Jabiru power increase

[RFguy]

OK back to the topic

 

you want increased efficiency , that is get more power from improved caloric efficiency ?

 

That will be hard for a specific design.  you can improve the way it breaths, but that doesn't increase the caloric efficiency in most cases, just enables it to consume more air fuel mixture.. more output and heat !

 

You might use the water cooled heads as a starter. that helps a bit with temps all round, including piston temps (top of bore gets conduction cooled by hold heads) . 

 

But that's not more EFFICIENCY

 

 

 

[danny_galaga]

I mentioned fuel injection. I've been chatting to a guy named Ray out at Boonah. He has been fitting a Rotec fuel injection system to his Jabiru. I don't believe it's fuel injection in the common electronic solenoid system we see on cars, but it's supposed to improve on the carb. Have you looked into that? You won't have to modify your engine, and as well as getting a few extra ponies, you should be using less fuel too.

 

https://www.rotecaerosport.com/tbi-34-s

Edited June 12, 2021 by danny_galaga

[Paul davenport]

All good fellas and on my wish list but on 24 or factory built aircraft is just that. Wishful thinking, how good could we make it though

[facthunter]

A version of the almost universal in VH drip system is OK. NO electrical power needed and it can be leaned out for altitude work.. Slightly more difficult to start than a pumper carburetter. Close to port fuel feed points makes engine damaging backfiring unlikely. Nev

[RFguy]

Their TBI is great but you need to be prepared for some fiddling getting it right. It is not an " install and fly " option.

there are many people here who have good experience with such things, search through the forums....

[skippydiesel]

3 hours ago, Paul davenport said:

All good information and I take your point about attention to detail and your Cummins referral but I caution you about wandering away from my initial question and remind you I asked about Jabiru and nothing else and would ask you keep to ONLY Jabiru

The principals are the same, no matter what engine or its application.

[Flightrite]

In answer to yr original question seeing as you are angry...NO! Mr Jab would have done/tried plenty of ways to gain more GeeGee's but he hasn't & for probably good reason!

[coljones]

On 20/05/2021 at 7:22 AM, turboplanner said:

Well tweak is not an engineering term, so maybe you could explain yourself?

Tweed might not be a mathematical term but it is an engineering term.

[Red]

3 hours ago, coljones said:

Tweed might not be a mathematical term but it is an engineering term.

Blimey is it?, I thought it was a type of material used to make jackets out of 🤪

[pmccarthy]

Also a popular name for a sheepdog. Named after Charles Gibson's Tweed, which won the sheepdog trials at Forbes in 1879. My family had several dogs named Tweed.

[440032]

At the 2021 Australian sheepdog trials, how many were found guilty?

[Paul davenport]

No Flightrite I am not angry, but I am disappointed that so often these discussions deteriorate from what was a reasonable question to just plain waffle about anything . The question was ,I thought plain enough and I would have thought those with FIRST HAND information would have either told me yes it is possible this is what I did ,OR no this is what we have and it’s not possible under the current rules. I thank those of you that did enter the conversation in the spirit it was intended and ask those of you that didn’t to consider the worth of what you said in light of the original question. We seem to be discussing DOGS now so as far as I am concerned this topic is now closed 

[turboplanner]

2 minutes ago, Paul davenport said:

No Flightrite I am not angry, but I am disappointed that so often these discussions deteriorate from what was a reasonable question to just plain waffle about anything . The question was ,I thought plain enough and I would have thought those with FIRST HAND information would have either told me yes it is possible this is what I did ,OR no this is what we have and it’s not possible under the current rules. I thank those of you that did enter the conversation in the spirit it was intended and ask those of you that didn’t to consider the worth of what you said in light of the original question. We seem to be discussing DOGS now so as far as I am concerned this topic is now closed 

You also don't seem to have understood the answers which apply to all four cylinder engines including Jabiru.

[Flightrite]

Paul whilst I somewhat understand your frustration there one has to remember that this is a public forum where anyone who is a member can reply. ALL threads on many forums tend to wander off on a tangent especially when there is little actual/factual info that can be added after the first few replies, see it all the time on numerous forums I visit from time to time. Like I've alluded to before if there was 'free' HP that could be extracted Mr Jab would have done it, as they say there's no such thing as a free lunch:-) I operate 8 Jab cylinders & accept the power output as final, and I sleep well at night too:-):-)😉

[coljones]

7 hours ago, coljones said:

Tweed might not be a mathematical term but it is an engineering term.

Effing spellcheck

[APenNameAndThatA]

On 19/05/2021 at 11:12 PM, Paul davenport said:

So I take it none of you have actually tried any of this on a JABIRU. Engine and at best it’s speculation . My initial question stands what can be done to tweak without modifying to make it more efficient and possibly gain some free hp 

Do you want your money back? 

[APenNameAndThatA]

On 12/06/2021 at 1:42 PM, Paul davenport said:

All good information and I take your point about attention to detail and your Cummins referral but I caution you about wandering away from my initial question and remind you I asked about Jabiru and nothing else and would ask you keep to ONLY Jabiru

😆

[APenNameAndThatA]

55 minutes ago, Paul davenport said:

No Flightrite I am not angry, but I am disappointed that so often these discussions deteriorate from what was a reasonable question to just plain waffle about anything . The question was ,I thought plain enough and I would have thought those with FIRST HAND information would have either told me yes it is possible this is what I did ,OR no this is what we have and it’s not possible under the current rules. I thank those of you that did enter the conversation in the spirit it was intended and ask those of you that didn’t to consider the worth of what you said in light of the original question. We seem to be discussing DOGS now so as far as I am concerned this topic is now closed 

OME have you appropriated *another* account? 😧

[APenNameAndThatA]

1 hour ago, Paul davenport said:

No Flightrite I am not angry, but I am disappointed that so often these discussions deteriorate from what was a reasonable question to just plain waffle about anything . The question was ,I thought plain enough and I would have thought those with FIRST HAND information would have either told me yes it is possible this is what I did ,OR no this is what we have and it’s not possible under the current rules. I thank those of you that did enter the conversation in the spirit it was intended and ask those of you that didn’t to consider the worth of what you said in light of the original question. We seem to be discussing DOGS now so as far as I am concerned this topic is now closed 

To be honest, I have actually got my J230 to run faster and cooler. 

Edited August 15, 2021 by APenNameAndThatA

[Thruster88]

On 19/05/2021 at 6:41 PM, Thruster88 said:

More power always equals more heat, not what the jabiru needs.

I will stand by my comment.

[kgwilson]

I got considerably better performance from my Jabiru Gen 3 3000 engine by getting rid of the original wooden propellor which had disappointing performance from day 1. This is not a Jabiru prop but one supplied by my aircraft designer. Cruise was about 100 knots at 2850 rpm and climb although pretty good at 1000 fpm at 80 knots was not exceptional. I destroyed he first wooden prop in a test flight landing fxxxxup and the second was no better. Fast forward 2 years and I got a top of the range carbon fibre Bos-5 ground adjustable 2 blade prop from Bolly. Initially I set it fine & it climbed like a sick angel. At 75 knots I climbed at 16-1800 fpm but straight & level I could exceed max rpm (3300) and get around 120 knots.

 

A bit of fiddling changing it coarser each time I got it to where I like it and have not touched the pitch since then (October 2018). Now I climb out at 1200 fpm at 80 knots and cruise at 120 knots 2850rpm indicated at 4000 feet which is about 130 knots TAS. A side advantage of the Bos-5 is better cooling due to the torus curve on the last inboard 25mm of trailing edge of the prop forcing more air into the intake nacelles. This was the best $1700.00 I have spent on my aircraft since it was built.

 

Jabiru have their own composite prop made by Bolly and do not recommend any other props so for a 24 registered Jabiru you are limited. While the Jab composite prop is set to a pitch, it is adjustable like all bolly props.

[RFguy]

Interesting about the cooling  and the curve near the air intakes. 

 

Your performance figures are about same as with my 2013 jabiru composite prop. 

The Jabiru  wooden props suffer quite a bit of efficiency loss due to deformation, they're just not as stiff... 

[APenNameAndThatA]

2 hours ago, Thruster88 said:

I will stand by my comment.

Richer mixture, less friction, cooler oil, better air ducting in AND out. Worked for me. Theoretically, heat lost from oil cooling can contribute to thrust. 

[RFguy]

I explore this in some depth :

 

 

[Flightrite]

The best way to improve perf is thru airframe improvements, DRAG is our enemy! You can F&ck around with the donk till the cows come home as long as it runs within it's designed parameters then look elsewhere !