Jewell Aviation - Kennett MO PIREP

[daytonabch04]

On 6/26/2023 at 12:41 PM, billy hellcat said:

This is where GMAX has there engines overhauled.  FYI

I just had my engine overhauled by GMAX and it did not go to Jewell. 

[MikeOH]

4 hours ago, daytonabch04 said:

I just had my engine overhauled by GMAX and it did not go to Jewell. 

@daytonabch04

 

Where did it go for overhaul?

[201Steve]

5 hours ago, daytonabch04 said:

I just had my engine overhauled by GMAX and it did not go to Jewell. 

Great news. Maybe they have learned, as I did, whatever their reputation was built on ,is now a smoking hole in the ground. 

[EricJ]

6 hours ago, daytonabch04 said:

I just had my engine overhauled by GMAX and it did not go to Jewell. 

Where did they send it?   Was it because Jewell was busy or other reasons?   Were the results good?

[kortopates]

I am sure GMAX will send a customers engine out to overhaul anywhere the owner wishes - it’s just truck freight. But like Lance @lancecasper said earlier, if the work is to ready a plane for resale, different criteria applies in selecting a shop.


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[daytonabch04]

On 6/30/2023 at 6:03 PM, EricJ said:

Where did they send it?   Was it because Jewell was busy or other reasons?   Were the results good?

@MikeOH Mine went to Mena Aircraft Engines in Mena, AR.  Not sure why GMAX sent it there, but 27 hours in have had no issues and the engine is running butter smooth. It looks pretty too! 

[Bigdaddie]

On 6/29/2023 at 12:54 PM, neilpilot said:

Using your logic, why even overhaul. Just sell your core and buy new….

LyCon does some trick stuff such as porting and flow matching.  I had them do this on my LongEz O235 and it was good for 10-15HP increase.

[MikeOH]

1 hour ago, Bigdaddie said:

LyCon does some trick stuff such as porting and flow matching.  I had them do this on my LongEz O235 and it was good for 10-15HP increase.

Is porting/polishing legal for certified aircraft?  I didn't think so, but??

[EricJ]

1 minute ago, MikeOH said:

Is porting/polishing legal for certified aircraft?  I didn't think so, but??

They can be ported/polished to the limit of the certified spec, which sometimes just means removing flashing or rough spots.  Reports of benefits vary.

https://www.aviationconsumer.com/misc/trick-cylinders-porting-and-polishing/

 

[GeeBee]

Carlus Gann is the master of porting and polishing.

 

[201Steve]

I talked to Zephyr about port polish, from his perspective it’s a waste of time polishing a tractor engine only turning 2700 rpm. Not saying he’s right but, it’s not unreasonable logic. 

[kortopates]

46 minutes ago, 201Steve said:

I talked to Zephyr about port polish, from his perspective it’s a waste of time polishing a tractor engine only turning 2700 rpm. Not saying he’s right but, it’s not unreasonable logic. 

Well of course, they don't provide the service. For an objective answer read the article above provided by Eric.

[MikeOH]

3 hours ago, 201Steve said:

I talked to Zephyr about port polish, from his perspective it’s a waste of time polishing a tractor engine only turning 2700 rpm. Not saying he’s right but, it’s not unreasonable logic. 

Just an FYI: Charlie Melot sold Zephyr back in 2016.

[aviatoreb]

4 hours ago, GeeBee said:

Carlus Gann is the master of porting and polishing.

 

Does he do that kind of work on certified engines?

[GeeBee]

9 hours ago, aviatoreb said:

Does he do that kind of work on certified engines?

Yes, did it on my O-320 on my SuperCub. Yes, documented it in the log too.

 

 

[201Steve]

11 hours ago, MikeOH said:

Just an FYI: Charlie Melot sold Zephyr back in 2016.

His name is LJ, an understudy of Charlie who was able to take over. 

[KSMooniac]

What's funny/interesting is that some shops freely advertise porting & polishing and a power gain, while others will wink at you and say they cannot advertise such, and simply "remove casting flaws."  I think that varies by region and the associated FAA overlords that have different opinions around the country.  Kinda like the disclaimers on supplements you can buy. 

When I overhauled my IO-360, I had the shop working my cylinders do that service and flow-match all 4, along with precision balancing of all of the rotating parts.  After break-in and a dynamic prop balance, we were able to get my installation down to 0.01 IPS.  I believe all of the little things/attention to detail add up to a smooth-running engine that maximizes efficiency.  

[aviatoreb]

5 hours ago, GeeBee said:

Yes, did it on my O-320 on my SuperCub. Yes, documented it in the log too.

 

 

WOW!

...and how do you figure the performance of that engine?  Is it nice - do you notice?

I see he does a standard build and a performance build - are you describing his performance build?  Which seems to have better and flow balanced cylinders with better valve lapping and the better cam.

 

[GeeBee]

38 minutes ago, aviatoreb said:

WOW!

...and how do you figure the performance of that engine?  Is it nice - do you notice?

I see he does a standard build and a performance build - are you describing his performance build?  Which seems to have better and flow balanced cylinders with better valve lapping and the better cam.

 

He did not offer "performance build" at the time. It was basically "cafeteria" style upgrades. I did have the flow balanced cylinders as well as the mains doweled and pinned. It was a primo engine that turned 173 hp on dyno versus 160 hp rated. I had to re-pitch my prop to handle the power. 

[aviatoreb]

48 minutes ago, GeeBee said:

He did not offer "performance build" at the time. It was basically "cafeteria" style upgrades. I did have the flow balanced cylinders as well as the mains doweled and pinned. It was a primo engine that turned 173 hp on dyno versus 160 hp rated. I had to re-pitch my prop to handle the power. 

Wow - that's a lot of up power.  My 305hp would plausibly make 330hp if it had the same percentage increase.

I have already narrowed down my shopping list for best shops to be either power master or Gann.  So I am super interested in your feedback.

I keep thinking I will do it it imminently but my darn engine just keeps on truckin' with all systems go and all systems health monitoring tools showing a good engine even though I am at 1950hrs on a 1600 tbo.  But eventually....  So thanks for the feedback.

[GeeBee]

1 hour ago, aviatoreb said:

Wow - that's a lot of up power.  My 305hp would plausibly make 330hp if it had the same percentage increase.

I have already narrowed down my shopping list for best shops to be either power master or Gann.  So I am super interested in your feedback.

I keep thinking I will do it it imminently but my darn engine just keeps on truckin' with all systems go and all systems health monitoring tools showing a good engine even though I am at 1950hrs on a 1600 tbo.  But eventually....  So thanks for the feedback.

Carlus Gann is the engine guy for Elliott Racing. He does engines, and only engines. He is one of the few guys I know of who has a "P" but not an "A". He has forgot more than most people know about engines. He builds up each engine personally. 

[Fly Boomer]

6 hours ago, aviatoreb said:

My 305hp would plausibly make 330hp if it had the same percentage increase.

Factory rates the NB at 310HP @ 2700.  Other versions of the 520 are 325.  Geared, they go up to 375.  For some reason Rocket "de-rated" the NB to 305 -- possibly for structural reasons.

[aviatoreb]

2 minutes ago, Fly Boomer said:

Factory rates the NB at 310HP @ 2700.  Other versions of the 520 are 325.  Geared, they go up to 375.  For some reason Rocket "de-rated" the NB to 305 -- possibly for structural reasons.

I bet they did it in a negotiation process with the FAA as to what the FAA was wiling to certify.

but you may be right

that said...

would an engine that has become more efficient by porting and polishing or whatever reason that uprates 100% from say...305 to 330 at a given setting - in my engine that setting is 38'' and 2650 - (and at 310 I believe it would be 2700 - but my prop governor has been governed to not go there) - then would it be similarly more powerful at settings like say 65% of 305 (or of 330?).

[Fly Boomer]

2 minutes ago, aviatoreb said:

would an engine that has become more efficient by porting and polishing or whatever reason that uprates 100% from say...305 to 330 at a given setting - in my engine that setting is 38'' and 2650 - (and at 310 I believe it would be 2700 - but my prop governor has been governed to not go there) - then would it be similarly more powerful at settings like say 65% of 305 (or of 330?).

I suspect "similarly" is the right word -- not sure that would be exactly a linear function.

[PT20J]

Porting and polishing helps the engine breathe better which means that you can burn more fuel to produce more power because there is more oxygen in the cylinder on each intake stroke.