Geo engine

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Kmccune

Well-Known Member
Joined
Aug 5, 2007
Messages
162
Depends on what your building.

Raven has a wide spectrum of Suzuki redrives and engines.

Kevin
 

Von Richter

Active Member
Joined
Feb 26, 2010
Messages
38
Location
Antioch Illinois
If it's a small plane, needing 65-75 HP use a CHEVY sprint engine if you can find one. They were built by Suzuki for Chevy till about 1988. They use the same block as the 999 cc Geo but a hemi head with better breathing and much bigger valves. They had a 75HP "stock" turbocharger option. If you have a smaller plane needing less hoespower, and a little less weight, 10#less, use the Geo. Both engines can pull 5-10 HP with a little tweeking and throwing away the emission stuff. More HP with cam, carb, and exhaust tunning. The Raven drives are ok, and will adapt to the Sprint, but so far I've only made my own drives. The 1599 cc Tracker engine is just a longer 4 cyl Sprint engine pulling 75 HP stock and can be tweeked to 100HP easily. The Raven drive can be "adapted" but again, I build my own. They all, are all aluminum blocks with forged cranks, and rods. Bill
 

LittleBird

Active Member
Joined
Nov 9, 2009
Messages
34
Location
Harrisonville, MO. USA
Try to find a set of lifters for a 3 cylinder Geo engine. I did 5+ years ago and couldn't find them then. I bought every one I could find at every dealer in KC and still couldn't get a full set.

Kevin
 

BG12

Member
Joined
Jan 3, 2011
Messages
8
Location
Western WA
So far on the pages of this forum I have found the opinion that the 1000cc three cylinder Metro/Sprint engine has excessive vibrations and should never be used in an airplane, and another in direct conflict that says the three cylinder engine is a great engine. Both can’t be totally correct. Since I already have a 3 cylinder sitting here waiting to be used for something, I have an interest in a valid answer. There either must be a fatal flaw for aircraft use, or there must be a range of correctness, with some common or theoretical mods to reduce some of the bad traits to an acceptable level. So some useful questions to those who may have answers are:

Does use of the Suzuki three cylinder also mandate using the stock (heavy) flywheel to tame engine harmonics? Are there any alternative mechanical means to reduce vibration (like torsional dampers) that might do the same thing at a lower weight penalty? Would three bladed props offer a reduction in resonances? Would wood props be the best choice for direct drive?

There was also one, and only one, mention of using this engine direct drive rather than with a PSRU. The tradeoff of the PSRU’s greater thrust vs lower weight and complexity of direct drive is clear and would probably be a subjective decision. The question is really whether the engine produces enough torque at 3000-3400 rpm to be a useful choice, compared to the engine weight and other competing engines. Assuming the torque curve of the 1300 would be similar to the 1000, the torque curve over this rpm range is almost flat. (re post #4 at Technical Discussion Areas/Auto conversions/Suzuki 1.3 hp torque).
Are there any successful examples of direct drive 3 cylinder Suzukis in airplanes?

Regarding resonant frequencies… virtually all engines have some harmonic resonances, so the question is more one of degree. And there are some certificated aircraft that have resonant frequencies that the operation manual simply says to avoid. Also associated with the engine’s harmonics are the combined prop/engine resonances. Elsewhere on this forum, someone mentioned this, but did not add that prop indexing on the crankshaft is a significant factor. Yet another comment said that opposed engines should have the prop aligned with the cylinders to avoid the engine/prop resonances that indexing elsewhere would produce. Could someone with more knowledge than I address some of these questions?
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
13,078
Location
Memphis, TN
You need to be an experimenter not a consumer when doing that kind of stuff. It is "not that you cant" but " why?" If you like machining and testing, you are going to be happy. It is more about your butt is in the seat and do you trust it? You can make it work but you will probably have to make all the parts to do it, or if you find a PRSU, you will have to develop it more. Forcing the engine to do something it was not designed for is what causes the problem; not being a bad engine. On flat cylinder engines props are indexed at a certain place on the crank; a PRSU will depend on the ratio if it will index at the same place or not..
 

ubugarrity

New Member
Joined
Jan 22, 2011
Messages
1
Location
Northern NJ
Anyone have any info for converting the G10? I'm starting a complete restoration of a Hoverstar hovercraft. I'm trying to locate the a carburetor with vacuum advance model so I don't need the ECU or all the other parts the TBI needs. I have a 97 Geo Metro I can get for $500 for the whole car but I've heard that year is complicated to convert. I haven't decided on drive yet. After talking to the guy at Raven, I've given up on just making a belt drive myself. I like the Raven drive as it is very compact (only a couple inches from flywheel to hub) but there is engine mods needed. The redrive gearbox from airtrikes is just bolt on but its a lot longer and will take up about another 8". But for now I just want to get a G10 and get it running without a car around it. Any info would be greatly appreciated.
 

charles

Well-Known Member
Joined
May 3, 2010
Messages
120
Location
northcarolina usa
lifters dont go bad; its the mechanic that took them out.when you take them out the engine, set them up just as you took them out the engine for storage -never bath them in oil - or lay them sideways cause they will expand and drive you nuts.the only way to get them in shape to put in engine after screwing them up is to apply pressure on each one with a c-clamp every day for a month to get the proper length to put back in engine, and then you will have to turn the engine over without the coil hooked up for another month each week to get them to seat properly before the engine will even crank up.
Try to find a set of lifters for a 3 cylinder Geo engine. I did 5+ years ago and couldn't find them then. I bought every one I could find at every dealer in KC and still couldn't get a full set.

Kevin
 

mastic

New Member
Joined
May 20, 2011
Messages
4
Location
Melbourne, Vic. Australia
So far on the pages of this forum I have found the opinion that the 1000cc three cylinder Metro/Sprint engine has excessive vibrations and should never be used in an airplane, and another in direct conflict that says the three cylinder engine is a great engine. Both can’t be totally correct. Since I already have a 3 cylinder sitting here waiting to be used for something, I have an interest in a valid answer. There either must be a fatal flaw for aircraft use, or there must be a range of correctness, with some common or theoretical mods to reduce some of the bad traits to an acceptable level. So some useful questions to those who may have answers are:

Does use of the Suzuki three cylinder also mandate using the stock (heavy) flywheel to tame engine harmonics? Are there any alternative mechanical means to reduce vibration (like torsional dampers) that might do the same thing at a lower weight penalty? Would three bladed props offer a reduction in resonances? Would wood props be the best choice for direct drive?

There was also one, and only one, mention of using this engine direct drive rather than with a PSRU. The tradeoff of the PSRU’s greater thrust vs lower weight and complexity of direct drive is clear and would probably be a subjective decision. The question is really whether the engine produces enough torque at 3000-3400 rpm to be a useful choice, compared to the engine weight and other competing engines. Assuming the torque curve of the 1300 would be similar to the 1000, the torque curve over this rpm range is almost flat. (re post #4 at Technical Discussion Areas/Auto conversions/Suzuki 1.3 hp torque).
Are there any successful examples of direct drive 3 cylinder Suzukis in airplanes?

Regarding resonant frequencies… virtually all engines have some harmonic resonances, so the question is more one of degree. And there are some certificated aircraft that have resonant frequencies that the operation manual simply says to avoid. Also associated with the engine’s harmonics are the combined prop/engine resonances. Elsewhere on this forum, someone mentioned this, but did not add that prop indexing on the crankshaft is a significant factor. Yet another comment said that opposed engines should have the prop aligned with the cylinders to avoid the engine/prop resonances that indexing elsewhere would produce. Could someone with more knowledge than I address some of these questions?
There must be hundreds of Geo/Suzuki G10 three cylinder engines flying so the guy who said they should never be used in an airplane is 100% wrong, in fact they have a history of reliability and success. Gearbox and belt redrives are available to bolt on to them so you don't have to fool around making your own or adapting a drive made for a different engine. There is an excellent Yahoo Geo/suzuki engine group Yahoo! Groups that you should join.
 

Ulmpanpa

New Member
Joined
May 13, 2011
Messages
3
Location
france
Hello,

I have a practical experience of the use of this type(chap) of engine because I steal with a toyota 3 cylinders of origin Aygo. I equipped him(it) with a mechanical rotax reducer, 3,47/1.
97 hp in 6500 tr / min.

Panpan

 
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cecil

New Member
Joined
Jul 15, 2012
Messages
3
Location
eunice,louisiana
i plan on using the 1.3 direct drive at 3200 with a 60 x 3? prop inverted on a300 lb. plane. change valve cover to oil pan. rerout oil pickup. steam holes at bottom-now top of water jacket. any other changes needed?
 
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