Hirth anyone?

scottessex

Sling-Wing Pilot
Joined
Nov 12, 2003
Messages
11,111
Location
central, ga
Aircraft
Dominator 582
Total Flight Time
200+
Perhaps Hirth owners should consider this as preventive maintenance as well?

.
Tim, on the Hirth the spark plugs are so close together that when you drill them out for the helicoil, there is NO meat between the plugs to hold the helicoil.
you will end up with a figure 8 hole in the cyl head.

That is why Hirth owners do not, cannot helicoil the plugs.
 

barnstorm2

Platinum Member
Joined
Nov 1, 2003
Messages
14,572
Location
Cincinnati, Ohio
Aircraft
2-place Air Command CLT SxS (project), & Twinstarr Autogyro
Total Flight Time
750+hrs and climbing
Tim, on the Hirth the spark plugs are so close together that when you drill them out for the helicoil, there is NO meat between the plugs to hold the helicoil.
you will end up with a figure 8 hole in the cyl head.

That is why Hirth owners do not, cannot helicoil the plugs.
Wow!!

Doesn't that cause cracks to develop between the plug holes???

Having steal plugs (spark plugs) set in alum that close together it seems like it would be just a matter of time before faults and cracks developed between the holes??

.
 

scottessex

Sling-Wing Pilot
Joined
Nov 12, 2003
Messages
11,111
Location
central, ga
Aircraft
Dominator 582
Total Flight Time
200+
Mine cracked between the plugs and blew the plug out, threads and all. I had always torqued them with a calibrated wrench. (working as an A&P torque wrenches have to be calibrated on a regular basis with records kept)
like I said earlier, there are certain quality issues with the Hirth, that being one of them.
Plus they seem to vibrate much more than a rotax,
They are less prone to seizures due to the nikasil cyl coating, the pistons and cyls expand at the same rate. The rotax cast iron cyl liner is more prone to cold seizure and seizure if not properly warmed up. But the rotax can be bored oversize, the hirth cannot.
They just do not have the quality that the rotax has, I wish they did, as they have many more engine models available.
 

TimMoses

Junior Member
Joined
Sep 26, 2005
Messages
45
Location
Monroe, NC
Aircraft
Quicksilver GT-500
Total Flight Time
1800+ Many more hours unlogged)
Ron's hard-on for Hirth engine bashings know no bounds.
 

scottessex

Sling-Wing Pilot
Joined
Nov 12, 2003
Messages
11,111
Location
central, ga
Aircraft
Dominator 582
Total Flight Time
200+
Hey Tim, you know Ron! :)

I would love to see the Hirth 80 hp 4 cyl on a single place gyro!

I liked my Hirth when I owned it, but it did require more maintenance than the rotax.
Like I said I would love to see Hirth step up to rotax quality, they have so many more engine options, plus fuel injection.

All rotax sells now is 503 - 582 - 912 series.

They quit making the 447 and the 618.
 

fiveboy

I FLY THE JUNGLE JET!
Joined
Jan 28, 2007
Messages
2,324
Location
Panama City Central America
Aircraft
AC Tandem Elite F30
Total Flight Time
Almost 200 hours
@ Tim Re Rons Bashing

@ Tim Re Rons Bashing

:whip: :flame: :whoo:

Ron yes your evidence is overwhelming :cool: but there is great danger in generalizing based on a specific example. Things break. Some break more than others, some dont.

As the man on the midway says - you pays your money, you takes your chances!

fiveboy
 

GyroRon

Former Gyro know it all
Joined
Oct 29, 2003
Messages
16,532
Location
Fort Mill South Carolina
Aircraft
Waiex/3300 Jab, Phantom UL, Flightstar II UL
Total Flight Time
ALOT
Ron

The bottom line is no 2 stroke will be as reliable as any 4 stroke over the long haul. The rest of your assertions dwell in the realm of broad generalizations opinion and conjecture.

The guy who had the covering on his bracket shouldnt blame the factory.... thats why we call it pre flight. If they had left a plug out and he flew it would it be the factory`s fault?

Not a pissing match... I just dont like to propagate myths as truths based on no more than hearsay or the same three or four testimonies or examples.

Like I said,my Hirth might be a piece of crap and kill me in a week but until that time its been ok so far.

fiveboy
Huh? You mean to tell me that as part of Tim Moses pre flight inspection he should remove the starter ( that the Hirth factory installed when the engine was new and shipped the engine to the USA this way ) to check to make sure some dumbass line worker at the Hirth plant was not either too lazy, too stupid, or too drunk to peel off the protective coating on the raw aluminum stock they used as part of their " aircraft " engine? I can see checking to make sure there are spark plugs in all the holes, and even the normal stuff such as double checking the torque on the cylinder head bolts, etc.... but not needing to remove the starter to make sure there is no plastic coating left on by accident!

You bought a used gyro from Skip Komlodi. I have seen your gyro in person and up close. It is very nice. I do not know if your gyro has ever had a engine problem, but you have not owned it long enough nor flown it long enough to have a good track record or history with it. It is possible that some of the previous owners had problems or issues that were never recorded in the logbooks...

Any engine is prone to failure, and yes a two stroke can be more prone to sudden failure more so than a good four stroke, butThe problem with Hirth engines, is when they fail it is usually because of some part of it failed due to poor engineering, or poor manufactoring tolerances or poor/ improper assembly. Look at the 3 failures Ultracruiser had with his new style watercooled 70 HP Hirth.... The cylinder head starts leaking coolant right out of the side of the head! Not as a seam or at a gasket, but right out of the side through the metal!!! How does that happen on a quality engine? I wouldn't even expect that on the cheap chinese stuff, much less a German designed and built aviation engine.

I hope you never have problems, but it is more likely that you will have one than won't.
 
Last edited:

GyroRon

Former Gyro know it all
Joined
Oct 29, 2003
Messages
16,532
Location
Fort Mill South Carolina
Aircraft
Waiex/3300 Jab, Phantom UL, Flightstar II UL
Total Flight Time
ALOT
Ron's hard-on for Hirth engine bashings know no bounds.
Oh come on.... I am not bashing them, simply saying that may not be up to the level of Rotax, and from what I have seen so far they are much more of a gamble reliability wise than other mainstream engines. You and I talked about it the other day, I would strongly consider putting the same model F-30 Fiveboy has on his aircommand onto my Dominator ( the 110 horse fuel injected model ) if I could find one for sale at a reasonably price. It would be much easier to install and lighter overall than a Rotax 912S and much cheaper even new. I would fly a F30, only cause Rotax doesn't make a compariable engine in that size and power range without a 20 thousand dollar price tag.
 

fiveboy

I FLY THE JUNGLE JET!
Joined
Jan 28, 2007
Messages
2,324
Location
Panama City Central America
Aircraft
AC Tandem Elite F30
Total Flight Time
Almost 200 hours
Oh come on.... I am not bashing them, simply saying that may not be up to the level of Rotax, and from what I have seen so far they are much more of a gamble reliability wise than other mainstream engines. You and I talked about it the other day, I would strongly consider putting the same model F-30 Fiveboy has on his aircommand onto my Dominator ( the 110 horse fuel injected model ) if I could find one for sale at a reasonably price. It would be much easier to install and lighter overall than a Rotax 912S and much cheaper even new. I would fly a F30, only cause Rotax doesn't make a compariable engine in that size and power range without a 20 thousand dollar price tag.
Ron yes I have Skips machine. There have been some safety related mods along the way (like tightening the spindle bolt which was turning!) but all in all she looks just as nice today as ever (and flies really nice).

Your comment about my not having it or flying it long enough to know is quite correct the engine is under 200 hours. If Skips logs are to believed (and I do beleive they are) there have been no issues beyond standard maintenance. Not shooting plugs, not factory stickies, no crank shafts shooting off into space... not even any leaking oil). It is about to get the high temps high humidity test, as this week my rotor is back on and Im back at crow hop city!

Enough bickering. I (like all of us I suppose) cross my fingers and swear to God Ill be good if I dont have an engine problem in the air. So far so good for me.... if that changes and I live to tell then everyone here will know.

I just tend to shying away from painting (anything) with too broad a tar brush..

That said I am sure someday we will meet, have a beer and swap engine out stories.... yours will be Rotax and mine may be Hirth.... though I would prefer we can only just have the beer.

Color me out of this pee pee match! LoL

Fiveboy
 

GyroRon

Former Gyro know it all
Joined
Oct 29, 2003
Messages
16,532
Location
Fort Mill South Carolina
Aircraft
Waiex/3300 Jab, Phantom UL, Flightstar II UL
Total Flight Time
ALOT
Hey it was not my intention to make it a pissing match...

The guy who started the thread wanted to know why Hirths aren't more popular in the gyro world, I was just sharing my opinion that part of why you don't see more of them is they have had a bad track record for reliability in my opinion.

I do not know every Hirth owner out there, but I do personally know of probably 20 or more Hirth owners and out of those only two claim to have not had some kind of malfunction. Everyone else has had some kind of issues with their engines, be it bad crankshafts and clutches ( Dave Seace ).... crankcase halves not aligning properly, spark plugs being blown out of the cylinder ( Mike Solano )..... Sparkplugs blowing out of the cylinder ( Tom Carslie ) .... Bad clutches, fuel injection system running to lean, fan bearings siezing, etc.... ( Maxie Wildes ) .... Broken cylinder, oil leaks, vibration induces cracking off of coil mounting plate ( Robert Klutz )..... Spark plug blowing out of cylinder, vibration causes coil mounting plate to break off engine ( Mike Bantum ) ..... Engine starts weaping coolant out of the side of the cylinderhead, engine vibration cracks off 4 studs that hold on waterpump, engine vibration causes one of 4 bolts that hold coolant manifold to rear cylinder to unscrew and cause loss of coolant in flight leading to overheat and forced landing, ( Barry Kroplien ) I could go on, but you get the point.

Sure Rotax owners have had failures too over the years, And not all Hirth owners are sure to have problems. But to me, there is certainly more risk flying Hirth than Rotax. Like I said last night, I would love to have a Hirth F-30 on my gyro, not because I think it is a great engine though, only because it is the only engine in that power and weight range that I think I could afford to buy.
 

barnstorm2

Platinum Member
Joined
Nov 1, 2003
Messages
14,572
Location
Cincinnati, Ohio
Aircraft
2-place Air Command CLT SxS (project), & Twinstarr Autogyro
Total Flight Time
750+hrs and climbing
Ron's hard-on for Hirth engine bashings know no bounds.
Oh come on.... I am not bashing them, simply saying that may not be up to the level of Rotax, and from what I have seen so far they are much more of a gamble reliability wise than other mainstream engines......

Funny how 'brand' topics get so controversial on the forum eh?

I have found that if you make any kind of remark that is not obviously positive some XYZ fan/owner will take it as a knock or a 'bash'.

That is a shame because one of the most valuable things this forum can offer is product feedback and experience from people in the hobby.


Personally, I don't think someone is 'bashing' a product, item or concept unless they are just putting it down without providing some reasoning or experience to support the opinion.


Brand XYZ sucks period! = bashing

Brand XYZ is unreliable because three friends of mine had them and they all failed = not bashing.

Brand XYZ is unreliable because they are designed with _____ and that can be a problem because of ______ . = not bashing.

IMHO.


.
 

All_In

Gold Supporter
Joined
Apr 21, 2008
Messages
14,627
Location
San Diego, CA. USA
Aircraft
Piper Archer, Aviomania G1sb
Total Flight Time
Not sure over 10,000+ logged FW, 260+ ultralights, sailplane, hang-gliders
I agree with Tim O!

Not bashing!
---

I would like a survey sent to all members asking them to list hours flown and failures found in those hours of all engines we fly?

Wouldn't that be telling!
 

fiveboy

I FLY THE JUNGLE JET!
Joined
Jan 28, 2007
Messages
2,324
Location
Panama City Central America
Aircraft
AC Tandem Elite F30
Total Flight Time
Almost 200 hours
@ John

Yes thats what I was suggesting in an understated way. Not because I am a defender of Hirth (hell I am only flying with it because thats what my gyro came with.) I agree with Ron though that for the money vs power to weight its a great engine on specs.... if mine craps out in any of the listed ways Ill probably switch either to a Subaru or maybe one of those Suzuki snowmobile engines that seem so promising.

I agree that the back and forth (as long as it remains civil which sometimes it dont here) is a very goodthing.

Creativity is forged in the cauldron of conflict and honed on the whetstone of ideas.

fiveboy
 

snowbird1

Junior Member
Joined
Mar 9, 2005
Messages
35
Location
Ypsilanti, Michigan
Aircraft
snowbird single place
Total Flight Time
52hr in a KB3, 20hr in Sparrowhawk, 85 in Snobird
hirth engine

hirth engine

I personally had bad luck with my 65hp EFI engine. Within 4 hours of operation, one siezure from main bearing and then again one siezed piston- both required forced engine-out landings and 2+ hours to get the gyro out of
a field and onto a trailer. No damage to the gyro though. I now fly rotax 618....so far no problems....
 
Top