Did your Engine reach TBO?

[facthunter]

Cost of cyls etc.

 

Macnoz, that is a lot more than I would have hoped you would have to pay. You can replace the 4 cylinder barrell & head assemblies on a Cont. 0-200 for less than $4400 Aud. This includes pistons, rings gudgeons & all valves & valve springs fitted as well, and all this is certified. You have a 2400 Hr. TBO & probably get 800 hr on a "TOP". Pity you could not seal the corroded area without replacing the Cyls. What did you do about the corrosion on the crankcase face? Nev..

 

 

[Guest Macnoz]

GlennS

 

Maybe I’m doing something wrong in % or this “made in China calculator” I use is wrong but

 

Reality is the 2220 engine max continuous is 3300 rpm

 

To run it at 3050 rpm would be running it above 92% power

 

If 3050rpm is the recommended cruise and it represents 75% of total power then max continuous rpm capability of the 2200 engine is 4066 rpm and a new engine has come out that I was not aware of!

 

To run it not below 2950 rpm would be running it above 89%!

 

To run at 75% would be 2475 rpm

 

I run it at 2850 or 86% according to my Crazy Clark’s abacus

 

 

Maybe I should have gone to Narromine – gone to the forum and upgraded my engine just by listening!

 

 

Nev - to answer you question I did two things to the early signs or corrosion on the block

 

1. wet and dry

 

2. pray

 

I suppose the next stage would be liquid metal on the block

 

 

Aside I am told that the reason for the sudden increase in the price of the pistons is that the manufacturer / supplier only recently discovered that they were being used in aircraft engines ( what the heck they thought Jabiru were doing with them up to now beats me) and had to charge more for insurance / indemnity purpose.

 

 

Next question

 

Electrolysis?

 

Chemical reaction between the differing metals / alloys at the juncture?

 

Any takers

 

 

[glenns]

Isn't this always the joy? trying to decipher all the info! I just checked my flight manual and it states 75% power at 2800 rpm? (maybe I should have done that prior to the post :big_grin: )I can see from the detailed use of the calculator that this in fact is not 75%?

 

I am sure there were others at the maintaining your Jabiru session that would backup the recommended cruise statement from the speaker but then again maybe I didnt hear correctly. its certainly happened before

 

 

[Harthy]

I think when the % is calculated you have to take into account that RPM range is from 900 RPM (or what ever the recomended idle speed is) to 3300RPM, not 0 to 3300. So calculate 75% of 2400 which is RPM range, and add that to your 900 idle RPM and come up with your 75% power rating.

 

Hope this will help out.

 

Harthy

 

 

[vk3auu]

Macnoz, I think you forgot the square root in your calculation of the power with a propellor connected to the engine.

 

David

 

 

[Harthy]

David,

 

Have you got the formulae, it would be useful information to have.

 

Harthy

 

 

[Jabiru Phil]

Has anyone seen a power/efficiancy curve graph for these engines?

 

Maybe this would clear up the 75% query

 

Phil.

 

 

[glenns]

http://www.jabiru.net.au/4%20cylinderbodyFrame-1.htm

[Guest Ken deVos]

I am sure there were others at the maintaining your Jabiru session that would backup the recommended cruise statement from the speaker but then again maybe I didnt hear correctly. its certainly happened before

I was at the Jab session and can backup the cruise statement. The speaker also said you will destroy your 2200 if you cruise on 2600rpm. Funny, that's the setting I was told to use in all my flight training in the LSA55.

 

 

[Geoff]

Glenns you heard the man correctly 2950 to3000 and I must admit that is the sweet spot for our 2200. Has now reached 825 hrs. Fingers X ed ;)

 

 

[glenns]

Wow I am jealous. I only reached 550 . Mind you I probably could have pushed on but after 2 barrel bolts breaking on seperate occassions I went for the overhaul option :big_grin:

 

 

[facthunter]

Horsepower/ RPM.

 

Chaps, you have to refer to the Dynamometer curves to derive horsepower figures, but with the propeller application perhaps IT is the determinant.(being fixed pitch). It will certainly be a squared relationship, ie double the revs= 4 times the power.

 

Macnoz, there are standard metal preparation procedures for Aluminium alloys in aircraft assemblies (engines) and there would no doubt be an electrolysis possibility with the two dissimilar metals. This would be more significant in a salt laden environment. ie near the sea. Nev..

 

 

[Captain]

If that is correct my calculator says that for 75% power you need 86.6% of max revs, so for a 2200 with max 3300 rpm X .866 = 2858 rpm.

 

 

 

On my 3300, when cruising at 2850, all it needs is another 20 rpm for all 6 EGT's to come down to J's stated desired EGT range of 680 - 700 C.

 

 

 

I suggest that it is that slight drop in EGT that you are looking for to get the optimum cruise mixture.

 

 

 

[Guest J430]

Fans run on the cubed law.

 

the HP curve of the engine is different animal.....you need to verlay one curve on other.

 

Not sure anyone has them anyway!

 

J

 

 

[Captain]

Fans run on the cubed law.the HP curve of the engine is different animal.....you need to verlay one curve on other.

 

Not sure anyone has them anyway!

 

J

 

 

The power & torque curves are in the engine maintenance manuals on J's website, but I don't know how to copy them over here for further discussion.

 

 

 

I also note in the 2200 Manual that they specify 680 - 720 C for cruise EGT's

 

 

 

[jetboy]

Yep 75% power is not the rpm shown on the engine spec charts, with a prop load its entirely different. when I changed my prop the cruise spot for same airspeed, fuel flow and EGT moved from 2900 to 3050 rpm, 250 rpm off full power.

 

The Continental 0-200 manual has a useful table showing HP vs rpm and fuel flow for a propellor load. The difference between 100 hp and 75 hp is 200 rpm, that is 2750 - 2550 rpm, and thats how mine flew too. (after fitting new cyls and getting the timing and prop right)

 

Ralph

 

 

[Captain]

Yep 75% power is not the rpm shown on the engine spec charts,

My J Engine Manual states that 75% power at cruise with the 3300 engine is 2750 rpm, but haven't been able to locate that same line yet for the 2200 engine. Does anyone else have it from the J's documents?

 

 

[glenns]

I just checked my flight manual and it states 75% power at 2800 rpm

See above, this was taken from my original manual when I picked the aircraft up in 2006

 

 

[vk3auu]

Facthunter is pretty close to the truth as far as power versus revs is concerned. The graphs for a dynomometer don't really apply when you attach a propellor. Fuel flow is also a good indicator, provided the mixture is correct. 20 litres per hour is approximately equal to 70 HP, 15 liters equals just over 50 hp in a Jab or a 912, regardless of what the manufacturers might say.

 

David

 

 

[Yenn]

From my manual for the 2200 engine:-

 

3300 rpm 80 hp

 

3100rpm 77 approx

 

2900rpm 73 approx

 

2700rpm 69 approx

 

2500rpm 64 approx

 

It is not recommended to run at 2400rpm under power.

 

Torque peaks at about 2300rpm at about 134' lbs, falling to about 128' lbs at 3300rpm.

 

If anyone is interested I could photograph the chart and post it but the info is probably available on the Jab site.

 

 

[Guest dracer]

4000+ hours is a hell of alot for ANY internals!

 

 

[vk3auu]

Yenn, those figures look like they're off a dynamometer, not what you get with a propellor. Is that right?

 

David

 

 

[Guest J430]

Here is a tip, and I have made it before many times. Do not try to skimp on a couple of litres of fuel per hour.

 

I was talking to a guy yesterday who ran 1000 hours to top end TBO, and the valves were fine. Secret is, do not sit on 2800 RPM and just on the edge of the taper of the needle. The Jets of the economy kit are fine, so long as you do not run on the lean transition.

 

Ensure your tacho is correct, run closer to 2900, and if you have a fuel flow meter, make sure you know its error rate or if its accurate, and then fly in the cruie at 22-23LPH for a 6 cylinder or 14.5-15.5LPH for the 4 cyl, and its that simple.

 

Do not be too surprised if you find Jabiru release a bulletin shortly. I should check myself as they could well have.

 

Why do some go 1000 and like the valves I saw yesterday look like new, and others are stuffed in 300? Its the operator that is the biggest variable.

 

Fuel is the cheapest thing you will put in the damn thing so fly it without skimping because you will pay for it and pay dearly.

 

J:wave:

 

 

[Captain]

and then fly in the cruie at 22-23LPH for a 6 cylinder or 14.5-15.5LPH for the 4 cyl, and its that simple.J:wave:

J

 

 

 

What you are saying is spot-on, however I note on the Engine section glossy blue page of the J website for the 3300 they are saying 26 LPH at 75% power.

 

 

 

Also, based on J's Service Bulletin JSB 018-1 of 05.10.07 they specify in Table 4 titled "Allowable EGT Range" a Mid-Range/Cruise EGT Allowance of 680 - 720 C and a Preferred Target EGT of 680 C.

 

 

 

I believe that higher EGT's have a firm relationship (even direct but inverse) to valve life or valve stress.

 

 

 

That bulletin also mentions on P11 a fuel consumption of approx. 23 - 25 LPH for the 3300 @ 2850 rpm.

 

 

 

As mentioned a few posts ago in this thread, my 230 will drop all 6 EGT's below 700 C if it is run at about 20 RPM faster than the normal 2850 cruise and I believe that is just getting it off the step of the needle. By coincidence the Dynon shows a fuel flow at those temps of 26 LPH.

 

 

 

My engine is still pretty tight at 25 hrs.

 

 

 

I agree with you that good valve life and temps are way more important than an extra litre or two of fuel/hr.

 

 

 

Yet I spoke at length to several 230 owners at Natfly who are still quoting cruise fuel consumptions of 19 - 20 LPH. Such a fuel burn would worry the heck out of me.

 

 

 

[facthunter]

Power output.

 

RPM is but one element of the power equation. Without knowing the TORQUE being absorbed by the propeller, (which changes with density altitude , propeller condition & type, Airspeed etc.) you are almost nowhere. Fuel flow can be a pretty good indicator ( especially with jet engines but need altitude related charts. Engine mass airflow would be good too . all you would need to know with the bing carbs is the position of the dashpot slides. I agree that lean mixtures are the most likely culprit, which I have always stated, but there are some snake oil salesmen out there who suggest otherwise. Nev..