Building a VW Aero-Engine

[Flyguyeddy]

Solved! - A Standard Engine for Homwbuilts

The final piece of the puzzle fell into place when DuraFix altered the alloy of their aluminum brazing rod. The new rod allows us to apply...

bobhooversblog.blogspot.com

 

[Flyguyeddy]

We are way off in the weeds here now as the OP is building an 1835 for his purposes

 

[Pops]

Nope.
When I built VWs for pay I had a shop in Denver that did my rods in bulk. They matched the sets for me. Since then I farm out this kind of work to a local shop that specializes in balancing.
When I needed to DIY I cobbled something together using my chemistry lab equipment.



It has been a few years and my memory isn't 100% today but I seem to remember that the older gasket style flywheel/crank used larger ID shims and I had a selection of both sizes on the pegboard at the rebuild station?

The 1200 cc 40 hp crank has a slightly different ID on the end of the crank. So the shims for this crank has a different ID than for the 69 mm stoke crank.
I just overhauled a 1965, 1200 cc engine and had to go thru my stash of shims to find what I needed.

 

[flitzerpilot]

I believe if you went to less pitch you will get more climb with the same top speed.

It over-sped in a shallow dive with a 30" pitch propeller (3400 rpm). Red line in the UK for the VW is 3300, although some racing types exceed this. Initial tests were performed with a fine prop and in a TV dive at 125 mph IAS the tips reached Mach 1. The noise was shattering at nearly a mile distant! :0) The present airscrew was modified with some under camber and maintains 3000. The Aerovee -powered Z-21 operated by Hercules Propellers turns a 65" dia x 32" pitch prop @ 3000 throughout continuous aerobatic routines with a full throttle setting. I intend to replace my propeller in due course with a Herk prop.but I am fairly happy with this one - although it's been cropped slightly after an altercation with a charging deer on take-off a few years ago, which forced me to enter standing crop.

 

[JimCrawford]

Regarding the crankshaft end float shims. There are two possibilities for the bit of the crankshaft protruding from the no. 1 (flywheel end) bearing. When the 'flywheel' (or alternator adaptor or whatever you may be using to drive a prop from this end) uses an O ring oil seal then the crankshaft from just outside of the bearing to the end steps down to 53.5 mm for all of this length (~10mm) and provides a land for the O ring contained in a groove in the flywheel. On other crankshafts the 53.5mm part is only about 3mm at the end, doesn't allow space for an O ring and the oil seal is provided by a paper gasket trapped between the end face of the crankshaft and the flywheel. So for the O ring crank you need shims with an ID of 53.5mm and for the gasket crank you need shims with an ID of 55mm. The OD is the same for both at 70mm (?).
Strangely the 55mm shims seem unobtainable in the UK but I made up a tool to clamp 53.5 shims, which are readily available, and enable me to open them out on the lathe.
Two of my three engines need the larger ID but the third is a Revmaster 1834 and the crankshaft float is shimmed forward within the crankcase so no number 1 bearing shim is required.

 

[Pops]

Worked on the VW engine for the mud buggy today. Pressed the cam gear on the crank and now about ready to close the case. This engine also has the Bob Hoover HVX oil mods. Also will be using single port heads for slower off road use.

 

[Flyguyeddy]

Worked on the VW engine for the mud buggy today. Pressed the cam gear on the crank and now about ready to close the case. This engine also has the Bob Hoover HVX oil mods. Also will be using single port heads for slower off road use.

Pops, how big is the woods buggy engine going to be?
Jake raby used to sell single port big vw’s for busses back in the day, he posted a good combo a while back. I bwlieve it was a 2100 cc engine

 

[Flyguyeddy]

From a thread on the samba:

“This is for a VERY good running 2110

82X90.5
Web 218+5/218
1.25 rockers
8.3:1 CR
Single 44IDF center mounted (have to fab your own intake)

Heads were stock single ports with ported intakes and only polished exhausts. (I have flow data in my files) valve sizes were 37.5mm intake and 35.5mm exhaust. Single springs and conventional (Non semi hemi) chambers. I unshrouded the valves and worked the chambers by hand to get to about 62cc. Deck was set to .060

Exhaust ran was a 1-1/2 header with dual quiet packs

At the time I was using a single vacuum dizzy.”

 

[Hot Wings]

Pressed the cam gear on the crank

Pressed on?
I have an old gland nut welded to tab so I can put the crank in the vise for assemble.
Put it in the vise vertically for the bearing and gears. Horizontal for the rods.
I balance the cam gear in the end of the crank, squirt a little assembly lube on it and heat it with a propane torch until the oil just starts to smoke (don't want to over heat the gear). I then just grab it with a folded up shop rag and it slips into place - sometime a little tap with a plastic tipped hammer. Follow the same procedure with the brass gear, but only heat until I see a change in viscosity/wetting of the oil.

 

[Pops]

I shouldn't have used the word "Pressed" Should have used "dropped".
I put the crank in the freezer for a couple of days, Take it out and put in my big vice just enough to gently hold it vertical. Heat the cam gear in oil until the oil is smoking. Drop the #3 bearing on with the locating pin towards the flywheel end, take the cam gear out of the hot oil and drop it on. If you are fast enough the gear drops all the way on. Yep, same for the brass gear, but just get it a little hot and it will drop on. Didn't have to tap ether one with a hammer.
I always bolt the crank to a old flywheel that I use and stand the crank up vertical and put the rods on.

If I have to tap the cam gear with a hammer, I use a old wagon wheel hub from my grandfather's black smith shop that I have, the small end is just the right dia to fit the cam gear. Built many VW engines with the old wagon hub. Grandfather would just smile if he saw me using it.

 

[Pops]

Pops, how big is the woods buggy engine going to be?
Jake raby used to sell single port big vw’s for busses back in the day, he posted a good combo a while back. I bwlieve it was a 2100 cc engine

I have a stock set of 85.5's but think I'll buy a set of bolt on 87's. Don't need a lot of power, just running the back logging roads and trails. Also have a 40 hp , 1200 cc, I might put in if I want to get some high mileage. Will not be much running in 4 th gear. My aluminum fuel tank holds 13.5 gal.
Going thru my stash of VW engine parts, I found another good German stock crank the other day that I didn't know I had.

 

[Hot Wings]

I use a old wagon wheel hub from my grandfather's black smith shop that I have, the small end is just the right dia to fit the cam gear. Built many VW engines with the old wagon hub. Grandfather would just smile if he saw me using it.

 

[karmarepair]

Opening the middle bore of the shims would be super simple in a lathe with a tool to hold them. Just do a big stack of them all at once held in an OD fixture that clamps them in place

Another way to do it, for those of us without lathes. Sketch courtesy of R.S. Hoover, who was a friend of mine.

 

[Pops]

Another short video.
To find the simple formula for working out the length of the torque extender for the length of your torque wrench go to utube and type in a search of " torque wrench extender bar". Several videos on the subject.

 

[n45bm]

Another short video.
To find the simple formula for working out the length of the torque extender for the length of your torque wrench go to utube and type in a search of " torque wrench extender bar". Several videos on the subject.

Pops, Thanks for your videos, they are informative. However, I would like to make a suggestion: locate the camera where we can get a closer view of your matter subjects. I believe a closer view of your home made tools and other engine mods would be easier to understand if we could get a better view. Thanks.

 

[Pops]

Pops, Thanks for your videos, they are informative. However, I would like to make a suggestion: locate the camera where we can get a closer view of your matter subjects. I believe a closer view of your home made tools and other engine mods would be easier to understand if we could get a better view. Thanks.

I agree, after watching the video. I do no editing, so I should have redone it with the camera closer.

 

[don january]

I was more worried about you doing what I would probably have done and that is drop the torque wrench and shatter the glass table top. Wouldn't that make for a unexpected re-do on the video. Bummer

 

[lakeracer69]

Pop's, what nut are you using to hold the "prop hub" onto the crankshaft? Is it the gland nut that would be there anyway for a car, or something else?

Thanks

 

[Pops]

I was more worried about you doing what I would probably have done and that is drop the torque wrench and shatter the glass table top. Wouldn't that make for a unexpected re-do on the video. Bummer

Don't even say that.

 

[Pops]

Pop's, what nut are you using to hold the "prop hub" onto the crankshaft? Is it the gland nut that would be there anyway for a car, or something else?

Thanks

If it's a flywheel drive , you use the large Gland nut that holds the flywheel on. If you are using a prop hub on the pulley end and large bolt comes with the prop hub that GP's sells with either the Shrunk on or the tapered hub.
Prop hub for standard cranks for the pulley end. 0072 / Shrink Fit Prop Hub Kit

The large gland nut and washer on the flywheel end can be bought made with chromoly steel and also a wider head. I just use the stock VW gland nut.

Chromoly Gland Nut & Washer, Economy, 42mm Head, 031-2242 - Aircooled.Net VW Parts

Chromoly Gland Nut & Washer, Economy, 42mm Head, 031-2242 is a fantastic Gland Nut that uses a 42mm Head Socket. Super strong 4130 Chromoly steel billet that is precision machined on CNC equipment. Comes with OEM style pilot shaft bearing for long life.

vwparts.aircooled.net

Stock Gland Nut (Flywheel Bolt/Flywheel Nut), Type 1 Based Engines

This is the bolt that holds the flywheel the crankshaft on VW Upright Engines, and also Type 3s. This comes WITH the Needle Bearing (Pilot Shaft Bearing) inside the gland nut too! Make sure to torque this to spec!

vwparts.aircooled.net

Chromoly Gland Nut & Washer, Economy, 36mm Head, 031-2236 - Aircooled.Net VW Parts

Chromoly Gland Nut & Washer, Economy, 36mm Head is a fantastic Gland Nut that uses a stock 36mm Head Socket. Super strong 4130 Chromoly steel billet that is precision machined on CNC equipment. Comes with OEM style pilot shaft bearing for long life.

vwparts.aircooled.net

Chromoly Gland Nut & Washer, Economy, 44mm Head, 031-2244 - Aircooled.Net VW Parts

Chromoly Gland Nut & Washer, Economy, 44mm Head, 031-2244 is a fantastic Gland Nut that uses a 44mm Head Socket. Super strong 4130 Chromoly steel billet that is precision machined on CNC equipment. Comes with OEM style pilot shaft bearing for long life.

vwparts.aircooled.net