Rpm 340 Cyl heads on a 318 !

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nm9stheham said:
What are you doing with this engine? The usual questions of SCR, DCR, cam size, fuel type and all that jazz apply. The pN 60779 version of these heads that you are looking at have 63 cc chambers, and that + a stroker kit will push the SCR/DCR well above the stock 318 levels. You gotta do the same homework each time.
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nm9stheham said:
What are you doing with this engine? The usual questions of SCR, DCR, cam size, fuel type and all that jazz apply. The pN 60779 version of these heads that you are looking at have 63 cc chambers, and that + a stroker kit will push the SCR/DCR well above the stock 318 levels. You gotta do the same homework each time.
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Just doing some research , I might build a 30 or 60 over 318 and plan on running some compression so the heads I have were ported and the job was nice but I'm afraid they would run out steam on the 340 combo I had so doing some research and might put a nice 318 together with a tunnel ram and large solid cam and use the rpm 340 heads .
 
Im trying to hort up some early model 318 blocks because the late models are junk I tore two aprt this weekend a 1974 standard bore and a 1985 40 0ver . The 74 model weighed 10lbs more with just block and maincaps on a scale .
 
I could save you a ton of hassle and sell you a allready done, and running W2 340
 
let's talk about your heads for a minute
Those heads do not have the standard LA open chamber
they have a .060 cut to clear the standard .340 piston which comes above the deck
The KB solid pistons come up .200 above the deck of the piston
obviously you would have to run a shim to keep that piston from hitting the head- or mill the dome
so figure out your deck height- KB's target is given on the piston spec page 9.578 you may have to deck your block to get that figure
now figure half your stroke plus rod plus compression height given and see how far the dome comes out of the block (in a perfect worlds- we're just estimating here
now how far does that dome come out of the block?
you can mill the dome to get proper quench of .030 to .040, play with gaskets,etc/

The FT pistons- if they install ad 0.0 deck add gasket and the recess in the head would give you about .088 to .100 quench which is way too much
so you are looking at milling the heads and/ or the block
start doing the math and making notes
now figure out what gas you are going to use and what cam so you can target a compression ratio (more for a light stick shift car- less for a heavy tight converter car- others will help here)
 
Wyrmrider said:
let's talk about your heads for a minute
Those heads do not have the standard LA open chamber
they have a .060 cut to clear the standard .340 piston which comes above the deck
The KB solid pistons come up .200 above the deck of the piston
obviously you would have to run a shim to keep that piston from hitting the head- or mill the dome
so figure out your deck height- KB's target is given on the piston spec page 9.578 you may have to deck your block to get that figure
now figure half your stroke plus rod plus compression height given and see how far the dome comes out of the block (in a perfect worlds- we're just estimating here
now how far does that dome come out of the block?
you can mill the dome to get proper quench of .030 to .040, play with gaskets,etc/

The FT pistons- if they install ad 0.0 deck add gasket and the recess in the head would give you about .088 to .100 quench which is way too much
so you are looking at milling the heads and/ or the block
start doing the math and making notes
now figure out what gas you are going to use and what cam so you can target a compression ratio (more for a light stick shift car- less for a heavy tight converter car- others will help here)
Click to expand...
Yes engine builder has mentioned surfacing the heads and yes motor will be for a lite weight Gasser 4 speed.
 
Wyrmrider said:
Those heads do not have the standard LA open chamber
they have a .060 cut to clear the standard .340 piston which comes above the deck
Click to expand...
Just information.. there are 2 Edelbrock RPM heads... one has the .060" deep recess like mentioned above (PN 60179 loaded), and the other has no recess and is a closed chamber head (PN 60779 loaded). IIRC there are also unloaded PN's for the 2 versions and maybe a 3rd configuration option...
 
nm9stheham said:
Just information.. there are 2 Edelbrock RPM heads... one has the .060" deep recess like mentioned above (PN 60179 loaded), and the other has no recess and is a closed chamber head (PN 60779 loaded). IIRC there are also unloaded PN's for the 2 versions and maybe a 3rd configuration option...
Click to expand...
I have .060 recess
 
you need to notch the bore to maximize flow. I take it, you're gonna rev this 318 to the moon. so flow is your friend.
do you want to be limited !
 
Check and see if the block is square first
read the oiling thread and the sticky
lite weight Gasser 4 speed. what fun
what no Hydrostick :)

mill the dome on the high compression pistons for correct quench on the intake side and enough on the spark plug side to get the cr you want
or
mill the heads to get rid of that .060 detonation chamber
or exchange the heads
did you say what compression you are lookig for and head cc's
 
Wyrmrider said:
Check and see if the block is square first
read the oiling thread and the sticky
lite weight Gasser 4 speed. what fun
what no Hydrostick :)

mill the dome on the high compression pistons for correct quench on the intake side and enough on the spark plug side to get the cr you want
or
mill the heads to get rid of that .060 detonation chamber
or exchange the heads
did you say what compression you are lookig for and head cc's
Click to expand...
Thank you my engine builder
Ben Watkins - in Forest Park GA
Said the same thing .
 
fishmens67 said:
you need to notch the bore to maximize flow. I take it, you're gonna rev this 318 to the moon. so flow is your friend.
do you want to be limited !
Click to expand...
Thank you for the info and your comment is correct I want it to live and be able to rev just north of 7500rpm.
 
1Badcolt said:
Thank you for the info and your comment is correct I want it to live and be able to rev just north of 7500rpm.
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I have never had to notch a bore for any of my 5 builds but Im going to see if I can find some images of the finished procedure.
 
1Badcolt said:
Just doing some research , I might build a 30 or 60 over 318 and plan on running some compression so the heads I have were ported and the job was nice but I'm afraid they would run out steam on the 340 combo I had so doing some research and might put a nice 318 together with a tunnel ram and large solid cam and use the rpm 340 heads .
Click to expand...
You know how hard that is on a stock-stroke 318, right? You are starting with a fairly modest swept volume of 672.4cc @30 over. For an 11/1 engine that means a total chamber of 67.24cc, doable yes, but not cheap. Jus saying. Between that and the smaller bore.......
Speaking of which; some guys have successfully punched out 3.91s to 4.04, making a swept of 696.4 possible, and so, for an 11/1 engine, the total chamber volume becomes 69.64cc; a lil easier.
'Course a 3.94x3.58 makes it even easier at 72.61
But I guess none of that solves your running out of steam ,problem.
I'm not helping am I,lol.
 
AJ/FormS said:
You know how hard that is on a stock-stroke 318, right? You are starting with a fairly modest swept volume of 672.4cc @30 over. For an 11/1 engine that means a total chamber of 67.24cc, doable yes, but not cheap. Jus saying. Between that and the smaller bore.......
Speaking of which; some guys have successfully punched out 3.91s to 4.04, making a swept of 696.4 possible, and so, for an 11/1 engine, the total chamber volume becomes 69.64cc; a lil easier.
'Course a 3.94x3.58 makes it even easier at 72.61
But I guess none of that solves your running out of steam ,problem.
I'm not helping am I,lol.
Click to expand...

Oh yea taking it all in
This forum is Awesome lot of guys with tons of experience and info to offer .
 
2.02’s clear a stock 318 bore. No “NEED” to notch the cylinder but it would help in a minor way.
Never heard of a 318 being punched out to 4.04. 4.00? Yes 4.04, no.

Build the 318 like a 340, don’t look back.
 
rumblefish360 said:
2.02’s clear a stock 318 bore. No “NEED” to notch the cylinder but it would help in a minor way.
Never heard of a 318 being punched out to 4.04. 4.00? Yes 4.04, no.

Build the 318 like a 340, don’t look back.
Click to expand...
Thank you Sir
That makes since Edelbrock states these heads fit the
318 340 360 and dont note any modifications needed to install.
 
sure edelbrock says they will bolt on
and they will clear the out of block early high compression 340 pistons
not your problem
Trying to get high compression in a 318 is
and as I mentioned there are several ways to get there
none are out of the box
you do want some tight quench so figure 6- + 40 = .100 with a fel pro or 88 with the ,028 gasket with a FT piston at 0.0 deck and figure out a way to get it down to .030-.040
but first you have to find a piston that gives a true 0 deck or cut the dome on the dome pistons
keep us posted
ps the notch/ bevel is a continuation of your port and valve job due to the chamber being larger than the bore
 
Wyrmrider said:
sure edelbrock says they will bolt on
and they will clear the out of block early high compression 340 pistons
not your problem
Trying to get high compression in a 318 is
and as I mentioned there are several ways to get there
none are out of the box
you do want some tight quench so figure 6- + 40 = .100 with a fel pro or 88 with the ,028 gasket with a FT piston at 0.0 deck and figure out a way to get it down to .030-.040
but first you have to find a piston that gives a true 0 deck or cut the dome on the dome pistons
keep us posted
ps the notch/ bevel is a continuation of your port and valve job due to the chamber being larger than the bore
Click to expand...

When my block gets home from machine shop I will bolt head on block and flip it over and see whats going on also note I will most likely be boring block 60 over w-Hardblock so maybe the bore @ 60 over will relieve this issue if it exists correct ??
 
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1Badcolt said:
Sold most of it I have one more block and two cranks but they are at machine shop getting checked out .
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Ok but why a 318 then instead? Dont missunderstand me here i like 318s but if you are going to do a good high powered smallblock the bigger bore is kind of a nice feature to have and having both options i would certainly have done a 340.
 
yo will still need the intake eyebrow (keep above the to of the top ring) exhaust not needed for flow yes for mechanical interference
flip that block over and scribe around cylinderhead
 
Wyrmrider said:
yo will still need the intake eyebrow (keep above the to of the top ring) exhaust not needed for flow yes for mechanical interference
flip that block over and scribe around cylinderhead
Click to expand...
Ten 4 engine builder overseeing entire build he is the brains.
 
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