Briggs vanguard conversions

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Vigilant1

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Of note: Briggs and Stratton has filed for bankruptcy protection. They are blaming poor sales since the COVID 19 pandemic, but the company's fortunes (and stock price) have been declining for awhile due to some poor earlier business decisions (debt, unwise acquisitions, and unfocussed and overly aggressive growth plan, some illl-advised contracts that increased their labor costs in some locations, etc).
A private equity firm has announced they'll buy the company (a higher bidder still might come along, and any purchase needs to be approved by the court). The Board of Directors/management didn't help matters by approving a big bonus payment to management just a few weeks ago when it was already clear the ship was headed for the rocks. Not unusual behavior these days, but also not the kind of thing that makes present debt holders and bond holders eager to take a haircut to keep those folks in their corner offices.
Production of engines will continue, and often these things leave the company in better shape than it started. Old debts will be marked down, some contracts that increased labor costs may be nullified by the court, etc. It is possible that the company will be in a better competitive position at the end of this, especially if some competent management with the long-term interests of the company takes the reigns. Stockholders, bond/debt holders, and present/former employees (in some locations/situations, probably not all) will be the surest losers.

There's money to be made in the small engine business, but it is competitive. The previous B&S managers made some bad choices. Things might have worked out if the overall economy had stayed perfect , but that's no way to plan. Doesn't seem to have hurt them much, which is part of a bigger problem (IMO).
 
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Hot Wings

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As long as we can get engines and parts.
No way to know what happens when a private equity firm gets their claws in. If they happen to also have holdings in a competitor in the same market............though that doesn't seem to be the case here?
 

Armilite

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Of note: Briggs and Stratton has filed for bankruptcy protection. They are blaming poor sales since the COVID 19 pandemic, but the company's fortunes (and stock price) have been declining for awhile due to some poor earlier business decisions (debt, unwise acquisitions, and unfocussed and overly aggressive growth plan, some illl-advised contracts that increased their labor costs in some locations, etc).
A private equity firm has announced they'll buy the company (a higher bidder still might come along, and any purchase needs to be approved by the court). The Board of Directors/management didn't help matters by approving a big bonus payment to management just a few weeks ago when it was already clear the ship was headed for the rocks. Not unusual behavior these days, but also not the kind of thing that makes present debt holders and bond holders eager to take a haircut to keep those folks in their corner offices.
Production of engines will continue, and often these things leave the company in better shape than it started. Old debts will be marked down, some contracts that increased labor costs may be nullified by the court, etc. It is possible that the company will be in a better competitive position at the end of this, especially if some competent management with the long-term interests of the company takes the reigns. Stockholders, bond/debt holders, and present/former employees (in some locations/situations, probably not all) will be the surest losers.

There's money to be made in the small engine business, but it is competitive. The previous B&S managers made some bad choices. Things might have worked out if the overall economy had stayed perfect , but that's no way to plan. Doesn't seem to have hurt them much, which is part of a bigger problem (IMO).
===========================

I figured that was coming. The Honda/Clone Engines have been dominating Go-Kart Racing for years! They're showing up on more Garden Products and Generators, and other Tools more and more. The only Good Engines Briggs make is the V Twins and there Pricing themselves right out of Business. These Honda/Clone Singles are up to (100mm x 86.5mm) 679.6cc. Most Ultralights and Small Kit Planes have an MTOW of 540 lbs to 660 lbs, where 660 lbs need's only 40.1 hp. A 460 Clone Single with 11.0cr, 34mm Carb, 307 Cam, 40mm/32mm Valves, can make 37.37hp@5000rpm.

Clone 460 HP Graph.jpg
 

rv7charlie

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- - - Our redrives for commercial V-Twins.
Also redrives for many other engines: Predator 670 cc, Honda Silverwing 600, Gaokin V-Twins (650, 800, 850 and 1000). All commercial V-Twins and singles.
info@aceaviation.co.uk
www.aceaviationi.co.uk
Hi John,

I've been reading about your products. Whenever I see a posting about the Gaokin V-twins, I ask about 'firewall forward' (all-up) weight, but I've never gotten a clear answer. Can you publish a weight breakdown for at least one example engine, showing bare engine weight, weight of the drive including all required hardware, and cooling bits (radiator, hoses, etc)? The engines seem to make really good power, but some airframes are very weight-limited (ex: my original Kolb Twinstar, which doesn't even seem to have a published gross weight). I know that it can be safely flown with a Rotax 503 (around 95 lbs all-up) and with a 582 (obviously a bit more). But I'd be leery about adding an extra 20-30 lbs to the airframe.

Related question: Have you considered doing a drive for the Yamaha Phazer snowmobile engine (4 stroke version)? 2cyl inline, rated at around 80 HP in the sled. Would probably need a drive ratio of around 3-1.

Thanks,

Charlie
 

Armilite

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Hi John,

I've been reading about your products. Whenever I see a posting about the Gaokin V-twins, I ask about 'firewall forward' (all-up) weight, but I've never gotten a clear answer. Can you publish a weight breakdown for at least one example engine, showing bare engine weight, weight of the drive including all required hardware, and cooling bits (radiator, hoses, etc)? The engines seem to make really good power, but some airframes are very weight-limited (ex: my original Kolb Twinstar, which doesn't even seem to have a published gross weight). I know that it can be safely flown with a Rotax 503 (around 95 lbs all-up) and with a 582 (obviously a bit more). But I'd be leery about adding an extra 20-30 lbs to the airframe.

Related question: Have you considered doing a drive for the Yamaha Phazer snowmobile engine (4 stroke version)? 2cyl inline, rated at around 80 HP in the sled. Would probably need a drive ratio of around 3-1.

Thanks,

Charlie
=====================================

Kolb Aircraft TwinStar MK II
Specifications:
Empty weight: 441 lbs (200 kg)
MTOW: 992 lbs = 449.9636 kg / 10 kg = 44.99636 kw needed = 60.3 hp needed!
Stall speed: 27 kts (31 mph) (50 kph)
Cruise speed: 70 kts (81 mph) (130 kph)
VNE: 92 kts (106 mph) (170 kph)
Climb: 984 ft/min (5 m/s)
Take-off distance: 164 ft (50 m)
Landing distance: 131 ft (40 m)
Engine: Rotax 503 (50hp) A 503UL with an R&D Tuned Pipe made 62.3hp@6500rpm!
Fuel consumption: 4 GPH (15.1 LPH)
===========================================

Kolb Aircraft TwinStar MK III
Empty weight: 475 lbs
MTOW: 1150 lbs = 521.6312 kg / 10 kg = 52.16312 kw needed = 69.9 hp needed!

582UL is rated 65hp@6500rpm
Cylinder & Case Porting can Gain you 10-15% more hp. 65 hp + 10% = 71.5 hp!
A Skidoo 521, 580/582/583, 617 used 38mm-40mm Carbs.
So maybe just a Carb Change and a Muffler Mod might get you 69hp.
A 582UL with a Tuned Pipe would get you 80-82hp!
==========================================

ACE Belt Drive 623 cc = 3.9 Kg (8.6 lbs). 993 cc = 4.2 Kg (9.3 lbs)
==========================================
V-Twin 800cc Cruiser Engine.
Weight 65Kg (143.3 lbs)
44.5Kw@6000rpm = 59.7 hp@6000rpm!

KOLB TWIN STAR II.jpg
 
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rv7charlie

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Hi Armilite,

Thanks. But...

Not a Mk2 or Mk3; an original Twinstar. Empty weight with added Black Max 6x6 wheels/brakes, 6x6 aircraft tires, and a 503 is 382 lbs. So structurally, it's likely to be a lot less substantial than a Mk2 or Mk3.

The engine you linked appears to be the motorcycle version, which has an integrated transmission. Lots of unneeded weight. The UTV/snow/water-craft engines have separate, removable gearsets, but it seems somewhat difficult to get a bare engine weight without the transmission and/or shipping container.

Charlie
 

karmarepair

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These Honda/Clone Singles are up to (100mm x 86.5mm) 679.6cc. Most Ultralights and Small Kit Planes have an MTOW of 540 lbs to 660 lbs, where 660 lbs need's only 40.1 hp. A 460 Clone Single with 11.0cr, 34mm Carb, 307 Cam, 40mm/32mm Valves, can make 37.37hp@5000rpm.
Sources for single cylinder engines of this size please.
 

Armilite

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AMES, IA USA
Hi Armilite,

Thanks. But...

Not a Mk2 or Mk3; an original Twinstar. Empty weight with added Black Max 6x6 wheels/brakes, 6x6 aircraft tires, and a 503 is 382 lbs. So structurally, it's likely to be a lot less substantial than a Mk2 or Mk3.

The engine you linked appears to be the motorcycle version, which has an integrated transmission. Lots of unneeded weight. The UTV/snow/water-craft engines have separate, removable gearsets, but it seems somewhat difficult to get a bare engine weight without the transmission and/or shipping container.

Charlie
=========================
Says Variants: Did Kolb change the name from Firestar II to Twinstar?

Kolb Firestar I at Sun 'n Fun 2006.

This post at: Kolb TwinStar experimental aircraft, Kolb TwinStar experimental lightsport aircraft, Kolb TwinStar homebuilt aircraft, Kolb TwinStar amateur built aircraft, Lightsport Aircraft Pilot News newsmagazine. Shows 454 kg = 1000 lbs.

Firestar I Single-seat, high wing ultralight, powered by a 28 hp (21 kW) Rotax 277 engine or optionally a 40 hp (30 kW) Rotax 447 or a 50 hp (37 kW) Rotax 503 two-stroke engine.

Firestar II Two-seat, high wing ultralight, powered by a 40 hp (30 kW) Rotax 447 or a 50 hp (37 kW) Rotax 503 two-stroke engine.

Tandem Two-seat, high wing ultralight trainer, powered by a 64 hp (48 kW) Rotax 582 two-stroke, liquid-cooled engine.

Firestar II SS Two-seat side-by-side configuration seating and 50 hp (37 kW) Rotax 503 two-stroke engine or optionally a 64 hp (48 kW) Rotax 582 two-stroke engine. Introduced in 2012.

Specifications (Firestar I)

General characteristics

  • Crew: one
  • Length: 20 ft 3 in (6.17 m)
  • Wingspan: 27 ft 8 in (8.43 m)
  • Height: 5 ft 10 in (1.78 m)
  • Wing area: 143 sq ft (13.3 m2)
  • Empty weight: 254 lb (115 kg)
  • Gross weight: 550 lbs = 244.9399 kg / 10 kg = 24.49399 kw needed = 32.84698 (33 hp) needed!
  • Fuel capacity: 5 US gallons (19 litres)
  • Powerplant: 1 × Rotax 277 single-cylinder, two-stroke aircraft engine, 28 hp (21 kW)
Performance
  • Maximum speed: 63 mph (101 km/h, 55 kn)
  • Cruise speed: 53 mph (85 km/h, 46 kn)
  • Stall speed: 27 mph (43 km/h, 23 kn)
  • Never exceed speed: 80 mph (130 km/h, 70 kn)
  • Range: 130 mi (210 km, 110 nmi)
  • g limits: +4/-2

This AD says: 1993 KOLB KOLB TWINSTAR Ultralight for sale - 2380793

1993 KOLB TWINSTAR.
Useful Load: 450 lb with a 503UL. You might e-mail him for the Empty Weight.
 

karmarepair

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These Honda/Clone Singles are up to (100mm x 86.5mm) 679.6cc. Most Ultralights and Small Kit Planes have an MTOW of 540 lbs to 660 lbs, where 660 lbs need's only 40.1 hp. A 460 Clone Single with 11.0cr, 34mm Carb, 307 Cam, 40mm/32mm Valves, can make 37.37hp@5000rpm.
Sources for single cylinder engines of this size please. I have seen performance parts for the two cylinder engines, but not the singles. Please enlighten us.
 

rv7charlie

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Firestars & Twinstars are different a/c. Firestars are single seat, or 2 seat tandem. Twinstars are side-by-side 2 seaters ('twin'...). The yellow wing/green fuselage a/c pictured in the 2nd link is an original Twinstar. But the specs listed with the pic are almost certainly for the Mk2 (as the header says), or a Mk3. It's difficult to believe that a plane designed in the early 1980s (at the latest) has a GW almost 3 times its empty weight.

BTW, that's an impressive asking price for an original Twinstar. Maybe they're collector's items now. Mine had a frame up restoration three years ago, and I'd be happy to get less than 15% of his asking price for mine.

Charlie
 

Vigilant1

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Armilite said:
These Honda/Clone Singles are up to (100mm x 86.5mm) 679.6cc. Most Ultralights and Small Kit Planes have an MTOW of 540 lbs to 660 lbs, where 660 lbs need's only 40.1 hp. A 460 Clone Single with 11.0cr, 34mm Carb, 307 Cam, 40mm/32mm Valves, can make 37.37hp@5000rpm.
Sources for single cylinder engines of this size please. I have seen performance parts for the two cylinder engines, but not the singles. Please enlighten us.
And maybe somebody can show us a picture of the cooling tin and a no-kidding look at the CHT of that 460cc single after 10 minutes at 37 HP.
 

Armilite

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Sources for single cylinder engines of this size please.
==============================

Remember, most USA Part 103 Ultralights and Small Kitplanes have an MTOW of 540 lbs 33hp needed to 660 lbs 40.1 hp needed!

These Honda/Clone Engines are real popular in Go Cart Racing, Mini Bike Racing, Off-Road karts, Air Boats, Hover Craft, etc. The ones that are most useful to us for Airplanes are All based off the Honda GX390 Engine, so Google GX390 Racing Parts and eBay for performance parts. There are many videos on Youtube on doing these Upgrades needed usually $400 for a Single! Red Beard and Pauls Carts are some of the best Videos. A 4 Strokes weakest link is the Valve Train. For Plane use I would use the Billet Needle Bearing Rocker Arms $200 more. Some Upgrades are just to save Weight. Like Stock Cast Iron Flywheels are good to Max 5000rpm but very Heavy. The Billet Flywheel is way lighter and good to 8000+rpm. The Highest I would turn these for Plane use is 5500rpm.

A few of the 30+ sites that I consider better for Honda/Clone parts is:

Bullfrog Racing

ARC Racing

NR Racing

Performance 670

For All of these Industrial Engines for Airplane use:
1. Disable Governor.
2. Disable Low Oil Sensor.
3. Install a Bigger Carb usually a Mukuni 34mm Flatside.
4. Install a K&N Air Filter.
5. Install Billet Rod.
6. Install a Better CAM.
7. Install a Tuned Header Exhaust.
8. Mill Head for a Higher CR. 11.5cr is the highest I would use.
9. Install Hi -Rev kit for 5500rpm.
-------------------------------------------> Where most people Stop.
10. I would use the Needle Bearing Rocker Arms!
-------------------------------------------> If you want more hp.
11. Use Bigger Valves.
12. Port & Polish the Heads.
13. Change Bore & Stroke for more CC.
===============================

A 460 Single using 11.0cr, 34mm Carb, 307 CAM, K&N, Tuned Header, 40mm/32mm Valves made 37.37hp@5000rpm. So if a 440 was built the same way it would make about 2hp less, a 420 about 4hp less. I would figure a +/- 20cc = 2hp and it would be real close. A Duromax 440 18hp with Electric Start when On Sale was $289.00.

ACE Belt Drive to USA $669.
Duromax 440 $289 when on Sale with Electric Start.
1-9 Upgrades $400. Total $1358.00
With #10 Upgrade $200. Total $1558.00

Would give you a Solid 35hp@5000rpm Engine!

With #11, #12 you could probably have a 40hp Engine. You can Buy New Heads already Ported & Polished and with Bigger Valves for around $350.
 

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Armilite

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And maybe somebody can show us a picture of the cooling tin and a no-kidding look at the CHT of that 460cc single after 10 minutes at 37 HP.
===============================

First, these are Fan Cooled Engines designed to be stationary at 3600rpm all day long! When used on things that Move they get way more Cooling Air. These Honda/Clone Engines are used with No problems at 5000rpm to 8,000rpm on Racing Go Karts all year long. This 460 was built for a different purpose so hp maxed out at 5000rpm. NO Engine used on any Airplane is used at MAX FULL POWER continuously, only for takeoff, usually 2-3 min, then throttled back to 75% Power. Most Racers I have talked to like regular Mobil 1 Oil in them.

Test Runs Chinese 800cc 61hp ATV V Twin converted to Ultralight Engine. "Claimed 61hp, not sure what the carburated version is. I'd think it's short of that as holding it down to 5000-5500 and peak's at 6250-6500."

A Single is just 1/2 of a V-Twin.
 
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Armilite

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Firestars & Twinstars are different a/c. Firestars are single seat, or 2 seat tandem. Twinstars are side-by-side 2 seaters ('twin'...). The yellow wing/green fuselage a/c pictured in the 2nd link is an original Twinstar. But the specs listed with the pic are almost certainly for the Mk2 (as the header says), or a Mk3. It's difficult to believe that a plane designed in the early 1980s (at the latest) has a GW almost 3 times its empty weight.

BTW, that's an impressive asking price for an original Twinstar. Maybe they're collector's items now. Mine had a frame up restoration three years ago, and I'd be happy to get less than 15% of his asking price for mine.

Charlie
==========================

A T-Bird II made for 40 years has an MTOW of 1310 lbs = 594.206 kg / 10 kg = 59.4206 kw needed = 79.68434 (80 hp). That's why they used the Rotax 912 80hp on it. For the 582UL (65hp) they drop the MTOW to 1,071 lbs. The T-Bird I & II use mainly .065" Wall Tubing.

Many of these Old Planes were never properly Load tested, the Original CGS Hawk was, and many just Copied the CGS Hawk Wing. If you look at the Aerolight 103 today it uses predominantly .058" Wall Tubing and has an MTOW of 600 lbs, the very similar Phoneix 103 is built with the same .058" Wall Tubing and has an MTOW of 650 lbs. My T-Bird I which both of them 103's are patterned off uses predominantly .065" Wall Tubing and has an MTOW of 660 lbs with a 582UL (65hp). Which 660 lbs needs only 40.1 hp and Rotax doesn't make a 447UL anymore! Where their T-Bird II with a 582UL (65hp) has an MTOW of 1071 lbs = 485.7974 kg / 10 kg = 48.57974 kw needed = 65.1465 (65hp) need. Indy Aircraft never used any Engines but Rotax. The previous owner of the T-Bird line when West of Des Moine, IA put just about every engine you can think of on them.

Today, we have 400cc Singles making 54hp@6500rpm. 382cc Singles 48hp@6500rpm, 362cc 44hp@6500rpm.
 
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