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302 Crank in a 289 Block?

DEL65

DEL65

Of The Morons
I'm planning the rebuild of 289 block and have been discussing with my builder. My block is currently at the machine shop being magna-fluxed. I've got a pair AFR 165's for the project and am close to selecting a cam. We're looking for 10.0 compression.

My builder/machine shop suggested replacing the crank with a 1970 302 version, stating it's beefier, will add a few inches (no big deal to me), and provide more piston options.

I can't remember if it was not good to put a 302 in a 289 or vice-versa. Any problems with this combo? Thanks.
 
works fine, I put a 69 302 crank in a 66 289 bored .030" over for my dad's 66. He has been running it since the 80's!
 
Wow, this is timely for me since I just discovered that my motor has a 302 rotating assembly and 302 heads in a 67 (C5AE) 289 bock. I am concerned about the amount of added stroke the 302 crank provides on a bock with short cylinder walls.
I have read that it is a no-no to do this.
 
"Coupe" said:
short cylinder walls.
I have read that it is a no-no to do this.
Click to expand...
Internet myth. Several engine builders have proven that 289s and 302s have the same length cyl walls
 
"gotstang" said:
Internet myth. Several engine builders have proven that 289s and 302s have the same length cyl walls
Click to expand...

And actually the early 289 blocks and 302 blocks are highly sought after to build stroked engines ie 331/347's.
Bill
 
That's good news, mine will also be .030 over..etc.

Thanks a bunch for the quick responses, everyone.
 
"67 Fastback" said:
And actually the early 289 blocks and 302 blocks are highly sought after to build stroked engines ie 331/347's.
Bill
Click to expand...

So why not stroke it? :sm_NTA

fd
 
we built my dad's "306" before all the aftermarket stuff was around. We even put 69 351 Windsor heads on it. It's quite the mix of engines.
 
"DEL65" said:
My builder/machine shop suggested replacing the crank with a 1970 302 version, stating it's beefier, will add a few inches (no big deal to me), and provide more piston options.

I can't remember if it was not good to put a 302 in a 289 or vice-versa. Any problems with this combo? Thanks.
Click to expand...

It works - just need to take the 302 rods along with the crank. 289 rods are to long for the combo with an off the shelf piston (other than the B302).

But good 347 stroker kits are around for $1K...
 
I wouldn't waste the time/money for the extra 13 cubes. It's really not worth having to pick up all of the extra parts, and gains are pretty much negligible. On the other hand, if you're willing to do all of that, you may as well go with a 331 or 347 stroker kit. Those will get you some more measurable gains with little (347) or no (331) downside, aside from $.
 
"Starfury" said:
I wouldn't waste the time/money for the extra 13 cubes. It's really not worth having to pick up all of the extra parts, and gains are pretty much negligible. On the other hand, if you're willing to do all of that, you may as well go with a 331 or 347 stroker kit. Those will get you some more measurable gains with little (347) or no (331) downside, aside from $.
Click to expand...

Don't get caught in the internet myth of rod ratio's and oiling problems with the 347. I'd take the extra 16 cubes for the same money.
Bill
 
Rod ratios aren't an 'internet myth.' A long-rod 331 (like the one I have) has a much better rod/stroke ratio than a 347 kit. The rod ratio on a 347 puts a lot of sideways stress on the pistons and cylinder walls, which, in addition to providing added wear, is also flat wasteful as far as combustion energy is concerned.

:pbj
^My gf made me add this. She's new to our smileys.
 
"Starfury" said:
Rod ratios aren't an 'internet myth.' A long-rod 331 (like the one I have) has a much better rod/stroke ratio than a 347 kit. The rod ratio on a 347 puts a lot of sideways stress on the pistons and cylinder walls, which, in addition to providing added wear, is also flat wasteful as far as combustion energy is concerned.

:pbj
^My gf made me add this. She's new to our smileys.
Click to expand...
The 400 smallblock Chevy had a worse rod ratio and they are claimed to be great motors.
Bill
 
The early engines in the race car were 289 blocks with the 302 crank and 289 rods and special Venolia pistons (this was back in the 70's) and C9 351W heads and a Holman/Moody camshaft. Saw some of them go 10's with a top loader but mine only went 11-teens with the C4. Pretty reliable and made good power for mostly stock parts. My vote is yes. My only 'tricks' were some oiling system modifications and putting 11/32" Chevy rod bolts in the 289 rods. The engines were shifted at ~6.8K and went ~7.5K through the lights in 1/4 mile work.
 
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