I've had several questions concerning clearance issues that
may be encountered using the BPE 4.250" stroke crank. I mocked
one up in a +.030" 340 block using both the Compstar 6.200" and
Oliver 6.200" rod.

A mile to the pan rail.

Compstar rod will require minimal clearancing at the bottom of the bore(4.070") for rod bolt.

As does the Oliver.

Clearance to the oil pump and Milodon pick-up was checked with both
rods in standard and HV Melling 72 oil pumps. Over .100" in all instances.

Not a concern with this block but, something else to check for.......to the dipstick boss.

Thanks for the post & pics !!

good tech be interesting how long a stock block lasted and what kind of power it made with that crank.

Looks like a lot less clearancing than I needed to get a 3.55 aluminum rod crank in a 318!!

Speaking of which, I'm thinking about using the 4.25 as a torque monster in a 318 block (since I already have one) Something with about 525 lb/ft at 3200 rpm to use as a tow rig.

That looks great!!
I can see 1 of these combos in my future!!
Thanks again for trying to make the S/B market affordable, but still quality!

Vic,
What are you waiting for? put one in your R block and go fast.You told me you could not find a decent stock crankshaft anyway.
Just
Let me know if you still need a crank and I will make some calls on Monday.
Keith

I would not be too concerned with a stock block,properly prepared and depending on it's use.My 4.125 BPE crankshaft is in a stock 360 block and has been being abused for a long time with no issues.
I run mine to 6500 every pass,and used to wind it to 7000.People worry about longevity but how many of us would run something like this for 100,000 miles anyway?
Big block guys run strokes this big or bigger all the time.The lightweight parts that tend to go with the longer strokes really help IMO.
Just my
Keith

I filled your block.

I wouldn't hesitate to build a stroked SB that sonic checked good though.

BTW, the problem I'm having finding a stock crank is, all of them
are .010"/.010", .010"/.020", etc. H-bearings are only available
in standard or .010" and I'm too picky with my clearances to buy
one already "turned".

That or they want stupid money for them.

I would not anticipate any issues with steel rods on that crank. A little nip in the bottom of the cylinders and you should be fine. Be careful not to cut into water getting greedy with the grinder. Guys need to remember though, a stock 340 4.040" bore. A 318 is only 3.910". The diiference in bore .130". You only need to know half of that .065" when clearancing. This should not be an issue, but something to keep in mind. And unless you plan to run with bent rods or worn out bearings .015 is all the clearance you need.

Something else I have ran into big differences in rod length can change cause a clearance issue if you were already really close.

I have heard people cringe at the XR2 blocks worried about the cam tunnel. I wouldn't get too exited as it is nowhere close on an A engine block.

I have run BIG alluminum rods in the past and the internal oil pump was the only item that took extra work to clearance. Would run an external in the future on any build like this.

Now if someone wants to give away a XR2 with the lifters done and no oil leaks I will be glad to show you how a back yard hillbilly can make a huge engine on the cheap. LOL

Leon

rod do you have a list of compression hight on your pistons ??
i like to get a 4.125 or 4.250 crank i all ready have a set of 6.300 h beam rods 2.000 b end .927 s end

There really isn't a specific compression height on the pistons I offer. What I do is have pistons made for your build. After the engineering costs we only need to stay within a few perameters. I currently offer a -17cc dish and a flattop for the 4.125". We can adjust for rod length, deck height, bore size, ect. So, it's like getting a custom piston without all of the costs associated with it. We are currently working on the 4.250" stroke combo's.

Rod

thanks