Articles, Blog

Thor | 1500HP to 3000HP Of Custom Billet | Time Attack Champion [TECH TALK]

September 8, 2019


– After setting a new pro class World Time
Attack lap record at World Time Attack 2018, with a one minute 19.8 second lap time,
the RP968 Porsche, has definitely turned World Time Attack
on its head. We decided to get a little bit more involved
with exactly what powered this engine, and we’re here at PR Technology with
Oskar from Elmer Racing, all the way from Finland, the designer
and builder of the Thor billet aluminium engine. So Oskar for a start I think we’re gonna go
back a little bit earlier in the week leading up to World Time Attack and
while probably most of the spectators had no idea of the troubles that
PR Technology were going through, there were a few issues around the
head gasket sealing on the Thor engine. So can you give us a run down on what
caused these issues and why they came up? – So in hindsight of course now it’s clear
what happened, or more or less clear, but then there were a lot of questions
marks, I didn’t really know the specs and everything. But so I designed the engine to run
a flat gasket and I try to know a lot about a lot of things but there are a lot
of things of course that I’m not a super good expert on. And so apparently it’s quite usual to have
steps in the MLS gaskets around the cylinders to concentrate the clamping
force there but I’ve designed that clamping force into the actual engine block and
head design instead. So the MLS gasket the team got for the
engine, did have a step in it, and a sleeve installation step is not large
enough to support that extra clamping force on the actual sleeve so it’s
designed to support that from the sleeve and also the aluminium around that sleeve
so the actual block material. So with the extra step there and
concentrating the force on the sleeves, that was pushing the sleeves in,
because it was OK when you mounted it but then at running temperature,
the yield strength of the aluminium goes down, and then it reached the
critical limit and the sleeves pushed down a little bit and then of course
when all the bolts and everything are tightened to spec when it’s cold,
and something goes a little bit, then it’s not going to seal anymore
and yeah they had big issues with that. – So essentially what that does is allow
that combustion pressure to make its way out of the combustion chamber
where we wanna keep it and it makes its way into the water jacket and pressurises
the water jacket? – Yeah that’s correct, I mean they’re a
super professional team, so they have a sensor in the coolant system
for pressure and the noticed that and so they didn’t end up breaking any. Typically you see the radiators balloon
or something like that, but they caught that early and they
didn’t create any further complications with that so that was one of the things
that allowed us to get that fixed. – I think another point, just while you’re
talking about that coolant pressure sensor, as you say it’s not a sensor that is that
common but not getting on top of that really quickly as soon as that pressure
builds up in the cooling system, if you continue to run the engine under
high boost, we also see essentially it torches a path from the combustion chamber,
from the cylinder out to the side of the block so that can actually ruin
the deck surface of the block as well as the cylinder head. Now I just wanna touch on a slight
difference here between your bespoke engine design and we do hear a lot
of problems where people are fitting aftermarket ductile iron sleeves to a
conventional aluminium engine block. Let’s say for example here, Nissan SR20
or maybe Mitsubishi 4B11. So when people get beyond the limits
of the factory aluminium block there, it’s quite common to fit ductile iron
sleeves and we hear a lot of problems with those dropping. That’s more in line with issues around
the accuracy of the machinist’s ability to fit those sleeves in the first place,
but this, just to be clear, is a very different situation, correct? – I would think so, I mean there really isn’t,
when you’re running an engine, the really shouldn’t be any forces pressing
down on the sleeve from the actual running I mean, it’s a clamping issues
mostly. I’m not really that familiar with those
issues so yeah I don’t think they’re the same thing but I’m not sure,
I would need to be more familiar. – Now in terms of the sleeves you’ve
got fitted to this, and really this is one of the areas where this problem was
highlighted. You’ve kind of alluded to it, the width
of that flange at the top of the sleeve that locates on the aluminium block,
is quite thin, how wide is that, where it locates? – So we’re running dry sleeves in the
engine because we want to keep as much of the real block material as
possible because that increases the rigidity of the block and that’s incredibly
important to keeping all of the surfaces flat and keeping the pressures as even
as possible. So that helps everything live and
everything seals better and everything is happier. So when we’re running the dry sleeves,
we want to run those as thin as possible to keep as much aluminium as
possible between the cylinders. So the sleeves we’re running,
I think it’s safe to say we’re running as thin sleeves as possible and it’s
a little bit over a millimetre. I won’t disclose exactly what the dimensions
are, but very very thin. Then the step at the top, we run that
as small as it needs to be so we can run round sleeves ’cause that helps with
fitting and there are lots of engine builders that prefer the option of being
able to change the sleeves at the track if a piston breaks or something and
you just end up stretching that. So then having a round top is really
important so you can just slam in a new one. – So in other words those sleeves aren’t
siamesed into the neighbouring sleeve? – Yeah that’s correct. And that ends up giving you a really
thin step at the top to locate the sleeve height wise. – So that’s where that force acting on
what is a very narrow width of that lip is what’s dropped the sleeve. So the team had this issue before you
actually got to the track and essentially on Thursday afternoon, the media day
before the actual World Time Attack event started, the team were basically at a
point where they were ready to pull the pin, I believe they’d already gone
through the process of having the deck surface of the block machined
flat again, had run it again with a new gasket and exactly the same problem
happened it had forced those sleeves down, so what was your solution to this
issue? – Well it was of course team stuff and I
don’t know everything and I’m not like the guru that arrives and says how
everything should be done and it works like that but I mean I at least like to
think that I had a major influence on that. But yeah so we looked through the event
like how things have lead up to this. And I concluded OK it’s reasonable to
expect that this is what’s causing it, that there is actually a step in the MLS
gasket, it wasn’t clear to me before that, even if there was a step or not. Then I did some very very quick
calculations and realised OK I mean there’s no way that that tiny step
on the sleeve is going to be strong enough to hold, hence that clamping forces. So yeah we looked at the dimensions
and how thick that step is and how much the sleeves have pushed down and all
the sleeves have pushed down in equal amounts. So we were looking around OK I mean
I thought it should be good, I mean just put in a new head gasket,
put the head back on, don’t do any decking at all, it should
be good to go because that was closer to what I’ve designed it to do. But it was really touch and go,
Rod sent a message, the owner and great guy that does the whole team,
so yeah he sent a message over on Thursday before we got to the track,
like yeah we had a problem again and we needed to pull the head gasket
and we’re not going to be able to run. And yeah got there and looked at the
things and OK maybe it’s not so bad, but I was giving it maybe 75%, 80% chance
trying to estimate conservatively if it will be good or not. And Rod said yeah he was maybe 50/50
that we would be able to do one lap. – Sounds like you should maybe be a
betting man ’cause obviously history has shown that it did work and it did
hold together. So I think the point I’ll just make there
as well is the conventional wisdom when a sleeve has dropped, which I’ve sort
of alluded to there, it is a common problem in the aftermarket with OE factory
blocks that have been modified, the conventional wisdom would be to
do exactly what the team did to deck the block so everything’s flat again,
but as you’ve said there, with the thickness of that lip and the strength
of the aluminium material supporting it, of course it was just gonna continue to
push that sleeve lower and you’re gonna go through exactly the same
problem so at least you got on top of that and got a solution. It was probably great for PR Technology
and the owner that you did turn up there. Now I just wanna go back to those sleeves
there because you’ve sort of alluded to the thickness there, well we don’t
have an exact number, around about one millimetre. For the sort of specific power levels that
this engine is capable of, you said around 1500 horsepower in a
circuit race application. To me that sounds like a very thin sleeve,
so where is the trade off between, you’ve said you wanna keep maximum
aluminium between the sleeves for strength, but where’s your tradeoff
between keeping the aluminium for strength and sacrificing some of
the thickness of the ductile iron sleeve or liner? – Well we basically want to run the sleeves,
basically only as a coating, so as thin as possible. The thinner we can make it, the better
for the engine. But you don’t want to make it so thin
that you start cracking it and losing pieces because then it’s going to have
a bad day of course. – So in conventional factory engines that
are aluminium, we’ve seen over the last few years, a lot of manufacturer’s have
now ditched liners and are using a coating on the aluminium directly
so that the rings will not wear the soft aluminium, is that an option or is that
really not suited, you’ve just not got enough strength in the raw aluminium
at these sort of power levels. – Well the aluminium alloy we use is
around twice as strong as the aluminium alloy typically used for blocks so I mean
it is very very strong. The only reason we’re running a sleeve
is basically a Nikasil coating would be the ideal solution but the only reason
we’re not doing that is because we don’t have any test results for that
yet. And I don’t feel comfortable testing stuff
on customer engines unless they specifically request that, and it’s very
very performance critical thing. On this type of engine it’s, getting the
last two or three horsepower isn’t that important when they were running
around 1000 kilowatts this weekend, and they hadn’t had to turn it up to
11 yet. – I guess that other aspect there if you
run that Nikasil coating or a similar coating on the bore, it removes that
ability to replace an individual liner if you’ve had a problem and let’s be
honest, even with the best of intentions, the best of everything, when you’re
running engines at this sort of power level, things can and do go wrong. So the ability to fix a problem like that
without scrapping an entire expensive billet aluminium block is obviously
essential. Now there’s one other aspect I just
wanted to talk about here with these billet aluminium blocks. They have come through and become
more popular but we’ve seen them really come out more from the drag
racing world initially and now we’re starting to see them become adopted
more and more for circuit racing. And there’s a very big difference between
what will work for a drag application where the car is only under high load
for maybe six or seven seconds, and then obviously you’re talking about
a circuit car that needs to be under high load for a minute 20, minute 30 in a row. The area I’m looking at here or interested
in is the thermal expansion of the aluminium, it’s obviously a lot higher
than a cast iron block. So does this cause you any issues when
you’re choosing suitable bearing clearances, particularly for the main bearings? – Yeah that is a major aspect to look into
and that of course needs to be taken into consideration like what the power
levels are and how much flex are you expecting in the crankshaft because
it’s nice and straight when you have it on the table but when it’s running in
the engine and you’re really pushing it as hard as it can be pushed, it moves
around by a significant amount. So you need to have enough clearance
there so that you’re not going to start cutting the edges on the bearings. And beside that you need to get
enough mass flow through the bearing gaps to cool the bearings also. But in practice you want to run a really
small gap at room temperature because the expansion rate, because the crankshaft
is an iron based alloy that has a much lower thermo expansion rate than the
block that is aluminium. So at around the same temperatures,
the hole is going to get much larger than the pin inside it so the clearances
are going to increase quite significantly. – I think there’s a general trend when you’re
building performance engines to go with a clearance that is slightly looser
than what would work for a factory engine, for exactly the reason you’re saying,
obviously everything does tend to flex and move at very high specific power
and RPM levels. But of course it is that tradeoff as well,
as those clearances get bigger, you also tend to lose oil pressure too
so where’s the tradeoff on those two factors, is oil pressure a problem,
have you seen issues with that with aluminium blocks as well? – Well with the oil pressure you only
really need enough oil pressure to get the oil to the locations you need it to
be, then it’s just a question of mass flow basically. And one of the main things you need
to get the oil to the connecting rod pin from the main bearing. Depending on the type of drilling you
see, a lot of OEM styles and a lot of aftermarket cranks also that have
just through drilled mains basically, so you need to have enough oil
pressure to push the oil all the way into the centre of the crankshaft before
it starts making its way out to the connecting rod bearing and that’s
something that we’ve addressed, we have I think it’s a cross drilling,
I’m not really sure what the correct term for that is, but we have angle
drillings that go to connect those together and that are specifically angled
and modified to not create stress, high stress locations for that,
but that helps a lot to minimise the required oil pressure for that. Of course then you end up having
the oil squirters which if you need to cool the pistons on the way up also
to get more cooling capacity then you again need to run quite a high oil
pressure to get enough exit velocity from the nozzles. But there are lots of things that need
to be taken into consideration with that. – Of course I guess you’ve got a little bit
more flexibility around oil flow and oil pressure when you’re using
a dry sump system over a conventional oil pump? – Yeah that is, I mean you can afford to
squirt a lot of oil around all over the place basically and not have big issues
with that. I mean you can scavenge the oil so
efficiently. Especially with a complete custom engine
that is built specifically to be dry sumped, then you can have low locations where
you suck out the oil from and you can dimension all the holes correctly to
not have any back flow into the crank case and it helps a lot. – Now you’ve just also mentioned under
piston oil squirters. So I just wanna dig into that a little bit
because particularly with modified factory engines used for circuit racing,
there are two schools of thought on the under piston oil squirters,
one is that they aid lubrication and also cooling the underside of the piston. But the other school of thought is they
take needed oil away from the bearings because obviously some volume of oil
will be lost to those under piston oil squirters. The fact that you’re using them in
the Thor engine obviously suggests that you are a believer but can you give
us some insight into your thoughts around them, pros and potentially cons? – Well we’re running a really large piston,
we’re at 160 millimetres, and thermal conductivity scales very poorly
with the diameter because when you increase the diameter, the surface area
increases quicker than that and then you have less area to transfer the heat
away from the piston so the larger the piston you have the more cooling you
need on the underside and that increases that. But we’re also running piston guided
connecting rods and that needs extra oil also for the guiding surfaces at the
top of the piston. So that’s also a huge requirement,
and of course when you’re doing a custom engine you just need to dimension the
parts to be able to flow enough oil to make that happen. – Let’s just go back to that piston guided
conrods, can you give us a little bit more explanation around what exactly that
means and why you’ve done that? – OK yeah so when you have the
connecting rod, basically you have just a cylinder at the bottom and a cylinder
at the top that locates those, so it will go out the end of the engine,
of course you need some surface at some point to limit that movement,
and there are of course two ways to do that, you can do that either
from the top or from the bottom, and traditionally that’s been done from
the big end at the crankshaft end. But then you end up needing a lip
on the crankshaft to do that, and then that lip also needs a counter
balance on the other side of the crankshaft. And with the piston guided option we’ve
probably been able to pull maybe a kilo or something off of the crankshaft
with that so I think it’s a very good option. – That makes a lot of sense, so essentially
what you’ve got there is tight clearances between the pin end of your connecting
rod and the pin boss in the piston, and that’s what locates the connecting
rod? – Yeah, yeah. – Alright look it’s been some interesting
insight there Oskar, finding out about those problems
because as I say, not everyone knows, but of course when you’re trying to
develop an engine at this level, unfortunately things can go wrong
that were outside of your specification list and it’s great that you guys have
managed to work through it and get a solution and a lap record. And we hope that the car’s back next
year because my understanding is that it wasn’t running full power,
there were still some developments that were being worked through with
the car to improve its performance, so it’s the second fastest car currently
around Eastern Creek and it’s been beaten only be an open wheeler A1GP car. So we look forward to seeing if that car
can actually become the fastest car ever around Eastern Creek. Thanks for the chat Oskar. – Excellent, thank you. – If you liked that video,
make sure you give it a thumbs up and if you’re not already a subscriber,
make sure you’re subscribed. We release a new video every week. And if you like free stuff,
we’ve got a great deal for you. Click the link in the description to claim
your free spot to our next live lesson.

34 Comments

  • Reply Max Brown February 4, 2019 at 8:27 pm

    The fuel is not compatible with the nikasil coated bore

  • Reply BoostHit February 4, 2019 at 8:45 pm

    Another awesome interview!

  • Reply Fabian Franzmann February 4, 2019 at 9:06 pm

    Billet blocks and parts are so beautiful. Why does every beautiful piece of machinery have to be so expensive?
    Amazing Video as always. Love you guys.

  • Reply Jamie A February 4, 2019 at 9:37 pm

    Very cool. Lots of solid info!

  • Reply karim hassane February 4, 2019 at 9:38 pm

    3000?!

  • Reply george piakoulis February 4, 2019 at 9:56 pm

    Wow!! 1000cc per cylinder thats an imressive number for a 4 banger!!!

  • Reply akmal muhammad February 4, 2019 at 9:57 pm

    More info is always good

  • Reply Josh Lewis February 4, 2019 at 10:08 pm

    Pics or it didn't happen

  • Reply Nathaniel Nixon February 4, 2019 at 10:24 pm

    Why did you not do the interview while looking at the actual part in question the ENGINE not to be rude but from an engineering standpoint would rather look at the engine than your faces.

  • Reply MoonStar Productions February 4, 2019 at 10:25 pm

    Learning so much from this channel, well done.

  • Reply Chris Bruton February 4, 2019 at 11:01 pm

    Love the way this dude almost massages the info out of these engine builders and more often than not the interviewer sounds like he knows more than the engine builder bout his own engine.
    Obviously not but another great interview๐Ÿ˜Ž

  • Reply lenzo mustang February 4, 2019 at 11:17 pm

    What engine is this based off of 4G53?

  • Reply High Performance Academy February 4, 2019 at 11:17 pm

    Make sure you check the description for a link to some more videos about this car and engine ๐Ÿ˜‰
    Grab your HPA merch here! Yuki, Ben's dog, signs each black one with a black marker. Hard to see, but you knowing it's there is what counts: https://shop.hpacademy.com/

  • Reply michael williams February 4, 2019 at 11:23 pm

    Taz went in hard for the first few minutes of the video had that man pushed into the corner think you caught him by surprise ๐Ÿ˜‚๐Ÿ˜‚

  • Reply Trent Marlowe February 5, 2019 at 1:18 am

    Awesome content. ๐Ÿ‘Œ

  • Reply MrCornholios February 5, 2019 at 1:54 am

    Would be nice to get more information how they modify the drivetrain.

  • Reply molak34 February 5, 2019 at 2:09 am

    10:20 "I don't feel confortable testing stuff on customer's engines"… Are you kidding me ??? the freaking headgasket was never tested..

  • Reply Dave H February 5, 2019 at 3:29 am

    If im hearing correctly, the head was intended for a "flat gasket" but a gasket with cylinder "rings" was installed. The gasket compressed until the embeded rings contacted the tops of the cylinder sleeves, at which point the act of tourquing the headgasket forced the sleeves to drop?. … Great vid as usual gents! (saving for your whoooooole package as we speak. ๐Ÿ˜ #alloftheeducation )

  • Reply PANTYEATR1 February 5, 2019 at 3:39 am

    I'm guessing that billet blocks can't be made closed deck with sleeves?

  • Reply Santso February 5, 2019 at 9:18 am

    Suomi mainittu, torilla tavataan!!!

  • Reply Shazam February 5, 2019 at 6:23 pm

    No worries he is not a super good expert, just a expert ๐Ÿ™‚

  • Reply ther1kid February 6, 2019 at 9:03 am

    Please go to Oskar shop give him a few beers and do a long format engine build/design debrief.

  • Reply ElmerRacing February 6, 2019 at 5:11 pm

    Thanks to HPA for another great tech chat! Not many would have known about the big dramas leading up to #WTAC2018 without this.
    Doing new things on is not always rainbows and sunshine. But knowing your work, and making the best of the situation at hand, can sometimes allow you to take home the win!

  • Reply Jean-Simon Ruel February 9, 2019 at 3:27 pm

    thanks HPA ๐Ÿ˜Ž๐Ÿ‘Œ๐Ÿ‘Œ๐Ÿ‘Œ

  • Reply Artec12 February 10, 2019 at 4:24 pm

    So the cylinder liners were machined to sit higher than the engine block on purpose, but because the mls gasket had grooves around it that caused the liners to sit? And the solution was to machine the engine block including the liners flat or I got something wrong? Thanks! As usual amazing content!!

  • Reply 5000TQ February 11, 2019 at 12:47 am

    Love the Porsche typ912 engine drawing on the wall! Wonderful inspiration to gaze at the first 1500hp Porsche race engine.

  • Reply badbrooko February 21, 2019 at 9:57 pm

    In diesel they have been wet sleeving with liners since the 50 s
    Linner protrusion is in crucial in building Wet liner Diesel engines.

  • Reply T C February 22, 2019 at 6:51 am

    Now let Shane T put a compound turbo setup on it.

  • Reply Supercar Savers February 22, 2019 at 7:32 pm

    Awesome as usual. Love your interviews and what a great interviewee as well. Masses of learning from my side so thanks guys.

  • Reply Andy Burns February 27, 2019 at 2:42 pm

    AT LONG LAST…. A CURE FOR INSOMNIA !!!! ๐Ÿ˜ดzzzzzzzz

  • Reply TxTex777 March 8, 2019 at 4:22 pm

    Oskar seems like a really awesome dude. I love the interviews you've done with him! I also appreciate how much knowledge is condensed into these interviews. Excellent questions being asked with really clear answers.

  • Reply Adam Naylor May 22, 2019 at 8:25 am

    Gun drilled rods is my favorite type of piston oiling i wonder why it was ruled out or not considered ..

  • Reply Donovan Wallace June 8, 2019 at 3:54 pm

    That's some extreme block webbing

  • Reply Loki August 3, 2019 at 11:26 am

    Not a bad way to spend $133,554.36 usd

  • Leave a Reply