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327 sonic check question
Posted: Tue May 25, 2021 2:49 pm
by 31 a coupe
I have a pretty rare 362 casting 327 66 chevy II bare block that i bought bored and plate honed for .002 clearance for the .060 over sealed power forged pistons l2165 that came with it. I decided to sonic test it for the hell of it even though it was an early enough block i thought it would be plenty thick. I was wrong i discovered that # 1 cylinder has .098 thickness 1 inch down from the top on major thrust side and .108 at the bottom of cylinder it is .262 on minor thrust side and .247 at the bottom of minor side .180 thick front and .133 thick rear . I am going to run 64cc heads basically a 350 hp l-79 build was my dream but I don't know now . Is there a way this will work?
Re: 327 sonic check question
Posted: Tue May 25, 2021 6:40 pm
by bill jones
--here's some pretty good info about cylinder wall thicknesses
viewtopic.php?t=924
Re: 327 sonic check question
Posted: Tue May 25, 2021 9:10 pm
by af2
31 a coupe wrote: ↑Tue May 25, 2021 2:49 pm
I have a pretty rare 362 casting 327 66 chevy II bare block that i bought bored and plate honed for .002 clearance for the .060 over sealed power forged pistons l2165 that came with it. I decided to sonic test it for the hell of it even though it was an early enough block i thought it would be plenty thick. I was wrong i discovered that # 1 cylinder has .098 thickness 1 inch down from the top on major thrust side and .108 at the bottom of cylinder it is .262 on minor thrust side and .247 at the bottom of minor side .180 thick front and .133 thick rear . I am going to run 64cc heads basically a 350 hp l-79 build was my dream but I don't know now . Is there a way this will work?
Are you sure you got the major and minor correct? Sounds backward to me....
Re: 327 sonic check question
Posted: Tue May 25, 2021 9:17 pm
by 31 a coupe
lifter valley side of number 1 cylinder is what I am calling the major thrust side. The outside or plug side (calling minor thrust side) is way thick.
Re: 327 sonic check question
Posted: Thu May 27, 2021 11:28 pm
by 31 a coupe
So It looks like I am screwed with this block?
Re: 327 sonic check question
Posted: Tue Jun 29, 2021 1:22 pm
by Diodedog
31 a coupe wrote: ↑Thu May 27, 2021 11:28 pm
So It looks like I am screwed with this block?
If it's not a race engine, I think it'll be ok, short stroke and 1.75 rod ratio are in your favor.
Re: 327 sonic check question
Posted: Tue Jun 29, 2021 5:00 pm
by PackardV8
Diodedog wrote: ↑Tue Jun 29, 2021 1:22 pmIf it's not a race engine, I think it'll be ok, short stroke and 1.75 rod ratio are in your favor.
X2 - an L79 street build should be OK, barring unusual rust inside.
Re: 327 sonic check question
Posted: Thu Jul 01, 2021 10:31 am
by frnkeore
There is also the option of sleeving that one cylinder.
Re: 327 sonic check question
Posted: Sat Jul 03, 2021 11:14 am
by Firechicken
31 a coupe wrote: ↑Tue May 25, 2021 9:17 pm
lifter valley side of number 1 cylinder is what I am calling the major thrust side. The outside or plug side (calling minor thrust side) is way thick.
I think you've got that backwards.
Spark plug side of cylinder 1 is the major thrust side. You're fine.
Re: 327 sonic check question
Posted: Sun Jul 04, 2021 3:19 pm
by V12MECH
When I replaced my 283 w/ 60 over 327, I had to also replace a perfectly fine , temp wise, radiator, with a big block a/c unit, definitely ran hot, bigger rad fixed it.
Re: 327 sonic check question
Posted: Sun Jul 04, 2021 9:26 pm
by MadBill
Firechicken wrote: ↑Sat Jul 03, 2021 11:14 am
I think you've got that backwards.
Spark plug side of cylinder 1 is the major thrust side. You're fine.
Err... no. After tdc, the big end of the rod moves towards the plug side of the #1 bore, so cylinder pressure creates a lateral force component in the opposite direction.
Re: 327 sonic check question
Posted: Tue Jul 06, 2021 9:45 pm
by Firechicken
MadBill wrote: ↑Sun Jul 04, 2021 9:26 pm
Firechicken wrote: ↑Sat Jul 03, 2021 11:14 am
I think you've got that backwards.
Spark plug side of cylinder 1 is the major thrust side. You're fine.
Err... no. After tdc, the big end of the rod moves towards the plug side of the #1 bore, so cylinder pressure creates a lateral force component in the opposite direction.
Correct, my mistake. Must have got up on the wrong side of the bed...