Turbos

[Lou Girardin]

I used to work on compressors for a living,back then a mobile compressor like an Atlas-Copco would be a V4 reciprocating job with 2 large low pressure pistons feeding high pressure pistons,powered by a 6cyl Ford turbo engine - they were complicated to set up and we did various things with the 2 taps to load and unload the compressor to test valves etc...with both taps wide open it would be working at max to keep 100psi.I remember the first rotary screw that I worked on,it was powered by a Duetz aircooled diesel - starting with taps closed it would start with a blip and idle - that was it up to pressure...with taps wide open it would sit just above idle maintaining it's 100psi working pressure - fucking amaizing,and with a pump you could fit on the carrier of your bike.I remember some compressors were rotary vane,same as a Shorrocks blower - superchargers are just compressors after all.

As I understand them, Rootes blowers are not compressors, they are displacement pumps. There's no internal compression of the air they shift.

[Motu]

True of any pump Lou - you don't get pressure until you apply restriction,the Roots (no ''e'',that's Hillman you are thinking) blower is like a gear oil pump,a centrifical blower (used by the Yanks a lot,the Studebaker had them) is like a water pump.

pixie - I had a TS3 as my avatar once,but only know a delta from pictures.

[pete376403]

While we were discussing the TS3 and the Deltic a while back, I did a bit of research (bless the 'net). The Deltic was originally designed as a boat (navy torpedo boat) engine, where it would have recieved proper care and attention. When it was put into the BR locos, it was de-rated to compensate for the extended duty but was still over 2000 HP.

Later used in torpedo boats in Vietnam, two 3100 HP engines in an 80 foot boat would be quite a ride

http://www.ptfnasty.com/ptfDeltic.html

[ajturbo]

Z1tc (Z1000)



XN85 (GS650)
http://www.turbomotorcycles.org/Images/Bike_s_xn85.jpg

think this was the SEXIEST one of the lot!!!!

[lukehyslop]

Most anti lag systems work by retarding the timing a huge amount (say 50 degrees) when the throttle is closed. The mixture is then ignited while the exhaust valves are open and the flame front goes straight into the exhaust powering the turbo. Obviously this will wear the turbo out in no time but eliminates lag.

[speedpro]

Nah, I have the twin turbo one. But the numbers I posted are for the latest single turbo version. I agree that a bigger engine is the way to go in the very low end, but you tend to drive in the middle of the rev range (on the open road at least) and this is where aturbo shines.
Ball bearing turbo's make a huge difference- my old mans Cefiro used to go amazingly well, almost no discernable lag and it pulled around 2000rpm. Then one day the turbo died- he reckoned it was like driving a Morri 1100! He then discovered it had a non servicable ball bearing 'sports' turbo. He went for the cheaper rebuildable version. It ruined the car- big lag coupled with an auto is not much fun...

My cefiro ceramic turbo shit itself, I found the exhaust turbine in the catalytic converter, and I'm reasonably sure a Morri 1100 would have blown it's doors off. It had very little turbo lag if any in real life. However the replacement turbo was a bit bigger but otherwise bolted straight on and lag was a real problem AND fuel consumption increased lots. This turbos ex outlet was 60mm across versus the old ones 50mm. Above 140kmh it was definitely faster but in situations like going up City Rd off Queen st it crawled because the engine speed wouldn't increase enough to flow the ex gas to spin the turbo and without the turbo spinning it didn't make enough power to spin the engine up. With the old one you could lay rubber all the way up the hill. Evidently "Diesel and Turbo" on Wairau Rd had never had a complaint before me. With the horrible restrictive ex manifold plus the turbo these engines (RB20DET) are never going to be powerful off-boost plus they are going to be inefficient due to the restriction in the exhaust.

[Motu]

The Napier Deltic was an intriguing design.
See who can figure this out:

18 cylinders
three crankshafts
36 pistons
no heads
two stroke
6 cylinders long

http://www.craftsmanshipmuseum.com/images/clen2.jpg http://www.craftsmanshipmuseum.com/images/clen1.jpg http://www.craftsmanshipmuseum.com/images/clen4.jpg http://www.craftsmanshipmuseum.com/images/clen30.jpg http://www.craftsmanshipmuseum.com/i...enSectionM.jpg

Um...yeah...um....if I only had time....

story of this engine

[speedpro]

Also I ran my bike on a dyno when it was first built. It made 73KW at under 4000rpm. Later with bent exhaust valves (again) it made 175hp at <9000rpm and 105ft/lbs around 6000rpm. The valves were bent enough to make it REALLY hard to start. That's rear wheel horsepower.

[Coyote]

http://www.craftsmanshipmuseum.com/i...enSectionM.jpg

Um...yeah...um....if I only had time....

story of this engine

Looks good, not sure how it works

[Ixion]

Looks good, not sure how it works

Actually quite simple in theory. Take 3 60degree two stroke V twins. Throw away the cylinder heads. Put the engines in a triangle so the tops of the bores are up aginst each other. Now the combustion space will be the space between the opposing pairs of pistons. now extend the idea lenthways so that the Vtwins become V 12's. You now have 36 cylinders and 36 pistons. Connect all the crankshafts together with gears. Light blue touch paper and stand well clear.

I do not want to think what the firing order would be.

[speedpro]

Neil Hintz (mince) has built a couple of uniflow 2stroke engines that appear to be using a similar principle. 2 cranks, 4 pistons. The first was a bucket motor, the later ones are meant for gyro copters. He did all the casting molds himself, primarily because he was told it couldn't be done. His later engine has enhancements and refinements that this one could use. That is one cool bit of engineering though.

[Jeremy]

Looks like a plain delta design to me. They use them on trains usually. Been a very long time since I've seen one though as the only time I was interested in trains was when I was 8 or so.

[pete376403]

Brit Rail used Deltics for a while but maintenance costs were too high. BR prefers things that can be fixed with sledge hammers. Perhaps Deltics (the real ones) were most recently used in Vietnam war era fast patrol boats - theres a link several posts back

[RiderInBlack]

Thanks for the Deltics links guys My Dad has really enjoy reading those sites. The big surprise for us was the Deltic History: Napier Heritage page, which lead us to do a seach on Supermarine S6B Seaplane (1931) and Schneider Trophy Aircraft. These were designed by Napier as well. Dad loves his planes and used to draw the Supermarine as a kid, so it was quite a kick for him to be able to read more about them on the net
Who would have thought that this thread on Turbos would have lead Dad and I to the Supermarines
Thanks again guys

OK back to Turbos