wasted horsepower

[tappy]

Performing such test without a load is not accurate.
Blocking the outlet or inlet stops the airflow through the fins and the amount of power taken will be much lower , if not zero.

The "load" would be the air being moved around. And even blocking the inlet/outlet doesn't stop a fan from moving air. It may circulate (bleed) past it's blades but moving air it will. Unless you create a vacuum in there.

Those blades are hitting molecules and they demand to be paid in the form of energy.

Blocking the outlet or inlet will indeed leave air in the fan, so as the fan "stirs" the air there will be some losses. With zero flow however the fan blades will essentially be "stalled" however, so the amount of work it does will be far, far less that compared to with the outlet open enough to allow the design flow rate.

[tappy]

OK I should have written "almost stops the flow", but a fact is: (edit)fan power consumption depends a lot on the load.

There is a nice write-up from albertaphil in de "doing things with air section"
He states:

The cooling system is not capable of producing any pressure at all. Nor are air scoops. An aviation magazine I used to read had an article on such things, and the resident expert (Peter Garrison in Flying magazine) stated that an air scoop on the cowling of an aircraft will produce 1psi at about 300mph.

If the fan indeed produces 1 psi I doubt the airflow at 60 mph will be enough to keep the engine cool enough

For 300mph I calculate about 1.6psi, but it's relative to ambient conditions so if the aeroplanes at even a couple of thousand feet altitude then 1psi would be about right.
Makes you realise how little pressure boost the "ram air" on sportsbikes has - unless you're doing 150mph+ it's pretty pointless.

If you tried to use an airscoop on the bike to push air through the existing cooling fin ducting, then it would indeed do naff all, but that's because you're trying to push it through a small outlet.
If you take all the shrouding & ducting off the engine and just let air flow over it naturally then there really ain't gonna be a problem.

[Nanko]

If you take all the shrouding & ducting off the engine and just let air flow over it naturally then there really ain't gonna be a problem.

But thats not possible in most cases because the fan generated flow enters the cilinder and head sideways.
With the cooling fins orientated left-right,airflow coming from the front will be blocked (at least that is the case with an IB40)

[tappy]

If you take all the shrouding & ducting off the engine and just let air flow over it naturally then there really ain't gonna be a problem.

But thats not possible in most cases because the fan generated flow enters the cilinder and head sideways.
With the cooling fins orientated left-right,airflow coming from the front will be blocked (at least that is the case with an IB40)

Well, that's true for some engines.
Perhaps then we should also be concerning ourselves with ensuring that the fan centres on those engines are fed by enough clean, smooth airflow to do the job.
Those fans are designed to suck stationary air. Air moving past the inlet face at 50mph, at low pressure due to the bow wave of the bike's movement, and with all the turbulence of flow moving over something like a motorbike, is not "stationary air".

So, for engines that can be air cooled front to rear - e.g Hatz 2G40, Lombardini / Ruggerini LD series, it's probably acceptable to remove the ducting and fan and let it be cooled by the bike's movement.

For engines that can't be cooled that way, maybe the existing fans aren't fed very well?

[XLerate]

If one is going to remove the shrouds and fan from a forced-air cooled engine it might be good to fit a large oil cooler to make up for some of the cooling loss.

Don't know how well it would work but a guy might also fit a radiator, then wrap small copper tubing tightly in voids between engine fins, with a small electric pump to circulate water. Possibly the heat transfer to tubing would equal the former air cooling.

[Anorak_ian]

I have thought about using the fan air for engine intake for some time (years).

I looked it up in my workshop manual (RD211 Rug twin) it says the fan generates more airflow than the engine uses on air intake.

Airflow is different to air pressure of course.

On my bike I have taken all cowling off with no cooling or over heating problems at all (that I know off).
I have fixed a steel plate on the top of the fan cover (looking down) where the ducting was, if I put my hand near the plate when riding I can feel the air flow that shoots from under the plate.
The only reason I have not plumbed it in to the air intake is purely because the look of my bike will suffer.

The conclusion I have come to is, fans, use them or loose them.

I had also heard a few years ago that a 1.5hp increase could be had if the fans were removed, but I think the flywheel could be lightened a lot more than just the fans.
I have been toying with the idea of turning a smaller steel version, but I don't know if kick starting the engine would be problem with the weight removed.

[alexanderfoti]

Just to keep everyone updated, I have purchased a GSXR600 electric cooling fan for £2 on ebay. When I have some more funds available, I am going to get another flywheel and get it turned down by my local engineering shop. Will then fit a thermostat and relay to turn the cooling fan on and off based on cooling fin temperature.

Will see what happens.

[Sphere]

I could do a few testruns with and without the shroud but a 12v fan to cool the head might be nice. And a GPS based measuring device.

[Rhynri]

Makes you realise how little pressure boost the "ram air" on sportsbikes has - unless you're doing 150mph+ it's pretty pointless.

That comment ignores the primary purpose of a ram air - to get cool air from outside the engine bay and to overcome the negative air pressure inside the airbox, essentially to fill a vacuum. Sure it doesn't generate PSI in the same manner of boost, but PSI does not equal flowrate. A great example is a well ventilated computer chassis. Great flow, no PSI to speak of. Opposite of course is a tyre, great PSI, no flowrate. This article shows some rather intersting data. It's worth noting the flow rates they required for this article, 185cfm x2. In many of the cases in this article they are going from -11 millibars to +11 millibars, a difference of .3 PSI, yet are seeing gains of up to 10hp, on a dyno style that is understating the values. I've seen others where there are statistically significant differences even at normal road speeds. If even the tiny change in pressure caused by changing altitutes (or temperatures, or humidity, my diesel car drives better in certain weather) can make a difference, why would you ever say getting a better air supply and overcoming a vacuum (even a small one) would not?

[tappy]

Interesting stuff there Rhynri and I totally accept your point that - clearly ram air effects are not "pointless" and it was a rather careless statement. I also accept your point that zero-flow pressure and flowing low pressure are different - given that I design jet engines, you'd be forgiven for worrying about flying if I didn't.
If I'm teaching you to suck eggs with the following I apologise, if not, I hope you find it as interesting as I found the info you posted.

Whilst flow speed and pressure are difference, they are related. For incompressible flow (below Mach 0.3) "total pressure" = "static pressure" + 0.5 x density x velocity squared.

In a well ventilated computer the flow area is large, so the flow speed is low, so the pressure head required at the fan is low. And when the air comes out of the casing, it's already been through all its pressure losses so its static pressure = ambient pressure, and because it's low speed, it's total pressure ain't much higher.
If you put only a small hole in the casing, the air would have to move much faster as it came out, so the difference between its static and total pressure would be greater. Again, at the exit its static pressure = ambient pressure, so now the fan must have to generate a larger pressure head to move the same flow.

Exactly the same situation with our engine cooling ducting. If the engine ducting is removed, the flow area is large, the air entry area is large, the air exit area is large, so all the flow speeds are relatively low, and there's little driving pressure needed.
If the ducting is fitted, the exit area is definitely smaller, so the exit speed is higher so the flow's exit total pressure is higher. The cooling flow area is also smaller (the ducts don't cover the entire engine) so again, the flow speed is higher, and the losses much higher. So in this case the pressure head generated by the fan will be higher. Which is why they have a fan, and why prelim analysis of the fan suggests a couple of hp of power.

Interesting link you gave to the ram air testing - I've never seen data for airbox pressures before.
What concerns me about the numbers is that I expect the pressure tappings were static pressure, not total pressure. We don't know the flow area or flow speed where the pressure measurement was taken so it's therefore not possible to calculate the total air pressure from the static pressure, and it's this total pressure that is crucial to knowing what air pressure the engine ultimately sees as the air comes to a stop above the piston, actually giving the power boost. So although the static pressure difference is very small, the total pressure difference (that gives the boost) may have been higher.

In the case of altitude, my Hatz engine is quoted as losing 1% per 100m. So 1000m should lose 10% power. At 1000m the air density & pressure is about 90% of that at sea level. So to get 10% more power, I'd expect to need about 10% extra density or "total pressure" in the airbox - i.e. about 100mb, not the 25mb difference in "static pressure" from the bike testing.

I think your point about the air source is kinda the key. In a non-ram-air bike, the air is drawn into the airbox from a warm, low pressure area, through a small restrictive trumpet (designed to reduce noise) so the total pressure and density in the airbox will be poor. In the case of a ram air bike, it's at least coming through big flow passages, drawn from a nice cool source at ambient or greater.

I need to go think about that test data a lil more and think a bit about what's going on. In particular, the tests without ram-air boost probably had a source pressure about equal to ambient, which means we DO know a little more data, and it might be possible to do a bit of back-calculation

In any event, for now I stand by my statement - at the start of this thread - that the pressure and work delivered by those fans may well be the 2 to 3hp suggested.

[Rhynri]

That is very good information Tappy, and you are amenable to polite conversation on a subject, for which I thank you. I can see what you mean by the changes in air density versus altitude (10% reduction in atmospheric is 100mb/1.45~psi) so we'd expect the ram-airs not to work as well. I think it's mostly a function of less work on the engine to draw the intake charge, in combination with a cooler, denser charge that produces most of the effect. I remember there was a 2000 camaro (one of the special factory limited edition numbers) that made 125 HP more than stock, something the tuner attributed mostly to "better breathing" which I can see. With our diesels and their sensitivity to their intake charge in regards to power output, I could see this being something to look into once we find that ideal, reproducible build everyone is trying to duplicate (the tiger, perhaps?). I find it fascinating that you design jet engines, even though that's a little vague (turbofan, turbojet... propfan? ), we'll have to discuss particulars sometime. Also, I completely agree with your initial statement on fan power usage.

Who knows, maybe if we can get enough engineering know-how together we can design our own dieselbike.

[tappy]

Hmmm - you've mentioned in there something I hadn't twigged on previously.
I was focussing on the pressure & density of the air going into the engine affecting the amount of mass flow going in, the peak combustion pressures etc and therefore its power.
I'm now sitting here trying to work out whether in the non-ram-air situation the power the engine uses just trying to suck the air through is actually where the difference lies.
In short, I'm having too hard a week to think about it this evening, but as you say - it's definitely worth thinking about 'cos these diesels need everything they can get!

Personally I think a 2-stroke diesel with a 4-stroke bottom end and an unusual scavenging system is the way to go to get a compact, efficient, powerful (relatively) engine, but funnily enough that's not without its issues either

[Rhynri]

There is a lot to think about, which makes you respect the engineers that turn out powerful, efficient, quiet powerplants that much more. Our biggest issue with our bikes is the long stroke of the diesel, which makes the engines tall for our purposes. I know VW powerplants are able to be mounted up to 45 degrees from vertical, which does help some, but then you still have the issue of powertrain. Perhaps a small DSG or automatic might fit the bill. There are so many variables, and the most welcome class of adventure / sport-turing style bike poses many of the issues in regards to reduction of ground clearance and volume constraints on the engine. I still remember the small deutz diesel my father pulled out of our little skidloader when I was a kid. That would most definitely fit our bill, and it made decent power while being very frugal and simple (and oil cooled). Once I am able, I intend to get measurements.

[XLerate]

Okay, so we're talking about wasted horsepower from the fan & flywheel mass and changing the airflow characteristics to increase or equal stock cooling while increasing hp production. So, flywheel is needed for a bunch of reasons but maybe the cooling fan isn't.

Why not use alternative cooling methods like an oil cooler or other suggestions made eleswhere in this forum section, then attach only the compressor half of a turbo to the flywheel so that crank direct-drives turbo? The turbo isn't just a spinning fan blowing air, thanks to the tight tolerances between impeller and compressor housing.

That's my plan for my future build. I have the turbo off a Mopar 2.2L 4 and will be using a fairly large diesel engine, 3-4 cylinder, that can gobble some serious air/fuel. Using radiator cooling plus oil cooler on my [future, haven't got it yet] water cooled engine. Separate turbo drive section from compressor, then drive compressor directly off crank. Lots easier to plumb exhaust-wise, simpler to build and no big hot hunk of cast iron in the exducer housing or parasitic loss of exhaust flow through exducer. Instead of a turbo I guess it becomes a supercharger.

I'm not that bright though so maybe there's stuff I'm not seeing.

[Anorak_ian]

the exducer housing or parasitic loss of exhaust flow through exducer. Instead of a turbo I guess it becomes a supercharger.

Well, you use your tongue better than a twenty dollar hooker

[Sphere]

I think driving something off the crank defeats the purpose. The real goal is getting rid of losses that may impact the performance of the larger single cylinder engines in such a away that you can drive them along a road at more than terrifying (read: low) speeds. I can't comment sensibly on whatever impact lightening the flywheel has, but it seems very heavy for my application, to the point where it will lockup the drive train, if you are not careful.

So, if you can fit a temperature gauge to your cylinder head (this is the part that will suffer from insufficient cooling) it would be nice to see some readings. I'm not sure an oil cooler will help much in this respect as the head might still overheat. On the other hand, if the engineer designing the fan is worth his salt, it's safe to assume the cooling capacity will be quite a bit larger than needed for ambient (293K) tempratures.

Thirdly, if you can find the flow that the fan provides at 3600 rpm or whatever your engines revs at, it should be possible to create a ram air solution that will generate the same flow accross the head from driving wind. How this will affect aerodynamics is another matter Because ultimately, as Allard from the Quest recumbant bikes has shown, lowering th Cw value of your vehicle is where the real gain is to be had.

[manousos]

Personally I think a 2-stroke diesel with a 4-stroke bottom end and an unusual scavenging system is the way to go to get a compact, efficient, powerful (relatively) engine, but funnily enough that's not without its issues either

What about the PatPortLess design ?



It is a 2-stroke uniflow engine with an unusual built-in piston-type scavenging pump.

It combines 4-stroke lubrication, 4-stroke lubricant consumption and 4-stroke scuffing resistance with the advantages of the 2-strokes.

The pulling-connecting-rod arrangement (the combustion pressure loads the connecting rods in tension) increases the time provided for the injection and the combustion of the fuel by some 30 to 40% (depending on the con-rod to stroke ratio) as shows the plot :



and the array:



improving, as compared to the conventional Diesels, the combustion efficiency at specific rpm and increasing the power density (the combustion remains efficient - and the torque high - at revs wherein the torque of the conventional Diesel falls steeply). Also the efficient rev-range of the Diesel widens substantially.

More details and variations at http://www.pattakon.com/pattakonPatPortLess.htm

Manousos Pattakos

[Sphere]

Hello Manousos, another of the engines on that (your?) site is also covered here: https://www.dieselbikeforum.com/view ... =21&t=2288

[tappy]

attach only the compressor half of a turbo to the flywheel so that crank direct-drives turbo? The turbo isn't just a spinning fan blowing air, thanks to the tight tolerances between impeller and compressor housing..

Centrifugal compressors (like in a turbo-charger) generate pressure as a result of wheel surface velocity, and for something with a small enough flow for a diesel engine the compressor will be spinning well over 100k rpm. So if you want to drive one from a diesel crank you'll need to gear it up by a factor of about 40. That'll need a compound gear train and a belt drive. Naturally the engine will use some of its power driving the compressor, but should generate more power due to the supercharging. It will also use more fuel however, and more energy will go out the exhaust, so over all the efficiency will drop a bit.
A centrifugal compressor won't generate any pressure at low speeds, generate a bit at medium speed, and start generating decent pressure at high speed, so with it gear driven it wouldn't deliver the same effects as either a turbine-driven one (turbo-charger) or a crank driven volumetric supercharger (roots type, or vane type).

I have considered such an arrangement for a different reason though - it would allow a slightly lower volumetric compression ratio which would give smoother idling (at low rpm the turbo-compressor won't generate any pressure). At higher rpms the compressor generates pressure, increasing the pre-combustion pressure, speeding up the burn, and giving a high peak power & peak power rpm, which might improve engine flexibility.

I also considered making a larger, light-weight, low pressure, low speed centrifugal compressor - think along the lines of the plastic or light metal impellor in your hoover. The idea being to avoid some of that compound gear train I mentioned. To generate decent boost pressure at the crank speeds we're using would require a compressor diameter even larger than the cooling fans, so it's not that useful an idea yet.

[tappy]

What about the PatPortLess design ?

I've been looking into various engine configurations and a colleague of mine has invented an alternative crank arrangement that gives even more top dead centre dwell, and a piston arrangement that gives positive scavenging and transfer. I've been helping him develop the design and we're looking to start making and testing, but on limited budget it's gonna be a while before it's a useful engine.

[XLerate]

The turbo I have is very small and compact, yet it's plenty to charge a hot 2.2L. I wouldn't want to do a gear drive, far too complex and expensive. The idea is to stay light and simple. So a flat toothed belt overdriving compressor to about 7:1 or 8:1 ought to kick some air into the mixture, meaning a max of 20-25K rpm or so compressor at governed limit. Certainly a very large increase in airflow over a normally aspirated engine. It would have the same drawbacks as a supercharger, with most of the real power on top end and not a torque monster.

[mark_in_manchester]

Hi Folks

I've been following this thread with interest. At work I'm into air-flow...but ac flow (acoustics), which isn't such a help here.

Still, on my bike (Daitatsu Charade turbo - 3cyl 993cc - in a Ural) the input impedance (which we could define as pressure / volume flow) at the inlet valve is sufficiently high to require quite a lot of pressure to get extra air in. I happened to have a 0-10psi gauge which I attached to the inlet plenum, really as a silly pose...but it tells me that bumbling around the turbo is driving about 3-4psi (and not making much difference, compared to running it with the plenum vented to atmosphere), and at full-ish throttle (when I'm wondering if the rubber couple on the drive shaft is quite ready yet to explode and remove my right ankle) then it gets up to 9-10psi, before the in-built diaphragm valve starts spilling some excess pressure itself. And then yes, it makes a big difference. (oh - and edit to add, there's a diaphragm valve on the injector pump which detects plenum pressure and puts more fuel in when there is more boost).

Incidentally the boost gauge is useful as a sort of backwards inlet-vacuum gauge on a petrol engine - if I want to make the fuel last, I keep it below 4 or 5 psi. All very Mad Max...

[tappy]

meaning a max of 20-25K rpm or so compressor at governed limit.

If you can find out the make, model and cut of the turbo, we could have a look for some flow characteristics and see if we could estimate the flow / pressure etc delivered.
Up front, I think that if you're aiming for 20 to 25krpm, you'll generate so little pressure (and therefore flow) that it might prove to be more of a restriction than a boost. BUT, at that speed, an impellor out of a decent size hoover might actually be very effective, and a lot cheaper and lighter!

There are old vacuum cleaners that crop up on freecycle from time to time so a cheap experiment and a few approximate calculations might be quite interesting.

[tappy]

but it tells me that bumbling around the turbo is driving about 3-4psi (and not making much difference, compared to running it with the plenum vented to atmosphere), and at full-ish throttle then it gets up to 9-10psi. And then yes, it makes a big difference.

At low boost pressure, the turbo shaft speed will be low, and both the compressor and turbine will be at low efficiency. Therefore the amount of exhaust back-pressure the engine's seeing, will offset the boost pressure. Once the turbo's spinning at higher rpm and the efficiencies are improving, the boost becomes more significant.

If there's no turbine restricting the exhaust flow, and a relatively efficient belt drive from crank to low pressure compressor, then I'd hope that 4psi would make a useful contribution. That's only my thinking tho' - if anyone knows better please pipe up

[BertTrack]

I have considered such an arrangement for a different reason though - it would allow a slightly lower volumetric compression ratio which would give smoother idling (at low rpm the turbo-compressor won't generate any pressure). At higher rpms the compressor generates pressure, increasing the pre-combustion pressure, speeding up the burn, and giving a high peak power & peak power rpm, which might improve engine flexibility.

Tappy how would it smooth idling? To my knowledge increasing the spinning weight of the engine will smooth out idling. Increasing the inlet pressure won't.

Small detail on speeding up the burn. Diesel burns as it's injected. By increasing the temperature (through compression) you decrease the ignition delay of the fuel after initial injection. But the burn speed remains the same.

[tappy]

Cheers for the detail correction . Combustion generally does happen faster at higher pressures tho' hence I expected that would also be a factor.

Regarding the smoother idling, I suggested a lower volumetric compression ratio. Dropping from 20:1 to 18:1 would make a big difference to pre-combustion pressure so there would be increased delay after injection, effectively retarding "ignition timing" giving a smoother idle.

At higher rpm when the centrifugal compressor is generating some boost pressure, the incoming pressure will raise the pre-combustion pressure to even higher than the normally aspirated engine running 20:1. This would now give less delay / faster burn, equivalent to "ignition advance" so make decent power.

How effective it would be in practise I'm not sure, but if someone's thinking about using a crank driven centrifugal compressor then it's worth considering changes in compression ratio or static injector timing at the same time....

[XLerate]

meaning a max of 20-25K rpm or so compressor at governed limit.

If you can find out the make, model and cut of the turbo, we could have a look for some flow characteristics and see if we could estimate the flow / pressure etc delivered.
Up front, I think that if you're aiming for 20 to 25krpm, you'll generate so little pressure (and therefore flow) that it might prove to be more of a restriction than a boost. BUT, at that speed, an impellor out of a decent size hoover might actually be very effective, and a lot cheaper and lighter!

There are old vacuum cleaners that crop up on freecycle from time to time so a cheap experiment and a few approximate calculations might be quite interesting.

Don't want to pirate this thread any more.

Garret Air Research Turbo, '86-'89 TO3, Dodge 2.2L Shelby GLHS Intercooled & wastegated for 2.5" exhaust [wastegate housing is now removed].

Compressor housing A/R .42, Exhaust housing A/R .48, Compressor inducer 42mm, Compressor Exducer 60mm, Exhaust Turbine 48mm. Produces up to 30 psi boost, supports 250 HP in a gasser 2.2L.

http://www.thedodgegarage.com/turbo_turbo.html

BTW the direct drive part is just a thought at present. May be able to cobble up an exhaust housing that will work depending on engine's exhaust configuration, haven't gotten there yet.

I'll assume the Hoover vacuum reference is some part of your sense of humor...

[tappy]

Okey dokey. Following that link, then hitting the 1984 Turbo link, then scrolling down and going to the "Advanced Turbo Page" brings you to a few flow characteristics for the compressors http://www.thedodgegarage.com/turbo_advanced.html .

When you say "fairly large diesel engine" in your earlier posts you could mean a fair few things, but taking say, a 1.8L 4 cylinder, revving to say 5krpm as an example:

1.8L * 5000/60 * 0.5 = 75L/s of air = 0.075m^3 per second. Air density is around 1.225Kg/m^3, so that's about 0.09Kg/s. The boost pressure will increase its density so maybe it'll actually flow about 0.15Kg/s if you've got plenty of pressure.

0.15Kg/s = 20lb/s air flow.

Reading from the characteristic for the T3, on that webpage, 20lb/min is pretty much halfway along the bottom axis.
If you want 7psi boost, that's a pressure ratio of about 1.5, so reading across to the curved line, you'll need about 96000rpm. With a crank speed of 5k, that's a 20:1 gear ratio.
Alternatively, come down to the 78,800rpm line, and maybe accept a bit less flow - 17lb/min, and the pressure ratio is 1.3, so about 4.4psi boost.
Come down to the 56k rpm line and you get 1.2PR (3psi) boost at the surge limit, falling probably to about 0psi boost at 15lb/min flow.

To get something useful at the kind of rpm you're talking about you're going to need a much larger diameter compressor wheel. Something off a dirty great truck engine might work, but I'm not sure how well it'll react to the small flow quantities you'll be demanding.

I wasn't joking about the vacuum cleaner impeller. If you read around on the internet you'll find plenty of people that have made small jet engines out of turbos, and a handful of people that have made their own compressor wheels or use stuff similar to hoover impellers.
Given the low speeds, low pressures and low temperatures you're likely to use, having an aluminium impeller capable of 200krpm (overspeed) in a thick, heavy aluminium housing built to contain much higher pressure seems like lots of extra weight.

[pietenpol2002]

I'll assume the Hoover vacuum reference is some part of your sense of humor...

I'm not necessarily assuming he's joking. If you look at the specs on the 2 stage Ametek full house vacuum blowers they are capable of over 100 CFM while generating upwards of 6 PSI of boost if mated to one of our little 10 hp Yanclones. Not bad for only weighing a few pounds. I picked up several new ones on "that auction site" for $9.99 each to toy around with before finally settling instead on the Aisins. The biggest challenge is that they produce those kinds of numbers by turning 25,000 RPM. Rather stiff overdrive when you're starting at 3600 RPM. I did ponder driving one from the full diameter of the Yanclone flywheel which would get you the required 25,000 with yet a reasonable size pulley on the blower. Never got beyond the pondering stage. Service life is 500 hrs continuous which works out to somewhere between 25,000 and 30,000 miles. Not bad for 10 bucks. But who knows if it would even work.

[alexanderfoti]

Just an update that I posted in the other thread:

I have started the flywheel modification, and I have found somebody who will balance it after I do some of the work.

Here is the start of it:



Im going to keep about 5-10mm of the vanes, as my tach sensor uses them for the rpm gauge,. I am going to grind down the additional longer vanes flush and then once all that is done, it will go down to dynamic balancing in bristol. (I am waiting for them to get back to me on pricing).

I have a spare flywheel now, so if this goes tits up, its not the end of the world.