Topics

Post top end start up


Mick O'Connor
 

No exaggeration, engine started on 1/4 revolution of prop !
Idled at 1200 rpm like a sewing machine. Ran until CHTs were over 100 deg C then shut down.
No leaks and then removed valve covers to check oil flow. Surprised no. 1 and 2 very little oil but 3 & 4 lots.
Engine sits slightly low at the rear, so maybe gravity ?
Will investigate, but can confirm oil feed from T piece into heads clear.
Compressions equal and extremely strong on all cylinders on pull through.
Mick


Mark Dunstone
 

Mick, looks like you’ve got it back together.  A couple questions about your top end overhaul.  Did you buy the top end overhaul kit from Jabiru and replace all parts they ‘mandate’ for cycle 1, ie. 1000hrs?  Did you have to modify tge crankshaft/flywheel joint by adding dowels and then replacing the flywheel with one with the steel ‘starfish’adapter etc.  I’m asking as I’m deciding whether to purchase a late  Gen3 with 1100 fault free hours from a flight school (leakdowns good but oil consumption increasing), or a Gen2 serial number around 1500 with less than 200 hours that has been sitting around for years on a hanger floor for a few dollars less.  The Gen3 is all up to date and well documented but requires a top end overhaul (a kit is a bit over $2000AUS), while the Gen2 will need quite a bit of work to get it OK.  Cheers, Mark


Mick O'Connor
 

Mark,
I only carried out the following:
Honed cylinders 
New rings
New valves, double springs washers and collets
New through bolts, ARP nuts and washers (washers ground to clear cylinder fillet)
New rocker bushes 
Reversed rocker shaft
All new O rings 
Flywheel fixing mod of steel spreader washer, longer bolts and Nordlok washers installed.
New dizzy caps and rotor arms
Cylinders, pistons and valve guides  all measured and well within spec. and in excellent condition.

I did not change everything mandated by Jabiru e.g. conrod bearings. I’d be very surprised if anyone follows every single part mandated in the manual.

I bought all the parts direct from Jabiru.

FWIW I’d go for the solid lifter engine, as long as it had no corrosion. I put a solid lifter engine back into service that had 120hrs TT and had been standing idle for 9 years in a dry hangar. Honed cylinders, new rings and new exhaust valves. Still going strong after 200 hours.

Mick


On 16 Mar 2021, at 00:42, Mark Dunstone <mark.dunstone@...> wrote:

Mick, looks like you’ve got it back together.  A couple questions about your top end overhaul.  Did you buy the top end overhaul kit from Jabiru and replace all parts they ‘mandate’ for cycle 1, ie. 1000hrs?  Did you have to modify tge crankshaft/flywheel joint by adding dowels and then replacing the flywheel with one with the steel ‘starfish’adapter etc.  I’m asking as I’m deciding whether to purchase a late  Gen3 with 1100 fault free hours from a flight school (leakdowns good but oil consumption increasing), or a Gen2 serial number around 1500 with less than 200 hours that has been sitting around for years on a hanger floor for a few dollars less.  The Gen3 is all up to date and well documented but requires a top end overhaul (a kit is a bit over $2000AUS), while the Gen2 will need quite a bit of work to get it OK.  Cheers, Mark


Ron Milan
 

Mick/Others: For those of you that have run solid lifter engines and other hydraulic lifter engines on the same air-frame---was there any noticeable power increase/decrease? 
 I remember watching a video interview of Pete Krotje made with "Dan Johnson," sometime ago, where "Pete" touted an increase in power output with the hydraulic roller tappet versions of the "Gen-3" engines.  I have also heard claims where the older solid lifter engines made more power than the hydraulic lifter successors.
Some folks feel that the newest Gen-4 hydraulic roller tappet engines make the most power and idle the smoothest?

Questing feedback from folks that have been there and done that with their own personal experience(s).

Ron M




-----Original Message-----
From: Mick O'Connor via groups.io <mickoconnor909@...>
To: main@jabcamit.groups.io
Sent: Tue, Mar 16, 2021 4:39 am
Subject: Re: [JabCamit] Post top end start up

Mark,
I only carried out the following:
Honed cylinders 
New rings
New valves, double springs washers and collets
New through bolts, ARP nuts and washers (washers ground to clear cylinder fillet)
New rocker bushes 
Reversed rocker shaft
All new O rings 
Flywheel fixing mod of steel spreader washer, longer bolts and Nordlok washers installed.
New dizzy caps and rotor arms
Cylinders, pistons and valve guides  all measured and well within spec. and in excellent condition.

I did not change everything mandated by Jabiru e.g. conrod bearings. I’d be very surprised if anyone follows every single part mandated in the manual.

I bought all the parts direct from Jabiru.

FWIW I’d go for the solid lifter engine, as long as it had no corrosion. I put a solid lifter engine back into service that had 120hrs TT and had been standing idle for 9 years in a dry hangar. Honed cylinders, new rings and new exhaust valves. Still going strong after 200 hours.

Mick


On 16 Mar 2021, at 00:42, Mark Dunstone <mark.dunstone@...> wrote:

Mick, looks like you’ve got it back together.  A couple questions about your top end overhaul.  Did you buy the top end overhaul kit from Jabiru and replace all parts they ‘mandate’ for cycle 1, ie. 1000hrs?  Did you have to modify tge crankshaft/flywheel joint by adding dowels and then replacing the flywheel with one with the steel ‘starfish’adapter etc.  I’m asking as I’m deciding whether to purchase a late  Gen3 with 1100 fault free hours from a flight school (leakdowns good but oil consumption increasing), or a Gen2 serial number around 1500 with less than 200 hours that has been sitting around for years on a hanger floor for a few dollars less.  The Gen3 is all up to date and well documented but requires a top end overhaul (a kit is a bit over $2000AUS), while the Gen2 will need quite a bit of work to get it OK.  Cheers, Mark


John Miller
 

Mark

A friend and I both had Gen 3 engines that sucked exhaust valves shortly after 1100 hours so I recommend you change all the exhaust valves.

John M


John Miller
 

Mick

Did you measure the guides with a go/no go or ball gauge? Big difference between the two.

John M


Mick O'Connor
 

John,
I’ve changed all 8 valves, springs, washers and collets 

Mick

On 16 Mar 2021, at 14:28, John Miller via groups.io <skypics234@...> wrote:

Mark

A friend and I both had Gen 3 engines that sucked exhaust valves shortly after 1100 hours so I recommend you change all the exhaust valves.

John M


Mick O'Connor
 

John,
Go/no go gauge. My expert engineer who CNC manufactures guides said mine were in very good condition and within spec. Manual actually says it is rare for guides to need changing at 1000hr top end.

On 16 Mar 2021, at 14:30, John Miller via groups.io <skypics234@...> wrote:

Mick

Did you measure the guides with a go/no go or ball gauge? Big difference between the two.

John M


David Amsler
 

Converted my Hydraulic lifter Jab 3300 to solid using CAMit's drop in lifter conversion kit.  Power output based on static runup before and after, increased about 15%, and was about same as my Camit 3300 that was installed later.

David A.

On Tue, Mar 16, 2021 at 7:20 AM Ron Milan via groups.io <ronmilan=verizon.net@groups.io> wrote:
Mick/Others: For those of you that have run solid lifter engines and other hydraulic lifter engines on the same air-frame---was there any noticeable power increase/decrease? 
 I remember watching a video interview of Pete Krotje made with "Dan Johnson," sometime ago, where "Pete" touted an increase in power output with the hydraulic roller tappet versions of the "Gen-3" engines.  I have also heard claims where the older solid lifter engines made more power than the hydraulic lifter successors.
Some folks feel that the newest Gen-4 hydraulic roller tappet engines make the most power and idle the smoothest?

Questing feedback from folks that have been there and done that with their own personal experience(s).

Ron M




-----Original Message-----
From: Mick O'Connor via groups.io <mickoconnor909=btinternet.com@groups.io>
To: main@jabcamit.groups.io
Sent: Tue, Mar 16, 2021 4:39 am
Subject: Re: [JabCamit] Post top end start up

Mark,
I only carried out the following:
Honed cylinders 
New rings
New valves, double springs washers and collets
New through bolts, ARP nuts and washers (washers ground to clear cylinder fillet)
New rocker bushes 
Reversed rocker shaft
All new O rings 
Flywheel fixing mod of steel spreader washer, longer bolts and Nordlok washers installed.
New dizzy caps and rotor arms
Cylinders, pistons and valve guides  all measured and well within spec. and in excellent condition.

I did not change everything mandated by Jabiru e.g. conrod bearings. I’d be very surprised if anyone follows every single part mandated in the manual.

I bought all the parts direct from Jabiru.

FWIW I’d go for the solid lifter engine, as long as it had no corrosion. I put a solid lifter engine back into service that had 120hrs TT and had been standing idle for 9 years in a dry hangar. Honed cylinders, new rings and new exhaust valves. Still going strong after 200 hours.

Mick


On 16 Mar 2021, at 00:42, Mark Dunstone <mark.dunstone@...> wrote:

Mick, looks like you’ve got it back together.  A couple questions about your top end overhaul.  Did you buy the top end overhaul kit from Jabiru and replace all parts they ‘mandate’ for cycle 1, ie. 1000hrs?  Did you have to modify tge crankshaft/flywheel joint by adding dowels and then replacing the flywheel with one with the steel ‘starfish’adapter etc.  I’m asking as I’m deciding whether to purchase a late  Gen3 with 1100 fault free hours from a flight school (leakdowns good but oil consumption increasing), or a Gen2 serial number around 1500 with less than 200 hours that has been sitting around for years on a hanger floor for a few dollars less.  The Gen3 is all up to date and well documented but requires a top end overhaul (a kit is a bit over $2000AUS), while the Gen2 will need quite a bit of work to get it OK.  Cheers, Mark


Jay Scheevel
 

I did the same conversion as David on my 3300, but never ran it prior to converting. I have both external oiling (original) and hollow push rod oiling (due to the conversion). I think the extra oiling is probably a good thing. I am very happy with the performance.

 

Jay

 

From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of David Amsler
Sent: Tuesday, March 16, 2021 1:15 PM
To: main@jabcamit.groups.io
Subject: Re: [JabCamit] Post top end start up

 

Converted my Hydraulic lifter Jab 3300 to solid using CAMit's drop in lifter conversion kit.  Power output based on static runup before and after, increased about 15%, and was about same as my Camit 3300 that was installed later.

 

David A.

 

On Tue, Mar 16, 2021 at 7:20 AM Ron Milan via groups.io <ronmilan=verizon.net@groups.io> wrote:

Mick/Others: For those of you that have run solid lifter engines and other hydraulic lifter engines on the same air-frame---was there any noticeable power increase/decrease? 

 I remember watching a video interview of Pete Krotje made with "Dan Johnson," sometime ago, where "Pete" touted an increase in power output with the hydraulic roller tappet versions of the "Gen-3" engines.  I have also heard claims where the older solid lifter engines made more power than the hydraulic lifter successors.

Some folks feel that the newest Gen-4 hydraulic roller tappet engines make the most power and idle the smoothest?

 

Questing feedback from folks that have been there and done that with their own personal experience(s).

 

Ron M

 

 

 

-----Original Message-----
From: Mick O'Connor via groups.io <mickoconnor909=btinternet.com@groups.io>
To: main@jabcamit.groups.io
Sent: Tue, Mar 16, 2021 4:39 am
Subject: Re: [JabCamit] Post top end start up

Mark,

I only carried out the following:

Honed cylinders 

New rings

New valves, double springs washers and collets

New through bolts, ARP nuts and washers (washers ground to clear cylinder fillet)

New rocker bushes 

Reversed rocker shaft

All new O rings 

Flywheel fixing mod of steel spreader washer, longer bolts and Nordlok washers installed.

New dizzy caps and rotor arms

Cylinders, pistons and valve guides  all measured and well within spec. and in excellent condition.

 

I did not change everything mandated by Jabiru e.g. conrod bearings. I’d be very surprised if anyone follows every single part mandated in the manual.

 

I bought all the parts direct from Jabiru.

 

FWIW I’d go for the solid lifter engine, as long as it had no corrosion. I put a solid lifter engine back into service that had 120hrs TT and had been standing idle for 9 years in a dry hangar. Honed cylinders, new rings and new exhaust valves. Still going strong after 200 hours.

 

Mick

 


On 16 Mar 2021, at 00:42, Mark Dunstone <mark.dunstone@...> wrote:

Mick, looks like you’ve got it back together.  A couple questions about your top end overhaul.  Did you buy the top end overhaul kit from Jabiru and replace all parts they ‘mandate’ for cycle 1, ie. 1000hrs?  Did you have to modify tge crankshaft/flywheel joint by adding dowels and then replacing the flywheel with one with the steel ‘starfish’adapter etc.  I’m asking as I’m deciding whether to purchase a late  Gen3 with 1100 fault free hours from a flight school (leakdowns good but oil consumption increasing), or a Gen2 serial number around 1500 with less than 200 hours that has been sitting around for years on a hanger floor for a few dollars less.  The Gen3 is all up to date and well documented but requires a top end overhaul (a kit is a bit over $2000AUS), while the Gen2 will need quite a bit of work to get it OK.  Cheers, Mark


Mark Dunstone
 

Thanks Mick for the detailed reply.  The steel spreader flywheel modification....is that a UK thing?  Jab here in Australia recommend the new ‘starfish’ flywheel complete, but that requires a new alternator stator as well, and drilling out the crankshaft to a fine tolerance which I’m not that keen on doing.

John, the metallurgists’ technical report on the valve failures in the UK (a copy is in the files section) make it clear that going beyond 1000hours is risky as the exhaust valves reach the end of their life due to fatigue a bit after that, or before if EGTs exceed 750C.....a bit like us I suppose after 3 score and 10 years of life.  I guess your and your friends experience pretty much confirms that metallurgists findings.  That report has some great pics of annular cracks around the neck of exhaust valves that precede the valve head coming off.

I’m a bit biased to internal oil feed motors, and already have a 2200 roller cam Gen3 in a Cygnet with 200hrs on it.  Ron, it will idle smoothly down to 500rpm, but if the oil is hot at that rpm the oil pressure drops to about 5psi.  It needs to idle at 900 to keep oil pressure to 10psi.  And I’m not fussed about power.....anything over 50hp is surplus, and lots can be achieved performance wise by tossing unnecessary junk overboard (including pilot weight reduction) and a drag reduction campaign.  If one wants more power just add a couple more cylinders. The vibe here is that the roller cam makes no material difference compared to the plain hydraulic motor......the 7/16 through bolts, piston change and valve springs ‘fixed’ the issues with the hydraulic lifter motors....at least that is what flying school maintenance guys tell me, though they are moving to Gen4 motors rather than overhauling existing motors.  Old guy tinkerers still prefer the solid lifter ones.


Mick O'Connor
 

Mark,
I’m not sure of the history but it has been approved by the UK LAA.
I’m sure my friend got his spreader washer and Nordloks from Jab Australia, I’ll check 

Mick

On 16 Mar 2021, at 21:39, Mark Dunstone <mark.dunstone@...> wrote:

Thanks Mick for the detailed reply.  The steel spreader flywheel modification....is that a UK thing?  Jab here in Australia recommend the new ‘starfish’ flywheel complete, but that requires a new alternator stator as well, and drilling out the crankshaft to a fine tolerance which I’m not that keen on doing.

John, the metallurgists’ technical report on the valve failures in the UK (a copy is in the files section) make it clear that going beyond 1000hours is risky as the exhaust valves reach the end of their life due to fatigue a bit after that, or before if EGTs exceed 750C.....a bit like us I suppose after 3 score and 10 years of life.  I guess your and your friends experience pretty much confirms that metallurgists findings.  That report has some great pics of annular cracks around the neck of exhaust valves that precede the valve head coming off.

I’m a bit biased to internal oil feed motors, and already have a 2200 roller cam Gen3 in a Cygnet with 200hrs on it.  Ron, it will idle smoothly down to 500rpm, but if the oil is hot at that rpm the oil pressure drops to about 5psi.  It needs to idle at 900 to keep oil pressure to 10psi.  And I’m not fussed about power.....anything over 50hp is surplus, and lots can be achieved performance wise by tossing unnecessary junk overboard (including pilot weight reduction) and a drag reduction campaign.  If one wants more power just add a couple more cylinders. The vibe here is that the roller cam makes no material difference compared to the plain hydraulic motor......the 7/16 through bolts, piston change and valve springs ‘fixed’ the issues with the hydraulic lifter motors....at least that is what flying school maintenance guys tell me, though they are moving to Gen4 motors rather than overhauling existing motors.  Old guy tinkerers still prefer the solid lifter ones.


Ron Milan
 

Mark:  Thanks for the reply and the included information.  At 142 lbs (64.5 Kg for the folks that need this conversion) I cannot afford to be too much lighter myself.  My SONEX (conventional gear) is a rather clean air frame with only small "drag" gains left to tidy up.  I already have the two extra cylinders (3300A) and the total mass of the plane, me and fuel is <900 lbs (<409 KG) when I am flying alone which is most of the time.  
there is not much 'unnecessary junk" to toss overboard! 

I figure that at 10.2 gallons/hour (take off climb out fuel burn) that equals ~122 hp at 1/2 lb fuel/hp/hour.  I usually cruise (my economy cruise) at ~145  miles per hour consuming ~ 5.0-5.2 gallons of fuel /hour (pending temperature and plane load).  At some point I want to make some ignition system and induction system upgrades but for now----this is my current data. 

Ron M


-----Original Message-----
From: Mark Dunstone <mark.dunstone@...>
To: main@jabcamit.groups.io
Sent: Tue, Mar 16, 2021 5:39 pm
Subject: Re: [JabCamit] Post top end start up

Thanks Mick for the detailed reply.  The steel spreader flywheel modification....is that a UK thing?  Jab here in Australia recommend the new ‘starfish’ flywheel complete, but that requires a new alternator stator as well, and drilling out the crankshaft to a fine tolerance which I’m not that keen on doing.

John, the metallurgists’ technical report on the valve failures in the UK (a copy is in the files section) make it clear that going beyond 1000hours is risky as the exhaust valves reach the end of their life due to fatigue a bit after that, or before if EGTs exceed 750C.....a bit like us I suppose after 3 score and 10 years of life.  I guess your and your friends experience pretty much confirms that metallurgists findings.  That report has some great pics of annular cracks around the neck of exhaust valves that precede the valve head coming off.

I’m a bit biased to internal oil feed motors, and already have a 2200 roller cam Gen3 in a Cygnet with 200hrs on it.  Ron, it will idle smoothly down to 500rpm, but if the oil is hot at that rpm the oil pressure drops to about 5psi.  It needs to idle at 900 to keep oil pressure to 10psi.  And I’m not fussed about power.....anything over 50hp is surplus, and lots can be achieved performance wise by tossing unnecessary junk overboard (including pilot weight reduction) and a drag reduction campaign.  If one wants more power just add a couple more cylinders. The vibe here is that the roller cam makes no material difference compared to the plain hydraulic motor......the 7/16 through bolts, piston change and valve springs ‘fixed’ the issues with the hydraulic lifter motors....at least that is what flying school maintenance guys tell me, though they are moving to Gen4 motors rather than overhauling existing motors.  Old guy tinkerers still prefer the solid lifter ones.


John Miller
 

Mick

On my Gen 3 I looked for carbon trails from under the exhaust valve spring. After spotting the carbon trail I pulled the valve and found the valve guide worn. They didn't wear concentrically, but in an oval shape which could only be detected using a ball gauge sometimes called small hole gage. I had my guides relined on two of my engines.

The go/no go only works if the wear is concentric.

My friend an I though that since our engines were running so well at 1000 hours we would shoot for 1500 hours. Rotax started out with 1200 TBO then 1500 and finally 2000 hours TBO. Of course, Rotax still has issues with early failures of the gearbox and sprague clutch.

Both of us had a sucked exhaust valve head shortly after the 1100 hour mark. Broke the piston and bent the rod.

John M