Need Input - Possible 2056 or 2270 Build

[Clatter]

It's only Money, right?
https://type4store.com/cylinder-heads/rs.html
https://fatperformance-rimco.com/collec ... heads-pair

[Vee Dub Nut]

This is kind of a tough one...

A stock bus motor, and what you plan to build, actually share very few of the same parts.

I'd be inclined to leave the bus motor together,
and either run it with very low expectations,
Or sell it altogether and recoup costs.

Yea, I certainly see that.. Apart from the case, exhaust, and cooling, most all else would be changed/purchased new. The ONLY consolation is that the stock parts are pretty low use, and I can recoup at least some $$ from them. That, and the stock engine is essentially "free" to me, as its a take out from my Bus.

I have floated the idea in my head of abandoning this T4 path altogether, and building another big T1. I could certainly try and sell my current engine. I'm sure I can find a late Bus owner that would scoop it up. Then I'd have to flip the shroud and header too. They are good parts, so it wouldn't be too difficult. Probably loose a few bucks in the process though. The T1 would certainly not last as long, but for how much this car gets used/driven, it would certainly last longer than my ability to leave it alone.

That brought the other thought of just doing a basic 2056 as sort of a middle ground. Doing a swap for flat top 96mm p/c, bumping the compression, and a real mild cam would probably make ~115-120hp pretty easily though my 40 IDFs, and last a good long time. Plus I could essentially re-use all the current internals (at least I think). Maybe use my existing heads, or find a nice milder upgrade.

Something I don't like about those AA heads.. Well a couple of things anyway.

First, they leave the plug angle in the crappy bus/411 location.
The 2.0 914 plug angle is good for a LOT of power with little downside.
If they are welding up reinforcements between the fins next to the plug hole,
As well as doing seats, etc.
Why not go ahead and re-locate the plugs?

48 x 38 valves are going to be a waste with even a 96 bore, IMHO.
For what you gain in valve weight, you'll be shrouding your 'flow cone' with cylinder wall at that valve size.
If you go up to 103s or something, then that's different..

Bet you a set of nice stock 2.0 914 heads would make more useable power under the curve than those "stage II" AA heads.

Spending that much of my money, I'd get a set of heads from the type 4 store, FWIW.

Excellent info, thanks Clatter!

re: plug angle - it does look like you can get all versions of their heads with the relocated plug. Seems as though that might be a worthy selection.

re: valve size - I wondered the same thing on the valve size. Seems like Jake had spoke highly about 44mm being sort of the maximum for the smaller bore combos that worked the best. I guess the stock 914 heads where 42???

I did look at heads offered by the t4 store. The price on the AA stuff already stings, so naturally the t4 store heads hurt even more. I realize they are probably better, but the thought process was to try and draw the line somewhere. The AA heads ranged from $2300 to $2900, where as the T4 store were $3500 to $4000. Ouch...

-AA/AMC 48x38 valves, dual springs, either their STG I or STG II port
-DPR 78mm crank, T1 journal
-5.325" H-beam rods, T1 journal, 22mm pin
-96mm AA Stroker piston kit (JE pistons) - still sort of a toss up between the birals or just standard iron jugs
-Cam (Still trying to get more info, but thinking 86b/86c. What would you recommend?)
-Little bits and bobs (cam gear, lifters, chromoly pushrods, solid rocker shaft kit, etc)
-Dual Weber 48 IDFs
-DTM Cooling (HAVE)
-BAS header (HAVE)

^^This looks like a good choice^^
Switching to type 1 rod setup makes sense.

With your 1 5/8 exhaust, I'd maybe be inclined to stay at 163/86b vs. 86b/86c.
I'm doing a motor with 163/86b right now,
and was able to run beehives, provided the valves got sunk a bit in the heads; it's right at the limit.
Single springs last longer and run cooler, the valve guides stay in place better when the bosses aren't cut.

Build your type 4 around the exhaust.
Too big of an exhaust might make it a bit 'peaky' and that's not the end of the world.
Too small, and you leave power on the table, and possibly run hot.
I'd stay 42 x 36 and 2270. Basically copy the Jake 'Type 4 torquer' of yore (it ran 163/86b equivalent BTW).
You'll be quite surprised at how big/fat it will be.

Big problem I have with building type 4s is that they just stay together forever.
I keep wanting to tear it down and do this/that, but it just makes no sense to take apart a perfectly running oil-tight motor.

I think this recipe is close if I go 2270. Certainly would be good to consider some other head options to try and better optimize. What sort of power band does the 163/86b have versus the 86b/86c?

Regarding heads, looks like I can get an AMC 2.0 914 style head from AA too:

https://aapistons.com/collections/stock ... 42x36-pair

Edit: same heads with 44x36 valves are available too:

https://aapistons.com/collections/cylin ... 44x36-pair

I guess maybe the 42x36mm valves in these might be a better path? Are these heads with the 42x36 size valves, relocated plug holes, and the 163/86b a decent combo? Big enough for a 2270? What sort of power expectations should I have? I also thought these heads might be good on a real nice 2056 too. At least a step up from my stock 2.0 T4 ones. How far does a stock port really go on the T4 head? I know in the T1 world stock ports don't go far. The T4 ports are certainly larger, but I don't have a good feel for it.

I'll look up the type 4 torquer thread and do some reading. Sounds like it might be a good read.

I hear you on wanting to tear into stuff. That's what kept me mixing up all sorts of combos for this car before (big carb'ed NA motor, couple turbo variations, mega squirt, etc). It was in constant flux for years until I get bit by the Bus bug, which has pretty well left this car sitting w/o a motor since (~5'ish years). Time to fix that.

[Vee Dub Nut]

It's only Money, right?
https://type4store.com/cylinder-heads/rs.html
https://fatperformance-rimco.com/collec ... heads-pair

LOL.. Interestingly, the FAT page shows the large 48mm intake valve like the AA ones too.

[Vee Dub Nut]

I've a a friend with a 2.6 making close to 200hp with a 1 5/8 header and 48 IDF's
Hoffman machine , (Len Hoffman) is the person who developed heads for Jake Raby .
Fat Performance
EWM all have type 4 know how.
New 2lt 914 castings with 44 or 46 intakes and 36 exhausts would be my choice Len mentioned in an old thread that the plug angle is worth about 10% power gain . And still would work in a 96mm bore.
Clatter is spot on with the beehives . (get from John AC parts net or Dan Ruddock on the Samba)
Cam depends on where you want the power .

Yea, I think the 1-5/8 header would certainly support my ~175hp goal. Raby had posted some comments about the primary tube length on the BAS header, but it was a bit contested by others. Who knows for sure. I think I personally would be hard pressed to notice any short comings.

Thanks for the recommendations/comments on the heads. All good info.

[Vee Dub Nut]

Thank you all again for the input so far. All good discussion.

As I sit here *right now*, the thought of doing a more simple 2056 build is gaining traction. It would allow me to use more of my existing bottom end in the engine, admittedly at the cost of performance, but the cash outlay would certainly be less.

Certainly haven't made a final decision, and the thought of building a nice 2270 is still very enticing, we'll see whether *want* vs *practicality* wins out.

[Clatter]

A 2056 with an all-stock bottom end
(Maybe a spin-balance and some ARP rod bolts)
Some nice 42 x 36 heads, More CR, and a cam will surprise you.
I’m doing this combo right now with a 163/86b for my Fastback at 9:1.

The only caveat is the large chambers on the 2.0 head;
Hard to get the CR you want because you can’t flycut a type 4 head like you can a beetle head because the head studs are right in the way.
That’s why a 1.8 head with the plugs relocated is so popular; you get the plug angle you want without the huge chamber..

[Clatter]

FWIW, if you find a set of 1.8 heads they have bigger valves than bus heads, almost 2.0 914 size at 41 x 35.
They don’t have the plugs moved, but the chamber is smaller.
Part number ends in ‘S’..
You sometimes can luck into some of those.

Bus heads have very small valves stock. First rebuild all type 4s should get 42 x 36; even a stock bus.

FWIW, whenever I have a type4 case apart bare, I like to get the deck kissed off to check for straightness a.k.a. ‘Sag’ from the center main pounding.
You can get some CR there if needed as well.
AA cylinders tend to run longer than stock..

So there’s a big regurgitation for you.. :-p

And as always - you can’t compare these things to a beetle motor. No comparison. Drive one and you’ll see.
Remember how hard a stock motor pulls in a huge heavy bus??

[wreck]

. The AMC "2lt" heads have the smaller combustion chamber (approx 50cc) from memory .On the cheaper option you can get the AMC heads you have now fitted with 42/36 valves and the seats throated out to suit the bigger valves . Not perfect but it does work.
Back in the late eighties before the internet and global shopping ,I had a 1970cc made from second hand parts , a stock balanced crank ,stock rods and bolts , badly ported heads with stock springs/valves and a locally ground cam . with a set 45 Dellortos and a bus 4 into 1 with cut down heater boxes. It did a 15.5 quarter in a full weight 68 bug with stock gearing and a 3.88 diff . I used to rev it to just over 7500 rpm and had that motor for years .