360 stroker questions

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Jarlaxle

Jarlaxle

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Found a great deal on a short block...I think. So, I'm asking the people here:
.060 over 360 LA block (80s van)
4" Eagle crank
KB 356 pistons
360 rods
Purple shaft cam
Torker 2 intake

So...good start for a pump gas street machine?
 
60 over may be a bit much for overcome size. Especially in a later model 360. I would not be so confident to use this for any racing or long term driving conditions. Just my 2 centavos!
 
Daily driver street use,in a highway geared Dart. How is the compression on the 356 pistons?
 
Early/mid or late 80's?
Roller cam block?
Block should be check to go .060 over.
The cam will be mild in the stroker.
 
Jarlaxle said:
Found a great deal on a short block...I think. So, I'm asking the people here:
.060 over 360 LA block (80s van)
4" Eagle crank
KB 356 pistons
360 rods
Purple shaft cam
Torker 2 intake

So...good start for a pump gas street machine?
Click to expand...
Maybe, missing information. What is the actual compression ratio. There could be a big swing if the engine block was machined or not, are the flats of the piston at zero deck or .030 below? The head gasket thickness is missing.What heads and chamber cc?

Purple cam?!?! You do know they made about 50 different grinds right? It could be a small 280/.480 Hyd or a 275@050 mechanical. WTF? Which one?
LMAO! Dude! Come on now. LOL!

worry about cylinder wall thickness if it breaks.
I have found that no matter the year, there are good and bad blocks. Even the so called (LMMFAO!!!) “Good year 340 blocks”, I had one tank at the normal .030 overbore. It had several very thin cylinder walls as thin as .032.

Yea! You read that crap right…. From one of the “Good Year Blocks” that everyone says to get. Total **** bag loaded with barf! Absolutely garbage block.

(I should make a freakin coffee table out of it!)
 
rumblefish360 said:
Maybe, missing information. What is the actual compression ratio. There could be a big swing if the engine block was machined or not, are the flats of the piston at zero deck or .030 below? The head gasket thickness is missing.What heads and chamber cc?
Click to expand...

No idea, it's just a short block.

Purple cam?!?! You do know they made about 50 different grinds right? It could be a small 280/.480 Hyd or a 275@050 mechanical. WTF? Which one?
LMAO! Dude! Come on now. LOL!
Click to expand...

I don't know, would probably replace anyway.

worry about cylinder wall thickness if it breaks.
I have found that no matter the year, there are good and bad blocks. Even the so called (LMMFAO!!!) “Good year 340 blocks”, I had one tank at the normal .030 overbore. It had several very thin cylinder walls as thin as .032.

Yea! You read that crap right…. From one of the “Good Year Blocks” that everyone says to get. Total **** bag loaded with barf! Absolutely garbage block.

(I should make a freakin coffee table out of it!)
Click to expand...
Sleeve it?

I'm more concerned about the rest of it. Worst case, I can dig up a 360 block. But I don't want to end up with race gas compression.
 
OK then, I out the horse before the cart, sorry about that.

Find out if the guy sonic check it and get the rear out if you can. Find out where the piston sits in the bore and how many cc’s the dome is.

A Purple cam is old tech that works just fine. I would not be in a hurry to change it if it fits the application of your end goal. Single pattern cams are known to make a little more down low torque.

Construct your exhaust system wisely!
 
OH! Sleeves are expensive and you might want to start fresh with a virgin block or a known hood core with thick cylinder walls.
 
Jarlaxle said:
No idea, it's just a short block.



I don't know, would probably replace anyway.


Sleeve it?

I'm more concerned about the rest of it. Worst case, I can dig up a 360 block. But I don't want to end up with race gas compression.
Click to expand...
From the pics I've seen of that p8ston, and the info I found about it, it looks like close to a zero deck piston, with a little quench dome for an open chamber head, and a pretty substantial dish, a necessary feature for a street compression stroker piston.
As always, compression is wholly dependant on parts chosen, and deck height. And accurate, REAL numbers depend on REAL measurements, not theoretical numbers in a book. Just look at 906 big block heads, where "blueprint" spec is 75 cc, and they are really pushing 90.
 
Those cc specs are for class racers../

:rofl:

But you are correct!
 
rumblefish360 said:
OK then, I out the horse before the cart, sorry about that.

Find out if the guy sonic check it and get the rear out if you can. Find out where the piston sits in the bore and how many cc’s the dome is.

A Purple cam is old tech that works just fine. I would not be in a hurry to change it if it fits the application of your end goal. Single pattern cams are known to make a little more down low torque.

Construct your exhaust system wisely!
Click to expand...
The info I found says that piston is close to zero deck, has a .080 quench dome, HUGE valve reliefs, and a d-dish with 24.5 cc net volume, if I remember right.
 
My thin walled 340? Sorry… are you asking for a price for a coffee table base? LMAO!
 
Jarlaxle said:
So...are any currently available aluminum heads open chamber?
Click to expand...
Kb356 pistons... With closed chamber heads ..all you can do is use a really thick head gasket .110 think...bad idea/compression killer... or machine the close $ide of the head$ open..or you can pull the Pistons and mill about .060 off of the quench pads and use a sd521/519 @.054 compressed gasket.
The kb416 Is zero deck.
That motor as is it's built for an open chamber and it's not even blueprinted. .080 fits in a stock 72 cc shallow side chamber and yields about .040 quench.. so even then you would want to mill the head to tighten the quench and keep some cyl pressure.
An example... I use those pistons milled .040 with milled j heads @59.8 cc with a shallow .028 chamber and a .046 crushed gasket
...so gasket minus the piston =.006 +.028=.034 quench. It's my opinion that .030-.035 quench is optimum, effective and trouble free.
 
Last edited:
mopar65 said:
Didn't Edelbrock make a open chamber small block head or am I thinking big block?
Click to expand...
I don’t think it’s considered open chamber but the 65cc version of the small block head has room in the chamber to clear stock high compression 340 pistons which are .025”-.030” above the deck. I think they are PN 60175.
 
For what it´s worth: the step on the KB356 can be milled so that closed chamber heads / .039" head gaskets could be used. Did that before, still got the fixture to clamp the pistons in a lathe. I´d be more concerned about the eagle crank - is it a cast one? i´ve seen some broken ones. The rods would not be my first choice....but they work in mild applications.

It all comes down to how good this deal really is.

Michael
 
360duster said:
For what it´s worth: the step on the KB356 can be milled so that closed chamber heads / .039" head gaskets could be used. Did that before, still got the fixture to clamp the pistons in a lathe. I´d be more concerned about the eagle crank - is it a cast one? i´ve seen some broken ones. The rods would not be my first choice....but they work in mild applications.

It all comes down to how good this deal really is.

Michael
Click to expand...
Forged crank. This would be a street motor that will probably never see over 5500rpm.and look like a 318.
 
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