Parked it at the perfect time.

[toddtheodd]

So... about a year ago, my 72 c-10 started making a small knocking sound, especially under load. So I parked it.
Fast forward to last week, and I have pulled the motor and have sent it to the machine shop. For a while, I was hoping maybe it was the flexplate, or harmonic balancer, but both of those looked fine when I pulled them off (replaced balancer anyway).

So... I get a call from the machine shop a couple days ago... Turns out it's going to cost me a little more because I lost my crank core. Yeppers... one of the rods had tore up the crank journal pretty bad, and according to the mechanic, I was lucky I didn't throw that rod.

Talk about making a good decision...

[Green Machine]

Nice save - glad you caught it before it blew up, you know a 383 crank is only a few dollars more than a 350 crank, right ??????

[toddtheodd]

Originally Posted by Green Machine

Nice save - glad you caught it before it blew up, you know a 383 crank is only a few dollars more than a 350 crank, right ??????

Yeah... but I don't want to have to screw with clearance issues with the block.

Now... there is a crank with a 3.56 throw, that fits in the 350 with no modifications. (don't even have to change the rods or pistons... unless you have the block decked big time).
With a .060 bore, and the 3.56 crank, that would turn a 350 into a 369...
Could be kinda fun.
"What motor you got?"
"369."
"You mean 396?"
"No... 369."

[FRENCHBLUE72]

Nice save for sure..

[laplander]

What crank has the 3.56 stroke? Is it aftermarket? Not to hijack, just never heard of that one.....

[unclewatts]

Moral to this story is that an odd sound usually means something. Good save Todd.

[Green Machine]

"Different strokes for different folks" comes to mind here !
Anyway I had our block clearanced for about $75. What does a 3.56 crank cost since the 383 cranks can be had for about $150 ?

Is a 3.56 still internally balanced ? You could save a few bucks there because the 383 crank requires a new balancer and flexplate.

[toddtheodd]

Originally Posted by Green Machine

"Different strokes for different folks" comes to mind here !
Anyway I had our block clearanced for about $75. What does a 3.56 crank cost since the 383 cranks can be had for about $150 ?

Is a 3.56 still internally balanced ? You could save a few bucks there because the 383 crank requires a new balancer and flexplate.

It's actually quite a bit more for a 3.56 stroke crank, because it's only offered (that I've ever found) forged, and not cast. It is internally balanced though.
3.562 stroke crank at Summitracing.com

[toddtheodd]

Originally Posted by laplander

What crank has the 3.56 stroke? Is it aftermarket? Not to hijack, just never heard of that one.....

It is aftermarket. I don't think it was ever in anything.
From my understanding, it was for people that wanted to stroke their 350, but not too much, and not with block clearance issues.

[ChevLoRay]

$660 for the 3.562 stroke SCAT crank....yow! Yeah, I'm cheap-minded, too.

[toddtheodd]

Tis one of the reasons I haven't stroked my motor yet...
Truthfully though... I'd rather turn a 400 into a high revving 377, than make a torquey 383.
I like it when a motor screams.
Hmm... wonder what a 400 would be if you put say a... 3.25 stroke crank (from a 307 / 327) in it...
Let's see... say we bore the 400 0.030 over... that would give us a 4.155 bore
half of that is roughly... 2.0775, so that is the radius.
M'kay... 3.14(pie)x2.0775 squared gives us... 13.5522596 as the area of the bore...
13.5522596x3.25(stroke) gives us... 44.04484378... which is the total volumn of the cynlinder... and since there is 8...
44.04484378x8=352...
That would be one hell of a high revving 352. Should expect (with roller cam and rockers, and everything perfectly balanced) at least 8000 to 9000 rpms...
Should sound like a banshee screaming. ... wouldn't be worth a crap from a standstill... but once out on the highway it would fly.

[toddtheodd]

Doing further math on that... (because I freaking can!)
A 352 doing 9000 rpms would need...

352x9000=3168000
3168000/3456=916.6
916.6@80%(because no motor runs at 100% efficiency)=733...
Well what do ya' know... the first 350 small block that would ACTUALLY REQUIRE a 750 cfm carb.
Though of course if I were to be building that, I would also cam it and have some darn good heads on it... which would actually get me closes to 100%... so I would probably run an 850 cfm carb on it.