Author Topic: Has anyone sonic mapped a 330FT block?  (Read 3548 times)

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Fordman

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Has anyone sonic mapped a 330FT block?
« on: July 24, 2020, 10:19:37 AM »
I just tore down what I thought would be a 361ft but turned out it was a 330ft. Just thinking out loud but if the 330ft block(3.8750" bore) is cast with 352/390 cylinder cores that would theoretically add an additional .080 thou wall thickness. It should make a very sturdy block. I was wondering if anyone has had one of these blocks sonic mapped and what the average cylinder wall thickness was. A ford 5.4 mod motor has a bore of 3.550" and 4.160" stroke so got me thinking about a small bore stoker. opinions welcome

mbrunson427

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Re: Has anyone sonic mapped a 330FT block?
« Reply #1 on: July 24, 2020, 10:39:31 AM »
I went back through my photos and found a picture of a NOS 330 block we have. We sonic check the blocks before we put them on the rack, I toss a sonic sheet into the bag with the block but we always write the thinnest reading on the front of the block. It's hard to see in this picture, but when I zoomed in I read .270". That would be the thinnest reading shown on our sonic sheet. As I remember some points on this block were near .400".

Mike Brunson
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Fordman

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Re: Has anyone sonic mapped a 330FT block?
« Reply #2 on: July 24, 2020, 10:53:31 AM »
wow!!. That is thick!. Is my math right when I calculate that block has a std bore of 3.8750" with a MINIMUM thickness of .270 leaves a possible overbore of .240(.120 per side)would achieve a 4.115 bore with a minimum cylinder wall thickness of .150
Is that right??

Joey120373

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Re: Has anyone sonic mapped a 330FT block?
« Reply #3 on: July 24, 2020, 11:42:09 AM »
I’ve got one of those 330s in my 69 f250, at least it was sold to me as a 330 out of a dump truck.

Might have to pull it out and tear it down one of these days.

TomP

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Re: Has anyone sonic mapped a 330FT block?
« Reply #4 on: July 24, 2020, 11:56:43 AM »
Or leave it standard bore and offset grind a 332 crank to shorten the stroke and make a 289 big block!

Joey120373

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Re: Has anyone sonic mapped a 330FT block?
« Reply #5 on: July 24, 2020, 12:40:54 PM »
Forged Pistons, rods & 360 crank, and a set of turbos....

mbrunson427

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Re: Has anyone sonic mapped a 330FT block?
« Reply #6 on: July 24, 2020, 01:11:10 PM »
wow!!. That is thick!. Is my math right when I calculate that block has a std bore of 3.8750" with a MINIMUM thickness of .270 leaves a possible overbore of .240(.120 per side)would achieve a 4.115 bore with a minimum cylinder wall thickness of .150
Is that right??

I don't know if you'd want to go that thin....I think typical consensus is to keep it above .200" if you can help it. Let me see if I can get at that block and take a picture of the sonic sheet. Then all the engine builders on here can chime in with how far they think they would take it.

My idea was similar to most the folks chiming in.....keep it normal bore/stroke and make a thick walled turbo motor out of it. Would be cool in a light car like a Falcon/Mustang.
Mike Brunson
BrunsonPerformance.com

frnkeore

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Re: Has anyone sonic mapped a 330FT block?
« Reply #7 on: July 24, 2020, 01:50:20 PM »
If you use a 427 block, as the minimum standard wall thickness. They are said to have 1/8-9/64 gaps, between outer cylinder cores. Using that standard and no core shift, you get the following:

1/8 gap x 4.234 = .1355 wall.

9/64 gap x 4.234 = .128

1/8 gap x 4.280 = .113

9/64 gap x 4.264 (.030 over) = .113

Frank

Joe-JDC

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Re: Has anyone sonic mapped a 330FT block?
« Reply #8 on: July 24, 2020, 01:51:42 PM »
My EMC Y Block is 3.862" bore, and it made 595 hp with water pump driven by belt from crankshaft.  Lots of pistons, thin rings, available for those bore sizes if you know a good machine shop that deals with the smaller bores.  I would love to have .150" on my thrust sides, so anything more is a bonus.  Joe-JDC
Joe-JDC '70GT-500

blykins

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Re: Has anyone sonic mapped a 330FT block?
« Reply #9 on: July 24, 2020, 02:27:12 PM »
If you use a 427 block, as the minimum standard wall thickness. They are said to have 1/8-9/64 gaps, between outer cylinder cores. Using that standard and no core shift, you get the following:

1/8 gap x 4.234 = .1355 wall.

9/64 gap x 4.234 = .128

1/8 gap x 4.280 = .113

9/64 gap x 4.264 (.030 over) = .113

True, but I'd rather have more. 

Boring to absolute capacity gets you less than a thick, stable bore. 

With a 427 or a 351C, you do what you have to do to work with what you have, but that's why a new aftermarket block will make more horsepower than a factory 427 block.  Ring seal is paramount.

I'd rather see that block with a 352 bore or a standard 390 bore. 
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thatdarncat

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Re: Has anyone sonic mapped a 330FT block?
« Reply #10 on: July 24, 2020, 02:36:29 PM »
Something to remember when talking about 427 block cylinder wall thickness is that most original Ford 427 blocks have the “cloverleaf” cylinder cores that are thicker in the “corners”, which should help some with strength. And that shows me that the Ford engineers thought more was better, but had to work with the package they were given.



« Last Edit: July 24, 2020, 02:42:19 PM by thatdarncat »
Kevin Rolph

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1967FEGT

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Re: Has anyone sonic mapped a 330FT block?
« Reply #11 on: July 24, 2020, 04:30:32 PM »
Based on the sonic on the two blocks I had. ( 64 and a 67) not all have the reinforcement.
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cjshaker

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Re: Has anyone sonic mapped a 330FT block?
« Reply #12 on: July 25, 2020, 08:04:34 AM »
I thought the cloverleaf design started in '65, with the introduction of the Medium Riser heads. I could be wrong about the time, but I know early 427's did not have the cloverleaf cylinders.
Doug Smith


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frnkeore

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Re: Has anyone sonic mapped a 330FT block?
« Reply #13 on: July 25, 2020, 04:29:15 PM »
mbrunson,
I'd be interested in the width of the gap, between cylinders on your 330 block.
Frank

brettco

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Re: Has anyone sonic mapped a 330FT block?
« Reply #14 on: July 27, 2020, 12:04:16 AM »
I had a 427 bored I think 047 over that had a .070 thick spot that ran for 20 years no problem. This could be a standard bore 427 with 110 thick walks? How thick are 447 walls usually? I thought .100 was safe for street use. I understand more is better.