ESE's works engine tuner

[nick gill]

Re polishing the beams on rods. When you do this you are cutting thru the highly compressed skin created by the forging process. The as forged skin may look like shit, but is in fact very strong. Polishing removes all the small imperfections and stress raisers, but then the rod MUST be re shot peined. The finished result will be much stronger again than the original as forged item, and lighter.

Hi Wob, Bob Mead (the Balancer you will know of) told me off for doing this to my Long^tm rods yrs ago as he'd seen a lot of rods stress relieve over subsequent days.
But I've always wondered about the Samarin Rods, TM, or those Cristian Polverelli is using in the V4 (yummy!!), where they are fully machined:



They are forging/hardening/machining/peening/mechanically polishing/final honing? Sound too expensive....
Or are they using another methout that eliminates the forging step?

[lodgernz]

The 75% area at the cylinder exit is just something I discovered after running hundreds of sims, most of them worked best with an oval to round transition in the flange that started with this area
and the pipe header diameter equalled the total effective area of the ports.
Its been tested and proven so many times now, by so many other people, that it should be the first mod to make to any T or tripple port engine.

Wobbly, you wrote this a long time ago, and it says the spigot final area should be 75% of the T-port or triple-port area, as is now well known thanks to you.
But I'm confused because it also appears to say that the area of the first header small diameter should be equal to 100% of the port area.
Doesn't this mean a step at the spigot? Or have I misinterpreted your post?

[nick gill]

Maybe make something out of copper that is pressed into the exhaust duct for better heat transfer to the water jacket.

Hi TeeZee
The Copper may have a really high thermal conductivity, possibly as high as 400 W/m.K, or as abismal as 100 W/m.K depending on the alloy. IMO you'd be better to have a low thermal conductivity as possible, keeping the heat in the gas stream (this was my understanding - to cool the port itself but not the gas inside?). And if not, then aim for the closest coefficient of expansion to the parent material, i.e. G-AlSi9 etc, or Iron for durability.

I have the same issue as you and I intend to replicate my molding in CAD and have it Ti printed by Electron Beam Melting (higher density and more dimensionally stable than SLS), and in my case because the ex duct is IAME/Parilla TAG style (very short to flange)

integrate it as part of the exhaust header, so as not to risk it departing and causing a Fukushima. I'm probably not going to get a chance for some months but that is my intention. Kermit Buller has probably already tried this.
I do a lot of CNC machining of copper billet of Grade 110 [electrical] (400W/m.K), and 147 [free machining leaded] (150W/m.K), I can give you some round bar to play with - PM me.
I don't advise anyone go to the trouble of making Bronze heatsinks as as although they are copper rich the conductivity is usually only as good as 356A/G-AlSi9 or worse. Aluminium 6061 is the best compromise between machinability and thermal conductivity, the presence of silicon being the enemy for the task.

[TZ350]

Hi TeeZee I have the same issue as you and I intend to replicate my molding in CAD and have it Ti printed by Electron Beam Melting (higher density and more dimensionally stable than SLS), and in my case because the ex duct is IAME/Parilla TAG style (very short to flange)

integrate it as part of the exhaust header.

I do a lot of CNC machining of copper billet of Grade 110 [electrical] (400W/m.K), I can give you some round bar to play with - PM me.

Your project sounds very interesting. PM sent, many thanks.

[wobbly]

The Samarin and TM factory rods are fully CNC machined from billet, there is no hard skin as we see from the forging process.
Not having to do the forging process is a huge saving in die and manufacturing cost, for relatively small runs of product.
In this case the heat treatment is vitally important.
But for big factories the accurate as forged rod needs minimal machining, a big saving when huge numbers of lowly stressed parts are involved, and the heat treatment cost can then also be minimized.
Hot Rods as another example do both, forging then alot of machining, and then do the shot pein as well, and this proves economical ( and technically superior ) when reasonable run sizes are involved.

Re the port/duct areas.
First we have the effective port area at the bore ( that includes the cosine factor of its down angle )
Then we have the duct exit area = 75% of this effective port area.
Lastly we have a tapered divergent ( CNC ) transition spigot, that connects the ( usually oval ) small duct exit, to the round header entrance that is back to 100% of the port effective area we started with.
Simple and remarkably efficient.

[lodgernz]

Ah. I get it now. Didn't click that the transition insert is divergent. Thanks Wobbly.

[ief]

ps, didn't mean jbweld or the like but something like this (english part of the site seems to be down)

[Frits Overmars]

Peak Torque or Peak Power, I chose peak torque because that is where everything is working at its best... Here is a trace overlay of Mach numbers... It is interesting to compare them to the torque curve.

Same here. There is no clear relationship between the Mach curves and the power curve at first glance, but you can see a direct correlation with the torque curve.

we might try an entirely different approach to the exhaust dam idea that incorporates Wobblys suggestion of using the insert to reduce the duct area at the flange face. Maybe make something out of copper that is pressed into the exhaust duct for better heat transfer to the water jacket.

Copper is a better heat conductor than aluminium alright, but the stumbling block for the heat is not in the insert; it's in the transition from insert to cylinder, and there's not much you can do about that, apart from welding up the exhaust duct and then ideally opening up the material under the duct so that coolant can come into close contact with the new duct floor.

The Copper may have a really high thermal conductivity, possibly as high as 400 W/m.K, or as abismal as 100 W/m.K depending on the alloy. IMO you'd be better to have a low thermal conductivity as possible, keeping the heat in the gas stream (this was my understanding - to cool the port itself but not the gas inside?). And if not, then aim for the closest coefficient of expansion to the parent material, i.e. G-AlSi9 etc, or Iron for durability.

That low-conductive duct would pass less exhaust gas heat on to the the cylinder, so the cylinder would stay cooler while the heat would stay on the inside surface of the duct. It would then neatly raise the temperature of the washed-through fresh mixture before this would get shoved back into the cylinder, ready to create the mother of all detonations.

The duct's coefficient of expansion might lengthen the exhaust system 0,1 mm more or less, compared to a different duct material. I would not loose any sleep over it.
Anyway, what matters in controlling clearances and avoiding stresses is not the expansion coefficient but the dimension change itself. So you would for example choose a high-silicon, low-expansion alloy for the hot piston and a higher-expansion material for the cooler cylinder in order to keep both dimension changes equal to each other.

First we have the effective port area at the bore (that includes the cosine factor of its down angle). Then we have the duct exit area = 75% of this effective port area.

You knew I was going to react, didn't you Wob?
First we have the blowdown area. I relate all other exhaust system areas to it; then I don't need to differentiate between 75% for a triple port, 90% for a single malt port, and so on.
Granted, establishing the blowdown area is not as simple as measuring the total exhaust window area; that is a clear factor in favour of your approach.

[TZ350]

Christmas has been good to me, got an essential piece of workshop equipment, a La-Z-Boy reclining chair big enough to have an afternoon snooze in ......




Now I can disappear out to the shed and only go back inside when called for meal times, "she who must be obeyed" is over joyed that I am out of the way.

[wobbly]

Sure did Frits,and I agree completely that we should be using the blowdown as a basis for all this,as its has a direct relationship to the power
capability available.
Now that we are seeing the real possibilities surrounding lifting the port floor, this is again making the port window area even more irrelevant so I need to
start generating a data point set to indicate the numbers we need to be looking at based on blowdown STA.
Add to this the duct length factors I detailed before and then real gains can be made with ease.
Neels has done an update to the EngMod RSW sim using the above numbers that will make your socks roll up and down.
We will see soon what he has come up with.

Re the Ryger, I have been monitoring the CIK published homologation site area, and sadly nothing has appeared yet.
But fear not, the instant it does, all will be revealed.

[nick gill]

That low-conductive duct would pass less exhaust gas heat on to the the cylinder, so the cylinder would stay cooler while the heat would stay on the inside surface of the duct. It would then neatly raise the temperature of the washed-through fresh mixture before this would get shoved back into the cylinder, ready to create the mother of all detonations.

Hi Frits. So I guess I've misinterpreted this part of my 2T education
This may also kill off my other two deto interventions, namely 1) Putting a Thermal Barrier Coating on the smooth surfaced ex port duct (easily removed, phew) 2) Fabricating a Ti header section.
Am I following your logic correctly? Or would I have been better to put the TBC on the textured transfers and keep the ex duct as a heatsink for the gas column?
A thousand thanks as always for your teachings.

[jonny quest]

I'm surprised there hasn't been a HP vs TQ debate here yet.

Did you just start one TZ350?

Wouldn't the RPM spread between HP and TQ be more important?

TQ is a static measurement. HP is not. Why isn't HP just the ultimate goal?

[jonny quest]

Re connecting rods

Hot Rods switched manufacturing to the USA recently.

I typically only use OEM, PROX, Carrillo. A few instances lately I had no choice but to use Hot Rods. These were on 250F's mind you, but basically stock rebuilds. Guess what happened. Blamo, through the cases. Not cheap fix. Not saying all their rods are faulty. ... but be careful

[husaberg]

I'm surprised there hasn't been a HP vs TQ debate here yet.

Did you just start one TZ350?

Wouldn't the RPM spread between HP and TQ be more important?

TQ is a static measurement. HP is not. Why isn't HP just the ultimate goal?

HP is merely the rate at which an engine performs TQ.

[jonny quest]

HP is merely the rate at which an engine performs TQ.

Ok, great. Our motors move the bike and us. Tq is a static measurement, not moving us yet until you enter time into the equation. Hp moves us. Rate is the time then, correct?