2143 motor build

[Timas]

Hey Gang 2 or 3 questions:

1) what is the projected cc volume for 96mm binal cylinders?
I know AA states that volume pocket is 3 cc +. 35.5 mm chamber. I do not understand how to calculate what mm:cc conversion is. I'm also lazy and haven't looked up the formula

2) Is it even possible to build a type 4 2143 engine?
I have not seen anyone build a motor this size seems like 2110 is common but I think that is just for type 1 right?

Anyways, thank you in advance.

[Bruce.m]

35.5mm is the compression height, which is the measurement between the piston pin centre line & the top of the piston.

The 66mm crank uses a different height piston so the overall length is the same

[Bruce.m]

If you want to calc compression ratio you need the head chamber volume and the deck height.

There are a couple of calcs online where you punch in the numbers & it does the calc

[Bruce.m]

74mm stroke crank & 96mm pistons get you that capacity. But not sure if there are parts (crank / rods / pistons) to make that combo work.

[Timas]

Well I guess that would explain why I have not really seen that figure as a common build.
Ok, so what motor would you all suggest I build?
I need lots of torque at low rpms for climbing up long hills, want to keep up with traffic and have my motor last.
The only things I think I would
like to keep are as follows:
Stock rods ( mine are genuine v dub)
Stock rocker arms. Already have these
I would like to save money by using some of the parts I already have.

[Bruce.m]

In you shoes (& I’m making some assumptions about the amount of experience you have building aircooled VW engines).

I’d rebuild it as a 2.0l with the stock 71mm crank & rods. You could go to 2056cc with 96mm piston but it’s a small gain. A flat top piston also bumps up the compression ratio.

Follow a good manual. Check the case properly. On these engines the case bores have a very tight tolerance of 0.02mm new & the wear limit is +0.01mm. Get the crank+ flywheel balanced.

You’ll run into challenges & need to figure out the right assembly technique, the right sealers to use, how to check the oil pump & such like. Original pumps aren’t available new so you need to use a modified type1 pump.

The original camshaft is probably worn, by worn out lifters. So that needs examining. You could get a non standard camshaft but that adds some extra complexity to the build (cam timing, rocker geometry etc), but not excessive effort.

You need to make decisions about the heads. Could go original 2.0 van heads… or maybe an upgrade to 1.7 car heads which have slightly bigger valves & smaller chambers. So careful consideration of the compression ratio is needed.

Then you need to sort out the fuel delivery, spark, exhaust etc.

Once that’s done you have a working vehicle again and a solid apprenticeship under your belt. You’ll probably be unhappy about the performance though…..

So at that point you look for a good core engine to buy and start gathering the parts needed to build the next engine with more power.

[Timas]

Bruce, your exactly the type of forum member I new existed. I've been on late bay, samba, STF, several others as well. Of all of them I think this site doesn't F around with people too much. Newbies deserve to run the gauntlet, but at least sound advise is given.
I split the case last night and it looks way better than I thought it would.
I know I need new bearings, I'll take pic of the inside tomorrow.

Crank end play is about 2.5mm, could someone tell me what the max tolerance on that is?

Since I have hydraulic lifters, I haven't seen a lot of cam options.

I forget what site I was on, but do the numbers in the web cam photo seem like they would get me some of that much needed low end torque ?

Perhaps get single h/d springs as well.

New set AMC heads / Port matched ?

Lighten flywheel to 12 lbs.

Thoughts?

[Bruce.m]

You can swap the lifter to solid. Might need to swap the pushrods too, for matching items.

End float is adjustable using a three shim stack at the flywheel. It compensates for wear of the #1 bearing thrust face.

If you google carefully, you can find a free download of the Bentley manual for the vanagon which gives all the build info. Also worth hunting out a download of VW “wog” (without-guesswork), a small reference booklet with all the important specs/ dimensions.

[Bruce.m]

If it’s for a bus, I’d probably leave the flywheel stock weight. It stores kinetic energy which is handy with a heavy vehicle.

[Bruce.m]

I’ve bumped up Clatter’s excellent budget build thread. Get a pot of coffee on, & study it for a great primer on the engine.

[Timas]

Greatly appreciate the clarification.
Truthfully, I drift in and out of realistic expectations.
I know these motors are supposed to be simple to work on, and in theory they are.
I struggle with excepting how people make an engine build look so straightforward vs what I am capable of doing.
I thankfully have a hard copy of the Bentley manual.
Plenty of smudged pages in that one

Seems like you had yourself a late night pal.

On that note, I will try and find Clatters write up.

I am very stubborn and my lack of experience is fueling my desire to still try and build something better.

Correct me if I am wrong, but aren't the dimples on the cam gear supposed to line up with a dimple on the crank?

[Bruce.m]

Yes. The single dot on the cam should sit between the two dots on the crank gear. That’s necessary or the valves open /close at the wrong time

[Timas]

That's what I thought.
Gears were totally not lined up with each other.

[Timas]

I can't seem to upload a little video, but I'm concerned about piston slap.
Is there a method of knowing what is ok vs problem

[H2OSB]

The shortest stroke AA sells for T4 after the factory sizes is 76mm, which makes a 2200cc with 96s. I'm sure you could get someone like DPR to custom grind a 74mm for you, but as Bruce said, it's not a common size, so it might be difficult to find in parts to support that displacement.

I know you've kinda moved on from planning to use a 74, but I thought this would be helpful info for the record.

H2OSB