Edlebrock head flow #

[priobe]

Hello,
Can anyone explain these numbers to me. I had my edlebrock heads for a 427 FE ported & polished. And these were the numbers that they gave me back.

2.190" Intake 1.730" Exhaust
.200 150.4 .200 114.3
.300 206.5 .300 151.5
.400 256.6 .400 179.2
.500 292 .500 195
.600 306 .600 208
.700 312 .700 220

Can anyone explain this to me.

They also gave me these numbers as well for my Camshaft

Cam

Intake
Duration @ .050 245 degree
Valve lift .660
Lobe Separation 112


Exhaust
Duration @ .050 250 degree
Valve lift .665

Opion are welcomed on this please

[Cracker]

priobe - Those are pretty good flow numbers for the heads. It simply is the amount of cfm (cubic feet per minute) that the heads allow thru the chamber at the corresponding valve lift ( ie. .500 = 1/2 inch of lift).

A ".660'ish" gross cam lift is mightly excessive for a solid flat tappet and even pretty aggressive for a solid roller - what are you looking to do with it?

[The Dreamer]

They gave you a table of numbers. Looking at the first row.

The first number is the lift of the intake valve (normally in inches)
The second number is the flow rate of the intake valve (normally in CFM or cubic feet per minute)
The third number is the lift of the exhaust valve (normally in inches)
The forth number is the flow rate of the exhaust valve (normally in CFM or cubic feet per minute)

Each row represents a different lift value.

Unported Edelbrock claims the RPMs flow

.200 153 .200 113
.300 195 .300 148
.400 233 .400 171
.500 265 .500 183
.600 270 .600 200

So you can compare your ported numbers to the unported to see how much improvement you received.

The cam is much more complicated, but if you go to the Comp Cam site, they have a lot of info to explain cams. I will say your cam has some BIG lift. Hope that helps.

[priobe]

Cracker,

I am looking to really enjoy my cobra. I told the engine builder that I wanted around 550 to 600 hp.

We got into a discussion about compression, I wanted 10.5 or 11.0 but he wanted 9.0 to 9.5.

Well he won he told me to trust him

[ItBites]

My opinion: 245-250 deg at .050 is at or beyond the limit of what will work well with 9.5 to 9.0:1 CR. I would be happier with the low CR and long duration if it were 114 lobe sep (you'd develop more dynamic cylinder pressure). Further, those flow numbers are way below what I usually see for big HP motors. It looks like those are torque heads with a higher-rpm cam. May work OK, but I'm a little concerned with the longish duration cam, even though it is not super-long.

Just for comparison, my ported FACTORY BBC heads (on my 427BBC) flow ~400Intake/330 Exhaust cfm at .700 lift.
I have ~12.5:1CR and use ~265/270 deg @.050, .675/.685 lift roller

[priobe]

Itbites,
This motor was Dynoed @ 551hp. I think with this pretty good with this CR

what do you think?

[Cracker]

Priobe - I remember your thread asking about details and power estimates earlier this year. I think it's almost too good but then again that's just me.

Here's why... I had a professionally built side oiler engineered last year with all the goodies along with a single plane intake (victor) built to road race spec with a .600 solid lifter flat tappet cam with a more aggressive dur. of 260 @ .050 than yours - outcome? 543 hp with 11:1 compression ratio - Either your builder is defeating the laws of physics which suggests BIG breather heads or extreme compression ratio's to accomplish big power. Just enjoy it - whatever it is - 500 or 750 hp! I bet since your builder engineered this strange beast he would have taken the time to sit down and go over every item with you in detail (i.e.. flow, dyno, cam & build sheets). We don't mind but nobody knows an engine like the builder. Best wishes.

[priobe]

Cracker,
I am flattered that you think it is almost impossible to create this type of power. Maybe I am leaving something out. All I know is what I read in books. I do find it strange that you are saying that my engine builder is defeating the laws of physics. I will be glad to share any information that you would like.

I dont know if you ever heard of Scorpion Performance. They manufacture rocker arms. They also have a company called Blue Thunder Engines. They are well known for offshore boat racing. You can look them up at www.scorpionperformance.com

I went to them with all the articles that everybody was using to build their motor. They told me to trust them and they will see what power they get. IF you would like a parts list I will be glad to discuss and compare.

I am not trying to start any arguments I am just looking to learn and share what information I come across

[SFfiredog]

P,
What is the displacement of your engine?
Is that a hydraulic or solid roller cam or a flat tappet?
What RPMs did the motor pull on the dyno?
Just curious.
--Mike

[ItBites]

Priobe,

551 HP from 427 ci with 9.0:1 CR. You asked what I think...

My first thought is "yeah right". But I've seen some big numbers in drag race motors from combos you'd not expect to work so well. Mostly those were at 7500 RPM though. You didn't mention RPM, but I'm guessing lower than that, based on 245/250 duration and 112 centers.

My second thought is I recall dyno operators may not include accessories, like alternators, water pumps etc... Also they tend to crank the timing way beyond what you can run reliably when the engine is hot in the engine compartment. Often they will also not use the exhaust that will eventually be used in the car. And on-and on...

I have never been a big fan of dynos except for back-to-back tuning runs, where they can be extremenly beneficial (have done this myself since I use EFI).

I'd be more interested in having you weigh your car; go run the 1/4 mile; then use a horsepower calculator based on mph and let us know what you get. That is really where the rubber meets the road...

Have a nice day

[marcocsx3121]

As long as we're talking about head flow (at least that's where this thread began), does anyone have unported flow numbers for the legendary FE performance heads of the 60s, the medium and high riser and tunnel port? Just curious as to how the giants of yesteryear compare to today's better designs.

[priobe]

I find this very strange with these comments that are being made.

Well first of all to answer some questions:

SFFiredog,

To answer your question it is a solid roller, and it has been bored 10 over. The RPM on the dyno was 5800 RPM an d then the power dropped off.


It bites,
I did notice on the dyno that the alternator was plugged in but it did have the water pump. This motor was dynoed not to bragg but to break in the motor and for me to know the power.

If these numbers are too good to be true what should this motor be putting out

[SFfiredog]

P,

I wanted to know some specs on your engine so I could answer your question properly.
The flow numbers on your heads are good.
Most uniformed people only look at the max flow numbers but the reason your motor makes so much power is because the 70%-lift flow numbers are very good and only slightly less than the max lift numbers.
Your heads may not flow huge numbers but they flow with very high velocity which is more important.
The valve is at 70%-lift twice in a power stroke (on the way up and on the way down) but only once at max lift.
The duration @.050 and the lobe center of 112 deg is why the engine makes good power with reletlivly low compression.
The ramps of the solid roller help make more power as well. (keep an eye on the valvesprings and distributor gear)
I have no problem believing the horsepower numbers.
With a bit more compression and the lobe centers a bit closer it would make power in the high 5s and pull over 6000 rpm.
--my 02
--Mike

[priobe]

Thank you SFfiredog for the explaination.

Whats usually the problem with the vavle springs and the distributor gear.

I know when they were building the motor they changed the gear but I am not sure what the springs were I think Titanium, does that sound right.

I know they make titanium valves.

Is there anything I could do to prevent any damage?

[ST]

Originally posted by marcocsx3121


As long as we're talking about head flow (at least that's where this thread began), does anyone have unported flow numbers for the legendary FE performance heads of the 60s, the medium and high riser and tunnel port? Just curious as to how the giants of yesteryear compare to today's better designs.

Here's some numbers
http://users.erols.com/srweiss/tablehdc.htm#Ford

[marcocsx3121]

Thanks for the data. Some of the numbers are surprisingly good, especially the 427 SOHC heads.

[Cracker]

Priobe

The "roller" cam answers one of my questions regarding the build and I am surprised that with that low of compression even that amount of HP can be had - pretty cool! I'm glad your flattered because I wasn't trying to offend rather simply be honest.

SFireday - Isn't the benefit of a solid roller besides aggressive ramp rates the ability to "rev" faster & higher? It's interesting because with Priobes engine the builder seemed to use this in a different manner (ie. 5800 rpm with that kind of cam) managing to keep revs down but with power up. Smart - I guess?

[priobe]

Cracker,

I completely agree with you. Thats why I wanted the high CR. It got to the point that he told me if I was not happy with the motor he would open it back up and raise the compression. He explained that it was easier to raise the compression than lower it.
Well with that being said, I shut my mouth and said ok you do what ever you have to do I spoke my piece.

I have seen motor that they have put together with some outragous power.

And again, I respect your honesty

[SFfiredog]

Originally posted by priobe


Thank you SFfiredog for the explaination.

Whats usually the problem with the vavle springs and the distributor gear.

I know when they were building the motor they changed the gear but I am not sure what the springs were I think Titanium, does that sound right.

I know they make titanium valves.

Is there anything I could do to prevent any damage?

There is any "damage" per se, but just more maintenance to perform.
The original distributor gear is cast iron which is not compatable with the billet steel of a roller cam.
The roller cam distributor gear is made of a bronze alloy that is "sacrificial", that is, the gear is designed to wear instead of the cam. Average life of a bronze distributor gear is between 10 to 20k, some more, some less.
Roller cam valve springs have a harder life than a flat tappet spring. They have a higher spring rate and the rapid opening and closeing rates of a roller cam (solid roller) build up more heat and fatigue the metal faster than a flat tappet spring.
The better the spring (read more expensive) the longer they last.
I have seen roller springs last 30k miles but on average it is much less. Your roller cam is relatively mild and I would expect long life for your springs as long as they are high quality.
Maintenence and inspection is the key to the longevity of your engine.

[ItBites]

SFconflagrationcanine is giving you the correct scoop on springs with roller cams. They will not last forever. I would add that the more oil you can get to them to cool them, the longer they are likely to last.

Additionally, you should check if your steel roller cam has a cast iron gear pressed on it. SF is correct about the bronze distributor gear if the cam gear is steel. But the bronze dist gears go away pretty quick. If the cam has the special cast iron gear option, you can run the standard distributor gear which will last effectively forever.

I have run several engines (currently have two - one for 13 years) with the cast iron gear option on steel roller cams with very good success. This option has been around a long time (at least 13 years from Crane), but it seems some folks still do not know about it.