This can go in the Industrial Engine sub-area, when it exists.
I visited HF today and noticed one of these 708cc engines on display. I'd not looked at this model seriously before. Why look at a Predator 22HP vertical shaft when they make a 22HP horizontal shaft engine that would require less work to mount in an airplane? But, this does have some interesting characteristics: It has more displacement (so, maybe could make more HP, or stay cooler at 22 HP) and might be lighter than the 22 HP HF horizontal shaft 670cc.
The engine definitely looks like it is made by Loncin in the PRC. The same/very similar engine is apparently used by Exmark for a ZTR mower, and they put out a nice video showing features of the engine. Their video: . Notice the layout of the engine case on the PTO side is identical to the Predator 708cc engine.
Specs and notes:
HF Model : 62879
Link to HF product page: https://www.harborfreight.com/708cc...e-epa-62879.html?_br_psugg_q=predator+engines
Link to owners manual: https://manuals.harborfreight.com/manuals/62000-62999/62879.pdf
Link to Mfgr's product page: https://loncinindustries.com/en/engine/ProductDetail.aspx?catid=8-15-16-30-50-66-2146779948#proFlag
3 June edit/correction: Above link is to the Loncin 803cc engine specs. 708cc engine page is here: https://loncinindustries.com/en/engine/ProductDetail.aspx?catid=8-15-16-30-50-66-2146779947#proFlag
Claimed HP: 22 HP (RPM not listed. Display in store said 3200 RPM. Owner's manual says max RPM is 3600. See Exmark video for details of governor). Note: The manufacturer claims 18 KW net power on their product page, so 24.1 HP. This 18KW does not match the dyno chart, however.
3 June edit/correction: The manufacturer claims 12.8KW (17.16 HP) at 3600 RPM for the 708cc engine. They claim 24.1HP for the 803cc engine.
Claimed max torque: 32.5 ft/lbs at 2500 RPM (3 June edit: Factory claims =35.03 lb/ft torque at 2400 RPM)
Displacement: 708cc (77mm bore x 76mm stroke)
Compression ratio: 8.7:1 (HF 670cc listed as 8.2:1. Vanguard 810cc = 8.4:1,
Price: $750 (regular price, not on sale)
Weight out of the box: 92.6 lbs (includes the muffler?). The horiz Predator 670cc engine is listed as 110.2 lbs. (Hot Wings actually weighed one before examining it: 109.25 lbs. The muffler was 9.75 lbs) The Vanguard 810cc engine weighs about the same out of the box (91 lbs), but a muffler definitely isn't included in that weight (but a heavy canister air cleaner is). I did notice that the vert 708cc engine had cast AL valve covers, the Predator 670cc engine had steel covers. The Vanguard 627cc (claimed 22HP) weighs 77 lbs out of the box, but there's no muffler in that weight.
PTO shaft: 1" dia, 1/4" keyway. Looking at dimensioned drawing of the shaft (p 27 of manual), the crankshaft might be 45mm in diameter
Construction: HF literature says "the vertical shaft is ball-bearing mounted" and that the cylinders are cast iron. (HF also claims there are ball bearings in their 670cc engine, Hot Wings didn't get any in the 670 he bought). The Exmark video also says cast iron sleeves, 5 bolt head, and a nice, wide head gasket. The Exmark engine shows a 2-barrel carb (one per jug) with an aluminum intake manifold. I didn't notice the intake manifold on the HF engine in the store. The Exmark video shows a nylon gear on the camshaft, but the Loncin web site says it has a "metal cam and forged crankshaft."
CC/rated HP (higher #= more conservative): 32.18 cc/hp for HF claim of 22 HP. Manufacturer (Loncin) claimed HP: 24.1 HP net = 29.4 cc/HP.
3 June edit/correction: Factory clams 17.16HP, so 41.26 cc/HP. This is the largest displacement per HP I've seen among any of these modern industrial engines.
Compare to: Predator 670cc horiz shaft: 30.46. Vanguard 627cc 23 HP: 27.26 Vanguard 810cc 26 HP: 31.15.
Note: If rated at 22HP, the 703cc engine seems to be conservative in this regard (longer engine life, better reliability?) If instead we used the same average cc/HP of these three other engines (29.6 cc/HP), then the HF 708cc would produce 23.7 HP, which is in line with the manufacturer's claim of 24.1 net HP. It is possible this could be a reliable 24HP engine, with a proper carb, attention to baffling, etc.
Misc: Reviews on the HF web site have been very favorable, but no one had been running it long. Maybe the Exmark repair shops would have some info on the long-term performance under hard use. I would prefer if it had a steel gear on the camshaft. The Predator 670cc horiz engine is the focus of a lot of aftermarket hop-up/tuning activity, I haven't noticed the same thing with this vert. 708cc engine, so 3rd party parts might not be very common.
Conclusion: This might be worth a look if turning the engine sideways isn't a concern. If it is lighter than a 670cc Predator after both are prepped for flight, it could be a good alternative (and cheaper than $1225 Vanguard 627cc horiz engine). There's a dearth of suitable horizontal shaft engines in the 671-996 cc range, so if that displacement isn't enough and the weight of a 993cc engine is too much, then a vertical shaft engine is the only choice in an industrial engine. It's possible the HF 708cc engine might be coaxed to reliably produce more than the 22HP claimed by Harbor Freight, at least based on its displacement and Loncin's specs. Among the other alternatives, a B&S 810cc engine of claimed 26 HP (claimed 28HP with EFI) would be more attractive, IMO. The cost is higher (Turf series: $875 , Vanguard: $1150) , but the weight looks to be about the same as the Predator 708cc, the HP is about 20% higher, they are made in the US and exported worldwide, and spare parts/support will be easier to get. Further, these B&S 810cc engines are already flying on SD-1 aircraft.
This info probably covers previosuly plowed ground, but I couldn't find any posts on this engine. Any opinions/experience with it?
I visited HF today and noticed one of these 708cc engines on display. I'd not looked at this model seriously before. Why look at a Predator 22HP vertical shaft when they make a 22HP horizontal shaft engine that would require less work to mount in an airplane? But, this does have some interesting characteristics: It has more displacement (so, maybe could make more HP, or stay cooler at 22 HP) and might be lighter than the 22 HP HF horizontal shaft 670cc.
The engine definitely looks like it is made by Loncin in the PRC. The same/very similar engine is apparently used by Exmark for a ZTR mower, and they put out a nice video showing features of the engine. Their video: . Notice the layout of the engine case on the PTO side is identical to the Predator 708cc engine.
Specs and notes:
HF Model : 62879
Link to HF product page: https://www.harborfreight.com/708cc...e-epa-62879.html?_br_psugg_q=predator+engines
Link to owners manual: https://manuals.harborfreight.com/manuals/62000-62999/62879.pdf
Link to Mfgr's product page: https://loncinindustries.com/en/engine/ProductDetail.aspx?catid=8-15-16-30-50-66-2146779948#proFlag
3 June edit/correction: Above link is to the Loncin 803cc engine specs. 708cc engine page is here: https://loncinindustries.com/en/engine/ProductDetail.aspx?catid=8-15-16-30-50-66-2146779947#proFlag
Claimed HP: 22 HP (RPM not listed. Display in store said 3200 RPM. Owner's manual says max RPM is 3600. See Exmark video for details of governor). Note: The manufacturer claims 18 KW net power on their product page, so 24.1 HP. This 18KW does not match the dyno chart, however.
3 June edit/correction: The manufacturer claims 12.8KW (17.16 HP) at 3600 RPM for the 708cc engine. They claim 24.1HP for the 803cc engine.
Claimed max torque: 32.5 ft/lbs at 2500 RPM (3 June edit: Factory claims =35.03 lb/ft torque at 2400 RPM)
Displacement: 708cc (77mm bore x 76mm stroke)
Compression ratio: 8.7:1 (HF 670cc listed as 8.2:1. Vanguard 810cc = 8.4:1,
Price: $750 (regular price, not on sale)
Weight out of the box: 92.6 lbs (includes the muffler?). The horiz Predator 670cc engine is listed as 110.2 lbs. (Hot Wings actually weighed one before examining it: 109.25 lbs. The muffler was 9.75 lbs) The Vanguard 810cc engine weighs about the same out of the box (91 lbs), but a muffler definitely isn't included in that weight (but a heavy canister air cleaner is). I did notice that the vert 708cc engine had cast AL valve covers, the Predator 670cc engine had steel covers. The Vanguard 627cc (claimed 22HP) weighs 77 lbs out of the box, but there's no muffler in that weight.
PTO shaft: 1" dia, 1/4" keyway. Looking at dimensioned drawing of the shaft (p 27 of manual), the crankshaft might be 45mm in diameter
Construction: HF literature says "the vertical shaft is ball-bearing mounted" and that the cylinders are cast iron. (HF also claims there are ball bearings in their 670cc engine, Hot Wings didn't get any in the 670 he bought). The Exmark video also says cast iron sleeves, 5 bolt head, and a nice, wide head gasket. The Exmark engine shows a 2-barrel carb (one per jug) with an aluminum intake manifold. I didn't notice the intake manifold on the HF engine in the store. The Exmark video shows a nylon gear on the camshaft, but the Loncin web site says it has a "metal cam and forged crankshaft."
CC/rated HP (higher #= more conservative): 32.18 cc/hp for HF claim of 22 HP. Manufacturer (Loncin) claimed HP: 24.1 HP net = 29.4 cc/HP.
3 June edit/correction: Factory clams 17.16HP, so 41.26 cc/HP. This is the largest displacement per HP I've seen among any of these modern industrial engines.
Compare to: Predator 670cc horiz shaft: 30.46. Vanguard 627cc 23 HP: 27.26 Vanguard 810cc 26 HP: 31.15.
Note: If rated at 22HP, the 703cc engine seems to be conservative in this regard (longer engine life, better reliability?) If instead we used the same average cc/HP of these three other engines (29.6 cc/HP), then the HF 708cc would produce 23.7 HP, which is in line with the manufacturer's claim of 24.1 net HP. It is possible this could be a reliable 24HP engine, with a proper carb, attention to baffling, etc.
Misc: Reviews on the HF web site have been very favorable, but no one had been running it long. Maybe the Exmark repair shops would have some info on the long-term performance under hard use. I would prefer if it had a steel gear on the camshaft. The Predator 670cc horiz engine is the focus of a lot of aftermarket hop-up/tuning activity, I haven't noticed the same thing with this vert. 708cc engine, so 3rd party parts might not be very common.
Conclusion: This might be worth a look if turning the engine sideways isn't a concern. If it is lighter than a 670cc Predator after both are prepped for flight, it could be a good alternative (and cheaper than $1225 Vanguard 627cc horiz engine). There's a dearth of suitable horizontal shaft engines in the 671-996 cc range, so if that displacement isn't enough and the weight of a 993cc engine is too much, then a vertical shaft engine is the only choice in an industrial engine. It's possible the HF 708cc engine might be coaxed to reliably produce more than the 22HP claimed by Harbor Freight, at least based on its displacement and Loncin's specs. Among the other alternatives, a B&S 810cc engine of claimed 26 HP (claimed 28HP with EFI) would be more attractive, IMO. The cost is higher (Turf series: $875 , Vanguard: $1150) , but the weight looks to be about the same as the Predator 708cc, the HP is about 20% higher, they are made in the US and exported worldwide, and spare parts/support will be easier to get. Further, these B&S 810cc engines are already flying on SD-1 aircraft.
This info probably covers previosuly plowed ground, but I couldn't find any posts on this engine. Any opinions/experience with it?
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