I'm getting close to having all the parts for the 2270 build, but have a few questions:

• Crank brand: DPR, Scat, or AA? AA and Scat are new forgings but cost a bit more than the DPR crank. DPR is well respected in these parts.
• Crank size: Seem like a shame to leave it at a 2270 (78mm) when I could go up to a 2316 (80mm). Chevy journals.
• Rod length and type: Planning on 5.325" and Chevy journals for both clearance and the better bearing availability. Can I go longer for a better rod angle?
• Rod brand: Anyone have a preference? They all seem to be in the $400 range these days.

This will be primarily an autocross engine with some weekend drives. I also drive to events. The engine needs to be able to spin to at least 7500RPM even if it's not making power up there.

Here's the rest of the config (all of these parts are in hand):

• JE 96mm pistons with AA barrels
• Type 4 Store 9550 cam (86b/86c variant)
• Set of beautiful Finch heads I scored from Len Hoffman years ago
• Tangerine Racing 1.75" header
• 48 Dellorto Carbs with a 38mm vent (probably need to go to a 40mm vent)
• Dry sumped (either CB or ideally TP)

I know some people have trashed on AA pistons in the past, but i have their cast pistons and rods in my 2056 autocross motor and have had zero issues so far and I have datalogs running it up past 7k RPM.


Only mentioned it because it seems to me like just going with their 96x78 engine kit just seems like the easy button, though maybe go with the JE piston upgrade if you are planning to really thrash it.

New forged crank vs something welded and cut down. I have heard DPR is great but i have also heard of a couple of their stroker cranks breaking. Supposedly the AA 96x78 kit can be dropped in with no machining of the case as well.


Why were you looking to have additional rod options?

I run the full AA piston and cylinder kit now on my 2056cc that regularly sees 7500RPM for short bursts. No problem here either. I already have the JE's that I got in a parts deal and they are set up for a stroker, so no extra costs here...

WRT to rods, I'm looking at both brand and length. I need to do some calculations, but I'd like to run as long a rod as I can without a ridiculous shim under the barrel. I'm trying to stay above 1.70 rod ratio.

5.1” Rods (stock 2L) = 129.54mm
* 71mm stroke = 1.82 rod ratio
5.325” Rods = 135.255mm
* 71mm stroke = 1.90 rod ratio
* 78mm stroke = 1.73 rod ratio
* 78.4mm stroke = 1.72 rod ratio
* 80mm stroke = 1.69 rod ratio
5.40” rods = 137.16mm
* 71mm stroke = 1.93 rod ratio
* 78mm stroke = 1.75 rod ratio
* 78.4mm stroke = 1.749 rod ratio
* 80mm stroke = 1.71 rod ratio
5.50” rodes = 139.7mm
* 71mm stroke = 1.97 rod ratio
* 78mm stroke = 1.79 rod ratio
* 78.4mm stroke = 1.78 rod ratio
* 80mm stroke = 1.74 rod ratio

+1 with the AA piston/cylinder kits. I used a 96mm set on a recent build and am very pleased with the results, sealed quickly.

Thoughts:

Keeping weight of reciprocating mass low helps the motor spin-up faster and balanced.

Light car, light flywheel.

Yes, get a quality forged stroker crankshaft. Suggest getting one without heavy counterweights or full circle that adds weight. Our project 2615 (102 "nickies" & 80mm stroke as 78mm wasn't available) has the larger type 1 journals.

Sleeve lifter bores and use type 1 tool steel lifters (53 versus 137 grams compared with type iv lifters).

Empi forged I-beam rods are stronger and lighter than H-beams rods (5.5" are 564 grams on our scale). https://empius.com/products/empi-pro-series...5-16-rod-bolts/

Have everything (dynamically) balanced together. Flywheel, Rods, pistons, crankshaft, etc.

Crower springs and lightweight retainers. Check your heads as they may have these already.

Best wishes for your project.

Whatever you buy, once you get the crank/rods/fan/etc ...all rotating parts.
Get them all to a shop for balancing.

I have read that getting clearance between one rod and one cam lobe is very challenging when you go over 78mm, even with the reduced base circle cam and the smaller big-ends on the rods. I think that's why people don't that often go up to 80mm stroke.

--DD

Just had a conversation last Friday with Jorge @EMS regarding a long stroke long rodded motor. My concerns were engine width and cam clearance. I built a 2270 in the stone age and went thru the knothole to get it right. I just sourced a W code case and wanted to build the biggest motor I could and still do a valve adjustment without dropping the motor.

My take away is over 82mm stroke=Chinese crank. No thank You.

No case clearing required with 2.0 journals. No rod cap clearing for cam. (I find this hard to believe but I'm going to go with it).

You have your heads and cam in hand. Confirm the chamber volumes first. This was the biggest problem with my build. They went to Headflow Masters with 60 cc volumes and came back with 54 cc volumes. They work fine it just made the process take much longer.

Is the cam on a reduced base circle? I used a 163/86b on reduced base circle. With VW journals I had to clear the endcaps.

I switched to the newer German swivel foot adjusters. Much easier to check the valve lash.

I think you're good @ 80mm with 5.5 rods. I think end cap to cam will be your biggest obstacle.

Not sure if this was directed at me, but I can concur with your ideas and stay within the subject matter of this thread.

We have three 1.7 liter cases (two are "W" cases) torn down and will pick the best of the lot for the project build.

Like your build, the cam on-hand is Webcam's 163/86b reduced base circle camshaft, unless we change the plan.

Crank is 80mm stroke with type 1 Journals. Rods are Empi I-Beam 5.5" length. Aftermarket tool steel swivel foot adjusters (German). Would have preferred a 78mm stroke crankshaft, but could not find one. Will clearance if/as needed.

Somehow got a link to “aircooled racing weekend” in Germany on Facebook
One of the videos was a guy with a beetle, type 4 motor, 2.9 liter.
He was tuning it on a dyno in the car.
245 wheel HP….and it did not sound like you could not drive it on the street.

I think there were a few questions for me. I'll try and answer them here.

1. I don't believe the 9520 from Type 4 Store is a reduced BC cam, so I need to work within those confines. That makes me think I want a max of a 78mm, but I'll ask EMW and see what they say. The cam card makes it seem like a WebCam 86B/86C variant.
2. EMW has a nice selection of forged cranks and rods in 2L journal sizes.
3. I need to actually measure the heads myself, but I believe the are at 50cc.

@ 54 cc I needed base shims with 5.325 rods. I will check my receipts to see if I can tell you how big they were. At the time, I wasn't aware that I could have higher pin placement & that could have been the reason that I needed such a large shim. I ended up @ 10.2/1 compression. Valve lash checking and adjustment was an adventure.

Might want to try Elgin camshafts also.

Regarding the full CC, and compression ratio..
Use clay to make sure...be prepared to measure and assemble a few times to get it spot on.
Including waiting for whatever shims you need to get shipped .
rich

If necessary I can either/both mill a dish in the piston to pick up some cc's to lower CR and/or mill pockets for the valves.

Not the thread-jack, but... @cgnj I, too, am interested in which shims you used. I purchased a 2270 Crank, P&C kit from AA and have the bottom-end together. When test fitting a P&C for deck height this weekend I see my cylinder sitting about 2mm _above_ the deck/proud. Therefore I assume I need a shim on the order of _one tenth_ of an inch (I'll precisely measure when it comes time to order, but I was just doing a sanity check). Couple of questions here:
1) I recall Jake saying using large shims requires lots of advance and is hard to tune, was that your experience?
2) I recall another forum member cautioning against stacking large shims, should you _not_ stack at this height?
3) Did you have this issue, and if so, which shims did you use?