compression or flow?

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My present cam is 236. I like the characteristics of it but not enough lift. Figure if I went 10 or 15 deg of duration higher and increased lift it should be what I'd want. Only have 3k stall so wasn't looking to change that out unless as usual totally necessary. Small changes not looking to totally change combo.
 
rumblefish360 said:
If the world and planets lined up…..

I wouldn’t worry about it. While another 1/2 point is what I’d shoot for, it’s not the end all. You could…. Just sayin… move the cam around and close the intake valve earlier.

If you don’t have the cam yet, I’d contact Bullet or Schneider cams and discuss it with them. FWIW, it’ll help to have your cylinder head flow numbers handy when you talk about this.

If you have the cam, just stab it and rock it, it’ll be fine @ 10-1.

Just what exactly is 240-ish?
Click to expand...
I have a cam, but dont know if it would work with the w-2 heads on the 360 or the 340. Its just one I already have that i used on a motor years ago. Im not apposed to buying a cam and lifers.
 
Others will know better but I believe with ported W2s you’re going to want high lift. Around .575 to .600 at least that’s what I’ve always thought. I know with my combo my compression isn’t that high. So looking to limit duration so I don’t bleed too much psi but have higher lift than I presently have. Definitely a solid flat cam. Since you have kinda unknown factors I’d get to measuring and calculating what you actually have
 
And gear it since you have 3.91s. I miss my 4.10s so I’ll be looking to upgrade
 
I’m running 11.2cr 200/205 cranking psi on a 360, with home ported J,s what do they flow?? I don’t know probably not much 230’ish.. so for an ill flowing head you better run some decent compression to squeeze what little you have in that cyl !! Now if I had ported W2’s I would not have milled them down to the 59cc my J’s have knowing I’m going to fill the cylinder especially at upper rpms. That said a junky, fussy, rascal of a setup like mine still will roast the 28” drag radials with 3.55 gears for a block. So I guess what I’m saying is go with the W2’s get your static in the 10,25 to 11.0 range call a good cam company like Bulit or Howard and they can get you something made that will give you around 185/190 cranking psi. Todays Pump gas is not as bad as everyone says, the worse part is the lower boil/heat soak temps at 170. Good luck !!
 
EL5DEMON340 said:
I’m running 11.2cr 200/205 cranking psi on a 360, with home ported J,s what do they flow?? I don’t know probably not much 230’ish.. so for an ill flowing head you better run some decent compression to squeeze what little you have in that cyl !! Now if I had ported W2’s I would not have milled them down to the 59cc my J’s have knowing I’m going to fill the cylinder especially at upper rpms. That said a junky, fussy, rascal of a setup like mine still will roast the 28” drag radials with 3.55 gears for a block. So I guess what I’m saying is go with the W2’s get your static in the 10,25 to 11.0 range call a good cam company like Bulit or Howard and they can get you something made that will give you around 185/190 cranking psi. Todays Pump gas is not as bad as everyone says, the worse part is the lower boil/heat soak temps at 170. Good luck !!
Click to expand...
What cam are you running?
 
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Just kicking around some figures. The open chamber part of the W-2 head is roughly .050 deep on all 8 chambers. if I cut the heads.050 and the intake side the correct amount I can use a .035 head gasket and have .040 quench on the 360 and 10.61 compression ratio

Same senerio on the 340, but with a .060 thick gasket. .040 quench and 10.73 compression.

That should help with a nice cam to bleed of some compression for pump gas.
 
mopfried said:
Just kicking around some figures. The open chamber part of the W-2 head is roughly .050 deep on all 8 chambers. if I cut the heads.050 and the intake side the correct amount I can use a .035 head gasket and have .040 quench on the 360 and 10.61 compression ratio

Same senerio on the 340, but with a .060 thick gasket. .040 quench and 10.73 compression.

That should help with a nice cam to bleed of some compression for pump gas.
Click to expand...

If you take the quench down it will kill power. BTDT.

I know it’s a PITA but you are better off decking whatever you need to get to .040 piston to head clearance from the block.

That area is around .100ish from the factory, maybe a bit more. That means you‘ll have taken at least .100 off the heads and head gasket sealing will become problematic.
 
mopfried said:
Just kicking around some figures. The open chamber part of the W-2 head is roughly .050 deep on all 8 chambers. if I cut the heads.050 and the intake side the correct amount I can use a .035 head gasket and have .040 quench on the 360 and 10.61 compression ratio

Same senerio on the 340, but with a .060 thick gasket. .040 quench and 10.73 compression.

That should help with a nice cam to bleed of some compression for pump gas.
Click to expand...

What cam are we running? Specs on the cam.
Clarification needed!
 
rumblefish360 said:
What cam are we running? Specs on the cam.
Clarification needed!
Click to expand...
As stated before, i have an old SSh-320 Crane cam but im pretty sure i need a different one from what i have learned here. Any suggestions?
I have tooling and can cut the valve pockets larger and deeper if needed.
 
Newbomb Turk said:
If you take the quench down it will kill power. BTDT.

I know it’s a PITA but you are better off decking whatever you need to get to .040 piston to head clearance from the block.

That area is around .100ish from the factory, maybe a bit more. That means you‘ll have taken at least .100 off the heads and head gasket sealing will become problematic.
Click to expand...
I bought the heads used and didnt know they had previously been cut. Didnt realize the open part was that deep stock. These heads cc to 75 cc!
 
Let me throw in a wild card here, out of curiosity... and it'll probably either open a can of worms or get completely ignored lol...
@mopfried, is E85 available locally to you, and would you be driving this at least once a week?
 
E85 is available. I dont figire i will drive it that often though,
show your cards!
 
mopfried said:
Thinking of a cheap build with avaiable parts that i already have.
360LA block with H116CP speed pro .030 over pistons, .005 in the hole.
Set of Edelbrock untouced (used, not ported) RPM 63 cc heads Quench closed chamber)
.036 head gasket... comes up as 10.6 static compressio.
4 speed in a dart. \
I know i need to be careful picking camshaft, but will 10.6 be too much compression for pump gas?
Hot street motor.. headers, 355 gear ..maybe fuel injection...

I have never ran aluminum heads.....
I have some W-2 iron heads (70 cc and no quench, Open chamber, ported .5 point dtop in compression)and all it take to run them except pushrods.

So the question is do i give up the poeted W2 flow for higher compression and quench?
what difference will either make?
Click to expand...
IMHO, deck the block to get a 0 deck height. Aluminium heads let you get away with higher compression. Then get a water injection system. You can spray in about 50% water volume as what amount of fuel you are using. So if you use fuel for 20 MPG, you can inject half that amount water in addition. Remember that water injection only comes into play as your manifold pressure rises or said another way, vacuum drops. The water injection should basically come on about the time fuel enrichment also comes into play. So you are not going to use 1/2gallon of dustilled water every 20 miles.
The quench aids turbulence or swirl in the chamber aiding fast combustion. Better power, fuel economy and lower emissions.
If you get the exhaust valves and seats cut for a 40° seat angle you can probably use a single pattern cam of about 220° @ 0.050" lift. I would look for 0.500" lift. To get that you may need higher ratio rockers.
Just my $0.02 for consideration.
 
Dale Davies said:
IMHO, deck the block to get a 0 deck height. Aluminium heads let you get away with higher compression.
Click to expand...
Not exactly true since you just need the octane not to knock and ping.
Dale Davies said:
Then get a water injection system. You can spray in about 50% water volume as what amount of fuel you are using.
Click to expand...
50% water, 50% fuel?
Dale Davies said:
So if you use fuel for 20 MPG, you can inject half that amount water in addition. Remember that water injection only comes into play as your manifold pressure rises or said another way, vacuum drops.
Click to expand...
Manifold pressure and vacuum are two different thing right?
Dale Davies said:
The water injection should basically come on about the time fuel enrichment also comes into play. So you are not going to use 1/2gallon of dustilled water every 20 miles.
The quench aids turbulence or swirl in the chamber aiding fast combustion. Better power, fuel economy and lower emissions.
If you get the exhaust valves and seats cut for a 40° seat angle you can probably use a single pattern cam of about 220° @ 0.050" lift. I would look for 0.500" lift. To get that you may need higher ratio rockers.
Just my $0.02 for consideration.
Click to expand...

His heads are ported and the best flow starts happening at .500 and better.


mopfried said:
As stated before, i have an old SSh-320 Crane cam but im pretty sure i need a different one from what i have learned here. Any suggestions?
I have tooling and can cut the valve pockets larger and deeper if needed.
Click to expand...
Sorry, I thought that cam was out of here and a new one is being selected. Since it’s not taking advantage of the ports flow and such.

The only suggestion I can give is getting the most valve lift you can to take advantage of the high flowing ports.
 
mopfried said:
Thinking of a cheap build with avaiable parts that i already have.
360LA block with H116CP speed pro .030 over pistons, .005 in the hole.
Set of Edelbrock untouced (used, not ported) RPM 63 cc heads Quench closed chamber)
.036 head gasket... comes up as 10.6 static compressio.
4 speed in a dart. \
I know i need to be careful picking camshaft, but will 10.6 be too much compression for pump gas?
Hot street motor.. headers, 355 gear ..maybe fuel injection...

I have never ran aluminum heads.....
I have some W-2 iron heads (70 cc and no quench, Open chamber, ported .5 point dtop in compression)and all it take to run them except pushrods.

So the question is do i give up the poeted W2 flow for higher compression and quench?
what difference will either make?
Click to expand...
255/70-14s are all that will fit in the factory tubs of any 67 up Dart. Criminy a half-decent stock 318 will smoke those all the way thru First with a 4-speed and 3.55s

But yeah, alloy heads will let you run the Scr up outta sight.
I have run a set-up about like what you are contemplating, to nearly 200psi on 87E10, so there's that. The Scr was 11.3 and the ICA of the cam was around 60 degrees, with a quench of lemmee think ....... 028 or maybe a lil less.
Yes on 87E10.

IMO the Eddies are more than enough in a hot-street-Dart with factory tubs; and you'll need Caltracs or similar.

Try and remember that
on the street,
some 90% or more of the time, yur gonna be running under 4000 rpm.
and
I mean, 3.55s and 28s, in Second gear, will get you about 12.2 mph per 1000rpm;
so 4500 is 55mph, 5500 is 67, 6500 is 79mph. So how often are you gonna run past 5500?

In my combo, I actually installed a bigger cam and a thicker headgasket to give away some cylinder pressure. I'm currently at 10.9 with a Q of .032, and last I checked, pushing over 180psi. I had to install a lower starter gear to get back some of the torque of the previous combo, but the top-end was a lil more funner.
I too am running 3.55s.
I highly recommend NOT to run the Mopar 292/108 cam, as, in my combo, it did not like those 3.55s. However, with 4.30s it was pretty good.
Another thing to think about is how slow can your car drive.
With 3.55s, 28"tires, and a 2.66 low gear, 700rpm is 6.2 mph, no slip. If you want to go slower, yur gonna have to figure something else out.
 
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Dale Davies said:
IMHO, deck the block to get a 0 deck height. Aluminium heads let you get away with higher compression. Then get a water injection system. You can spray in about 50% water volume as what amount of fuel you are using. So if you use fuel for 20 MPG, you can inject half that amount water in addition. Remember that water injection only comes into play as your manifold pressure rises or said another way, vacuum drops. The water injection should basically come on about the time fuel enrichment also comes into play. So you are not going to use 1/2gallon of dustilled water every 20 miles.
The quench aids turbulence or swirl in the chamber aiding fast combustion. Better power, fuel economy and lower emissions.
If you get the exhaust valves and seats cut for a 40° seat angle you can probably use a single pattern cam of about 220° @ 0.050" lift. I would look for 0.500" lift. To get that you may need higher ratio rockers.
Just my $0.02 for consideration.
Click to expand...


Head materiel does not change detonation resistance unless you don’t know how to drive. Nothing can fix that.

They Chrysler book says the pistons should be out of the hole. Why people still argue this and give up quench is beyond me. Zero decking the block is wasting money if you don’t close up the quench.

Get the timing curve in shape, get the coolant temp under control and you won’t need to screw with any water injection or the like.
 
AJ/FormS said:
IMO the Eddies are more than enough in a hot-street-Dart
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I agree :thumbsup:
AJ/FormS said:
In my combo, I actually installed a bigger cam and a thicker headgasket to give away some cylinder pressure. I'm currently at 10.9 with a Q of .032, and last I checked, pushing over 180psi. I had to install a lower starter gear to get back some of the torque of the previous combo, but the top-end was a lil more funner.
Click to expand...
“Runner?” LOL!
AJ/FormS said:
I highly recommend NOT to run the Mopar 292/108 cam, as, in my combo, it did not like those 3.55s. However, with 4.30s it was pretty good.
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That’s the right gear for that cam.
:thumbsup:
AJ/FormS said:
Another thing to think about is how slow can your car drive.
With 3.55s, 28"tires, and a 2.66 low gear, 700rpm is 6.2 mph, no slip. If you want to go slower, yur gonna have to figure something else out.
Click to expand...
Thphhhhhh
 
mopfried said:
E85 is available. I dont figire i will drive it that often though,
show your cards!
Click to expand...
I appreciate you being open minded. If I was in your predicament, I would use the high flowing W2's, get a piston that'll give you good quench and around 11:1 compression, and run it on E85. ATM carburetors are fantastic, those guys understand alcohol fuels very well and build accordingly. I run 11.2:1 compression on my aluminum headed A Body (250/258 @ .050 Isky solid flat, spec'd by Brian at IMM - I love it), but my street/strip vehicle is 12:1 with 33lbs of boost on top of it from a Garret G30-900. Point is: E85 is amazing, as long as you don't let it sit. Start the car up once a week so the fuel doesn't sit in the bowls, and you're good.
P.S.: my apologies, I didn't go through the 4 pages of posts, time is tight right now. But the original query peaked my interest so I wanted to throw this in there as an option.
 
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