Question for the engineers

[Paul in NZ]

Lust...... Imagine the Guzzi with...... LUST......

[Motu]

Hm. The valve appears to be pure rotary, not reciprocating rotary like a Knight valve. How does it cope with deposit buildup . It's one thing to produce something like that which will run fine under racing condition, pulled apart every couple of thousand kilometres. Another matter to make it reliable for 250000 untouched miles.

That's always been the Achilles heel of rotary valves. Good as, to start with. 50000 miles later , oh dear.

I'm not knocking his work, just Devil's advocating. I've always hated the poppet valve myself, it offends my sense of engineering fitness.

All of Ralph Watson's cars were road legal,even the Lycoming - it was never trailered....Jim Boyd would toss a bag in and drive to Levin,Wigram,Invergargil,whatever,race for the weekend and then drive home again.They were all totaly driveable cars.The BSA had done 30,000 miles at the time of the article,Ralph had taken it on several South Island trips (makes us look like nanny bikers).Of course he had to keep an eye on it as part of his development,but he says it just needed a bit of a decarb and the seals cleaned.

There was a report from the new owner,and he was saying how surprised he was on how wide the power band was,considering that the valve timing would be considered quite wild for poppet valves.As it says,possibly the only working rotary valve engine in the world,as powerful and reliable as an ordinary valve train.Ken McIntosh gave Ralph a Manx motor and wanted him to do a rotary valve for it,but Ralph,always practical and honest said the power gains weren't worth the effort,he admitted that modern development had surpased his efforts.

Would look good on show on the front of a Morgan too eh?

[Pixie]

whats stopping manufactures using rotary valves on a 4 stroke? Can they not handle the combustion pressure or is lubrication their biggest issue (hence why they only seem to be doing big things on 2 stroke engines). It just seems better, not having anything upsetting the flow of air into the chamber ie the valve itself.

www.rcvengines.com

[Pixie]

Wow. Great answers guys.

Could you control valves with electromagnetics? Or is it just not fast enough?

From 2003:

Lotus and Eaton hope to have vehicles demonstrating AVT technology within two years and to have systems in production and available for delivery by 2008.

An undisclosed major European vehicle manufacturer has already signed an agreement to acquire the AVT system for one of its platforms.'Eaton's Automotive segment produces products focused on fuel economy, the environment, and targeted safety systems.Our collaboration with Lotus means we can get to market quickly with one of the most exciting developments in valve train technology for many years', said Stephen Buente, EatonSenior Vice President and Group Executive - Automotive.'Between Lotus and Eaton there is the right mix of experience and know how to make the AVT system a world-leading technology that is attractive to vehicle producers the world over'.

The fully variable AVT system is several generations ahead of the various mechanical systems introduced by OEMs to improve the flexibility of their engines.

It offers a level of valve control never seen before in production engines.

Replacing the camshaft with lighter and more compact hardware, the electrohydraulic valve actuation technology enables virtually infinite manipulation of the timing, duration and extent of lift for each valve.

The complex control system selects and implements the valve lift profile that achieves optimal operational efficiency across the engine's entire speed and load range.In addition to reduced emissions and fuel consumption,Lotus' AVT technology offers increased torque and power output potential from the engine.

Furthermore, the AVT system will subsequently be an essential enabler for new combustion processes.

For example, Lotus has demonstrated that controlled auto ignition (CAI) and homogenous charge compression ignition(HCCI) are capable of reducing engine-out nitrogen oxides (NOx)emissions by up to 98%.

[Pixie]

That and rotary valves (and rotaries) often end up producing very large combustion chambers that are horribly inefficient on fuel. Not a good thing in this day and age..

The RCV engine can have a combustion chamber smaller than a poppet valved engine

[Pixie]

haha are you sure? Renault have come from nowhere in the last 2 years.

I saw a very cool engine about 2 years it was a 36 cylinder (3 v12's) supercharged 2stroke desiel (well i think), i cant remember what it was called so cant find anything on in again but that was a true piece of engineering art, has anyone else seen this thing?

Napier Deltic
Here's a working model:
http://www.craftsmanshipmuseum.com/Tomlinson.htm

[TwoSeven]

My next project after the 600 engine is going to be either a window powered stirling engine, or a hand powered one. That is, work from the heat of the hand. But first, need to start off with the tin-can engine. But thats way in the future.

[thealmightytaco]

My next project after the 600 engine is going to be either a window powered stirling engine, or a hand powered one. That is, work from the heat of the hand.

What about running off the heat of your ass? Be a sore seat to ride but. Butt.