Chip

iTrader: (3)

The basic head casting on a honda engine lends itself better to massive revs than the YB one does.
But yes its certainly possible to get a YB to rev reasonably well.


I dont agree that over 400bhp from a YB in N/A tune is feasible TBH mate, but I havent seen enough people try to really know for certain which is why I havent bothered joining that debate in this thread, im only mentioning my opinion now to correct what you have presented there as believing my opinion to be, thats a LOT more power than any 4 stroke 4 cylinder N/A touring car engine has ever made etc and I know that gaining that sort of power from an already very highly tuned engine is not an easy task at all, thats 30% more power than a modern 2 litre touring car n/a engine makes, and merely running some more revs isnt enough to consume that much extra air IMHO, it would take some really drastic changes and Im really not sure they are possible within the confines of a YB head casting.

It's Czech Mate

This is a drag engine, so i assume comparing it to touring car engines as a power cap for that configuration is pretty irrelevant.

Also I would hazarcd a guess it uses something a bit more potent as fuel

It probably only has to last for 9 seconds lol

Chip

iTrader: (3)

Not really, the cap on power for a touring car is how much air they can physically make an engine of that type swallow in the first place, and that is exactly the same as the limit on an n/a drag engine.


Even on almost pure toluene you'd be really struggling to make that sort of power, it still requires you to consume the air in the first place to make that sort of power with, even if you are running truely massive amounts of timing due to the fuel involved, it still requires airflow in the first place!
You do get to a point where more octane rating is no longer useful, especially in situations of naturally low VE such as a high rpm N/A motor.

Even making that power for 1 second still requires your engine to be managing to swallow something in the region of 40lbs of air a minute, and thats no mean feat when you are relying purely on atmospheric pressure to push it through something as inherently restrictive as a YB head, even if you have 359 degree cams!

It's Czech Mate

Well if a race bda/bdx can rev to over 10k and as good as damnit 300bhp then i'm fairly sure another 100bhp can be squeezed with funny fuel and a lot of cash, plus an extra thousand or so rpm. Unless you're suggesting the graph is a fake.

Also dont forget the engine in question is 2.5 litres not 2.0

Chip

iTrader: (3)

An extra 0.5 litres of capacity makes VERY little difference to the ultimate N/A breathing limit of the head, im guessing you havent ever personally tried tuning engines on the same head and at various capacities to be aware how little difference it makes, particuarly on an inherently limited head design?
Increasing the capacity will actually make the engine LESS willing to rev for the same head characteristics, so while im sure its mechanically possible to rev a YB that far with the right parts, im not convinced it will yield significantly more power to do so, and even less so on a 2.5 bottom end.

An extra 30% power which you seem to be considering no big deal actually is a VERY BIG jump considering that the engines we are talking about as a starting point (ie touring cars etc) have had hundreds of thousands of pounds (if not millions in some cases) thrown into them already, im not accusing the graph of being faked deliberately, but I dont personally believe that the engine in question would make that same power on the dynos that I am used to.

It's Czech Mate

Clearly i havent tuned one lol

But the touring car engines are not funny fuel drag engines designed to last 30 seconds, thay have to last three races a day so dont keep banging on about them, you keep mentioning them as a starting point not me.

Seeing as a 40 year old BDX on pump fuel falls 25% short of the magic 400 i'll take a bet that 40 years of technology and innovation with some potent fuel can make that YB do 400 for 30 seconds or so

It's hardly as far fetched as the person i was actually talking to was making out.

Big Will_

Just as a comparison - i looked into making a 10,000rpm revving Zetec and found a suitable crank that would give safe mean piston speeds. I calculated the displacement of the engine using this crank and even on an 86mm bore the largest I could get it was around 1.55 litre. Torque dropped around 20lb/ft everywhere and power was poor at low engine speeds.

Compared to the 2.2 stroker crank i designed that would safely rev to 8000rpm and give around 15lb/ft more torque through the rev range on a theoretically standard engine, there seemed little point in having to uprate the valvetrain and lubrication system to take those extra 2000rpm.

Chip

iTrader: (3)

Staying in one piece or not is NOT an issue to the inherent breathing limits.


What do you think has change technology wise in a basic 2 cam in head valvespring controlled engine?
I dont think very much has changed at all, especially when still using an early 1980s cylinder head as your starting point.

What sort of technological advances specifically are you referring to which you think might help someone of today trying to make that power that werent available to the ford works development department 30 or more years ago?

Its NOT about the fuel quality with N/A engines once you are already onto a decent 100+ RON fuel anyway with the naturally low VE, its far more about the airflow. Its very different to turbo engines, you really do VERY quickly reach a point with N/A engines at high rpm where better fuel fails to make a significant difference any more.

What do you actually think is different about that engine to the BDX's you mention that will allow it to swallow over 30% more air than they did? (in fact its more like 40% TBH if you actually do the maths!)


I couldnt disagree more with that statement, I really think you have NO understanding of what is involved in trying to make an N/A engine swallow 40% more air!
With engines already tuned to that level 4% is a BIG gain, not 40%

Chip

iTrader: (3)

Agreed, in order to get a decent rod ratio for those sort of rpm you would need to do what martin has done and make the block taller, and that doesnt appear to have been done on the engine in question.

It's Czech Mate

Sorry Chip i never realised touring cars were tuned to ultimate power like drag cars


I was under the impression a yb head would flow more than 400bhp so why is the head a restriction if the engine pumps enough air at that rpm and capacity?

Theres plenty of tech that a 40 year old BDX from a ford works team couldnt have

Theres a lot lighter and stronger pistons for a start such as the mmc ones perfect bore do.

In all probability that engine probably has a taller block, if millington did it years ago i'm sure this guy has realised what engine geometry works.

Chip

iTrader: (3)

You keep missing the point that N/A engine tuning is limited by the breathing potential of the head!
Touring car engine builds get EVERY bhp that the flow limits they are working to will allow, they dont reign back 1 bhp in the interests of reliability as far as im aware, let alone 100bhp!



With what pressure differential?
In the case of a turbo motor (say 2+ bar of boost), you have 3 bar or more of pressure differential, with N/A you have less than 1 bar of pressure differential.
And further more on a turbo engine you have positive pressure differential for the whole intake stroke, on an N/A engine with 50% VE you have only got a positive differential for half the intake stroke.
12000 rpm
200 revs per second (.05 seconds per rev)

in that time you have to get 1 litre (approx amount of atmospheric pressure air to make 200lbft) into your engine through the heads with less than 1 bar pressure differential peak and with the vast majority of that time spent at a far far lower pressure differential than that.

Why is the head is a restriction?
Why is the neck of a bottle a restriction, because its the part that is hardest to get flow through.

Name something please from an airflow point of view?
What piece of tech were they missing that would allow 4 oval orifices with only atmospheric pressure behind them to flow an extra 40% more air?


Fantastic way of extracting a tiny tiny bit more power from lower sacrifical losses, but no use for the sort of increases you are discussing here.

Yes it probably does have taller than standard, but I doubt its enough taller to be anywhere near the rod ratio that he would like to achieve at that capacity (you want a rod ratio of 2:1 or more at those rpm), it will still be a compromise between the two unless its a millington block and then a martin style extension as well!

dug112y

iTrader: (1)

do some research...early 90's f1 engines revved around 12/13k. cosworth one revved to 10,750 @600hp v8 3.5l

cosworth engine(top end) was designed early 80's so not new technology.bottom end...60's??

maybe bda's can run at 10k....what power do they make??


cosworth head valve size cannot flow enough air N/A to make 416hp,no matter what mods you make to it.

design of the engine will not support the 'claimed' hp no matter what piston /rod combo you give it.

what is the highest n/a 4 cyl that you know of??

the honda engine is a much later/better design also.

its not a drag engine its used for rallys/hillclimb so has to last more than 8 seconds but he does drag in it too......all that power and got beat by other mk11 escorts with 25% less power.

the mods to get to the 2.5 litres it will have an even less chance of hitting 11,500rpm n/a

millington engine is prob the closest you will get to said engine...what power are they making at what revs? and they get a lot of money spent on them.FYI 340bhp@8700 with 243lb ft on the 2.7 version which is totally custom to suit N/A with billet block etc........only another 76 bhp and 2800rpm to find on an already highly tuned race engine.
mccraes millington done 335bhp at 7,750rpm with 235lb.ft at 5,600rpm with no expense spared at the time

turbotoaster

http://www.youtube.com/watch?v=ErRier3Ip3w

10.9@124mph all motor, no turbo or NOS, theres noway thats 280bhp

i believe its a k24 engine, ie a 2.4 bottom end with a 2.0 head(off civic type r)

turbotoaster

http://www.youtube.com/watch?v=cfmmZ...eature=related

at 148mph thats not 300bhp, and thats a 2.4 N/A engine aswell

http://www.honda-tech.com/showthread.php?t=1880928

dyno showing a fair bit of power


yes these are all honda heads so they flow well but shows if you can get a YB head flowing well enough it will produce the power

dug112y

iTrader: (1)

yep they defo have some poke.but they are a better later design compared to cossie. the cossie head cannot flow enough air to do the power he claims.

363bhp @ 8500 and 255lb ft @6000rpm on a 2.4 honda engine.
okay why does it and most other n/a 4 cyl seem to do max power at around 8500rpm (millington diamond 340bhp@8700 with 243lb ft on the 2.7l one)....could it be that thats about the limit of a 4cyl N/A engine in terms of airflow?? genuine question.bearing in mind greek boy is claiming 416bhp @12,200rpm and 200lb ft torque @ 9750.

turbotoaster

well give me a bit of time and ill have a look to find some more info on the first link as doing 148mph is not 350bhp, its an aweful lot more.

if it was a turbo car id guess it was making 600bhp

also the second link is 363whp, so about 400bhp at the fly.


here is a k series motor hitting 400bhp



it does seem to peak at around 8.5k like you say, but holds onto the power well


id say looking on honda-tech.com in the US is a good place to see where they are really pushing the N/A engines

dug112y

iTrader: (1)

i am not doubting that the honda engines cant hit 400bhp, as you have posted,but look at the figures compared to greek guy. what i am saying is he is not hitting the figures hes claiming with a cossie engine...and it was back in 2006. the cossie is allegdly doing 180bhp @6k where the honda is doing 275@6k..the honda is over 180bhp at 5k...look at torque figs too
if you look at honda s2000 compared to a cossie....the ports on a s2ooo are massive and it was designed with N/A in mind.

Chip

iTrader: (3)

dug112y, the YB head was also designed by cosworth with N/A in mind, the turbo was ford's idea as an afterthought, but it was never designed with massive revs in mind which was part of the brief from the outset on all the type R hondas of course.

Rsmat

iTrader: (2)

Injections nice but id rather be blown.

Trist

the reason they went for billet

Chip

iTrader: (3)

Wow, that certainly looks like it was making some monster fucking numbers to do that quite so dramatically (although not always the case)

Johnny Knoxville

looks like a vag engine not a evo engine

It's Czech Mate

Nice find, but Pointless even bothering mate. despite chip having only seen a pic of the engine installed he knows all about it, it's not possible! It can't have a custom billet head or a tall block, you can tell from the photo!

Chip

iTrader: (3)

If it has a custom billet head and a custom block, then its not a YB engine, as that would mean it literally has no internal yb components.
My comments were very clearly that a YB engine, and specifically a yb head casting wont do that power, not that no engine possibly can do so, Ive got a lexus V8 that will piss 400bhp in N/A form with moderate tuning, I can stick a YB cam cover on the top of that but I still wouldnt call it a YB

gjh

Impressive.

PAUL S

iTrader: (8)

some superb fabrication on the page of this site as well

http://www.kit-car-builds.socialgo.com/magazine.html

dug112y

iTrader: (1)

block above is a vr6 by look of it.




vw block 1.8t i think

Johnny Knoxville

The above block is a 1.8t and the owner removed the harmonic crank pulley and fitted a solid one i read.

Chip

iTrader: (3)

Good "upgrade" that proved to be then

D4nny8oy

Are they claiming that's an Evo engine?

The pic looks very similar to one Dave Rowe from EPS showed Gary, taken when the Golf drag engine blew on the engine dyno. IIRC, he said they then made billet braces front and rear in order for the new lump to hold together.

Not sure what VAG lump it was though.

dug112y

iTrader: (1)

its a vr6 lump

RickyLee53

Sorry to just pick a random quote.

I'm with chip here. I don't think on our dyno's the car would make over 400hp. I do however think its probably the highest powered n/a cossy. He reckoned in that thread he's seen 1.3-1.4 bar absolute on an n/a engine. I find that VERY hard to believe. Unless there was some random very high pressure that day in greece?

As chip said, nothing matters material wise, apart from the relatively small friction losses. Which are probably only 30-40hp MAX anyway, so totally removing these with exotic materials wouldn't give the type of gains he's seen.

I also question some of his parts. I.e. its easy for us to get pictures from random sites on the internet, the billet block for example. I've no doubt he's probably 1 of the most advanced tuners in the world. We'd all love his customer base.

He does make lots of references to old F1 turbo engines, i've also looked a lot into them, and they are truely YEARS ahead of "us" for example, they had vband back housing turbo's in the 80's. We got them a couple of years ago.

Sadly f1 isn't going back turbo I don't think. I wish it was, so the technology could phase down to us in 20 years time.

Chip

iTrader: (3)

F1 is going turbo in 2013 IIRC
But will be 1.6 litre making under 650bhp (plus a kers top up) so really pony compared to last time

AustenW

Interesting read

tigra turbo

i had a read at a Honda k24 that stroked it at 2.6 which made 424 N/A,all steel,even with a crazy piston/rod rate,over here in Greece,thank god we have very good tuners as far as engine builders/ECU tuning,they've done as you mention some crazy blue ovals,few LET's and Peugot 1.6T over 600hp some crazy turbo mini's (new) some corsa opc at about 600hp and some stroked ones to 1.8 to over 600hp,and vw1.8 20v at 700+
,and a few stroked to 2.0 vw.many of them are daily cars too !

Canada1

I am suprised that no one has made any comments regarding the Greek dyno graph. I have never seen such a dodgy looking graph. Engine torque output does not change like that.

Also the YB head does not have enough port cross sectional area to approach the airflow that Honda Kseries engines have. In fact there is not enough material at the inlet flange to get to 2 square inches. 2 sq. inches will flow 146 X 2 = 292 cfm @28" depression.
That is the reason HP limits are at the low to mid 300 hp range.
Honda heads are approaching - or exceeding 400 cfm @28"

Chip

iTrader: (3)

Was trying not to be too negative on the topic in general so didnt mention it, but agreed totally, it looks like the MAP on that engine is one from a TOMTOM GO or something.


Agreed, as mentioned by several of us, there is no way that a YB head is going to be doing over 400bhp N/A

andy@amt

Well said that man.

opposite lock

iTrader: (3)

just something i noticed on the graphs shown but i,m probably barking at the wrong tree but should power and torque figures cross each other at a certain rev point? i.e 5252rpm or near?

Mike

Chip

iTrader: (3)

Thats only the case when the axis are lbft and bhp