Need Input - 2056 Build

[Vee Dub Nut]

Ok, a few months back I posted up a thread about building either a 2056 0r 2270 motor from my 2L T4 engine for my '67 Bug. Long story short, I've finally settled on building a 2056, as that seemed like the best bang for the buck to get some more performance from the 2L, while still being able to reuse at least a good portion of the engine as it currently sits (which is/was a very fresh well built 2L).

So to that end, I've taken advantage of some of the Black Friday sales and ordered a few parts to get this project moving finally. I'm hoping that you seasoned T4 guys can look at the combo below and provide suggestions on anything I'm missing or off base with. This will be my first T4 build, but I've built a bunch of T1 engines (among other non-vw stuff), so not really an engine newbie.

Here is what I have for the 2056 combo so far:
-"stock" 2L bottom end: STD/STD 71mm crank (balanced), balanced stock rods, etc, etc REUSING
-AA 96mm hypereutectic pistons w/biral cylinders (24mm pins, 7cc valve pockets, for 2L stroke engines) PURCHASED
-relatively new (<3k miles) AMC 2L heads (39mm intakes, XXmm exhaust, ~55cc chambers) PLAN TO REUSE
-Web 86a cam, w/web solid lifters, and new cam gear PURCHASED
-Set of Web HD single springs (to be installed in my heads) PURCHASED
-034 SVDA distributor REUSING
-T4 style 200mm conversion flywheel, Kennedy STG 1 p/p HAVE
-DTM shroud w/T4 oil cooler HAVE
-Dual 40 IDF's w/CB linkage REUSING
-Ahnendorp T4 merged header HAVE

How does this combo look so far? What am I missing? A few thoughts/specific questions:

-What do I need to do valve train wise? I was really wanting to just reuse my current rockers (10mm std adjuster type). This is/will be a pretty mild motor, and all these parts I have are in great shape. I assume I should get a solid rocker kit for it to replace the stock springs/washers? I also just realized this morning that my current pushrods are hydraulic lifter specific, so I need to pick up a set of HD aluminum or chromoly pushrods as well. Do I need to change to the HD rocker shafts? With only single HD springs, I'm not expecting huge challenges here on the valve train.

-I realize my heads are going to be the limiting factor on this engine. My plan was just to clean them up, re-lap the valves, and run them as is (they are not very old and only have a few miles on them). How bad will they be performance wise? I also considered having them sent out for larger valves (who/where?), and considered picking up some different heads all together (AA has some AMC heads with 44x36 and 42x36 valve arrangments that are on a great sale through the weekend, ~20% off). I'm really trying to balance $$ vs HP to maximize my bang for buck. I don't expect this to be a screamer, I just wanted something a little more potent than the bone stock hydro lifter 2L.

-With the stock crank/rods and 96mm AA cylinders, where should I expect my deck height to roughly be? I'm not familiar with T4's in this regard. I know T1 jugs have varying lengths depending on bore. I was just trying to figure out what sort of deck I can expect to figure out what CR I might manage to get from the combo.

Any thoughts, comments, etc??? Any help is appreciated.

[Piledriver]

You need the hd rocker studs, as the original 7mm monstrosities can fail with stock bits.

You do want to fit the studs and rockers with solid spacers with the heads on the bench, a bit of fitting is required.

T4s never need new shafts unless they are galled up/worn out or rusty, the solid spacers and hd crmo studs convert things to "heavy duty".
The properly set up hd studs and spacers make for a bulletproof setup, I'd do it on an otherwise stone stock build without hesitation..

There is a place in Germany and one in USA making 10mm swivels... thread on tos. Elephant feet do good things for valve guide wear.

Just buy the CB or AC.net Manton crmo pushrods, the alloy ones are not worth it and lack the safety margin steel pushrods provide.
(lash increases if you overheat, does not go to zero)

Consider having the lifters SLR reground and parkerized. The cam warranty doesn't really help much if it all goes to hell..

The heads will hurt your top end a bit, an 86 might have been a better choice.
Consider a final 30 degree backcut on all 8 valves.
The AMC castings are good, the rest of the hardware is supposedly ok for the last few years,but make sure you use crmo keepers and retainers, and grind the keepers so they dont meet on both sides...

[Vee Dub Nut]

Thanks for the input Piledriver! Solid info, I appreciate it!

[Clatter]

^^X2 on what he said^^

You're going to want to do your valvetrain geometry anyways for a couple of reasons;
Mostly because AA cylinders are a bit longer,
And you might change things with the swivel feet.

Something else to consider with heads is the chamber size.
If you get the real 2.0 914 heads, they have large chambers.
It will be near impossible to get a good CR for your cam without using a stroker crank.
Therefore,
I'd be getting a set of AMC 1.8 castings with 42 x 36 if you were even getting heads at all.
Would be worth it to try your combo out with the bus heads and see how goes it.
Couldn't hurt to be sure they have a really good valve job,
And maybe that the ports were all clean and straight/smooth.


Will be interesting to see if you can get enough vacuum to get your SVDA to do it's thing;
Had a hard time with this before FWIW..

Motor shore is purdy with that DTM..
Can't wait to see it with the exhaust!

[Clatter]

Another thing to consider is a rod bolt upgrade.
With that much cam you are likely to start spinning things up enough to warrant better bolts.
If you have a good old automotive machine shop locally,
They can put in bolts and re-size the big ends easily enough.

[Vee Dub Nut]

^^X2 on what he said^^

You're going to want to do your valvetrain geometry anyways for a couple of reasons;
Mostly because AA cylinders are a bit longer,
And you might change things with the swivel feet.

Something else to consider with heads is the chamber size.
If you get the real 2.0 914 heads, they have large chambers.
It will be near impossible to get a good CR for your cam without using a stroker crank.
Therefore,
I'd be getting a set of AMC 1.8 castings with 42 x 36 if you were even getting heads at all.
Would be worth it to try your combo out with the bus heads and see how goes it.
Couldn't hurt to be sure they have a really good valve job,
And maybe that the ports were all clean and straight/smooth.


Will be interesting to see if you can get enough vacuum to get your SVDA to do it's thing;
Had a hard time with this before FWIW..

Motor shore is purdy with that DTM..
Can't wait to see it with the exhaust!

Thanks for the input Clatter!

I'll certainly be checking the rocker geometry out. Originally I was *hoping* I might avoid having to do a bunch of work/changes to the rocker assy and pushrods. Admittedly this was probably more of wishful thinking more than anything. Nothing I can't do/haven't done before, I was just hoping to be lazy

As far as my heads go, I *think* my current chambers are ~55cc. This is based on identifying what I believe my current heads are on AA's website, and seeing what AMC listed the chamber size at. I do have everything to actually check them, but haven't made it back out to the shop to do so yet (rebuilding the deck on the house project has jumped in line). I do agree that with this chamber size, the advertised 7cc valve pockets on the pistons, and a normal/acceptable deck height, CR is pretty poor. I'd like to get the motor around 9:1, as I think the cam would like that range and the motor would be nice and snappy. Not knowing what my deck is actually going to be yet, my best guess at chamber size is ~48cc to get it where I want. From a back of the envelope calculation, just flycutting the step out of the chamber should get me where I need to be (again, I need to actually measure the current step thickness, I'm just guessing based on what the step height typically is).

I'm still a bit on the fence about what I'm going to do, but I talked with Brothers Machine Shop and they offer a pretty fair price for installing 42x36 valves, guides/valve job, any required chamber work, and a mild port on my existing heads. I'm probably going to end up going this direction from the get go. If it weren't for the fact that I really need to get chamber volume down to get CR up, I'd probably try them as is. But I think it would end up being pretty lazy.

Thanks for the comments on the motor. It does look nice. Anxious to get it all buttoned up and get the car back together.

Another thing to consider is a rod bolt upgrade.
With that much cam you are likely to start spinning things up enough to warrant better bolts.
If you have a good old automotive machine shop locally,
They can put in bolts and re-size the big ends easily enough.

Gahh... this thing is snowballing. I was again hoping that the stock rods might live OK to ~6000rpm. The current rotating assembly is dynamically balanced, and the rods have all been balanced and rebuilt. All in all the whole 2L I'm starting with is REALLY well built, I'm just trying to milk some more out of it before getting it in the Bug. I've had a host of stroker/eft/turbo stuff through this car in the past, and I'm trying to build something that is admittedly mild, but hopefully something that will still be nice to drive and not disappointing to me.

[Piledriver]

You need less cam or a very tight lc to make it work with that cr...
Cutting out the step buys you nothing, you still need deck height. that's the step.
With a typical decked block and cleaned up head sealing surface, you would be at ~zero deck without the step.
You do not want to deck t4 heads for cr.

I'm still looking at a setup with 100mm bore and 1.7 register heads with a few guide dowels to align the jugs to the uncut heads.
I figure an extra ~1/4" of deck would be good for the head seal... Have been looking for 1.7 amc heads cheap.

You have had the block decked, right? it almost 50 years old, its saggy in the middle most likely.

[Vee Dub Nut]

You need less cam or a very tight lc to make it work with that cr...

Your suggesting that 9:1 isn't enough CR for the 86a? Or am I confused here?

Cutting out the step buys you nothing, you still need deck height. that's the step.
With a typical decked block and cleaned up head sealing surface, you would be at ~zero deck without the step.

Now that's news to me. Remember, I've never built a T4 before, only T1 stuff. I've been digging the forums trying to get an idea of what typical decks are on these engines (and by deck I'm referring to what is in the barrel, NOT including the step in the head). I can't find any measurements posted of typical barrel lengths, or deck to crank centerline depth. My *ass*umption based on what I HAVE found is that I would end up with some deck in the jug (nominally 0.040-0.060"), AND the step in the head (which I *think* is around 0.030"). This is where my comments come in regarding removing the step in the head, thinking I'm going to need to get overall chamber volume in the head down if I have 0.060" deck in the barrel to contend with. Again, I need to get my parts in hand and do some measurements, just haven't done it yet/don't have everything.

You do not want to deck t4 heads for cr.

Can you educate me on this one? I guess maybe if the actual deck in the barrel is near 0, there isn't really a need to reduce the chamber volume from how new castings are provided. But if you do need to, how do you reduce volume/raise CR on a T4?

You have had the block decked, right? it almost 50 years old, its saggy in the middle most likely.

I haven't done anything to the block, nor did I build this engine in its current form. What I have is a VERY fresh stock 2.0L rebuild (maybe 2-3k miles on it) that I'm trying to bump to a 2056. I don't know what the builder did to the case before the 2.0L was built, other than it appears to have been done very well (balanced rotating assy, balanced stock rods, mahle 94's, AMC heads, etc, etc). Obviously I'll need to check and see if the deck is flat/true.

[wreck]

you can flycut type 4 heads to get the compression needed , just not as deep as you can a type1 head , that is where the confusion is from .

Len Hamilton in the past has stated it is safe to go 2mm or .080 before issues with the exhaust studs .

you can put a straight edge across the case spigots to see if there is any need to surface the case . Also you should dry assemble the engine with all 4 cylinders and check deck height . aim for a total deck of .040 to .050 as a safe number . ( I'm getting away with .043 on a 103x78 that red lines over 7000 . )

Another thing to check , after the case is buttoned up and the cylinders are next . fit the cylinders and heads , torque to what spec you what to use and leave it for the sealant on the cylinder/case to cure . Remove the heads and check the cylinders are even with a straight edge . if they are your good to go , if they need a thou or 3 (in my case) to get them even ,remove the low cylinders and use base shims ,even paper gaskets will do to get the cylinders even . (that is a tip from a friend who is professional Formula Vee engine builder )

measuring cylinders .JPG

[Vee Dub Nut]

Thanks for the info Wreck!

I'll be sure to check the flatness across the deck to see what it looks like. Of course I'll be dry assembling everything as well to see where the deck ends up, and also to ensure that the jugs are flat/even across the tops.

On the subject of deck, Piledriver suggests that it will be near zero, you're saying shoot for 0.040-0.050", someone on the samba suggested it could be 0.060-0.70"? I'm still a little confused on what to actually expect (perhaps its a case of folks calling/including the step in the head as "deck", or Piledriver is assuming this for a decked case???). Ultimately getting my pistons/jugs on Monday and mocking them up will give me my answer.

Regardless, in the end I need ~0.040-0.050" clearance between the top of the pistons and pads in the head. Whether this comes from the step in the head, or from the piston down in the barrel is sort of inconsequential. With deck in this range, I still need to get actual chamber volume down to around ~48cc to hit 9:1 CR.

[H2OSB]

For a T4, I've always been told to shoot for a 1mm deck. Makes it easy to remember.

H2OSB

[Piledriver]

The t4 head seal has sealing issues over time in dead stock form, any removal not absolutely required should be avoided.
You can hack 1/4" out of a t1 head...

Building a bigger motor is generally considered a better plan to "fix" t4 cr. vs flycutting.
Note that domed pistons are a thing... used to set cr on almost all engines in existance, but acvws have relatively easy adjust deck a watercooled engine lacks, so not seen as often.

The actual deck of a 1.7/1.8 works out to right around 202mm, 2l 202.5mm, a 66 crank rod combo will be around 20 thou in the hole
I have run deck as tight as .026" on a stock freshen up and reved it to redline in all used gears on every onramp it saw for several hundred thousand miles.... (all assuming no base or head gasket, there is some variance)

.7mm is generally considered min safe deck. some say .040, some 050, I cannot suggest over .060 as you are losing all your squish, unless you are a gene berg cult member and ignore 50 years of development since the blue book was written.
If you only run the engine over ~5k rpm, deck doesn't matter.... so for a drag only motor .080 is probably just fine, but has no advantage.
Your step is likely .035" to .040". Build the motor ~zero deck and you can bolt it together.

withe provided data and a std 1mm deck, you have an 8.5:1 static cr and just over 6.6 dynamic... Great if you must run regular gas.
a web86a on 102-104 lc should get you in a better dcr area, and your exhaust can make it work well.
An 86a puts you in a rpm range where the 39x33 valves you have will kill the power the 86a would provide.
Tight lc might pull it in a bit, and fix dcr. A web 73 or 86 would arguably work better at 8.5:1.

Punch your data in the fine calculator...
https://uempistons.com/p-27-compression ... lator.html

[Vee Dub Nut]

The t4 head seal has sealing issues over time in dead stock form, any removal not absolutely required should be avoided.
You can hack 1/4" out of a t1 head...

I got you. Thanks for the explanation.

Building a bigger motor is generally considered a better plan to "fix" t4 cr. vs flycutting.
Note that domed pistons are a thing... used to set cr on almost all engines in existance, but acvws have relatively easy adjust deck a watercooled engine lacks, so not seen as often.

I'm trying REAL hard not to let this run down that slippery slope. It would be easy and fun to go ahead and order forged pistons, stroker crank, etc, etc and let it really rip, but practically speaking I don't have any desire to dump that much money in this car right now. I've already veered further than I had planned.

The actual deck of a 1.7/1.8 works out to right around 202mm, 2l 202.5mm, a 66 crank rod combo will be around 20 thou in the hole
I have run deck as tight as .026" on a stock freshen up and reved it to redline in all used gears on every onramp it saw for several hundred thousand miles.... (all assuming no base or head gasket, there is some variance)

This is good info, thanks. I did some quick and dirty measurements on my engine last night in its current 2L form. It nominally had ~0.025" deck in the barrel with stock rods, 94 jugs, and no shims (which is how it was assembled/running before). Assuming my heads are actually 55cc's as advertised by AMC (this includes the step volume), and the 94 Mahles had a dish of 15cc, static CR on that engine would have been ~7.6:1. That seems about right for a stock hydo cam 2L

.7mm is generally considered min safe deck. some say .040, some 050, I cannot suggest over .060 as you are losing all your squish, unless you are a gene berg cult member and ignore 50 years of development since the blue book was written.
If you only run the engine over ~5k rpm, deck doesn't matter.... so for a drag only motor .080 is probably just fine, but has no advantage.
Your step is likely .035" to .040". Build the motor ~zero deck and you can bolt it together.

0.7mm (0.028) I would generally consider pretty tight. I usually consider min at about 0.035, and usually target a more comfortable 0.045". I also agree that keeping it under 0.060 is best as well

withe provided data and a std 1mm deck, you have an 8.5:1 static cr and just over 6.6 dynamic... Great if you must run regular gas.
a web86a on 102-104 lc should get you in a better dcr area, and your exhaust can make it work well.
An 86a puts you in a rpm range where the 39x33 valves you have will kill the power the 86a would provide.
Tight lc might pull it in a bit, and fix dcr. A web 73 or 86 would arguably work better at 8.5:1.

What I'm curious about right now is how much longer (if any) the AA 96 jugs are. I've read some comments that suggest they are ~0.020 longer than stock barrels (also don't know if my current 94 barrels are same as "stock" length, I assume so, but...).

IF the AA jugs are +0.020", adjusting for the pin height difference on the 96 piston, I should be somewhere around 0.053" deck in the hole. Leaving the heads at 55cc, and having 7cc reliefs in the pistons would put me at only 8.2:1. Certainly on the low side for the 86a, and really too much deck (combined deck in barrel plus the step).

If the jugs are not actually longer, I come up with around 0.033" deck in the hole, and a predicted 8.6:1 CR. Still sort of anemic.

All of this is postulation until I get the rest of the parts in hand and can check them.

I am at a bit of a crossroad. I could just throw the 86a in and run the low ~8.x:1 CR and see what it does with the heads as is. I can send the heads out and have the valve size increased, the step cut, and get compression at (or above) 9:1. My concern here is that this would have a high likely hood of pushing me down the slippery slope into other "upgrades". Or I could just pick up a std Web 96, leave the heads as is, and just end up with a pretty mild engine (but hopefully something better than the bone stock 2L I started with). Dunno what my move is yet...

['77 Westy]

My 96mm AA Biral cylinders are 3.614"/91.79mm long – don’t know how that stacks up against standard length. The valve pockets in AA pistons are about 4cc according to someone who has used them recently so your SCR might be higher than you think.

[Piledriver]

If you buy the aa jugs from emw you can have them cut to whatever length you need, checked for round/taper etc.
There are reports of AA jugs being up to 3mm too long from awhile back.
(that would actually be a feature if it was known and consistent)

If you just want a nice driver using what you have now, a web 73 or 86 is the right cam.
It could be argued to keep the existing cam as it is already broken in.
(what is it?) Big valves and some porting would still result in a stout motor.

Too much cam has been the bane of a lot of hotrodders since we started.

Have you driven the car with the motor as-is? You might be pleasantly surprised, and they go in/come out easily enough.