- When it comes to import performance,
there's no doubt that the Honda and Acura brand are in a league of their own. Particularly in terms of the cylinder head
flow, it's hard to beat even a stock Honda cylinder head. We're here with Luke from 4 Piston
Racing. 4 Piston Racing are no strangers to the
Honda brand. Being involved with Honda engines
at all levels of motorsport, in particular their engines or cylinder
heads are involved with setting records in the sport front wheel drive
class. In particular their current record sits
at a 7.93 at 189 mile an hour. Now Luke getting that sort of performance
out of a stock B series engine is obviously going to be challenging. You're also involved with the K series
engines. Now I wanna start by talking about one
of the products we've seen on your stand which is the billet CNC machined cylinder
head for the K series. Now in its own right the stock K series
cylinder head is no slouch. So where is the requirement to jump
across to a full billet cylinder head? - A lot of the all motor racing is alcohol,
and we're getting to the point where we just need to run more RPM and we're
out of air flow. So we're trying to squeeze big valves in
there, and port sizing for those valves. They were having trouble fitting in the
stock castings. We were running into water, it's
getting hard to machine, the head castings were getting older. A lot of junkyard stuff and some of the
heads are out of production. So the heads that we could fit big ports
in are kind of going away. So we need to get more air flow,
more valve, and we need to be able to put the camshafts in a position that
worked with those big valves so that we can get the valve timing correct. - Now that's a good point you've just
touched on there. In terms of fitting larger valves,
I mean in the general off the shelf sport compact market, it's pretty typical to take
a one mil oversized valve from the likes of maybe Ferrea and generally those
can be fitted in on the stock valve seats but of course there's a limit before
you run out of valve seat or you have problems with valve to valve contact. So what have you done in the cylinder
head to get around that? - So we've changed the valve angle to
be able to fit a five millimetre oversize valve on the intake side. We're still, and then we were able to
straighten and change the shape of the exhaust port. We're still using the standard size exhaust
valve but in the past we were even shrinking those down to put bigger intake
valves in. But because we were able to move the
valve angle, now we have better separation and we can get our camshafts
back where they need to be. But we also were able to straighten those
port walls out and get a lot better exhaust flow, 40 CFM increase over the factory
exhaust port orientation. - Now in terms of changing the valve
angle, obviously that's starting to get into the realms of a major modification
to some of the factory geometry, and again really obviously stuff that
just can't be done with a factory head. Now in terms of changing that valve
angle or moving the valve centres, does that also necessitate you moving
the location of the cams in the cylinder head? - Right now we're able to work with
the factory location of the cam. We can move it depending on how much
change. But right now only a couple of degrees of
change is giving us a lot of flexibility on the cam position. So we are able to change the rocker
arm more so than the cam location and get it where we need it to be. - Now in terms of making these
modifications to the port shape, the combustion chamber shape as
well as the location of the valves, you're in the realms of basiclaly infinite
potential opportunities. Are you modelling this before you actually
put a piece of billet in the CNC machine and start making your head or is this
a literal case of trial and error? - This is years on enlightened trial and
error, what I call it. So we have a lot of experience with what
to do, what is working, what doesn't work. And so we're pretty well guided on what
we want to do without going into modelling, we can probably most of
the time, some of our ports are designed in computer programs. Most of them start from a hand pour
and somebody sitting in front of a flow bench or even a wet bench for many
many hours, for 100s of hours, to come up with this, over a long
period of time. We've been working with these K series
engines probably since 2003. So it's just years of experience and knowing
what we wanna try and then sometimes it's failing at it and trying to figure out
what doesn't work. - I think that's a good point to make there
in so much as the cylinder head porting is certainly not something that I delve into,
I like to leave that to the professionals. But this is one of the areas that I'd sort
of say that there's definitely a lot of science behind it but there is a lot of
art behind it as well and I think this is one area where you really do need
to work with someone who has a lot of experience with that particular cylinder
head you're working with. Otherwise you can take what is a stock
good flowing cylinder head and do something wrong with the port work and
you can destroy it, would that be fair? - Yeah that's fair. And we set up guidelines and a set of
rules that as we've learned, these are the things we know that we
need to be staying within this set of rules and we know not to try some
of the crazy things that are pretty out there. - In terms of fitting such a big valve
into the K series block, do you have problems with the valve
location in relation to the actual bore, 'cause I think that's probably something
that a lot of people would overlook, but that obviously can become an
issue? - Yeah it can be and in the early stages
of the development of this we kind of had the valves moved too far and got
into the bore and we still ran 'em like that with success and we've gone back
and moved things around a little more, that's part of the trial and error thing,
and deshrouded the valve a little bit more but even with the valve shrouded
up by the bore it still outperformed everything we could do in the stock
casting by leaps and bounds. - One of the focuses with head porting
as well is sort of getting a nice smooth shape on that short turn radius getting
that air flow to really turn around there and go down through the valve. So a lot of people with a billet head
have gone to the point of raising the intake ports in particular to get a straighter
shot at the valve. Is that important or is that not a
necessity for you? - It is and we do have limitations on
raising the port, but we do have a specific port shape that we're after that
may not be as tall as what you'd probably expect to see in a billet cylinder
head. But it again goes back to trial and error
and what we have found to work, and what works in the RPM range that
we're working with. And what we do on a two litre road race
engine with regards to air speed, and what we do on a 2.7 litre alcohol
engine is very different. A lot of times on these four valve
cylinder heads, we're trying to slow air down to round the short turn and make
sure that we're not creating much turbulence and if we can slow some of
that air down in certain areas and speed it up in other areas, we want
a good even flow throughout the port. If you measure air speed in one part
of a stock port, you'll find other areas of the port that are really slow going
air and if we can kind of get that to where we want it in every part of
the port, that's what's gonna work best for us, and we have a target number
that we're looking for. - In terms of RPM, you've just mentioned
there, what sort of RPM are you running these engines to and what is the usable
RPM range in, let's talk here about maybe a drag application, something
pretty extreme. - In a drag application, we're gonna be
leaving the line somewhere between 7000 and 7800 RPM depending on the
condition of the track. And it's gonna drop down into the high
sixes so we've gotta have some kind of mid range power to pull it back up,
but then on gear changes we're not gonna drop below 8300 RPM, we're gonna
run rom 8300 to 11200 and we want to extend that power band as far as we can. We're limited on displacement so we want
more RPM, as much as we can. So that's where we've gotten into needing
bigger ports and bigger camshafts and really stretching that out but we do
have to have some low end responsiveness where it's responsive as soon as we drop
that clutch and it has to pull the car through a good track. - Now the other thing with the sport
front wheel drive class as well, you are limited to the turbocharger. So everyone's running essentially the
same size turbocharger. So is this where maximising the air flow
through those ports as well as your cma profile really comes into its own? - Yeah and valve timing's very important
in sport front wheel drive and making sure that the cylinder head is responsive,
it's not just about going in and having a great big port that flows a lot of CFM. We really run into port sizing becoming
critical on the turbo cars even more so, because we've gotta stay in the efficiency
range of that turbocharger and when we're on gear changes, we're not allowed to
have sequentials but we do have strain gauges with, no one's clutching these cars. They're shifted pretty quickly but the
responsiveness and keeping it in full boost, keeping this thing above 60
pounds of boost, the whole way down the track is the key. So I think that's where we've found some
advantages is that our cylinder heads are a little more responsive and keep in
the meat of the powerband. The whole way we have the most average
horsepower going down the whole track. - I think a lot of people when they're looking
at flow numbers off a flow bench, think that more is more but really that
is only part of the whole story when it comes to how that head's gonna perform
when you actually put it onto the dyno? - It is, true, and it's hard to look at,
people look at a flow chart and it looks a lot like a dyno chart and they think that
it's gonna correlate and sometimes it doesn't, many times it doesn't,
it's not a dyno chart. So when you're looking at losing,
sometimes you may lose low lift flow or gain low lift flow and it doesn't
matter too much. It may have lost there and gained up
top and performed outstanding, depending on what you're doing. So you have to design it for the cam
profile, for the induction, it's a whole system that has to work
together. - Now back onto the billet cylinder head,
the other aspect there with the billet cylinder head, you are literally starting
with a solid block of alloy and it's got no water jacket in it. So this obviously isn't gonna be suitable
for your daily driver but for drag applications running on methanol,
the cooling isn't so much of an issue. Can you talk to us a little bit about that
and does that billet cylinder head with no water jacket also improve the ability
to seal the head to the block? - It does for sure, it's not moving around
as much, it's not as temperamental, the temperature change, so we don't
need to cool. Even when we're not on methanol,
even when we're on our class mandated turbo fuel which is C85, VPC85, we still
don't have a problem controlling the temperature. We're still running water through the block
but it's helping quite a bit in sealing the head gaskets. And just keeping things from moving
around. But we actually have trouble getting heat
into it and so we'll idle 'em a little bit longer to get the block heated up and
then run down the track. This size of cylinder head is not really
suited for other types of racing, so we're not gonna have this on a road
race car. It's way too big of a port, it's way too
agressive, it would be a dog. So I know a lot of people have looked
at the billet and said I want that on my car, oh there's no water jackets,
I can't have that on my road race car. It would be a dog on the road race
car, this is for high RPM extremely high horsepower. The engines that these are going onto
make over 500 horsepower naturally aspirated at 11000 RPM. It's not gonna work in our circuit
two litre road race car. - Yeah I think that's another aspect a
lot of people think that it's a one size fits all but really you do actually have
to design and develop the entire engine for a particular application if you want
to get the best results out of that engine. Now just talking about the block,
we've obviously focused on the head there, and as is common with most
import engines or a lot of engines these days that are coming out,
the block in the Honda, both the B series and the K series is alloy. Not an issue obviously in stock form
but particularly in high boost applications, this becomes a weak point
so how are you addressing the block strength? You don't see the need to go billet
there? - On the K series right now there's not,
there aren't blocks cracking. Even with huge turbos over 80 millimetres
making more than 1500 horsepower, the blocks are holding together. The B series, some guys have found
limitations. You guys are all probably very familiar
with Speed Factory, they run more than 100 pounds of boost on their B series
and the are running billet blocks. And that's because with that kind of
boost pressure, cylinder pressure, they have found the limitations of the
stock block. The K series not so much yet but there's
also not a lot of people pushing the limits like that at 2000 horsepower. And so there will be a market for billet
blocks and it's just gonna be guys finding that limit and pushing over 2000
horsepower with these little four cylinders. A lot of the class racing you're looking
at more in the 1300 to 1400 horsepower range, there's not a lot of issue with
splitting blocks. A lot of the tune ups are really good,
a lot of the tuners are getting better, the computers are better now,
so it's easier for guys to monitor the critical parameters that are gonna
keep these things alive. - So at that point, in the 1300, 1400,
1500 horsepower vicinity, a good set of ductile iron sleeves is
sufficient? - Absolutely yeah and not all sleeves are
created equal, some of 'em move around more, some of 'em are softer, some of
'em have more support in the block. So we try to stick with a sleeve that's
got a lot of meat to it. And that may work great in this drag
race application but might have cooling effects for an endurance application so
we have to pick the sleeve that's gonna be suited for that particular
type of racing, it may be a really thick rigid sleeve for drag race and 65 pounds
of boost. But in something that's gonna be 30
pounds of boost and run in a time attack, or maybe even a 24 hour endurance race,
we might have to give up some of that sleeve structure in order for better
cooling. - OK so I think one of the other issues
we often see when people go to an aftermarket ductile iron sleeve is that
they do that to fix the bore strength, which is great, but a lot of the time
we also see that that brings in a brand new problem which is the sleeves dropping
in use and then the head gasket leaking. And this is a common theme we hear
across a lot of people using these sleeves. So can you talk to us about that and
how do you fix that, why is this a problem we hear about? - It is installation related. So if you have a good process and you
are good with your machine and you have a good operator, and you're doing
things right and installing the sleeve properly where they don't move around
and you let them set, and get them into position, they're
not gonna drop, you're not gonna drop a sleeve. So you can do thousands of blocks and
never have a dropped sleeve, if the installation process is done right. - So basically have the right equipment
and read the instructions? - Yes read the instructions. No one wants to read the instructions,
everyone throws those away, and tries it on their own right? - That's pretty important when you're
talking about a finished engine that's gonna run out to thousands and
thousands of dollars. Look Luke it's been great to get some
insight into your engine components. If someone wants to get in touch with
you, how can they reach out? - 4piston.com and we are on Instagram,
@4pistoncylinderheads, and Facebook at 4 Piston. - That's great, Luke thanks for your time. - Thank you. - If you liked that video,
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