Date   

Re: Johns new Gen 4

Pete Twissell
 

I had similar comments about my Jab, subjectively quieter than the Rotax 912 and Lycoming engines.
I can understand it being quieter than the Rotax engines, which are geared and run at higher rpm, but I can only think that it's the prop that makes the difference to the Lycomings.

On Wed, 24 Feb 2021, 14:59 John Miller via groups.io, <skypics234=aol.com@groups.io> wrote:
Forgot to mention...

The pilots at my airport say that this warranty replacement engine runs much quieter that the one that died. Also my Jabiru is the quietest engine on the field.

Don't know what to make of these observations.

Maybe the dead engine had a loose rod connection???

John M


Re: Johns new Gen 4

Jay Scheevel
 

That’s what I was thinking, John (the bad rod connection, not the quiet…although your old engine went very quiet at the end..)

 

Jay

 

From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of John Miller via groups.io
Sent: Wednesday, February 24, 2021 7:59 AM
To: main@JabCamit.groups.io
Subject: Re: [JabCamit] Johns new Gen 4

 

Forgot to mention...

The pilots at my airport say that this warranty replacement engine runs much quieter that the one that died. Also my Jabiru is the quietest engine on the field.

Don't know what to make of these observations.

Maybe the dead engine had a loose rod connection???

John M


Re: Johns new Gen 4

John Miller
 

Forgot to mention...

The pilots at my airport say that this warranty replacement engine runs much quieter that the one that died. Also my Jabiru is the quietest engine on the field.

Don't know what to make of these observations.

Maybe the dead engine had a loose rod connection???

John M


Re: Johns new Gen 4

John Miller
 

WOW! I need to proof read my messages better.

Where is the edit function?

John M


Re: Inlet pipe couplers

John Miller
 

Have not had an issue with the coupler hoses on the 4 2200s I've owned.

John M


Re: Inlet pipe couplers

Mick O'Connor
 

If you go down the silicone hose route, make sure you use a hose that has a ‘flouro’ lining. Standard silicone hose is not fuel/oil resistant.

Ref your comment on a inlet pipe sealing, I’m not aware of any failure of this item, are you ? My inlet tubes were still 100% sealed when I dismantled them after 15 years and 850hrs
“If it ain’t broke........”

Mick

On 23 Feb 2021, at 15:45, Jay Scheevel <jay@scheevel.com> wrote:

I am also curious about this hose type. I will add to the request.

I am also wondering why Jabiru uses a brittle sealant to seal the base of
the inlet pipe where it fits into the manifold. It seems like this is an
invitation to a leak. Would it make more sense to seal with a silicone
sealant or similar, like Loctite 510.

Jay

-----Original Message-----
From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of Mick
O'Connor via groups.io
Sent: Tuesday, February 23, 2021 4:07 AM
To: JabCamit <main@jabcamit.groups.io>
Subject: [JabCamit] Inlet pipe couplers

Anyone used fuel resistant silicone hose for the couplers ?
If not, is it just standard A1/A2 32mm fuel hose ?

Mick











Re: Prop, flywheel bolts

Mick O'Connor
 

I’d want confirmation that those cap screws are the correct spec.
Mick

On 23 Feb 2021, at 15:41, Jay Scheevel <jay@...> wrote:

Sorry, wrong page. Try this:

https://www.mscdirect.com/browse/tn/Socket-Cap-Screws?searchterm=Unbrako&navid=12108780+4294688016#navid=12108780+4294688016+4287782255+4287879299+4287781649&searchterm=Unbrako

 

 

From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of Mick O'Connor via groups.io
Sent: Saturday, February 20, 2021 2:27 AM
To: main@jabcamit.groups.io
Subject: Re: [JabCamit] Prop, flywheel bolts

 

Jay,

Your link leads to #10-32 screws ?

They are very small and not flywheel type


On 19 Feb 2021, at 23:19, Jay Scheevel <jay@...> wrote:

Went back and checked a past order that I made. I had to buy a box of 100 (genuine Unbrako), but the price was not bad from this outfit.

 

https://www.mscdirect.com/product/details/67802488

 

Jay

 

 

 

From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of Steve Rance via groups.io
Sent: Friday, February 19, 2021 2:13 PM
To: main@jabcamit.groups.io
Subject: [JabCamit] Prop, flywheel bolts

 

Several years ago I was asked to remove the broken studs in the 2200 crankshaft, the prop departed on climb out. Aircraft fortunatly was high enough to turn round and land back on runway. What happened was the owner had put longer bolts in after fitting a supplied spacer behind the prop hub, the bolts bottomed out at the same time as lightly gripping the prop. Always check thread depth by inserting all bolts and measuring there is sufficient grip of at least 2 -3 full turns before bottoming out.

I have done several flywheels and prop hubs in the meantime and also found it impossible to find Unbrako UNF cap screws. All the big suppliers want to sell you a large expensive box which has to be specially ordered. That aside having done several flywheels and prop hubs in only one case found bolts marked UNB, presumably for Unbrako and that was an early engine. All of the subsequent 3/8” Bolts were marked YFS or TMS of origin unknown, so I assume the manufacturers by buying elsewhere are saving money or Unbrako supplies unavailable, another problem is stocks of Unified screws are drying up and only metric fasteners are readily available in UK.

 I have had an old box for years of Unbrako screws (wrong size) marked with the usual approvals and made in Brazil so they can be made anywhere to keep costs down.

Reminds me years ago we had a new Mill delivered at our works, we were having a quiet break when there was a loud crack like a gunshot, it took a while but it came from a M16 capscrew that let go off the milling machine bearing flange, snapped right under the head, it was unplated but clearly flawed.

 

Steve

 

Sent from Mail for Windows 10

 


Re: Inlet pipe couplers

Mick O'Connor
 

I’ve ordered a length 32mm ID silicone hose suitable for fuel & oil.
Mick

On 23 Feb 2021, at 15:45, Jay Scheevel <jay@scheevel.com> wrote:

I am also curious about this hose type. I will add to the request.

I am also wondering why Jabiru uses a brittle sealant to seal the base of
the inlet pipe where it fits into the manifold. It seems like this is an
invitation to a leak. Would it make more sense to seal with a silicone
sealant or similar, like Loctite 510.

Jay

-----Original Message-----
From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of Mick
O'Connor via groups.io
Sent: Tuesday, February 23, 2021 4:07 AM
To: JabCamit <main@jabcamit.groups.io>
Subject: [JabCamit] Inlet pipe couplers

Anyone used fuel resistant silicone hose for the couplers ?
If not, is it just standard A1/A2 32mm fuel hose ?

Mick











Re: Inlet pipe couplers

Jay Scheevel
 

I am also curious about this hose type. I will add to the request.

I am also wondering why Jabiru uses a brittle sealant to seal the base of
the inlet pipe where it fits into the manifold. It seems like this is an
invitation to a leak. Would it make more sense to seal with a silicone
sealant or similar, like Loctite 510.

Jay

-----Original Message-----
From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of Mick
O'Connor via groups.io
Sent: Tuesday, February 23, 2021 4:07 AM
To: JabCamit <main@jabcamit.groups.io>
Subject: [JabCamit] Inlet pipe couplers

Anyone used fuel resistant silicone hose for the couplers ?
If not, is it just standard A1/A2 32mm fuel hose ?

Mick


Re: Prop, flywheel bolts

Jay Scheevel
 

From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of Mick O'Connor via groups.io
Sent: Saturday, February 20, 2021 2:27 AM
To: main@jabcamit.groups.io
Subject: Re: [JabCamit] Prop, flywheel bolts

 

Jay,

Your link leads to #10-32 screws ?

They are very small and not flywheel type


On 19 Feb 2021, at 23:19, Jay Scheevel <jay@...> wrote:

Went back and checked a past order that I made. I had to buy a box of 100 (genuine Unbrako), but the price was not bad from this outfit.

 

https://www.mscdirect.com/product/details/67802488

 

Jay

 

 

 

From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of Steve Rance via groups.io
Sent: Friday, February 19, 2021 2:13 PM
To: main@jabcamit.groups.io
Subject: [JabCamit] Prop, flywheel bolts

 

Several years ago I was asked to remove the broken studs in the 2200 crankshaft, the prop departed on climb out. Aircraft fortunatly was high enough to turn round and land back on runway. What happened was the owner had put longer bolts in after fitting a supplied spacer behind the prop hub, the bolts bottomed out at the same time as lightly gripping the prop. Always check thread depth by inserting all bolts and measuring there is sufficient grip of at least 2 -3 full turns before bottoming out.

I have done several flywheels and prop hubs in the meantime and also found it impossible to find Unbrako UNF cap screws. All the big suppliers want to sell you a large expensive box which has to be specially ordered. That aside having done several flywheels and prop hubs in only one case found bolts marked UNB, presumably for Unbrako and that was an early engine. All of the subsequent 3/8” Bolts were marked YFS or TMS of origin unknown, so I assume the manufacturers by buying elsewhere are saving money or Unbrako supplies unavailable, another problem is stocks of Unified screws are drying up and only metric fasteners are readily available in UK.

 I have had an old box for years of Unbrako screws (wrong size) marked with the usual approvals and made in Brazil so they can be made anywhere to keep costs down.

Reminds me years ago we had a new Mill delivered at our works, we were having a quiet break when there was a loud crack like a gunshot, it took a while but it came from a M16 capscrew that let go off the milling machine bearing flange, snapped right under the head, it was unplated but clearly flawed.

 

Steve

 

Sent from Mail for Windows 10

 


Re: Johns new Gen 4

John Miller
 

Regarding my warranty replaced Gen 4 2200:

Now that OATs are up here in SoCal oil temp are finally above 170 F. 

When it was cooler and oil didn't get higher than 150 F I would check the bottle at the end of y air/oil breather line and found no oil. However, now that the temps are oats are up I checked the bottle and found only water. No oil, so it is working very well.

John M


Inlet pipe couplers

Mick O'Connor
 

Anyone used fuel resistant silicone hose for the couplers ?
If not, is it just standard A1/A2 32mm fuel hose ?

Mick


Re: Flywheel cap screws

Mick O'Connor
 

Bob,
I am using X series Nordloks with 12.9 spec cap screws as per Jabiru instructions .

Mick


Re: Flywheel cap screws

Jay Scheevel
 

Hi Bob,

 

Keep in mind that the Belleville washer is a spring with a spring constant that is likely much lower than the spring constant of the bolt itself. Since this is the case, the Belleville washer will be completely flat by the time the bolt is tightened to the required preloading. Once flat, the Belleville washer does not act differently than a flat washer. If the bolt were loose enough for the Belleville spring to come into play, it would already be too loose.

 

Jay

 

From: main@JabCamit.groups.io <main@JabCamit.groups.io> On Behalf Of jabcamit@...
Sent: Monday, February 22, 2021 3:01 PM
To: main@JabCamit.groups.io
Subject: Re: [JabCamit] Flywheel cap screws

 

Hi Mick, this doesn't answer your question either, but are your Nordlocs X type?  if not for a given torque  the HIGHER the tensile rating of the bolts, the SOONER  your flywheel will fall off.

If you have X series Norlocs the Belleville feature within the washer will maintain the tension when the joint settles (as well as preventing the bolt from unscrewing and allowing torque checking and re-torquing.

BobP


Re: Flywheel cap screws

jabcamit@...
 

Hi Mick, this doesn't answer your question either, but are your Nordlocs X type?  if not for a given torque  the HIGHER the tensile rating of the bolts, the SOONER  your flywheel will fall off.

If you have X series Norlocs the Belleville feature within the washer will maintain the tension when the joint settles (as well as preventing the bolt from unscrewing and allowing torque checking and re-torquing.

BobP


Re: Flywheel cap screws

Mick O'Connor
 

They are the ones !

Mick

On 21 Feb 2021, at 16:56, (null) (null) via groups.io <randyfrise@...> wrote:

I have a box with about 80 pieces left of 5/16-24 UNF x2" 1960 series unbrako socket head cap screws. ASME B18.3, ASTM A574.   I cut them to length for my needs.  I am in Canada and i am willing to ship some, if somebody is stuck.


Re: Flywheel cap screws

(null) (null)
 

I have a box with about 80 pieces left of 5/16-24 UNF x2" 1960 series unbrako socket head cap screws. ASME B18.3, ASTM A574.   I cut them to length for my needs.  I am in Canada and i am willing to ship some, if somebody is stuck.


Re: Flywheel cap screws

Mick O'Connor
 

Clive,
Spot on !
All I asked was, if fitting the spreader plate/washer and Nordloks mod, was it OK to have a cap head screw with a shank and whether it was OK to have a longer thread into the crank shaft
 !
Mick

On 20 Feb 2021, at 16:35, Clive James via groups.io <zcrj90@...> wrote:

Re-living the flywheel bolts discussion again.....the forum is a like a roundabout.....
;-))


Re: Flywheel cap screws

Clive James
 

Re-living the flywheel bolts discussion again.....the forum is a like a roundabout.....
;-))


Re: Flywheel cap screws

Ken MacLeod
 

FWIW I have installed ARP 12 points with Nordlock X series washers. No interference between nordlocks ( close though) or ARP bolt heads. I’m not a Mech Eng. but the the equal pressure ( compression) on the washers and compression ring makes sense to me. More than the cap screw thin overlap on the washer.

On Saturday, February 20, 2021, 9:27 AM, Mick O'Connor via groups.io <mickoconnor909@...> wrote:

Ken,
Looks like ARP do not offer socket head screws, only 6 or 12 pt bolts.
I know someone who used ARP 12pt bolts for the flywheel, they onlybfitted because he had a belt driven alternator, so plenty of room for the bigger head compared to a socket head screw.
Mick 

On 20 Feb 2021, at 14:13, Ken MacLeod <kmacleod777@...> wrote:

ARP manufacture high quality bolts. They are available from several reliable sources: Jegs or Summit racing.

Ken


Sent from Rogers Yahoo Mail for iPad

On Saturday, February 20, 2021, 8:32 AM, Pete Twissell <petetwizz@...> wrote:

Indeed so Ron.
Buyer beware!

On Sat, 20 Feb 2021, 12:17 Ron Milan via groups.io, <ronmilan=verizon.net@groups.io> wrote:
Pete:  My understanding of the rational of purchasing AN fasteners in addition to an almost infinite incremental selection of grip lengths, is that the credibility of the fastener can be traced.  Quality assured ???  Although one would want to believe that branded fasteners Unbrako, rather  "uMbrako" as you refer to---, SHOULD be a consistent high quality fastener.  After all, many folks rely on said fasteners to protect their life and limb.

Integrity cannot be substituted and is not always universal in our word today!.

Ron M

-----Original Message-----
From: Pete Twissell <petetwizz@...>
To: main@jabcamit.groups.io
Sent: Sat, Feb 20, 2021 6:52 am
Subject: Re: [JabCamit] Flywheel cap screws

It is worth noting that the strengths indicated by bolt grades are minimums, and that there are a lot of very dodgy manufacturers who will mark bolts as whatever they want to sell, regardless of properties.
At work, we once bought a batch of "Unbrako" bolts. After some failures and an investigation, it turned out they were marked "uMbrako" (my capitalisation) and they were fakes.


On Sat, 20 Feb 2021, 11:46 Mark Dunstone, <mark.dunstone@...> wrote:
Yes, to all that.  My experience with propellor bolt breakage:   I had 8.8 MPa ‘high tensile bolts’, and perhaps they were, but they were also very brittle.  After around 150 hours 4 broke in flight, necessitating an out landing in a rape seed paddock. With a wood prop these bolts are not torqued much at all.   Changed to 3,2Mpa bolts which easily handle the minimal torque, but are malleable rather than brittle, and the problem was solved..at least for the next 600  hours when the VW conversion was replaced with a Jabiru.  When investigating this (after the out landing) I noticed I could have purchased 8.8MPa bolts that could be bent and which weren’t brittle.

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