# Briggs vanguard conversions

Discussion in 'Firewall Forward / Props / Fuel system' started by Hephaestus, May 12, 2019.

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1. May 25, 2019

### blane.c

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2. May 25, 2019

### Vigilant1

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Northern Tool is a reputable outfit.
This is the place I normally find these engines listed at the lowest price: Small Engine Warehouse

Example right now:
$1150, so$550 less than the price shown by Northern Tools. That's a lot of beer and pizza. (15 shown in stock, shipping is $130 additional to anywhere in the continental US) : 49R977-0002 Edited to add: I just noticed that the engine you linked to at Northern Tool was the EFI model. That explains about$300 of the price difference. Would you want their EFI?

A few months ago they had a lot more Vanguard 810s on their web page, maybe they are low on stock or their web page isn't current. Anyway, it might be worth a call to them if you want an EFI engine, see if they have any in stock.

I'm looking for cheap basket case at local lawnmower shops to pull apart, measure, see how the lubrication is set up, get weights, etc. The non-Vanguard B&S 810s are a lot more common.

Last edited: May 25, 2019
3. May 25, 2019

### blane.c

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Yes EFI. (1) around 1600hrs of my flight time is with auto fuel. I don't have a problem using auto fuel, I have a problem with all the silly workarounds to 1/2 use auto fuel and 1/2 use av-gas and other weird things. I allegedly have cruised just fine at 15000ft with auto gas no problemo'. {2400hp "cruise" power [4x600 C-54]}
(2) these (little industrial) engines are designed to use auto gas, and using av-gas is likely to cause lead fouling and create other problems.
(3) Figuring a way to get auto gas to the plane may be a pain in the * but it is just got to be part of the program for using these engines.
(4) EFI is more fuel efficient, easier to start and less susceptible to Icing (nothing is icing proof).
(5) EFI has no float bowl so orientation is less of a problem.
(6) This ain't 1940, this is 2019 electronics has come a long way. I am willing to trust the stock modern electronic EFI more than a carburetor especially if the carburetor is being modified from stock.
(7) EFI is altitude compensated automatically, the carburetor is not, additionally the stock carburetor may not have the ability to adequately compensate for altitude and if it needs to be replaced with something that has adequate leaning capability you can kiss your $300 savings goodbye. Plus it'll be a pain in the * and a good waste of time. (8) A modern electric fuel pump is required to operate the EFI so you no longer need worry about a gravity feed fuel system, freeing up your mind to solve other problems instead. The EFI models are the same price @ both places, shipping to my location is$50 cheaper using Northern.

A basket case is a good idea. Having a physical specimen will solve many mysteries. But some things may be of different like crankshaft journal dia. and flywheel weight and configuration. Again the simple solution is to talk to somebody that knows.

4. May 25, 2019

### Vigilant1

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Okay, no problem, and I understand that line of reasoning. If going down that road, I'd want to know a lot about the failure/limp-home modes built into the EFI. The B&S literature claims it is a Delphi system, but how has it been programmed for this application? We know the OEM automobile EFI systems sometimes have limp-home modes designed to be very conservative to save the engine and may not provide enough power to stay airborne. That's a big consequence for a failed lambda sensor or a loose wire. The manufacturer is giving a 3 year warranty on this engine, they have no incentive to allow a user to do anything but stop if the EFI gets strange inputs. Also, B&S does offer an open-loop EFI for use on their maritime engines. May be simpler and more reliable (that would be one reason to go with an open-loop system on this maritime application).

I'm sure those folks are out there, but not as common as I'd thought. The folks in mower shops know how to get them running again, but may not know the differences between the B&S Pro series and the Vanguards, etc, especially if it's a metalurgical issue, crank bearings type, etc. They order the needed part number and install it. And the consequences of flipping an engine on its side and running it are not something they need to think about in their daily operations.

5. May 26, 2019

### blane.c

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With two (or more) engines "limp mode" is not as critical as with one engine. It is of course wise to understand the system and what it is going to do to you if it kicks in. I wonder if you could (for testing purposes) simply put a switch in line of various input sensors the computer uses and turn them off and on or run the wires thru a rheostat and vary there inputs to the computer and observe the effects. The open loop system is desirable? How difficult could it be to take the EFI off a marine engine and put it on a 810 lol.

Need a Robert Hoover of the B&S world.

6. May 26, 2019

### Vigilant1

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Of course, with EFI the plane's electrical system also becomes critical to flight. That means with 1 engine or 20, if they all use a single electrical system for high-pressure fuel then there's still a single point of failure. It would be important to know how long 1 or more engines could run on battery power, and if there's any way a voltage excursion (from one failed regulator) could cause multiple engine failures. [/QUOTE]

I think some of the sensors are analog, some are digital. And they can fail in a lot of ways (null. high, intermittent, etc). It's hard to check them all, and without the source code and a way to modify it, all you could do is (kinda) test, not modify/improve anything.

I've thought a lot about that. And Great Plains Aircraft Supply is up for sale--one person could take that over and add products/kits for converting B&S engines. A one-stop-shop for VW and industrial aero engines, they'd pretty much own the 4-cycle DIY aero market for 20-75 HP.

7. May 26, 2019

### BBerson

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It might difficult to run a business selling industrial engines. Leon Davis gave up on converting Briggs engines for his "mower power to the people" when Briggs refused to sell engines for aviation.
I think it needs to be sort of under cover or Briggs will sue. Individuals buying one or two might get by under the radar.

8. May 26, 2019

### Hot Wings

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Everything one needs to know to test the B+S FI
Looks like a pretty robust system.

#### Attached Files:

• ###### Vanguard 37 EFI Repair Manual.pdf
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4.9 MB
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9. May 26, 2019

### Vigilant1

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For reference:
(Page 2-2) If the system does not receive a signal from the crank position sensor, it shuts off the fuel flow.
(Page 2-2) If the system does not receive a signal indicating there are ignition pulses, it shuts off the fuel pump/fuel pump relay.
(Page 1-7) If the ECM receives a sensor input that is incorrect (as determined by the ECM), it will insert a calibrated default value. This will result in degraded engine operation.
(Page 3a-2) Describes the reason the system might go into open-loop mode, but doesn't provide details on engine operation in this mode (the extent of the default fuel maps, etc)
(Page 3b-11) Interesting-- the engine head temp sensor chart maxes out at 365 deg F. It's hard to know how important that is without knowing where the thermocouple is placed. If that's as hot as the head, near the exchaust valve, ever gets on even the hottest days and heaviest loads--then that would be very good news.

10. May 26, 2019

### Vigilant1

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I think you'd have to sell instructions, kits and parts (lightened flywheels, prop extensions, maybe an aviation-tailored EFI or EFI/electronic ignition, carburetors with associated manifolds and instructions, bits and instructions for turning an 810cc engine on edge, books and DVDs showing the steps, exhaust parts or complete exhaust systems for popular aircraft, an electronic engine monitor for these engines, etc). The builder would have to buy the engine (there's no profit in that for a small specialized company anyway). The lawyers might still swoop in anyway, but I'd think B&S's equities would be covered adequately if they continued to tell people the engines weren't for aircraft use. Companies sell hop-up parts for racing these engines and apparently B&S hasn't squashed them (despite verbiage in various places saying the engines aren't to be used for racing (except B&S sanctioned events) or airplanes).

11. May 26, 2019

### BBerson

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While I am a strong advocate of experimenting, I just don't see the 810 as an ultimate solution to base a small business. Looking at Hummelengines.com I noticed the smallest 28hp 1/2VW price isn't listed now (lack of interest?) The market seems be the 35-45hp 1/2VW for virtually the same price. Last year at Oshkosh all the flying Legal Eagles had even switched to the bigger three cylinder Verners.
So, I see no evidence of anyone flying with around 810cc. in the U.S. yet.

12. May 26, 2019

### blane.c

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Well if the 810 can be paired down to around 90lbs firewall forward then two of them would be around 180lbs and 56hp. This is comparable to a VW engine of 60hp for weight maybe a tad lighter and $3400 for two engines including ignition, induction and exhaust. Though modification is necessary it is a attractive price point for the power to weight ratio. 13. May 26, 2019 ### BBerson ### BBerson #### Well-Known MemberHBA Supporter Joined: Dec 16, 2007 Messages: 11,203 Likes Received: 2,035 Location: Port Townsend WA Yes, about 90 pounds each with starter, alternator and battery. You could probably get the 810 to 70 pounds (no electric) so two would be 140. Hummel sells a full VW that weighs 140 pounds. The market for twins is almost zero. Last edited: May 26, 2019 14. May 26, 2019 ### Vigilant1 ### Vigilant1 #### Well-Known Member Joined: Jan 24, 2011 Messages: 3,476 Likes Received: 1,480 Location: US I think there may be a bit of "chicken and egg" here. Are industrial engines not popular for aircraft in the US because there are few readily accessible designs that use them, or do we have few such designs flying here because people don't want them? We know that the SD-1 and the Luciole are fairly popular in Europe, and that these engines work in them. We know that not every American pilot weighs 400 lbs. As far as a twin (or triple): At least for me, a very important factor would be whether it is possible to legally fly an appropriately designed and constructed single-seat centerline-thrust twin without a multiengine rating or endorsement. 15. May 26, 2019 ### BBerson ### BBerson #### Well-Known MemberHBA Supporter Joined: Dec 16, 2007 Messages: 11,203 Likes Received: 2,035 Location: Port Townsend WA The SD-1 was marketed by a Utah dealer for a while a few years ago. But they didn't choose the Briggs 810. They had it set up with 50hp, I think. A test pilot was killed and it sort of ended after that. 16. May 26, 2019 ### Vigilant1 ### Vigilant1 #### Well-Known Member Joined: Jan 24, 2011 Messages: 3,476 Likes Received: 1,480 Location: US Yes, that plane was destroyed after the pilot performed some rolls (not approved in that aircraft by the manufacturer), lost control, and the ballistic parachute failed (more here). It did have a 50 HP Hirth F23 2-stroke engine. That distributor rolled up his carpet, but the present US dealer is in Ohio. The SE33 engine (their version of the 810cc B&S) only became available in 2017, and apparently US customers have to buy the whole engine kit (with cowling, engine mount, and a B&S engine that has been shipped to the Czech Republic, modified there, and shipped back to the US). The price is over$5500--which isn't outrageous if you are building an SD-1 and if you compare the cost to a Hirth, etc. The Valley Engineering setup was about that price, too--as much as a VW 1835cc engine or a 1/2 VW--with an alternator and starter. But if the price for a 28-32 HP engine, modifications for direct drive, and a prop was \$2500 instead of twice that much, maybe the idea would be more popular.

Last edited: May 26, 2019
17. May 26, 2019

### Hephaestus

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Not to speak for everyone but my intention was always to go MPFI probably with GM hardware (ok so is that Suzuki? Likely geo metro/Swift/firefly bits). Probably groan inducing - but I do have a MegaSnS board here, and I've got enough practice with conversions with it I'm comfortable with it.

The kart/tractor pull/etc guys remove all the flywheel that is not starter ring and replace it. The factory one is only good to 5000/5500 rpm anyway.

I've got to start tearing mine down, but got stuck with medical garbage (tests tests more tests) all last week, lawyer/court crap for the next 2 weeks so won't have much shop time for a bit.

18. May 26, 2019

### BBerson

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I agree, would be adequate for a particular design with a light pilot.
But for a business the single seat market is probably 1200cc -1600cc. Pete Plumb is at 1600cc, I suppose, because his original Daf of 750cc-850cc(?) was deemed too small.

19. May 26, 2019

### pictsidhe

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It is likely just a handy spot to put one. Briggs will have tested this a lot and detrmined what the allowable temperature at the sensor is. The exhaust valve will be hotter, but a fairly fixed amount. Allowable head temps are highly dependant on the actual alloy and other bits used. We'll need to fry some to find out how high is too high...

I won't be putting a Briggs in an aircraft anyway. I'm building a 103 and they are not legally aircraft.

20. May 26, 2019

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