A work of pure genius! - Brilliant "Revetec" Engine

[revetec]

There are also two reasons for the 3:1 gearing.
1) Provides normal output speed for current transmissions
2) Provides the correct ratio for balancing the pistons.

[Kozy]

Originally Posted by hightower99

This means that when the revetec is running 4000RPM with the geared output shaft it is running like a normal engine, however without the geared output shaft then the pistons and valvetrain have to run faster. To produce 4000RPM at the output shaft the pistons have to achieve the velocity that a normal engine does at 12000RPM, same with the valvetrain.

Yes that's what I mean. (I got the 3:1 the wrong way round) If it were to run at an equivalent 12000rpm maximum without a geared output, thus producing a maximum output speed of 4000rpm, and was then linked to a high speed diesel gearbox with ratios suited to that kind of engine speed, how would it perform.

Please consider that while I understand that Revetec is designing this engine as a fuel efficient economy engine, I am on a Motorsports orientated engineering course, and my project is to assess this designs suitability to a high speed racing unit.

My thinking is that if it can be used ungeared up to diesel operating speeds, then it could be used with a diesel gearbox to provide required road speed? I'm trying to figure out how this would perform in a real world situation.

The simple physical model I have in my head says that if power can be maintained up to that speed, then it should work quite well?

[revetec]

First you have to determine outright engine speed (reasonable performance) and then gear the engine to the wheels in a manor that creates your outright speed (providing the engine produces enough torque at that RPM or power to achieve this).

Whether you take power off the trilobe shaft and use a diesel type gearbox or use our current output shaft with a standard type ratio, the result will be almost the same, as the ratio from the piston to the wheel will be the same.

Does that make sense? Hmmmm....

[The Raptor]

Originally Posted by hightower99

Currently revetec uses a seperate geared output shaft that has a 1:3 ratio (not 3:1) so that 1 stroke of a piston now takes a more normal 180 degrees of output shaft rotation.

Brad is the engine to drive shaft ratio actually 3:1 OR 1:3 as you have not addressed this statement ?

Is the First figure not the Output shaft rotations ?
Is the Second figure the Engine rotation ?

If so, would 3:1 not make 1 piston stroke of an X4 be =120º degree of output shaft rotation ?
(360º ÷ 3=120º / 120º x 3=360º)
Maybe I am missing some simple mathematical equation.

[The Raptor]

Originally Posted by GTM
Hi Raptor,

The production cost of our current trike engines are confidential, however we are selling performance replacement units for between AUD7,200 to 9,500 depending on final config.

We have a target price set for the Revetec X4 trike engine, all indications show that we will meet this price target in production. Unfortunately I can't reveal the price. The ultimate outcome is to have the engine manufactured in China.

China sounds interesting !

It would be a Great envy to be the First to bring a Revetec engine to market place.

Was wondering approx. how many trikes are sold annually world wide ?
Are you the only Ozi outlet ?
Also, approx. how many Trikes would we turn over in Australian annually ?

[revetec]

Originally Posted by The Raptor

Brad is the engine to drive shaft ratio actually 3:1 OR 1:3 as you have not addressed this statement ?

Hmmm...This has been discussed several times on this forum and if you have bothered to read the last 6 posts, it has been addressed. It is also explained on our webpage, and you can see it in any of our renders of the internals on our website, in our gallery section. Plus I don't know why you have made this comment as I would have assumed you understand or know this point.

The output shaft is geared up three times meaning; if the output shaft is rotating at 3,000rpm the the trilobes are spinning at 1,000rpm and the pistons are going up and down 3,000 times per minute.

[The Raptor]

Originally Posted by revetec

Hmmm...This has been discussed several times on this forum and if you have bothered to read the last 6 posts, it has been addressed. It is also explained on our webpage, and you can see it in any of our renders of the internals on our website, in our gallery section. Plus I don't know why you have made this comment as I would have assumed you understand or know this point.

The output shaft is geared up three times meaning; if the output shaft is rotating at 3,000rpm the the trilobes are spinning at 1,000rpm and the pistons are going up and down 3,000 times per minute.

Sorry, I did get a little lost in all the ways that 1:3 & 3:1 are quoted in the conversation as in HT: post 959.

However, I try to read all the posts ...but get lost in all the other spin off conversations. or was it too many ...X4 or ...4x "Beers".
I found the problem I had bookmarked the wrong entry page ! SORRY

[jrobson]

Originally Posted by revetec

Next phase...Certifying our BSFC figure independently (next month) but I suppose, even if it shows it being great as we have performed in-house, there will always be someone there to knock it.

I will be away over the next month while independently certifying power, torque, BMEP and BSFC. I wont be available to comment on here until after certification. Cheers

Since you are posting again is it safe to assume you have your certification? I quickly glansed over the last few pages since the above post but haven't seen anything...

[revetec]

We are currently independently testing the X4v2 engine at the moment and we will release the report when testing is completed and the report becomes available to us. The report will be released on the NSXA first, then I will put it up on our website and email a link to everyone on our shareholder email list.

Cheers
Brad

[The Raptor]

DO you KNOW how many trikes are sold Globally per year ?

[GTM]

Hi Raptor,

If you contact me directly I can share these details with you and discuss more about the trike market.

[GTM]

Hi Hightower,

I have two questions:
1. What would you consider as a good BSFC figure for an automotive petrol/gasoline IC engine?
2. What is the best BSFC figure for any automotive petrol/gasoline IC engine?

[GTM]

I will broaden this question to all UCP members:
1. What would you consider as a good BSFC figure for an automotive petrol/gasoline IC engine?
2. What is the best BSFC figure for any automotive petrol/gasoline IC engine?

[hightower99]

Originally Posted by GTM

Hi Hightower,

I have two questions:
1. What would you consider as a good BSFC figure for an automotive petrol/gasoline IC engine?
2. What is the best BSFC figure for any automotive petrol/gasoline IC engine?

Do you want the answers in g/kWh or lbs/HPhr. ?


I would consider something around 0.350lbs/HPhr. (roughly 213g/kWh) for peak BSFC good as long as it stretches over more than 200RPM. Average BSFC for a good engine should be <0.480lbs/HPhr. (292g/kWh).

As for best BSFC figure for petrol automotive engine I haven't been able to find any definitive answers... It seems that it is possible to achieve just under 0.300lbs./HPhr (182g/kWh).

Due to you asking this question can I assume that some BSFC data for the revetec will be released soon?

[revetec]

So you are saying that you think a petrol engine can achieve a BSFC of 182g/kWh? That is 45% efficient. I think you better show some certified figures on that one....

I've heard of a hydrogen/petrol engine producing a figure just above that but not on petrol alone.