EngineAssembly

EngineAssembly

We decided to build an engine from new parts starting with a new Brazilian case... The case was costly to modify and this is what we had to do... Mostly the case has more material around the main bearing bosses and a reputation for needing line boring to match the case half's right out of the box... Our case matched between the case half's...

1) The rear main closing cover has to be on the boss face and not down inside the machined area as Leonard's plans show it... I think Leonard has changed to this mounting method...

2) The case savers on the rear cylinders have to be decked for the covers to seat down on the cylinder sealing surface...

3) The rear main thrust bearing will not fit on the center (#2) main web... We moved the rear main thrust bearing to the front (#3) main web and put 3 thrust washers on (both sides) of the bearing and machined about .180 (dimension may vary widely) from the back side of both cam gears to develop the .004 crank end play... The crank cut end washer and bolt was left on because the washer staking dowel pin (Leonard's plan does not show this) goes right into an oil gallery in the crank!... If you think about the thrust forces in the crank you'll really like this setup BUT it costs money... YOU MUST HAVE 45 POUNDS OF OIL PRESSURE OR MORE AT CRUISE WITH THIS SETUP!

4) We had to do a stroker clearancing job on the case because the 69mm (standard crank) counterweights hit the beefed up areas on the main bearing bosses... It just costs money to fix...

It's better to build from good used German parts...

5) We believe that it's best to use the 8mm cylinder bolts because VW has spent a lot of money getting the expansion characteristics worked out for an aggressive exercise... Bigger is not better!... You will need to cut some off these bolts - dry assemble first to see what fits as there are objects to clear in the rocker box and cosmetics outside the rocker box...

6) There is much discussion about the single rocker stand bolt mounting... DO NOT over tighten this bolt - put a new waver washer under the nut and torque to 13 foot pounds!...

7) We used non detergent #30 weight oil initially to speed the break-in process... The rings seated after about 30 minutes of running the engine at 1800 RPM in several short sessions... We are using a crankcase vacuum producing flapper valve on the generator stand opening instead of the simple flat vent cover... This device should not be used until the rings are seated due to excessive crankcase pressure caused by blow-by...

8) Please note that we do not have an external supplemental counterweight on the prop extension or the rear of the crankshaft... We will soon rebalance the crankshaft using the external counterweight method to achieve a more vibration free status... Scott Casler of Hummel Engines will perform the balancing process on your parts...

9) Don Bolton of The Bug Patch observed our engine running and suggested the baffles to prevent cooking the back side of the jugs... Don also theorizes that the jugs should be installed with the flat side forward on the 1/2 vw for better overall cooling in the cylinder area...

10) Roman Wasilewski, my aviation mentor, saw the engine run the first time - he held the fire extinguisher - and made me promise to put colored paint on both sides of the prop tips... It is true that you don't notice the prop when your working on the engine and it's RIGHT THERE...

11) We are getting a lot of erosion on the leading edge of the prop and will need to put 2 layers of bidirectional glass tape on the leading edge soon... Our operation area soil is DG (Decomposed Granite) predominately and it is really abrasive... We are testing 3M 8672 Transparent Protective Tape on the leading edge instead of glass tape...

Here's the assembly sequence...