Question to the braintrust for motor building Options

[Mikey914]

Looking to make a larger motor (4) planning on a 2665, as I don;t really want to go over 103mm to make cooling easier.

The 80 crank is available for stock rods not the Chevy rods. It is my understanding that the Chevy option offers a significant upgrade to the strength. I'm tempted to do the stock.

My question is : should I wait an indeterminate time for the crank with the Chevy rod option? What am I really loosing here? or is this just a must for the larger motors?

My 1st engine build.

[Mark Henry]

Toss the stock rod idea, they're heavy and a wider journal further weakening the crank. Chevy 2.0 journals and H beam rods are the way, one cam lobe where it meets the rod still needs major clearancing with 80mm. For longevity and an easier build I'd recommend the 78mm crank with type one journal size rods, the beefier T1 rod journal makes for a substantially stronger (less flex) crank.
Although there's no replacement for displacement depending on expectations I try to to talk peeps into a reasonable margin for safety.
My own engine (in a '67 bug) I built 78mm x 102mm (2.6L, nickies) mostly because I planned to put many street miles on my engine. When building my engine I had both a 78mm and an 80mm crank, I chose the 78 and sold the 80mm.

Biral cylinders...why?
Porsche abandoned biral's after only a couple years and LN found to make them properly they cost almost as much as nickies and also abandoned biral cylinders after just a couple of years. If the aluminum fins aren't perfectly (and I mean perfect) cast onto the steel it will have voids, at which point you may as well run no fins at all. LN found material separation to be be a huge problem in manufacturing. A china supplier working at a reasonable price point will fuch this up and a domestic supplier will be way too expensive. You will only be able to tell this by Xray and/or ultrasound of each and every cylinder further driving up costs.
I won't build a Biral cylinder engine (except stock 911), I don't give a flying fuch who made them. I'd rather walk away from the job.

Sounds like you are on the right track. Making it affordable, reliable and not needing a rebuild in 30k miles are the next big steps.

For a street car my engines require a valve job at 60k and the bottom end must be good for 2-3 times that. An 80mm crank engine requires a full teardown at 50-60K regardless. The slightly detuned 2.6-2.7 engine is a much better overall investment.

Edit; Note the china cranks are softer than OE, I'm expecting that a full tear down of the bottom end will be required before 100K to check for center main wear.