unmapped no ignition advance or need for aquamist etc etc I still produce 380bhp and 340ft/lbs Unmapped. Similar cars that have produced this kind of power are Fleas old setup with standard head, gt28rs turbo, however he had to run 1.5 bar to the redline to achieve the same or similar top end power with no where near the same power band as my current set-up.  If I do decide to get this engine properly mapped then we will truelly see the ptential of the work... To summarise (all ported, 3 angle seats etc etc) Torque Italia work Mavric - Big inlet Valve Head - 500bhp John S - Big Valve Head - 460bhp Barbz - Big Valve Head - 440Bhp Flea - Standard Valve Head - 480bhp Nigel - Standard Valve Head - 390bhp Myself - Big inlet Valve Head - 380Bhp - Unmapped Sheikhs- Standard Valve Head - 344Bhp - Unmapped Suba - Standard Valve Head @1.3bar no aquamist etc - 344Bhp Paul S - Big Inlet Valve Head - power Unknown Hyper - Standard Valve Head - power Unkown Others....(Guy croft, Nysaa racing ec etc) Begbie 16vt head - Power Unknown Sedici Rich 16v n/a (flowed gc head 3 angle etc) - 166bhp (standard engine 148bhp) Nyssa racing - 562Bhp (lag master special)
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Re: Head work..
#247510
12/12/2006 21:27
12/12/2006 21:27
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Anonymous
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Anonymous
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Flea a note about VE taken from Guy's site, "Vr is affected by almost everything else around it, for example: pressure waves (some useful, some not) across the inlet and exhaust ports - as the valves open and close (themselves dependent on the port lengths and sizes) , the effectiveness of cylinder purging of residuals on the exhaust stroke, the potential of the inlet tract to flow air, the valve size and camshaft lift/timing characteristics, air density, ignition timing, fuel distribution. (G Croft)" Now a few points about my production engine, its on std rods, std pistons, damn near std inlet cam, and std exhuast cam, it has the swan neck inlet manifold that is good for a 9cfm restriction - Lucky the 20v doesnt have that. If I can figue out what is causing the torque loss over 6500 it should regain about 20bhp. Probably a temp thing during mapping. The flow results can be seen on gcroft.com as the inlets are the same as beggars. Lets not turn this thread into 'who's better', I needed a race engine so I went to a race engine builder - and glad i did as I was told straight about what I must have e.g. triple valve springs which incidentally prob saved my engine at Oulton where the revs went off the scale on a accidental early down change (around 9000rpm). I have views on what is the right way to do things, but this is higher budget stuff, and if I was to look to another engine builder I would certainly be enquiring about a number of things especially the process and build environments. You pay for what you get, sometimes the problem for road cars is deciding what you really need. For race its simpler. Compare operating like Wilcox engines, http://www.wilcoxengines.demon.co.uk/engprep.htm like GC thats what an engine builders operation should look like. But that costs, and for the road maybe you dont need it. Some people are happy shopping in River Island some wont be seen dead in there. As said you pay for what you get, I know what I need perhaps better then the average owner, thus I have different criteria. Markus my std figure is 142bhp - its a 3 door. Right enough of my whittering.......suspension's my new mission.......
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Re: Head work..
#247512
12/12/2006 22:17
12/12/2006 22:17
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Anonymous
Unregistered
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Anonymous
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Flea no problem, but Ve is not flow, its the ratio of air inducted into the cylinder versus the air capable of occupying the sweept cylinder volume at atmospheric pressure. Remeber flow has a time unit e.g. Cubic feet per minute, or lb per hour. Thus the engines speed is important in this equation. If the Ve was a constant then you could keep reving higher and higher and make more power. You can estimate Ve at certain RPM ranges, and you could estimate it also on the generation of engine i.e. a very side drafted 8valve head will prove to have far lower Ve then a well down drafted head like a cosworth bd 4 valve. My Ve will be better in certain areas and lower then others (praying Ve isnt the torque issue I have higher in the power band). Ve for a 4 valve head flea will usually be pretty good as the efective area to flow at low lifts is much better then its 8v counter part, but ONLY when the port velocity is great enough to achieve the cylinder filling. Note the 8v lower down torque against the 16v (2v vs 4v), thus both units produce differing Ve. Go back to john s's scholar head, maybe this hust was not compatible with the cam and engine speed setup, perhaps if it could rev to 9k rpm it may have produced good results. but as you can see if the ports are too large for the rest of the engine there is a mismatch and the engine will never produce strong performance.
So reported 4v Ve average is 90 ish% i'd say i'd have 95%, with better cams and no plenum nearer 100 but after this the engine would maybe need to spin faster and the exhaust manifold maybe useless. Does that help??
Rich
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Re: Head work..
#247513
12/12/2006 22:49
12/12/2006 22:49
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Joined: Dec 2005
Posts: 132
Markus
On a journey
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On a journey
Joined: Dec 2005
Posts: 132
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Quote:
Now a few points about my production engine, its on std rods, std pistons, damn near std inlet cam, and std exhuast cam,
I thought u were running 5 door pistons (148bhp), columbo inlet cam and 5dr exhaust cam.........
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Re: Head work..
#247515
13/12/2006 00:48
13/12/2006 00:48
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Rich I know Ve is isn't flow but relates to the % of air so 1000cc would see 950cc filled at 95% and of course it is a dynamic state. The headwork should allow for better flow, certainly at the top end on a race engine where the power band is, so by having more efficient airflow the engine requires less "pump" energy to fill the cylinder which means increased Ve and more power What I was interested in was your figures i.e. what flow increase did the flow bench report and how did this relate to overall Ve and power where it matters at high rpms?
Less pump energy - Erm, new one that. The pump is atmospheric pressure, any assistance in filling is pulsing in the inlet, but as the inlet was not designed for the current set up then I think the plenum is not my friend. Increase ok, i cant publish all results without permission so a summary perhaps, but Flea I'm not sure you've got the Ve idea in perspective. You mention more efficient air flow, but what do you mean by efficient, a head can flow say 100cfm at 10" dep, but if its cam set up and rpm range are low lift low rpm then theres not reason why it will fill its cylinders as port velocity could potentially be too low. Remember the piston is sweeping a volume and the cam is controlling the valve opening in this period, the cam ramps up to open then back down, thus the flow abilty is proportional to area under the flow chart curve. So imagine a piston sweeping but a cam having some crazy short duration say 90degrees, here the cam would have to open and close with its profile shape, the chances are this abilty of the head to flow air in this time period will not be sufficient to fill the cylinder, thus Ve would be low with this cam. If the head was ported then Ve would improve but not by as much as putting a cam in with with a better duration. Also duration is too vague, our first cam may have a profile (theoretical) of say a rectangle ie. it opens to full lift instantly and closes instantly, but our second cam may have a mild profile taking a long time to open to FL and dwelling for very little time at FL before closing, in essence it could be possible to have let airflow with the longer duration cam if we dont know at what lift the duration is measured. Infact the only way to understand a cams characteristics is to plot the angle vs lift on a graph.
Right back to Ve so you can see that a cam is just one other variable that inpacts on the Ve significantly, and we have mention reversion overlap, etc. So back to what you asked my engine, well lets ignore the cams (one columbo inlet street spec I think 10.2mm lift, and std 3dr ex cam not very special compared to full race 12.7mm lift) With the head work (inlets only) it produced more power and more torque, thus somewhere in the rev range its Ve must be higher, but I wish I knew where I had the std engine plot. Now I have something odd happening at high rpm, the torque is dissapearing, the rate of loss is unlikely to be attributable to Ve as that will not show the rate of decay I have, so that will be and ignition fuel problem potentially, I can think of a few other potententials, but as I have to trailer it to the Rolling road I'm not that worried, another 200bhp might get .2sec a lap, my suspension investment will get around 4secs!!
Flow figures
Std BPF 16v 136cfm at 10"
Full inlet mod 158cfm at 10"
at 10.2mm lift std 126cfm 10"
at 10.2mm lift mod 148cfm 10"
Benefit of a flow bench is estiamting how a cam will flow by adjusting lift, i.e. if the cam is wild but the ports are std then the restriction may be found at lower lifts such that a wild cam will not show any improvement as a mild cam without additional work. Please read GC virtual workshop on his site, really it expalins all this far better then I can.
rich
Last edited by sediciRich; 13/12/2006 00:49.
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Re: Head work..
#247517
13/12/2006 01:27
13/12/2006 01:27
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Anonymous
Unregistered
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Anonymous
Unregistered
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yes, it was mapped on 97ron,well at 39 degrees in the test cell, it'll never detonate!! Prob why top ends poor, too hot on the day, inproving the oil cooler duct knocked 10degree off the oil!!
rich
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Re: Head work..
#247518
13/12/2006 02:39
13/12/2006 02:39
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Joined: Dec 2005
Posts: 5,405
Castle Combe
Flea
Forum is my life
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Forum is my life
Joined: Dec 2005
Posts: 5,405
Castle Combe
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Sorry Rich, I haven't studied this quite to the extent that you have but thankfully I don't need to either as I'll never be building engines In laymans terms I used the word pump in "" because, having done a bit of reading elswhere, I was referring to the engine as effectively pumping the air into the cylinder and therefore anything that makes this easier i.e. increased flow, less restriction, should allow the cylinder to consume more air and Ve increases. Anyway, without getting too technical (I know it's hard for you!!! ) I was just wanting to understand a little more about the relationship of the headwork > increased flow > Ve > power i.e. how the figures stacked up for you.
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Re: Head work..
#247520
13/12/2006 03:09
13/12/2006 03:09
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Anonymous
Unregistered
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Anonymous
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its the lower part that causes the issue taz, the 20v has simple straight runners like the cosworth yb, but the tipo has a 180 deg bend then a swan neck, doesnt matter how smooth it is, air wants to go in a straight line, and the offset acts as a narrowing, see the string trace on begbies head on gcroft.com. The integrales didnt have this they had a 90deg bend and straight in. No bend like on the 20v's is best, although they may have done this for space; but hell you'd expect some imporvement in what must be at least 10yrs of development between the 2.
rich
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Re: Head work..
#247521
13/12/2006 03:50
13/12/2006 03:50
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
)
Nyssa racing - 562Bhp (lag master special)
don't confuse a lack of low down torque with turbo lag. Turbo lag cannot be gauged from a power graph in just the same way that acceleration figures for a turbo car as taken by magazines also take no account of lag
My engine is weak low down because its a race engine with bespoke race cams. Pulls like a train from 4000 rpm despite the rolling road graph only showing something like 150bhp at 4000. But will never intentionally be running at revs that low anyway
That's not to take anything away from your engine, if I had the spare money I'd have bought it as a spare. With the rest of my set up I'd expect to get 500 bhp out of it
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Re: Head work..
#247523
13/12/2006 05:11
13/12/2006 05:11
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Rich - in the "pump" comment above, you mentioned that the "pump" is atmospheric pressure.
Surely an awful lot of VE is cylinder scavenging, meaning that the exhaust valve lift and duration, together with exhaust header tuned length is a major part in VE as well
I don't know much about it, but I used to run two stroke bikes, so I remember that getting the exhaust gasses out at the right rate could massively help the next lot of mixture going in
And I know 2 strokes and 4 strokes are *subtly* different - just seemed to recall that exhaust could play a big part in cylinder filling
But more like a vacuum then a pump. But you right Nigel, the negative pressure from exiting gases on the NA engine make a huge contribution, I read a figure somewhere, something like 70% compared to the piston induction stroke motion, why getting the header correct makes a huge differnce, i'm aware of this, but I guess this is why NA tuning gets crazy imagine having to test just 3 designs, big budget. Although this is vital on 2 stroke hance why the exhaust design makes or brakes engine in 2 stroke you'lll have seen that. Of course this effect is very different on a turbo car, as you have to have overlap for the exhaust gases to 'suck' in the inlet gases.
Trev you have 4000rpm power range, less then the gear seperation so thats not laggy, as you know a change down puts you at the start of the band -well if the rest of us are lucky you might be out of the power band with no boost....in the way.ha ha
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Re: Head work..
#247524
13/12/2006 16:19
13/12/2006 16:19
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Joined: Dec 2005
Posts: 132
Markus
On a journey
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On a journey
Joined: Dec 2005
Posts: 132
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@Rich...surely though, the race head you have had made has made little or no improvement over a standard 5dr engine with cams, a chip (or suitable mapping), exhaust, air filter etc etc...Surely the same or more gains are achieved with a stock head? ? @Nyssa...I cant imagine what your car must feel like after 4k!! Must be an animal for sure !!
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Re: Head work..
#247525
13/12/2006 19:56
13/12/2006 19:56
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
@Rich...surely though, the race head you have had made has made little or no improvement over a standard 5dr engine with cams, a chip (or suitable mapping), exhaust, air filter etc etc...Surely the same or more gains are achieved with a stock head? ?
Markus its not a 5 door engine. 'The same of more gains with the std head'? erm what?? So you think if my head was std but with the same stuff around it it would have produced the same output? Maybe, I dont think so though, I dont know why you would think that you're only guessing. But, feel free to purchase a 3dr sedici and give it a go, I know on a std car exhaust and filter made no difference to quoted figures. NA chips are BS, you dont put modified cams in a race engine and hope for the best. Markus you're only considering BHP, unfortunalty thats only a small part of what i'm after here; I need a reliable unit to RACE, I can have confidnece that it will finish, not suffer oil problems, not have compression issues, actually last for more then a season. It costs minimum £400 per race, it takes a lot of effort to get to the race as I have to hire a trailer, and trevor will agree that a DNF and the accompanying problems from an engine failure sacrifice not only the race day costs but the time, labour and rebuild costs after the race. I dont have the support that tev has via auto integrale, i'm a one man band with a 1 car garage. If I suffer an engine failure its me that has to change the unit and fork out for the costs. My investment was in a true race engine, and professional level of assembly where every bore, journal, shell, clearance and tolerance were checked. I paid extra for cross drilling the crank and addition of grub screws instead of bearing plugs on the oilways, one example of a modification for race that no average road car owner would ever consider, certainly not before 'what chip' should 'I' use. Similar for the colisbro race valve guides, tripple race springs, paddle clutch, capilary gauges, pressure accumulator, dry build - these are power 'hop up's' but risk management. I invest in build quality now it saves me money in the long run. And a note about the dry build; the only way to truely ascertain the piston to valve clearance, I'm glad I had this done as the pistons I obtained were incorrect for the engine and had to be pocketed to clear. This is not for power, and your average 'fast road' guy will miss such things out; I cant take that chance.
On the mech repairs rolling road the power is what it is, but at no point would I ever consider a production unit for the track. I know what he head can flow, I know what vauxhall XE heads flow, the the FL 16v flows far geater then the higest modified XE circa 245bhp units(exc swindon) so it has potential, but so much else would have to be changed to ensure reliabilty and acheive such an output, and unlike much of this road work I had to consider the entire build of the rest of the car not only the engine in a budget.
Cheers
Rich
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Re: Head work..
#247528
14/12/2006 16:49
14/12/2006 16:49
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Joined: Dec 2005
Posts: 132
Markus
On a journey
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On a journey
Joined: Dec 2005
Posts: 132
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Quote:
Markus its not a 5 door engine. 'The same of more gains with the std head'? erm what?? So you think if my head was std but with the same stuff around it it would have produced the same output? Maybe, I dont think so though, I dont know why you would think that you're only guessing.
Note really.......Tipoboys first 16v engine started off as a 3dr engine with no headwork except 3 angle seats, standard 5dr pistons, 5 dr inlet cam, exhaust, air filter and unichip and achieved an amazing 166bhp 
Quote:
If I suffer an engine failure its me that has to change the unit and fork out for the costs. My investment was in a true race engine, and professional level of assembly where every bore, journal, shell, clearance and tolerance were checked. I paid extra for cross drilling the crank and addition of grub screws instead of bearing plugs on the oilways, one example of a modification for race that no average road car owner would ever consider, certainly not before 'what chip' should 'I' use. Similar for the colisbro race valve guides, tripple race springs, paddle clutch, capilary gauges, pressure accumulator, dry build - these are power 'hop up's' but risk management. I invest in build quality now it saves me money in the long run.
Surely though you should have considered forged pistons and Forged rods Why go to all that effort and use standard fiat internals?? doesnt make sense to me
Anyway this thread is going off topic some what. We should be discussing the gains of headwork and my comments are only coming from my experiences in the coupe circles
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Re: Head work..
#247529
14/12/2006 18:20
14/12/2006 18:20
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Anonymous
Unregistered
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Anonymous
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I can't comment on a lot of the technical stuff posted here - I just dont know enough! Interesting to read though However for people reading this it's worth remembering that it's not just headwork that will enable you to run good power at very (or comparatively) low boost. On the same spec head I currently have, but with a 3 inch downpipe (with V-band and dropping to 2.25 mid section back) I got 308 bhp at 1.4 bar at PTS. My car without the headwork would have got the same IMO. However, when I opened up the exhaust to a full 3 inch and ditched the vband I got more power with SUBSTANTIALLY less boost. (half a bar less!  )....it was very clear that the increased flow of the head could not come into effect until the rest of the setup could take advantage of it. I'm tempted to run a aquamist with a bit of methanol - but with the ammount of ignition advance I can run safely without it I suspect I would gain very little, and add something else to go wrong!
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