Light Weight VW

[wanttobuild]

Does anyone have any ideas on how to shave a few pounfs off the VW?
It is so easy to add weight, and some things cant be avoided.
One member suggested stop eating. I dont really want 2 go that far.
I think swapping the carb 4 FI is gonna b a wash, or may weigh more.
Any ideas?

 

[Turd Ferguson]

Does anyone have any ideas on how to shave a few pounfs off the VW?

side grinder and 12 pack?

 

[Pops]

A 4 cylinder VW long block is 116 lbs. So make everything you add as light as possible. No electrics. I cut the top of the rear of the block above the top bell housing bolt holes to save weight. You can see in the picture. Replace the bottom round steel oil screen plate with one make from aluminum and welded a small sump to the plate and extended the oil pickup tube down in the sump with a 1/8" pipe plug for an oil drain. Replace the oil by pass plate where the stock VW oil cooler bolts on with one I made from aluminum. Moved the oil dip-stick tube to the rear of the block to make it easier to check the oil, no weight saving , but much better. Used the stock alum VW dog-house oil cooler by welding aluminum blocks on and treading for the oil lines ( full flow oil cooler). GP's single mag drive with a Slick mag. Welded up aluminum intakes except over the head, they are SS bathroom handrails from Lowes box store , use then because of the pre-formed bends and they cost a little weight over being made from alum. Also used the SS handrails for my exhaust stacks, wish the wall thickness was a little less. Welded the 4130 engine mount and used rubber shock mount rubber from NAPA auto store. Welded up a breather box that bolts on the generator stand. For the 1835 cc engine everything forward of the firewall weights 141 lbs. Wouldn't do any grinding on the block except for cleaning up flashing at molding seams.

 

[BBerson]

Aluminum jugs are available but expensive. No electric saves the most weight.
I would like to get the weight to 2 pounds per hp like a cont or Lyc. Say 1600cc 50hp and 100 pounds.
It would take some major surgery to do that.

 

[Pops]

Aluminum jugs are available but expensive. No electric saves the most weight.
I would like to get the weight to 2 pounds per hp like a cont or Lyc. Say 1600cc 50hp and 100 pounds.
It would take some major surgery to do that.

I have weighed a 1200cc, 40 hp, a 1600 cc, and a 1835 and 1915 engine and they all weighted 116 lbs for the short block. Never going to remove 16 lbs so would have to develop more HP.

2 pounds per hp could be done with a 2180 no-electric of 75 HP. Its just 2 lbs heaver than my 1835cc 60 HP. So I could change my 1835 to a 2180 and have a firewall forward weight of 143 lbs @ 75HP. Then that blows a hole in my 3 gph @ 80 mph cruise ( that is 26.6 mpg)

 

[BBerson]

I have weighed a 1200cc, 40 hp, a 1600 cc, and a 1835 and 1915 engine and they all weighted 116 lbs for the short block. Never going to remove 16 lbs so would have to develop more HP.

2 pounds per hp could be done with a 2180 no-electric of 75 HP. Its just 2 lbs heaver than my 1835cc 60 HP. So I could change my 1835 to a 2180 and have a firewall forward weight of 143 lbs @ 75HP. Then that blows a hole in my 3 gph @ 80 mph cruise ( that is 26.6 mpg)

But I don't want 75hp.
I really just want 30hp in a low rpm smooth running four cylinder. A VW at 2100 rpm is really smooth. Much smoother than a A-65
I think I can shoehorn a 100 pound VW into and ultralight. 100 pounds plus 154 pounds airframe = 254 pounds

 

[weasel]

But I don't want 75hp.
I really just want 30hp in a low rpm smooth running four cylinder. A VW at 2100 rpm is really smooth. Much smoother than a A-65
I think I can shoehorn a 100 pound VW into and ultralight. 100 pounds plus 154 pounds airframe = 254 pounds

Its a compromise man. If you want 4 cyl its gonna weigh 120 +lb. I have a 2400CC on the Fisher Classic with Ni-Com Cyl's minimal everything and even had the bell housing shaved off because I use a bed mount. came in at 126lb which includes carb, intake, magneto, ignition leads, engine mount bushings, engine mount bolts, and oil cooler.

If you want only 30 HP you would be better off weight wise with the 1/2 VW. Cassler makes a crank that is re-balanced with additional weights and runs much smoother than the homebrew 1/2 VW that only have a cut crank. I have operated both.

 

[Pops]

Its a compromise man. If you want 4 cyl its gonna weigh 120 +lb. I have a 2400CC on the Fisher Classic with Ni-Com Cyl's minimal everything and even had the bell housing shaved off because I use a bed mount. came in at 126lb which includes carb, intake, magneto, ignition leads, engine mount bushings, engine mount bolts, and oil cooler.

If you want only 30 HP you would be better off weight wise with the 1/2 VW. Cassler makes a crank that is re-balanced with additional weights and runs much smoother than the homebrew 1/2 VW that only have a cut crank. I have operated both.

View attachment 57461

Right on.

I have been in the process of building a straight drive 2180 flywheel drive with a bed mount, bell housing cut off and making a mag mount for the pulley end. ( no one sells a mag drive for the pulley end). Like my 1835, this 2180 will be built for low rpm torque for max performance at prop rpms. Everything firewall forward will be as light as possible. Have some ideas about making some carbon fiber parts.

 

[BBerson]

Its a compromise man. If you want 4 cyl its gonna weigh 120 +lb. I have a 2400CC on the Fisher Classic with Ni-Com Cyl's minimal everything and even had the bell housing shaved off because I use a bed mount. came in at 126lb which includes carb, intake, magneto, ignition leads, engine mount bushings, engine mount bolts, and oil cooler.

If you want only 30 HP you would be better off weight wise with the 1/2 VW. Cassler makes a crank that is re-balanced with additional weights and runs much smoother than the homebrew 1/2 VW that only have a cut crank. I have operated both.

View attachment 57461

Wow, that is light for 2400cc.
A half VW is major surgery. Just looking at new ideas for major surgery on a full VW for something different.
Casler told me the half shakes more, obviously. It has a rocking couple that can't be solved with crank balance. And I want 2100 rpm, not 3500.
For now, I am proceeding to test a 670cc Honda at 2700 rpm. The VW is just an option if significantly more power is desired or required.
Might be better to start with a different engine base to get to 1600 cc, but I don't know what. A flat four is always smoother than a v-twin. I have collected two VW engines in the past few months for less than $500 each.

 

[Pops]

The only time you have enough power is when you run out of rudder and then you can always make the rudder bigger.

 

[litemite]

There is a guy in Arizona who put a full VW in a Hummelbird. Talked with him and he did a lot of "grinding on the crank" machining the fins on the jugs, drilled out the cam and took off all he could off the case and got about a 110/120 pound engine. He flies it just about every day.

 

[Pops]

View attachment 58239 There is a guy in Arizona who put a full VW in a Hummelbird. Talked with him and he did a lot of "grinding on the crank" machining the fins on the jugs, drilled out the cam and took off all he could off the case and got about a 110/120 pound engine. He flies it just about every day.

By the straight down intake at the head and the single port head, its a 1200 cc , 40 HP case. They do make a large bore 83 mm pistons and jugs instead of the stock 77 mm pistons and jugs for a 1300 cc, 45 HP.

Picture of the 1200 cc, 40 hp VW that I had on the SSSC for the first 35 hrs. Great little engine. I was wanting better performance for my 230 lbs. Went to the 1835 cc, 60 HP engine.

 

[BBerson]

I have a stock 1600 core, how much heavier is that than the 1200c.c.?

 

[BBerson]

View attachment 58239 There is a guy in Arizona who put a full VW in a Hummelbird. Talked with him and he did a lot of "grinding on the crank" machining the fins on the jugs, drilled out the cam and took off all he could off the case and got about a 110/120 pound engine. He flies it just about every day.

That drilling and machining is my thought.
Please post more details if you have any more info about bore and stroke etc. Thanks.

 

[Pops]

I have a stock 1600 core, how much heavier is that than the 1200c.c.?

None. The 1200 has thicker jugs that makes up for the weight of smaller 64 mm crank over the 1600 cc , 69mm crank.

In post #5 I said, "Short block" that should have been "Long Block".

 

[BBerson]

Ok, so no need to find an 36hp or 40hp case.
If I were to make a hollow 64mm or less crank and thin wall jugs the weight could be 100-110 pounds.

 

[Pops]

Ok, so no need to find an 36hp or 40hp case.
If I were to make a hollow 64mm or less crank and thin wall jugs the weight could be 100-110 pounds.

Don't think of a hollow 64 mm crank if you like reliably. The only other jugs and pistons made for the 1200cc engine is a set of 83 mm oversize jugs and pistons and the weight is the same. The 36 hp engines are collectors items and a different engine from a 40 hp engine and very hard to find any parts. No matter what, you will be starting with a 116 lb VW engine and adding intakes, carb, exhaust, prop hub, mag drive and mag or a distributor and coil. Then the prop, engine mount and if needed an oil cooler and lines. Going to a 2180 will weigh 2 lbs more than a 1200 to 1914 cc engine. My 1835 cc engine on the SSSC weights 141 lbs firewall forward. I could save a couple of pounds going to thinner exhaust stacks and intakes. On my flywheel drive 2180 cc engine (75 HP) that I am building, thinking of making part of the intake manifold from Carbon Fiber to save some weight. If I cut the bell housing off as much as possible (be using a bed type of engine mount) and CF intakes, might get the firewall forward weight down to 138 lbs. That is watching grams.

 

[lr27]

Are there still some magnesium VW blocks (I think it was the blocks) out there? That might help.

Are the Verner engines any good? The 3 cylinder radial seems suitable. 34 continuous hp at 2200 rpm, according to them. I guess it might be harder to find parts than for a VW.

 

[bmcj]

Just curious, what would happen if you drilled holes through the cooling fins and fluted the edges? It would remove a little bit of weight and give the fins more radiating area.

 

[BBerson]

Don't think of a hollow 64 mm crank if you like reliably. The only other jugs and pistons made for the 1200cc engine is a set of 83 mm oversize jugs and pistons and the weight is the same. The 36 hp engines are collectors items and very hard to find any parts. No matter what, you will be starting with a 116 lb VW engine and adding intakes, carb, exhaust, prop hub, mag drive and mag or a distributor and coil. Then the prop, engine mount and if needed an oil cooler and lines. Going to a 2180 will weigh 2 lbs more than a 1200 to 1914 cc engine. My 1835 cc engine on the SSSC weights 141 lbs firewall forward. I could save a couple of pounds going to thinner exhaust stacks and intakes. On my flywheel drive 2180 cc engine that I am building, thinking of making part of the intake manifold from Carbon Fiber to save some weight.

I am talking about a severe power derating for an ultralight. I might be able to get a 100 pound engine into an ultralight but not 145.
Almost all airplane engines are hollow crank for lightness. It only needs to go to about 2600 rpm. 20hp at 2600 rpm with a large prop is significant thrust for an ultralight.