Shoptalkforums.com

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

So true, so true! You have to have good a balance in everything so you don't stumble (puns entirely intended) and that means all parts and components.

Lee

.040 to .050 is a tight deck that will give good efficiency . I'd also aim for 9.5 comp with the 86A , you won't have a cooling issue with a DTM and timing can be controlled with simple water meth injection , that boosted octane and also cleans carbon deposits off pistons and valves .
Put the AA jugs on without rings and measure what you've got , the only way to know , anything else is just conjecture . But please report back on what you find . if they have 0 deck , you can get shims from EMW . If too much, get who ever you choose to do the heads to shorten them .

For a 2 litre engine you do not need to port the intakes , maybe a little bowl work under the valve but the intake ports are big enough . The guides can be profiled and the exhaust guide boss shortened plus a little work on the long side of the port . Thats it , any more and you will loose a lot of torque.

I followed Len's advice ( https://www.shoptalkforums.com/viewtopi ... 96#p492496)coupled with information on port size from Pipemax ,a highly regarded engine /exhaust calculator and information from David Vizard.

The result is a true every day (regardless of ambient temp) 200+ hp engine with oodles of usefully power but will pull to over 7K . If you look at the picture I posted before you can see the ports aren't huge .

Pipemax is very informative, as is the EAPro demp...

Going from 39x33 to 42x36mm requires quite a bit of bowl work that's best left to someone who does it a lot...
but I agree, huge ports aren't needed, esp on a 2056.

The easiest way to get to 9.5:1 involves a stroker crank and correct pin height pistons...
Probably a lot more practical in USA vs. Oz.

'77 Westy wrote: ↑Thu Dec 05, 2019 10:17 am 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.

Thanks for the input!

If that length is accurate for my 96mm birals, it will certainly be better than what other have suggested. My stock Mahle 94 jugs measured out at 3.610" (measured with my chinesuim HF calipers ).

The valve pocket size you quoted is curious as well. The site is currently advertising 7cc valve pockets here:
https://aapistons.com/collections/pisto ... linder-set

I'll be interested to see what actually turns up in the mail Monday.

IF, that barrel length is correct and the valve pockets ARE 4cc, even with my heads remaining at 55cc, I should be in the neighborhood of 8.8:1. That would be nice. We'll see...

Piledriver wrote: ↑Thu Dec 05, 2019 10:38 am 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)

P/C kit has already been purchased through AA, and should show next week.

Piledriver wrote: ↑Thu Dec 05, 2019 10:38 am 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?)

I'm starting to tend to agree with the 73 or 86 being a good choice if I just reassemble "as-is".

I guess what I end up doing partly depends on what the actual AA jug length and resulting deck ends up at, and what the valve pockets actually are. That might give me a push one way or the other.

The cam that was in the engine was a stock hydraulic one. Fine for the Bus I guess, but I expected it to be pretty lame in the Beetle. Plus, I personally hate hydraulic lifters in these engines. They always seem to have a tendency to bleed down and make a lot of racket.

Piledriver wrote: ↑Thu Dec 05, 2019 10:38 am 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.

Agreed... But then I start asking myself if I should really be upgrading the rods, more valve train work, etc, etc..

Piledriver wrote: ↑Thu Dec 05, 2019 10:38 am Have you driven the car with the motor as-is? You might be pleasantly surprised, and they go in/come out easily enough.

No, I haven't driven the Beetle with the 2L in it. I had this same 2L in my late bay before I pulled it for the Subi-swap. Its a good runner no doubt. I was just hoping to spice it up a little before it landed in the Beetle.

wreck wrote: ↑Thu Dec 05, 2019 1:43 pm .040 to .050 is a tight deck that will give good efficiency . I'd also aim for 9.5 comp with the 86A , you won't have a cooling issue with a DTM and timing can be controlled with simple water meth injection , that boosted octane and also cleans carbon deposits off pistons and valves .
Put the AA jugs on without rings and measure what you've got , the only way to know , anything else is just conjecture . But please report back on what you find . if they have 0 deck , you can get shims from EMW . If too much, get who ever you choose to do the heads to shorten them .

Thanks for the CR recommendation. I was thinking around 9:1, but if I go down the road of doing the head work, etc, I may aim a bit higher.

Absolutely agree that this is all conjecture. I'll start actually measuring when the parts all get here. I just didn't have any idea where things might land while I was trying to plan ahead for the build, so I appreciate everyones input. At least I feel like I have some idea where things might be now.

I'll certainly post up all the measurements here.

wreck wrote: ↑Thu Dec 05, 2019 1:43 pm For a 2 litre engine you do not need to port the intakes , maybe a little bowl work under the valve but the intake ports are big enough . The guides can be profiled and the exhaust guide boss shortened plus a little work on the long side of the port . Thats it , any more and you will loose a lot of torque.

I followed Len's advice ( https://www.shoptalkforums.com/viewtopi ... 96#p492496)coupled with information on port size from Pipemax ,a highly regarded engine /exhaust calculator and information from David Vizard.

The result is a true every day (regardless of ambient temp) 200+ hp engine with oodles of usefully power but will pull to over 7K . If you look at the picture I posted before you can see the ports aren't huge .

Thanks for the input.. great stuff!

Piledriver wrote: ↑Thu Dec 05, 2019 3:15 pm Pipemax is very informative, as is the EAPro demp...

Going from 39x33 to 42x36mm requires quite a bit of bowl work that's best left to someone who does it a lot...
but I agree, huge ports aren't needed, esp on a 2056.

The easiest way to get to 9.5:1 involves a stroker crank and correct pin height pistons...
Probably a lot more practical in USA vs. Oz.

Slippery slope... SLIPPERY SLOPE...

First I'll say that you should avoid flycutting type 4 heads at all costs.
There were some cutaway pics put on here by Nate Morse that showed how dangerously close to the sealing surface the exhaust studs are.
Couple that with the asymmetrical head stud pattern, and you want to keep as much meat in the heads as possible.

While they have been demonized on TOS, steps are a good thing for head sealing.
Some have found that having the mating area 'buried in the wall' vs. 'stuck in the corner' will improve sealing.
They did it for good reason IMHO.
If you're going 96 then moot point anyways, right?

I'd put rod bolts in...
You'll only have to re-size and match the balance.
Static parts so no big loss.
They're just bolts. $140.
Some say you should replace rod bolts at every build. FWIW.
https://www.summitracing.com/parts/arp- ... ke/porsche
Type 4 rods are heavy as a tank and fail at the bolts.
Any V8 shop can install bolts and resize the big end.
You can balance at home.
If you are going to hoon on the thing, the rod bolts will be your weak link.

You're changing your PP and fly anyways so there goes your balance out the window anyhow, right?

If your head shop is going to put in new seats they might be able to weld up the chambers while the seats are out?
I'm worried that you're going to have to do something radical to get the CR you want, unfortunately..

A lot of how this goes might depend upon what resources you have available.
If there's a good prototype machine shop where you car bribe a friend with beer on a Friday afternoon,
Whipping up a live center to chop cylinders down is no big deal.

If you have a friend at a regular automotive machine shop doing rods anyways,
Then a quick re-size of the big end after bolt change is no big deal.

If you have to mail the stuff out and wait weeks and take a blind shot that you didn't get hosed,
Then it's another deal entirely...


Best to get your case decked.
Most cases are at least .002 - .003" to clean up.
You don't really want to be fudging .006 - .008" with RTV.
JMHO.
Not that it isn't a great idea to let the glue dry with heads just snug first every time you build one of these..


Did you look at the build thread in my sig?
it was kind of geared to a builder who already knows his way around, but hasn't done a type 4 specifically.
Might have a trivial bit or two buried in there..

Another option if you know a good machinist... these rod bolts are stronger alloy, better design, and you get an extra set for free...
Rods have to be reamed a few thousandts as these are 3/8" rather than 9mm.
I scored a set of these I was planning on using, got lost in a move... half went to Europe into a road raced 411...
https://www.summitracing.com/tx/parts/arp-235-6402
the std set are $66, arp-135-6402) ~equivalent material to the t4 set, except you also get a spare set.
The arp-2000 set comes with the nice 12 point nuts.

I would probably just go with emw hbeams given the cost of the bolts and rod work.
Might as well stroke it and go with 22mm pins etc, and enjoy skiing down the slope

...Also note that the motor was pushing a bus.
It will relatively be a rocket if in a T1.
Even a stock 1700 with Webers walks all over a typical 1835 build, most stock t4 heads out flow most off the shelf "hipo" t1 heads, even ones fitted with bigger valves. The AMCs may be a little better or worse, not sure.

It's such a shame that AA didn't put a modern shape small combustion chamber in their 914 2lt casting . If they did and released it with valves etc , it would be like a panchito head for type 4's off the shelf . I spoke to one of the AA guys a few years ago about them ,he admitted they realised the mistake too late in the process .

AA makes heads?
(wanders off to look...)
OK, AMC bsed, but given the prices is Len Hoffman building them?
The euro's pretty cheap these days...

AMC makes heads(out of Spain IIRC)
QSC made heads briefly, like T4, small and large port 910 knockoffs, still do for some apps I think...

The amc heads can be cnc'd to ==914 2L heads, which is a very good chamber design if you are building a 2.2l or larger motor.
For a hot 1.8-2L not so much. might be better under pressure so to speak...

No these are AA castings done in China by who ever does their other type 1 heads , not by AMC in Spain . I got that from Jonathon ? I think his name was from AA when he did a tout of Oz in 2017 .


https://aapistons.com/collections/bare- ... round-port

'77 Westy wrote: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.

Just checked them again if your still weighing up choices.. more like 3.5cc! If it's these

Sent from my SM-G930F using Tapatalk

Thanks all for the continued information... all very helpful!

Deefer66, that's really promising on the valve relief sizes! Those look like the same ones I'm getting (based on the picture). I'm hopeful that what shows up will actually only be ~3.5cc worth of valve relief. IF that is the case, based on the length of the Biral jug that I think was posted by 77westy, I could actually possibly hit around 9:1 SCR on the 2056. That would be great if so.

Clatter/Pile, regarding my heads and fly cutting, I certainly appreciate and heed the warnings about cutting T4 heads. The most I'd really be looking to do is to remove the step. This all depends on a lot of factors that I just don't know yet without mocking up the short block. Flycutting them would just be a move to drop chamber volume/raise CR and reduce total deck though.

Clatter, thanks for pointing out your cheap junk build thread again. I've skimmed through that before, and did again after you mentioned it. Some great info in there. I need to sit down and go through it more thoroughly to digest it better. Certainly some great T4 specific tips in there. Thanks for sharing.

------

Back to my plans. As for the rods, I went ahead and opted for some h-beam rods from Aircooled.net (darn that slippery slope). They are stock length (5.158"), 24mm pin, w/ARP bolts. As Pile mentioned earlier, by the time you factor the cost of bolts, and machine work to get them installed/resized, I'm over half way to the cost of new rods. As also pointed out earlier, I'm pretty well beholden to mail order machining services. Combine those two things, and I felt it was just better off to pick up some replacement rods, and reap the benefit of improved fasteners AND reduced weight. Seemed like the best choice??

Naturally before ordering the rods, I got to thinking about getting some 5.325 ones with 22mm pins and picking up a new crank. Maybe I should have, but I think I finally drew a hard line in the sand. Going down this path would have pretty well ended up with me having to buy ANOTHER set of pistons (forged w/different pin height), would push me to go back and change cams and valve spring plans (all of which I already have in hand for my planned 2056 build), and would requier bigger carbs, etc, etc, etc.... I had to draw the line somewhere.

So my current plans (which have gotten pretty far past the "I'll just throw some bigger P/C's and a new cam in this otherwise stock 2L and have some fun" ) are:

T4 2056
-Stock 71mm crank, 200mm conversion flywheel, Stg I Kennedy P/P
-AA 96 hypereutectic pistons w/biral cylinders
-Forged h-beam 5.158" rods, 24mm pins, ARP Bolts
-Web 86A w/Web solid lifters
-Web HD single springs
-AMC 2L heads 39x?? valves, w/55cc chambers (includes step) <--- Still considering sending these out for 42x26 valves, but I might just try them as-is first (with a clean up, and maybe a massage in the bowls)??
-Stock rockers, T4 Store solid rocker shims, HD rocker studs, and TP 10mm tool steel swivel feet
-Chromoly pushrods
-Dual 40 IDF Webers w/CB linkage
-Ahnendorp/BAS header
-DTM shroud w/T4 cooler

IF I can get this thing around 9:1, I think it should be a great little runner. I'm anxious to try it. I've been a T1 guy for a long time and have a few cool engines under my belt there. Although I certainly see the benefits to the T4 platform, the costs and difficulty of getting everything pulled together makes me question if the juice is worth the squeeze (I'm going to get myself run out of the T4 forum here saying that ). I'm hoping to be made a believer once its actually running and in the car. There is a lot said about the T4 not being comparable to the T1. We'll see..