compression or flow?

[PRH]

It sounds like a lofty goal for a cast piston pump gas 360, with a cam that’s really suitable for street use/4 speed/3.55’s.

I wouldn’t be surprised if the 500hp cam(whichever heads are used) needed more valve pocket than what the proposed 116’s provide.

The build outline in the OP of this thread doesn’t read like a “500hp” combo to me.

If the goal is actually 500hp, gonna need to step it up a bit.

 

[TT5.9mag]

@PRH

His quote from the other thread.

From the other post I have going about compression and flow, looks like the W-2 heads may be worthwhile. I have a Holley strip dominator for the W-2 heads.
What am I expecting? 500 HP would be nice. I just want a quick fast Dart! I have accumilated so many parts thru the years I need to quit collecting and build something and enjoy my dart. Its not much more that a painted shell at the moment. I could just as easily go with a 440, But not now.
Oh and I have a A833 4 speed and an blow proof belhousing.

PS its a sickness... Mopar sickness.

And I need to type slower and spell check. lol

 

[rumblefish360]

The W2 and W5 share a few parts, but a W5 is nowhere close to a square port W5. I own both. Exhaust ports and exhaust bolt patterns are different, intake port floor is raised and ports are rectangle. Very different heads that share a few parts.

That being said if OP has a ported set of W2's and all the parts I would run them everyday before I bolted eddies on.

I own both as well and while you’re right I was trying to make it a simple thing.

I guess I’ll be the outlier here……..

Mild stock stroke street motor with cast pistons, small-ish cam, 3.55 gears?

I’ll take the Ede heads.

I’m starting to lean this way myself.

How come? I mean if the hard part of W2s is obtaining all of the rocker gear, valves, etc,

It’s not. I used Milodon .100+ Chevy valves on both sides. I just moved away from the 3/8. But the valves are available in 3/8.
Rocker gear is available through Harland Sharp, Jesel, TD.
Springs and seal are easy as any other head.

and he has all of that, why wouldn’t you choose them over the Eddie’s?

The Edelbrock head is a very good street head and the W2 was more so designed as a race head. The ports really pick up good flow rates as the valve is lifters higher. Excellent street power can be made with a box stock Edelbrock head which will also use cheaper rocker gear. An OOTB heads valves springs would work excellent with the cam mentioned.

If he went with a W2, (and maybe this is just me?) but I would have the set up very much so on a heavy hitter side. It’s nearly impossible to find a dual plane (which I believe is counter productive on this ported head) and he has a single plane intake. The single plane will shine nicely with cams of 250 or 255@050 & larger with (IMO) lifts of better than .550.

With this type of induction and camshaft size, 3.55’s will kill the engines performance. A small tire will help the engine but traction will be an issue. Full throttle will be and it and spin.

It’s more of a balancing act of not just a well put together engine combo but also the rest of the drivetrain and car.

Now if the OP said I’m not using my 3.55’s but I’m sure ok with 4.10’s and up…. 500hp, I’d suggest the W2 heads and probably a camshaft that would work well with the single plane and use 4.30-4.56 gears.

 

[rumblefish360]

@PRH

His quote from the other thread.

Right! Not near 500. Not even close. Perhaps a stroker and a W2 top with a healthy cam…. Yea, that I can see that.

I’d suggest a solid (maybe a roller) with lift near/at/beyond .600.

 

[TT5.9mag]

@rumblefish360 yea I’m familiar with both heads, and what it takes to set both up, AND what they’re capable of. I made the mistake of reading both threads and mixing/matching what the OPs goals are. Seems like a sit down and “plan” step was missed and would be a valuable step here.

 

[rumblefish360]

@rumblefish360 yea I’m familiar with both heads, and what it takes to set both up, AND what they’re capable of. I made the mistake of reading both threads and mixing/matching what the OPs goals are. Seems like a sit down and “plan” step was missed and would be a valuable step here.

Gotcha brother! Yes! The two threads at the same time almost got me as well.

 

[273]

Here's a 537 hp W2 360 same pistons similar duration cam with more lift on 108 lsa plus 1.6 rockers.

https://www.motortrend.com/how-to/mopp-0408-w2-offset-rocker-heads-configuration/

 

[rumblefish360]

Here's a 537 hp W2 360 same pistons similar duration cam with more lift on 108 lsa plus 1.6 rockers.

https://www.motortrend.com/how-to/mopp-0408-w2-offset-rocker-heads-configuration/

IIRC, the OP doesn’t have;

An Indy intake
1/6 rockers

Also the cam is a solid not like his HFT.
.578/.586 lift is a big difference as well as the intake.

Somehow I knew you would show up with a rag article…..
You’re not comparing apples to apples.
Please don’t go with “I was just showing it’s possible to….”

 

[rumblefish360]

OH! The lift on the mag cam has a within what I was saying earlier. Getting into the heads best flowing area.

 

[273]

You act like I posted that article as an argument (against you I guess) the OP wants a 500 hp w2 360 here's a 537 hp w2 360 (agree/disagree idc) with same piston so he's in the ballpark all I was trying to show.

Had nothing to do with you.

 

[Mean416]

I'm probably wrong about this but I don't think that the extra flow will be much good with out compression. That's why I don't think that putting 360 heads on a stock 318 does much for performance, sure it helps flow but when the cr is under 8.0:1 the benefits of more flow has to suffer

You were right... you are wrong.

 

[Mean416]

What the hell happened to the "disagree" button?

 

[273]

What the hell happened to the "disagree" button?

Got to do it with words now

 

[Mean416]

You act like I posted that article as an argument (against you I guess) the OP wants a 500 hp w2 360 here's a 537 hp w2 360 (agree/disagree idc) with same piston so he's in the ballpark all I was trying to show.

Had nothing to do with you.

View attachment 1716189878

Some folks just get butthurt too easily bro. There's a few here that think FABO is the most important thing in the world.

 

[Mean416]

To the original question though, I'd pick the W2 setup in a heartbeat, unless you're thinking about using them in a more race oriented setup later.

 

[rumblefish360]

You act like I posted that article as an argument (against you I guess)

LMAO! No! Ha ha ha ha… sorry. I see what your saying though.

the OP wants a 500 hp w2 360 here's a 537 hp w2 360 (agree/disagree idc) with same piston so he's in the ballpark all I was trying to show.

And I outlined what’s different…. It’s not a combo I’d do with 3.55’s on any tire with a standard 4spd manual. Others may disagree.

Had nothing to do with you.

Not directly and I did t take it personally.

View attachment 1716189878

Is that ME?!?!?! ROFLMAO! I love it!!!,,,, me or not.

 

[273]

Yes definitely he'll will want more gear this engine lives in the 5,000-7,000 rpm powerband.

Dyno ResultsDTS DynoTested at JMS
RPM	Torque	HP
3,000	392	224
3,500	390	260
4,000	424	323
4,500	453	388
5,000	463	441
5,100	468	453
5,500	464	486
6,000	453	517
6,500	434	537
7,000	397	529

 

[Mean416]

Yes definitely he'll will want more gear this engine lives in the 5,000-7,000 rpm powerband.

Dyno ResultsDTS DynoTested at JMS
RPM	Torque	HP
3,000	392	224
3,500	390	260
4,000	424	323
4,500	453	388
5,000	463	441
5,100	468	453
5,500	464	486
6,000	453	517
6,500	434	537
7,000	397	529

That's gonna be more a function of the cam and vehicle setup rather than the heads.

No street motor lives in those rpm ranges anyway.

 

[PRH]

The build in the mag looks like a good blueprint to follow for 500hp.
A different manifold might perk up the tq down low a bit.

 

[273]

That's gonna be more a function of the cam and vehicle setup rather than the heads.

True

No street motor lives in those rpm ranges anyway.

Only when racing, this where the OP should decide what he values more driveability, an hp#, track performance etc.. The more things you want your car to do generally the less efficient it becomes at doing any of them.

If 3.55 are a must I'd build for that. (Peak hp around 5200-5600 rpm.)

 

[Dan the man]

You were right... you are wrong.

Question, how can flow be beneficial if the compression ratio is like 7.5:1?

 

[TT5.9mag]

Question, how can flow be beneficial if the compression ratio is like 7.5:1?

Because the engine still rotates. I’ll give you a homework assignment, go look up volumetric efficiency and read/understand it. You can make power with low compression. You cannot make power with no airflow.

 

[273]

Question, how can flow be beneficial if the compression ratio is like 7.5:1?

In a engine like this you gonna make around 1.7-1.9 hp per cfm, so eg. 240 vs 300 cfm = 408-456 hp vs 510-570 hp with appropriate cam intake exhaust etc.. Including CR so say 10.5:1 for these power numbers vs 7.5:1 is about 10% hp loss on so 40-60 hp power loss on some of these numbers. Worst case on your eg. the lowest 300 cfm - 60 hp basically ties the highest 240 cfm with high cr. But this is an extreme cr difference, generally your talking a a lot less. But in some cases the loss of cr can lose more than the gain flow depends on the numbers were talking about. But general the hp gain of good amount of additional cfm is gonna be a net positive even at the sacrifice of a point or so of cr.

 

[Dan the man]

Because the engine still rotates. I’ll give you a homework assignment, go look up volumetric efficiency and read/understand it. You can make power with low compression. You cannot make power with no aiairflow.

I'm going to look up and read about volumetric efficiency before I ask anything else about flow and cr. I'd like to know how to make power with low compression.

 

[TT5.9mag]

I'm going to look up and read about volumetric efficiency before I ask anything else about flow and cr. I'd like to know how to make power with low compression.

You’ll find one of the ways to get there is good airflow through the cylinder head. I call it the LS method. Or the gen3 hemi method. Small engine, low (ish) compression and excellent cylinder heads.