Who makes the best caps for a Big Block these days? Is BCR still selling them?

Thanks.

I bought a set from Jerry a couple years ago and was very happy with the quality. I think he is still making them.
https://www.bcrproducts.com/
I bought the girdle caps, in case I wanted to add the girdle in the future. He offers regular caps and girdle caps. So, the block is prepped for it, but I didn't go with the girdle since I was worried about the added clearance and sealing issues as well. But, if I was choosing new caps, I figured why not protect for it anyways. Next time I pull the motor to check things over I will see how the bearings look and it will tell me if I should add the girdle or not...just something to consider.

Do they have a predictable lifespan, and need changing out like Alum Rods?

Not that I know of. I ran them in my old 499, but when that engine let go, the caps got torn up from connecting rod pieces flying through the bottom end. I’m planning on building a 512ci street engine for my 69. It should be capable of making around 700hp on pump gas, but I want the block to have a chance to live.

Jeff...Have you checked with Indy? That's where mine originated from in my 512..

I've used two different brands,440 Source and the other that is no longer available.
Both sets are still living in drag race motors with no known issues so far

Mine are from Best Machine. I know they're closed. I just don't know if they were in house product or supplied from a vendor. This will be season 11 on them.

I find it amazing how much life is reported on alum caps and alum rods are mostly the opposite.
Alum is known to hate stress, and is forgiving under load and why it is preferred as a main cap?
But flexing and being loaded is what eventually kills all alum, so I find this a bit odd.
I am not disputing it, I'm trying to explain it.

Looking at it from a physics standpoint, the rods are exposed to compressive and tensile loads, where the main caps are mostly compression.
I'm sure there is some tensile loads in some outer locations of a main cap, but not the whole cross section as a rod when the piston reverses direction at TDC of the exhaust stroke for example.

I agree, stress reversal is a killer, but my thinking here is the loading point on a main cap is both compressive at the highest load point during rotation and has tension, all moving as it rotates, and the cap effectively resists opening up, meaning the load is not typical stress reversal, but it is constantly varying and moving at the same time.
So loading and unloading.

Make sense?

Stanke motorsports. Made right here. https://stankemotorsports.com/Products.cfm?pn=440STDMC&pID=30

I've heard of the old-style Indy caps cracking and IIRC 440Jim had a Best Machine cap crack... nothing lasts forever

jcc, that does make sense. The load point is rotating across the face of the lower bearing from one end to the other. Not a symmetrical load into both main bolts. Kind of like a wave of stress from one end to the other in the cap.

We agree.

What kills main caps is detonation - aluminum main caps can dampen some of it - hence the reason they became so popular. The best replacement main caps were the old Mopar Ductile Iron main caps and they are not available anymore - My choice as of late has been the aluminum main caps - my last set were from 440 source and they are still available - but it takes a competent machine shop to install them

Good reason to make sure you get new parts made of the right aluminum. For a street motor build, the amount of stress cycles will be low, compared to a race motor, so my guess is life should be excellent .

The BCR website infers that the original Indy-style caps are made of inferior material... which I'm stuck with for my backup block cuz that's what I could find when it was machined years ago. Mine's going together w/ a budget girdle to help reduce the "flagpole effect" that may be a contributing factor to them cracking.

Best Machine's were 7075 IIRC, which is "top of the line" for rockers, etc. The fact that 440JIm cracked one makes me wonder what the "ideal" aluminum grade would be for caps. BCR doesn't specify what they use.

I scored 2 sets of those ... low deck ... years ago , one set I had put into one of my 383 blocks , the other set are still in the box waiting for me to put into something else .

7075 would be my first choice, 2024 would also be in the running, 6061, as nice and affordable as it is, is not up to the task IMO in any case.
With all the machining talent I see many here many exhibit, can't see why homemade is not an option. it's not as they are a real complicated item, just need to be precise.

I made my main caps out of 7075. No issues. Also made the main caps on my Dana 60 out of 7075 as well. Definitely, a stronger and better grade over 6061.