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Tue Mar 02, 2021 8:50 am

Anyone have any experience with this crank yet? I'm tossing around the idea of building my stock 1500S Notchback motor using this crank. It needs a rebuild and the stock pistons and heads are shot. Just looking for best option on a "stockish" build but yet have decent performance.

Tue Mar 02, 2021 9:22 am

The crank just came out last week, not sure how many are gonna have much experience with it

Tue Mar 02, 2021 9:48 am

oh....I didn't realize it was THAT new! hah.

Tue Mar 02, 2021 10:05 am

I'm assuming these are for SCORE and limited displacement off road applications?

If you need a new crank anyway why not? Gets your piston .25mm higher up in the cylinder for better deck on a stock case. Lots of engines with excessively high deck could benefit.

Tue Mar 02, 2021 10:12 am

Hey Joel,

If its a stockish engine......use a stock crank. Amazing quality, easy, and pretty cheap. Get it all balanced, and it will work great.

On your engine, what are you using for carbs? The rest of the engine will need to be set up based on the carbs since the T3's are somewhat limited.

Single port, or dual port?

Brian

Tue Mar 02, 2021 1:54 pm

They will work great in any stock 1500/1600 engine. The extra .5mm stroke is to get you to the max engine size limit in those 1600cc limited classes.

There will be 200 new threads about those awesome 1653cc engines.

Tue Mar 02, 2021 2:06 pm

Big bore stroker 1653cc!!!!

Don't forget to add the 1 5/8" header, open stinger, and Kads with 160 main jets.

Brian

Tue Mar 02, 2021 2:09 pm

My favorite thing about this crank is that it is about the price of a certain other quality CAST crank, but the CB 69.5mm is forged 4140 instead! I do say, I think I'll try one. I'll order it in the next few days and post here.

Tue Mar 02, 2021 2:57 pm

unless you are running those limited classes than the $$ would be better spent on a 4340 74,76,78,82,84 or 86 or 88mm crank. the 4140 cranks are not nitirded and they wear much faster than a 4340 witch have been nitrided.

Wed Mar 03, 2021 3:07 am

For the average person I see only one advantage. - It will be easier to set a proper deck height without maching parts.
Its a class specific crank, and there every last cc counts.

Wed Mar 03, 2021 4:43 am

Also with the OP. since it is the S engine, ans assuming you are reusing the pistons, be aware that the S engine is high compression and wont tolerate more static with a stock cam unless you go high octane fuel.
If you use normal flat top pistons the problem naturally disappears.

Wed Mar 03, 2021 5:59 am

One plus, you can tell everyone that you have a stroker.

Wed Mar 03, 2021 6:20 am

Correct me if I'm wrong, but if you're looking at cranks just over $200 and no more, this forged CB 69.5mm and their nearly identical 69mm offering are the only forged options from a vendor that comes on here, cares about us and has a reasonable reputation for quality, right?

The "better" option would be the SCAT 4340 69mm counterweighted forged crank, at just over $300. (also a great crank by the way, IMHO, but $100 more)

Wed Mar 03, 2021 8:36 am

Brian_e wrote: Hey Joel,

If its a stockish engine......use a stock crank. Amazing quality, easy, and pretty cheap. Get it all balanced, and it will work great.

On your engine, what are you using for carbs? The rest of the engine will need to be set up based on the carbs since the T3's are somewhat limited.

Single port, or dual port?

Brian

The 65 notch was a 1500S motor. That said, it had domed pistons. I USED to have a set, but don't anymore. The motor's #3 piston is shattered in there from what I can see. I'm going to assume that I'm going to need heads and of course pistons. Not knowing what sort of shape the rotating assembly is in, I was looking at this crank as a way to go as it would help push that heavy type 3 car down the road in a somewhat stockish build. I was also looking at the L2 heads that aircooled.net offer. I'd like to keep it as stock appearing as possible. So yes, single port heads, stock dual solex carbs, etc....I'm open to advice. Honestly, I wouldn't even mind if you wanted to take this project on for me Brian. The engine is out of the car. It's still fully complete also. This is the first time it's been out of the car.

Wed Mar 03, 2021 9:28 am

I don't see any reason to get new heads unless yours are blown out or have other issues.

I am doing a quick set of heads for a guy in Canada doing almost the exact same thing you are. Stock appearing build for a notch with a little more power.

Here is what we are doing for his.

Stock case, whatever machine work needed
stock crank rebuilt, rebuilt stock rods,
stock flywheel lightened about 2lbs. everything balanced good.
AA 88mm thick walls, .045" deck height
OE single port heads, I will port them, do a good valve job, flycut for 8.5cr. new valves, and new guides. Single HD springs.
Stock rockers on solid shafts.
CB2232 cam, advanced 2 deg. CB cheap lifters, stock push rods cut down.
1 3/8" header and muffler, or VSpeed muffler.

I might be able to toss another set of heads together when I do his since they will be almost identical.

Brian

Wed Mar 03, 2021 9:50 am

That build may require its own thread.
A few thoughts based on experience to chew on. About half of the ACVW projects that I´m involved with these days are stocker plus engines, so I have seen a few different set ups. Some good and some that were better off to be taken apart and built different.

Back in the days the 1500S was a really nice and somewhat nippy car which was popular on the Autobahn too as it would outrun much pricier vehichles from the time. However, a good deal of these killed them selves due to the ability to "keep reving", lack of sufficient oil system and valve springs that were on the weak side for sustained higher rpm.

Next, the 1500/1600 series are "heavy" cars in ACVW terminology, so in order to make these cars/engines a little more up to date performance wise, they can really benefit from more displacement. The 1500S is most likely with the old style crank, so an upgrade to the new model is a good thing.

Dependant on how "crazy" you wanna go you can increase the venturi size in the old type 3 32 mm PDSIT´s, but be aware that you need to be a little carefull if you want to reuse the factory VZ distributor. The venturi size has to match the displacement.
If you are ready to use a newer ignition system you get a wider work range and can go 26 mm without too much trouble. Just remember that also here the aircleander assembly is a limiting factor and WILL need attention if you want anything more than just over stock power.

There is of course a slight difference in behaviure, but I have found that whether you build a 1776 or a 1745 (76 x 85,5) doesnt really make that much of a difference. The cam choice and the rest of the engine set up can be made to compensate (or cross over) each engine´s behaviure. The first one I ever built of this type was for a ´71 squareback and I built a 1745 because the customer wanted a wider torque band in each gear, and it was a nice engine, but today I can do the same with a 1776 by doing a few things a little different. It is however a little easier to make a wider power band with the 1745.

Also, with carburetion. If you want more you can source a set of 34 mm carbs from an early type 4 bus and use specific parts to make your 32´s to 34. It is NOT just taking apart and assemble, but doable.
Oil system. IMHO that is the achilles heel in these engines. When I use these early cases (the ones that have survived) I always drill out the oil gallery to match the later dual relief case, so the supply is not restricted. I also upgrade to a 26 mm oil pump, but do use a pump cover with pressure relief so I do not over strees the stock spring and plunger.

Camwise, you should keep in mind that "little is good" It is very easy to overcam these types of engines.

I´m sure Brian will be a good option should he decide to take on the project.

Have fun.
T

Wed Mar 03, 2021 9:56 am

Brian,

There is a good chance that my 3-4 head is shot. Literally the piston looks like it exploded in there. We won't know until it's apart. Let's talk private. I'm interested.

Wed Mar 03, 2021 7:05 pm

Quote: Dependant on how "crazy" you wanna go you can increase the venturi size in the old type 3 32 mm PDSIT´s, but be aware that you need to be a little carefull if you want to reuse the factory VZ distributor. The venturi size has to match the displacement. Didn't the 1500S carbs have 21 or 23 mm venturies? IIRC the 1600-engined dual-port head dual carb Solexes had 24 mm venturies. Just finding a set of the 24 would be a good starting point for your slightly increased displacement, and use the 1600's factory main jet size to start. The 24s are a direct replacement for the 21 or 23's.

Wed Mar 03, 2021 11:53 pm

Are you using the original case? Those things are frail, cam runs in case, 6V (180mm?) flywheel, 6mm studs for oil pump, small holes for oil cooler, etc...

The 1500 S needed premium gas from the factory, so I assume you are already running premium, and your wallet is used to it. The stock 1500S had 8.5:1, and ws pressured into making the same 54 bhp DIN as the later 1600.

21.5 vents were used only on the very earliest engines, I seem to remember, 23 mm for the 1500S from then on, until the 1600's 24 mm vents. Start with a "modern" 1600 case.

Thu Mar 04, 2021 1:29 am

I would not be surprised if CB discontinued the 69mm 4140 crank since they are the same price as the 69.5mm 4140 crank. I don't see why anybody building a stock engine could not use the new 69.5mm crank instead.

1500 is now 1503 (actually was 1493)
1600 is now 1596 (actually was 1585)
1641 is now 1653
1679 is now 1691
1776 is now 1788
1835 is now 1848
1915 is now 1929