How to tell if my block is thick walled?

[Heo]

My engine is the factory PI engine and it actually had
a 284 degree camshaft stock, less lift though.
I don't consider a 282 cam a big cam in a 400+ engine
with the right C/R and tight squish but it boils down
to personal preferences
I have the castiron shorty headers and i think i run a
duraspark dist and wish i could find an oem PI open
air cleaner. Im building a 2.5 exhaust with the  dealer
optional "Lakepipe" cut outs in front of the rear wheel
and Apple racing mufflers after the rear end

[BruceS]

Heo, is this the air cleaner type you're looking for?  http://www.cobranda.com/19dohuhiairc.html

I bought the later version 14" open air cleaner repro from them some years ago and it was good quality. 

Bruce

[Heo]

Yes  Bruce i think thats the one thanks for the link
 

[mungus]

Sounds like you will have a nice motor, hopefully both of us will!

To my earlier post regarding CR calcs;

I rejigged the calc on Barry's website and it came up a bit closer to the Summit calc and the Speed Pro spec's advertised  +.060 CR's on standard crank & rods etc. But its still out just a little. I'm wondering if the other calcs account for the space above the top ring? As if I reduce that to zero the calcs come out very close. Barry's calc page certainly takes in more variables, and we all know he likes to do things correctly, and his engines sometimes make big numbers where an accurate CR is important, so I'm guessing his is the closest.

In any case I have to admit that I am guessing at the ring space amount myself, as I don't yet have my new SP pistons, nor can I find that spec or any diagrams anywhere... I'm basing that value  on the stock dished pistons I pulled from my block. They had a top ring space to top edge of .30".
So perhaps the Speed Pros are a little less? In any case we're only talking a difference of around 0.27 for the CR.

[Heo]

I can messure my old speedpros

[mungus]

Thanks.

[Heo]

On my old dished SP from ring to top of piston 3/8
Dia. abow ring 4.087

[fryedaddy]

i read it in a mag back in the late 80s when i was into fe bigtime,still am,i read a article that said 66 model pi blocks have slightly thicker cylinder walls than the rest,but i dont know and i could not get anyone to agree with me on this,so i gave up on the idea,after i hoarded a few pi engines.

[Heo]

My 64 PI block have same cyl. wall thicknes
as other regular 390 blocks 060 is max bore
If you want 0.100 or more wall thicknes

[mungus]

On my old dished SP from ring to top of piston 3/8
Dia. abow ring 4.087

OK, sorry I don't quite follow. Do you mean the height ab0ve the top of the ring was 3/8"? (.375").
And the piston's diameter above the ring was 4.087" (i.e. worn down a smidge?). Sorry I might not quite be fully awake yet! (early Sunday AM here)

I guess being an older dished type they might be a little different to the new flat top SP pistons (with valve recesses) anyway.
But then I guess that's effectively dished anyway (they are +10 cc).
That's a little more height than I used from the stock pistons (.3") so would make the CR calc. split slightly bigger.

Thanks for measuring them though. Appreciate it. I'll be sure to measure mine and post it up here together with a PDF of the CR calc. from Barry's page, for future reference etc.

[mungus]

My 64 PI block have same cyl. wall thicknes
as other regular 390 blocks 060 is max bore
If you want 0.100 or more wall thicknes

I think mine might be a regular block, as it will be measuring about .125" on the thinnest bore once bored to +.060".
I certainly wouldn't want to go more, what with possible core shift issues etc.
If I had no choice I'd have to sleeve it.

My second (spare) block should be here in a week or so. Its late 60's or early 70's according to the MOC guy I bought it off ($100).
I never saw the casting markings but no matter, its a spare FE block, and here in OZ that's always worth having.
We had lots of Windsors and Clevelands but hardly any FE's made it here back in the day.

I'll be interested to see how that measures up. Was a runner before he stripped it and it seems pretty clean, so here's hoping.

[Heo]

Yes 3/8 is the height above the top of the ring
The pistons  allways have smaller diameter
above the top ring. Or most of the time.
They are dished with valve reliefs, looks like
the new ones exept the dish and no coating
Its not easy to find a 390 block in Sweden
either ...or a Cleveland anymore. In the 80s
it was no problem