# Generac 992cc V-twin four cycle EFI 37hp

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#### Armilite

##### Well-Known Member
Generac 992cc V-twin four cycle with EFI. Probably to Heavy for most Part 103 at 120lbs. A Smaller CC/HP V-Twin was 94lbs. You might be able to strip off some weight.
https://www.brandnewengines.com/61E477-0007.aspx

37hp Briggs VanguardNew EFI: Enables up to 25% fuel savings
1-1/8" x 4" shaft, tapped 7/16" with 1/4" keyway.
Cast iron sleeves, full pressure lube w/ oil filter,
Less fuel tank, less muffler.
Universal replacement engine for pressure washers, saws,
compressors, rollers, log splitters, etc.
3 year warranty.
Model 61E477-0007.
160 lbs

Vanguard™ 37.0 Gross HP* EFI
Vanguard™ is the innovator and proven leader for BIG BLOCK™ V-Twin engine power, performance and reliability. For the most challenging applications—where downtime is not an option—this BIG BLOCK V-Twin engine lineup has been expertly engineered to deliver the dependability hardworking people need to get a lot more done throughout the day.
Typical applications include: Concrete Trowels, Chippers/Shredders, Commercial Mowers and Mud Boats.

Compared to a Hith F-23(50hp) 78lbs, including reduction unit, full exhaust, and electric start or71lbs with recoil start reduction unit and full exhaust.

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#### Winchester

##### Well-Known Member
I am confused and would like some clarification: 1. Generac stopped making the 4 cycle 990cc vertical shaft motor some time ago. 2. Valley Engineering sold a conversion of the 990 called the 'Big Twin' for UL aircraft -but I believe they have stopped sales do to dwindling availability. Is this new Briggs Vanguard the same as the old Generac but with EFI? Hence the "Universal replacement engine" point? I believe Generac and B&S have been complete competitors for over a decade now.

#### lr27

##### Well-Known Member
I think the shipping crate must be very heavy. The Briggs site lists something similar, or maybe the same engine, at 125 lbs. The 37 hp is at 3,600 rpm, and a "high speed package" allowing 4750 rpm is available as an option. I expect the horsepower would be much more.
https://www.vanguardengines.com/na/en_us/product-catalog/engines/big-block-vtwin-horizontal-shaft/vanguard-370-gross-hp-efi.html

They also have a 40 hp engine like that:
https://www.vanguardengines.com/na/en_us/product-catalog/engines/big-block-vtwin-horizontal-shaft/vanguard-400-gross-hp-efi--marine.html
I imagine that could be pretty powerful with the higher speed, even if the horsepower ratings are gross and not net. Put that in your Volksplane. I guess on an airplane you could skip the cooling fan and have the net horsepower be close to the gross.

For a part 103 ultralight, they have a 23 hp engine which is supposed to be "only" 77 lbs.
https://www.vanguardengines.com/na/en_us/product-catalog/engines/small-block-vtwin-horizontal-shaft/vanguard-230-gross-hp-efi.html

I think there used to be a single cylinder Intek of comparable power that weighed less. But I suspect all of these could be made to weigh quite a bit less.

#### Victor Bravo

##### Well-Known Member
HBA Supporter
If I recall, there is something like at least 10-12 pounds of crap that can be removed from these engines for an aircraft application. Raising the RPM from 3600 to 4750 (per Briggs Vanguard website above) is a 32% increase in RPM which would certainly give you at least 10-15% more usable horsepower, 44 or 45HP or somewhere pretty close to that.

So if my guesses are correct you are talking about an engine that weighs 110-115 pounds and puts out 44+HP, that is still proven to run for long periods of time in difficult conditions with minimal maintenance.

It's also an engine that is reasonably quiet and is fairly inexpensive. Also an engine that has all sorts of options bui lt right in for mounting it (threaded hole bottom, rear and front mount patterns), that can also be used for bolting different accessories onto it (like a dirt-simple belt PSRU).

Now even the Briggs brand name offers EFI and computer controlled ignition options, resulting in less fuel burn. Seems like a pretty damned good powerplant for a cheap little airplane that costs very little to own and operate.

#### Armilite

##### Well-Known Member
I think the shipping crate must be very heavy. The Briggs site lists something similar, or maybe the same engine, at 125 lbs. The 37 hp is at 3,600 rpm, and a "high speed package" allowing 4750 rpm is available as an option. I expect the horsepower would be much more.
https://www.vanguardengines.com/na/en_us/product-catalog/engines/big-block-vtwin-horizontal-shaft/vanguard-370-gross-hp-efi.html

They also have a 40 hp engine like that:
https://www.vanguardengines.com/na/en_us/product-catalog/engines/big-block-vtwin-horizontal-shaft/vanguard-400-gross-hp-efi--marine.html
I imagine that could be pretty powerful with the higher speed, even if the horsepower ratings are gross and not net. Put that in your Volksplane. I guess on an airplane you could skip the cooling fan and have the net horsepower be close to the gross.

For a part 103 ultralight, they have a 23 hp engine which is supposed to be "only" 77 lbs.
https://www.vanguardengines.com/na/en_us/product-catalog/engines/small-block-vtwin-horizontal-shaft/vanguard-230-gross-hp-efi.html

I think there used to be a single cylinder Intek of comparable power that weighed less. But I suspect all of these could be made to weigh quite a bit less.
==========================================================

I haven't been following all these different Big Twins. The Phoenix 103 use's a Hirth F-23 50hp and it weighs 78lbs complete with Electric Start, so any 4 Stroke Engine that Weighs 78lbs Complete or lower weight could work for a Part 103 that really only need 26-35hp. You have to still add the Redrive to that 23hp Engines weight, which averages about 12-16lbs. It would be interesting to see a list of all the Mods that Valley Engineering did so you could apply it to any of these motors.

992cc at 3600rpm to make 37hp comes in at 88% efficient. So 992cc at 88% efficient at 4750rpm = 49hp.

At least there is some Belt Drives out there for the Briggs. I think one is even 3D Modeled on www.Grabcad.com.

#### Armilite

##### Well-Known Member
If I recall, there is something like at least 10-12 pounds of crap that can be removed from these engines for an aircraft application. Raising the RPM from 3600 to 4750 (per Briggs Vanguard website above) is a 32% increase in RPM which would certainly give you at least 10-15% more usable horsepower, 44 or 45HP or somewhere pretty close to that.

So if my guesses are correct you are talking about an engine that weighs 110-115 pounds and puts out 44+HP, that is still proven to run for long periods of time in difficult conditions with minimal maintenance.

It's also an engine that is reasonably quiet and is fairly inexpensive. Also an engine that has all sorts of options bui lt right in for mounting it (threaded hole bottom, rear and front mount patterns), that can also be used for bolting different accessories onto it (like a dirt-simple belt PSRU).

Now even the Briggs brand name offers EFI and computer controlled ignition options, resulting in less fuel burn. Seems like a pretty damned good powerplant for a cheap little airplane that costs very little to own and operate.
===================================================================

Yes, I'm sure it can be lightened like you say maybe 110lbs. When I visited Valley Engineering I was more interested in looking at the Airframe, I looked at an Engine he had on a Stand. I think you would have to get one that is equal too or under what the Hirth F-23 50hp weighs complete 78lbs to be used for any Part 103.

992cc at 3600rpm to make 37hp comes in at 88% efficient. So 992cc at 88% efficient at 4750rpm = 49hp.
https://www.mk5cortinaestate.co.uk/calculator3.php

This EFI version says 25% better gph use. So if Carbed version is say 2.0gph, the EFI version would be 1.5gph.

Most Part 103 only need 26-35hp, so if there is a Small/Lighter Vee-Twin, I would try to use that, but I didn't look to see if the Smaller ones had EFI.

It would be nice to get a list of what all they did to the Generac to lighten it, then you could apply that Info to any of these Vee Twins. Mods can make the Price go way up.

#### Armilite

##### Well-Known Member
I just don't know if they sell that engine retail. From the propaganda, it sounds like it's especially for mud motors, but I doubt you'd want to buy the whole package! Seems like the 37 hp engines with EFI are getting up near $3k! Kind of expensive, if you ask me, but maybe not compared to an Aerovee or something. I do wonder how well the redrives work. Have read some horror stories about redrives of various kinds on other types of engines. You do still need a Redrive Avg$950, and maybe other Mods for more .
========================================================
(28hp) 45lbs.
Hirth F-33 with Recoil Start $3786.00 F-33 with Recoil Start & 4V Belt Drive$4081.00
F-33 with recoil & Electric start & 4V Belt Drive $4432.00 ======================================================== (40hp) 89lbs to 95lbs. 2702 Fan cooled Recoil Start$4274.00
2702 Fan cooled Electric Start $4834.00 2702 Fan Cooled Recoil Start W/ G50 Gear Box$5605.00
2702 Fan Cooled Electric Start W/ G50 Gear Box $6137.00 Optional oil injection$ 259.00
=======================================================
(50hp) 78lbs Complete.
F-23 W/Electric-Start & Slide carburetor $5614.00 F-23 W/Electric-Start & Diaphragm carburetor$5912.00
F-23 W/Electric Start & Electronic fuel injection $7446.00 Belt reduction drive$974.00
Optional oil injection $383.00 #### Armilite ##### Well-Known Member The 33hp EFI 896cc is 125lbs. 8.2:1cr. 33hp@3600rpm comes in at 88%. 896cc at 88% at 4750rpm = 44hp. https://www.vanguardengines.com/na/en_us/product-catalog/engines/big-block-vtwin-horizontal-shaft/vanguard-330-gross-hp-efi.html This one seem like a better Option for Part 103. I would use all the Coatings, Full Synthetic Oil, and any Mods that Valley Engineering did to cut Weight and make more durable. The 23hp EFI 627cc is 77lbs. 8.3:1cr. 23hp@3600rpm comes in at 88% efficient. 627cc at 88% at 4750rpm = 31hp 627cc at 88% at 5000rpm = 32hp 627cc at 88% at 5250rpm = 34hp 5250/2750 = 1.9 Ratio. https://www.vanguardengines.com/na/en_us/product-catalog/engines/small-block-vtwin-horizontal-shaft/vanguard-230-gross-hp-efi.html Remember that 88% is with the low 8.3cr for 87 Octane. If you bumped up the CR for 91/93 Octane the HP will go up. Last edited: #### Armilite ##### Well-Known Member #### Attachments • 64.2 KB Views: 12 • 191 KB Views: 10 • 34.6 KB Views: 16 • 35.3 KB Views: 13 • 88.8 KB Views: 15 #### Topaz ##### Super Moderator Staff member Log Member I just don't know if they sell that engine retail. From the propaganda, it sounds like it's especially for mud motors, but I doubt you'd want to buy the whole package! Seems like the 37 hp engines with EFI are getting up near$3k! Kind of expensive, if you ask me, but maybe not compared to an Aerovee or something. I do wonder how well the redrives work. Have read some horror stories about redrives of various kinds on other types of engines.
You know what's frustrating? Went to their website (Vanguard). No prices. Saw that they work through dealers, so okay, fine. They have a nice dealer-lookup tool on their site. Plug in my information and... not a single one of the dealers in my area has a web page listed. Just a phone number. Which means I'm going to get a commission-pay sales person who will keep pestering me until he figures I'm not going to buy 500 of these things, and who will then not respond at all.

Potential Sale: Lost.

It's not 1957 anymore, guys. There's this "Internet" thing now. You should try it.

#### lr27

##### Well-Known Member
You could always try someplace like Northern Tool and ask them about an engine with the high speed package. Or do some favors for a mud boat vendor.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
It's not 1957 anymore, guys. There's this "Internet" thing now. You should try it.
Sent a question to Brandnewengines via eBay. Last time I asked them about a particular engine availability this way I got a prompt answer. Will report what I hear. I don't expect it to be cheap - By B+S standards.

#### lr27

##### Well-Known Member
NT got back to me, but wanted a specific model number. I found one to ask about, but I don't know if it includes the high speed package.

#### lr27

##### Well-Known Member
Okay, Northern Tool DID get back to me. Here's part of their response:
You can reach our Briggs & Stratton dealer, Power Distributors, at 800-554-3336 for assistance with determining the exact model and type number that you are looking for. Option 2 from the phone number is for customer service and option 3 after that would be for advanced technical support. I would advise speaking with a technician and just explain that you are looking for a 61G3 or 61G4 engine with the high speed package and that you need the model and type number for this engine. Once we submit the special engine request, we normally hear back in about 1-2 business days for pricing and availability. If you decide to proceed after this, we would just need to build in an item number for ordering which takes about 1 additional business day.

#### mcrae0104

##### Well-Known Member
HBA Supporter
Log Member
Pressing #2 for customer service is so 1988. (Or was it 1898? They're more similar than 1988 and 2018...)

#### lr27

##### Well-Known Member
If 2018 is so different, where's my flying car?

#### mcrae0104

##### Well-Known Member
HBA Supporter
Log Member
Oprima el numero dos.