Crank confusion

[Timas]

Appreciate the insight.

Pile driver, I was banking on that when I bought my bus.
Hard stop in California on vehicles built after 1975.

So what is the reason why stock exhaust has so many limitations? Flow and size? I think I’m running 1 5/8” exhaust headers ( very loose term )

What actually limits me from building a bigger motor?
I really want to take advantage of my current situation.

[Timas]

I’m an idiot.

Now do I have more options ?

[Timas]

While I’m at it, am I seeing the results of blow by or what?
I had lost compression on the 1/2 side. Ring gaps were right over each other.

Ordered case splitter so I am committed to a deep dive still.

[Timas]

Found this nick on the same #2 piston as in the other photo.
I can only assume that this would contribute to low compression? Can I fill that in somehow??
Steel stick or JB weld?

[Piledriver]

1: those are 94mm pistons, thats just never where you measure them, the crown is always smaller diameter to allow for expansion so it doesnt go negative clearance and insta-lock the motor at 4k rpm, and to allow a bit of gas flow to get to the rings so they can expand under pressure as they do.

2; I see the nick, need a better pic of location. Looks like the block where the jug seats, it looks cosmetic if it's the case.

Bummer about 1975+.(or is it 1976 and up, with 1975 still exempt?)

I don't know why the engineers at VW choked the t4s with the HX, In the amusement park of my mind. I suspect the German Engineer in charge of that was the new guy, and decided it was of sufficient size for the engines power level as it left the factory, and any more would be a waste and unacceptable.

[Timas]

I m not sure if 1976 was given a pass if it was built in 1975.

I will wear 3 coats if that means I can drive comfortably up hills without wanting to throw something at cars.

Knowing that I have 94’s does that mean I can build a 2110?
I can buy parts as time allows, but I would love to know what is actually possible.

[Piledriver]

The rings rotate. They can line themselves up. You will have a dead hole and an oil soaked plug....Had it happen to me on my sons '78 after 50k hard miles. Reoriented them, stuck it back together, ran like new.

That nick is cosmetic. Ignore it.

You do not need a case splitter, thats how you destroy blocks.

Hard rubber shot hammer, composite wedge shims (plastic) for doors/windows wont jack the block sealing surface.

There is always another nut or bolt.

[Timas]

Dang it! I already bought the dang thing.
I guess I can ship it back :/
Composite shims huh…. Clever.
The case is the poster child for RTV.
Crap is on everything, oil cooler, case halves, cam plug.
I’ve been spraying the case with WD40, something in it breaks down RTV I guess.

[Timas]

Alright piledriver. I feel like I should just inspect everything and put it all back together. Gotta tell you though, I feel like I should at least put a cam in it . Am I just stuck on stupid with all the YouTube videos?
Can I do something with the heads since I need to buy new ones?
Intake match port and larger valves? Nothing crazy, maybe 40/35?

[Piledriver]

The best place for RTV on an aircooled motor is in your toolbox.
(although it CAN be used a few places, like under the jugs, but we are talking thickness of a smear of RTV.)

Webcam 73/86 (224 degree intake, 234 degree ex (at .040") 108 degree, matching lifters.
If you don't care about warranty, same cam, but have a new set of CB lifters reground, polished and parkerized.
(Shag Leone at SL1 does this now)

Do Not Even Think About retaining Hydraulic Lifters.
They mask a couple failure modes, usually ending in a destroyed motor.
You STILL have to adjust the valves regularly.

Probability is ~1.0 your existing heads are cooked, deep fried to a crispy, cracked crunch.

If you DO decide to clean things up and reassemble, before you have a 3 angle valve job done...

Jakes valve seat test:
Take the valves/springs etc all out.
Clean the heads like your life depends on it.

Assuming you don't do the cooking, buy your SO a spa day pass.

When she is out, pop the heads in the oven at 450F for about 45 minutes.

When done, drop them from about 6 inches (chamber down) on a sturdy work table a few times.
(concrete with some news paper over it works well)
Odds are several seats will be out of position or laying on the work surface after 3 or 4 drops.

ALTERNATE: air hammer with a ~3/4" or so wide *flat bit around the bottom of the head just around the outside of the chamber
(not IN the chamber) works too. Don't hit the fins. That way you can watch them dance and/or fall out.

(* usually used for flush rivets, but has many uses)
(Note: Jake Raby does not build engines with used OR stock head cores)

After you have done all this buy some 42x36 heads made with AMC castings.
Bring your wallet.
(the machining and valve+seat costs exactly the same for any size/valve+seat, but will need more porting)

If you insist on going with a stroker crank, you will likely be needing custom pistons with a reduced deck height.
The stock T4 pistons are roughly the same as the T1 "b" deck height.(but with 24mm pins)

There is probably an off the shelf piston for that. (I recall doing this exersize a few years back)
You can have the rods rebuilt/bushed for lets say a 23mm pin and I'm pretty sure there are 94mm Subaru slugs (23mm pin) with about the right dish volume and pin height for a ~1mm deck clearance and a ~8:1 CR.
(remember we were talking about things get interesting with a stroker?)

I'm still trying to get to my 86 Vanagon project, there is a Subaru EZ36 hanging on the automatic with Audi 5000T guts...
Need to get it going before the motor finds its way into my 914.

[Timas]

Before I had known about all the CARB stuff I was going to go fj20 / ecotec 2.3 route in my bus.

Modernbay or busaru have a good amount of vids on these swaps. Kennedy adaptor w/ 210 flywheel.

I do not understand everything you said about cams, but I know my heads are f’d
Valve guides are garbage n u can see the condition of the guide boss.

Think I can do anything with my heads aside from cool paper weights?

[Piledriver]

The worst/impractical to fix cracks appear under the seats per Len Hoffman, who is a full time head guy. (I hope its still the case)

That crack/missing bits in the pic was possibly created by the last guy who rebuilt the heads, although it could have been from extreme overheating.
I'd strongly recommend Len if still available, but he wouldn't touch used Bus heads 20 years ago because doorstop.

Strangely, that particular damage is probably cosmetic and would disappear when you had them ported.
That guide could be a little shorter too, the last ~8mm the ID is bigger. for crud clearance.
Turbo heads have that bit of the guide and port removed as it tends to break free//seek freedom through the turbine.

If they pass the seat drop test, and have no cracks, (very unlikely given pushing a bay bus up hills) you might get away with it.

IIRC you can get an ODB1 Subaru swap through CARB cert, as well as a TDI motor and a few others.
(ODB2 works on some swaps too, but ODB2 Subarus require so much other junk from the original car on the ECU it isn't practical and may never be)
I suspect the TDI swap requires a taller ring and pinion, as I know mine doesn't willingly run at 4K+ RPM for longer than it takes to grab the next gear.
(The SVX 3.3L /6 motors are ODB1 and look like art)
Its easier on a Vanagon as it already has a place to put a radiator.