Galley Plug instructions - Type 4 aero conversion

[T4Flyer]

Hi there,

This is my first post on this forum, just joined yesterday!

I am building a new engine for my plane based on the 2000cc air cooled VW type 4 engine, with an aero conversion.
The engine is basically as follows.

• VW 2.0L block, Bored to accept the Mahle cylinders, fitted with new propeller hub bearing in nose of case, all oil plugs drilled, taped and fitted with brass NPT threaded plugs.
• VW 2.0L “71mm” crank, machined to accept the propeller hub.
• VW 2.0L connecting rods, resized, re-bushed and balanced to - - - - - - - - - - - -Big ends: (1-4) = 547.7 grams, Small ends (2&4) = 257.6, 1 = 257.5, 3 = 257.4 grams. Overall 2 = 805.4, 4 = 805.3, 1 = 805.3, 3 = 805.1 grams
• Big-end bearing “new” STD size
• Main bearings “new” +0.010”
• VW 2.0L flywheel, lightened to 2.732 Kilogram

• Porsche 914 cylinder heads
• Cylinder Heads machined for twin spark plugs (second plugs 10mm)
• Cylinder Heads = chamber capacity matched at = 58cc.
• Inlet Valves = 42mm, Intervalves (VW 2.0L – Porsche 914) Part # 039-109-601-G. (sourced from “Pelican Parts”)
• Exhaust Valves = 36mm Sodium Filled, Intervalves (VW 2.0L – Porsche 914) Part # 039-109-611L-M154. (sourced from “Pelican Parts”)
• New valve collets. (sourced from “Pelican Parts”)
• Heavy duty valve springs. (sourced from “Pelican Parts”)
• Rocker Shafts= New heavy duty # 8216 (sourced from “The Type IV Store”)
• Rocker Spacer Kit # 8220 (sourced from “The Type IV Store”)

• Cylinders = Mahle cast aluminum. (Nikasil re-plated)
• Pistons = JE Pistons, custom made 100mm, (using the Mahle pistons that were used with the original piston & cylinders as a pattern) piston crown machined with a dish of 80 x 1.5mm (all checked @ 8.4cc)
• Pistons balanced. (Pistons and matching pins balanced to 1 = 597.2. – 2,3&4 = 597.4 grams.
• Piston Rings = JE Pistons, 100mm (Porsche) Part # J660U1-3937 “ bore 3.937” Phosphate 1.5 x 1.75 x 3.0.

• Cam = WebCam, grind 73. (sourced from “Aircooled.net”)
• Cam followers = WebCam, High performance “solid” Part # 00-263 (sourced from “Cyberauto”)
• Cam Gear = Scat, Type 4 Bolt-on Aluminum cam gear – STD. Part # 20171STD. (sourced from “Aircooled.net”)
• Cam Bearings = Mahle original, double thrust Part # VW021.198.541. (sourced from “The Type IV Store” Part number # 4312)

• Oil Pump = Schadek, 30mm. (blueprinted and case oil galleries ported to match pump. (sourced from “Aircooled.net”)
• New oil pump cover and cover nuts (sourced from “Aircooled.net”)
• Oil Pump fitted with a 2mm aluminum spacer between pump and oil pump (gives better clearance between oil pump and cam bolts and better lines up pump and case oil galleries).
• Cylinder shims machined 2 x 0.25mm and 2 x 0.45mm to give a deck height of 0.93mm.
• Static compression ratio set at 8.561 – 1.
• Pushrods = Manton Chromoly 3/8” (sourced from “Aircooled.net”)

• Ignition is by two fully electronic, fully independent units, each firing its own set of plugs (no distributor at all) with 28 degrees of advance at 3,000 RPM
• Induction is normal atmospheric via a simple slide type aero-carb. (Mounted UNDER the engine!)

I would be happy to post some pictures if anyone is interested?

Cheers..

[JohnHoffe]

Hello T4,

Welcome.

Are you going to use some form of crank position gear (60-2?) to do ignition timing?

I have a T4 in a buggy running twin spark, a MicroTech management system, using a 60-2 gear and magnetic pick up, with 4 off dual output coils. Guess that won't work for you?

[T4Flyer]

Hi John,

I have an aluminium pulley attached directly to the lightened flywheel which drives the alternator. the pulley has two rare earth magnets epoxied into it, spaced at 180 degrees. the pickups (one for each system) are mounted on custom brackets straddling the pulley attached to the engine mounting case.

Quite difficult to explain, I can see it, but maybe I'm not explaining it so well... I can post some pic's if it is of any help

Regards

[eben]

Hi T4 saw your post on STF.

Please post some pictures yes.

Loads of work that you have done there.

Welcome

[T4Flyer]

OK Eben, here goes,

PISTONS:

My old engine had a set of Mahle 100mm pistons and cylinders (forged pistons & cast aluminum Nikasil cylinders) when I tore down the engine I found the cylinders were quite worn. After months of searching I was unable to find the correct rings for the Mahle pistons. Eventually I contacted JE Pistons and they said they could make me a new set of rings. However, after looking at their catalogue I decided to have complete new pistons made to take the Porsche 100mm rings. I sent a piston to JE and they sent it back with 4 shinny new ones (I had them made flat top as I thought that would be a better way to go)

I was wrong My plan was to increase the deck height to 2.06mm to achieve a static compression of 8.5 - 1... wrong wrong wrong!!!!! "to much deck height" I had to either remove +-8cc from the chambers or machine a dish in my nice new piston to achieve a deck height of +-1mm. I chose to dish the pistons. Long story, making up special tool to hold pistons took longer than the actual work, still all's well now.





Guys if you get bored, tell me to stop!

Gheers

[Rabid_ant]

engine engineering.....lol.....why would we get bored!! Bring it on!!

[Blitzkrieg]

We love all this Type 4 porn

[T4Flyer]

Ok you asked for it, engineering porn it is

I built my own rig for balancing the cylinder head chambers (Heads, a later story) I used it to check each piston after machining the new dishes, I was expecting to do some hand finishing to get the balance right, but they all came out at 8.4cc hows that



The next job was balancing the pistons, I contacted JE and they told me that 5 grams was considered Ok for road use and 1 gram for race use. My new piston were already +-1gram. Anyway, I thought I might be able to do better so I set to work weighing each piston and pin, mixing and matching to get the best balance and then grinding to achieve a final spread of only 0.2 grams. I became quite obsessive but its really hard to get better as you are working with only half a feather at weights of +- 0.2grams




Cheers for now

[Rabid_ant]

jekyll........

[eben]

wow. What work do you do? Ie. where do you get your knowledge skill from if you don't mind me asking?

[JohnHoffe]

Did you confirm valve to piston clearance?

I had to machine 9mm deep pockets into my 103mm pistons to prevent the valves (48 & 40mm) from hitting (in case a valve seized open) the pistons. The effective valve lift with my cam is about 10.8mm.

[Rabid_ant]

hhmmmmm....T4, you have such a long pipette......

[eben]

its the vaseline that worries me

[Rabid_ant]

ROFL......pipette and vaseline in the same photograph!!

[T4Flyer]

You bet yeh.... you should see the size of the stand I had to make to hold it upright

Some help please. I,m finding the site very slow. I just lost a post because the upload was taking so long it crashed (I hate typing so I,m very mad )

Also when I try to run a spell check it opens for a second or two then closes!

Whats going on... I,m using 3G, is that a problem with this forum (I heard it can be with some forums)

I know more about engines than computers, advice please.

Cheers