New Magnum heads for 347 with Flow data

-
Abodybomber said:
Best down to earth info,seen in a damn long time(on Magnums). Thank you ,Ramm. FWIW,what is the intake runner cc out to. I have heard of smaller than stock Magnum 153 c.c. replacements?...
Click to expand...

I wondered this as well so I found some time to check 2 ports. An untouched port came in at exactly 153cc's. The port I had been working with came in at a whopping 154cc's. J.Rob
 
RAMM said:
I wondered this as well so I found some time to check 2 ports. An untouched port came in at exactly 153cc's. The port I had been working with came in at a whopping 154cc's. J.Rob
Click to expand...

You havent even touched them then.lol
back to work! ;)
 
Here is where some may find this very interesting. I know that some porting info you may run across tells you to concentrate on the bowl and valve job for maximum gains and to leave the pushrod pinch intake flange area alone. Well we already know that it is abysmally small at the pinch and when it's this narrow you can bet that the air is being accelerated to a very high speed here. The air will not be able to make the turn past the S.S. and head down past the valve at such high speeds. So I know from past experience that it is very important to gain some real-estate here on Magnum heads.

As you can see from the pic-I used the end of a 12mm wrench which measures .735" across as a guide and visual aid . The port was less than .690" here at the roof to start with. You can see that I really did not remove much at all.

So how did it impact the flow?

.1 63.3
.2 130
.3 185.3
.4 206.5
.45 199
.5 199
.6 199

The port still stalls but it is important to note that it sounded much better than previous tests above .400" J.Rob
 

Attachments

  • Pinch work.jpg
    53.2 KB · Views: 664
There is a fairly large rib/vane that is cast into the floors of all the ports that runs right up to the S.S. that may be contributing to the ports early saturation. Next move is to take that out and retest. You can see it here, I've touched it with the burr to get it to show up better. J.Rob
 

Attachments

  • floorvane.jpg
    43.7 KB · Views: 701
Just the intake detail.
 

Attachments

  • graph 111813.jpg
    76.5 KB · Views: 663
Here is what happened once that rib/floor protrusion was removed. J.Rob

.1 63.6
.2 128.7
.3 185.3
.4 210
.45 207
.5 207
.6 206
 

Attachments

  • smoothfloor.jpg
    43.4 KB · Views: 670
At this point it's probably a good idea to give the port a little more area around the guide boss. Here is what it looked like after about 10 mins of fast carbide work. J.Rob

.1 64
.2 130
.3 189
.4 217
.45 214
.5 212
.6 212

Forgot to add: port volume is 160cc's now.
 

Attachments

  • guideprofile.jpg
    40 KB · Views: 931
This update includes the removal of the rib/floor protrusion and increase in port size to 160cc.
 

Attachments

  • graph 111813 -2.jpg
    73.4 KB · Views: 638
RAMM said:
Thanks for taking the time to graph this. J.Rob
Click to expand...

You're welcome!

Thank you for sharing your knowledge with us and making it available with such nice details. Your work is engaging me to get a better understanding of something I wouldn't ordinarily have access to.

I've been experimenting with line and plot graphs to find the best presentation for he data but at the moment the standard bar seems to be the easiest to interpret.
 
It's always nice to see a well documented logical approach to this kind of work.
Thanks for sharing.
 
Great work Ramm! Much appreciated. Should make for a real responsive street engine,with low &mid range flow like that.
 
Abodybomber said:
Great work Ramm! Much appreciated. Should make for a real responsive street engine,with low &mid range flow like that.
Click to expand...

I'm glad its being appreciated. I feel it's important to not get too caught up and start chasing a flow number. As it is now these flow numbers will support the power goals. However because the air speed is still way too high I may open the pinch further in an attempt to reduce turbulence. J.Rob
 
Solid gains for sure.
.1 65....64.....-1
.2 122...130...+8
.3 167...189...+22
.4 194...217...+23
.45 194..214...+20
.5 192 ...212...+20
.6 190 ...212...+22

Looks like a bit too much over hang on the SS in my humble opinion, but I know how the pics can be deceiving vs seeing in person. None the less in the big picture of what the build is targeted for they should rock. Lots of low RPM air speed should make for a very torquey responsive motor.

Thanks for the update. Much appreciated.

attachment.php
 
Just my $.02 from messing around with stock Magnums there were two main castings produced, one earlier that came on mostly 5.9's and some 5.2's and another later casting that became the replacement and started out mostly on 5.2's. The later casting has slightly smaller ports and combustion chambers; measuring the chambers myself the "early" casting had average volume around 66 cc while the later one was around 63 cc average.

This makes me really wish I had the means to port my Magnums before I put them on my 360 I feel like I could have made these mods myself pretty easily and picked up 20+ cfm... oh well I'll just wait till I upgrade to EQ's and port those ha
 
MOPEkidD-3 said:
This makes me really wish I had the means to port my Magnums before I put them on my 360 I feel like I could have made these mods myself pretty easily and picked up 20+ cfm... oh well I'll just wait till I upgrade to EQ's and port those ha
Click to expand...

That is exactly the way I've geared this thread-So that anyone can do this. I have been trying very hard to NOT put them on the CNC and put an oval/venturi shaped bowl and knock the pinch out to an exact, straight size. The steps laid out here are so anyone with 2 different carbides can replicate.

The EQ's are an awesome head and with my valvejob flow an honest 239-241 cfm everytime. Beautiful casting they are. J.Rob
 
I've always maintained the biggest issue with magnums is that pinch. So from what I can see (excluding the various retests) you've got about 20 minutes of grinding once you know where to touch. Correct?
 
moper said:
I've always maintained the biggest issue with magnums is that pinch. So from what I can see (excluding the various retests) you've got about 20 minutes of grinding once you know where to touch. Correct?
Click to expand...

I would agree--20 mins per casting excluding valve job of course. J.Rob
 
Great work. Really appreciate the time you're taking to share all of this information.

Graphs look nice too, AIV.
 
With the EQ heads availability I'm mostly looking at this thread as an indicator of contrasting financials between reusing factory or buying those. I like the idea of tracking the improvements and reusing what one has I'm just not certain about the economics of it.
 
This shows the amount of work just to end up with a closed chambered head that flows like a stock 1.88 360 head.

20 min per port, includes porting and NO valve job im sure. Not 20min per head

this is hillarious.

When you get done working a magnum head to where a mildly '250's cfm' ported La head flows, the port volume will the same..EXCEPT you will have major air speed issues from there out from things like the pinch and roof height . Get the ports big enough to slow things down, if you can without spending way too much time to almost get it and then having them crack on the motor.

what was it you said RAM, theres such thing as too much air speed? lol

And you started out pressing the velocity button and then turn around and tell me there "theres such a thing as too much air speed" back and forth you go.

You didnt respond to my points becaue they are all right on the money.
Ive been doing this for 18yrs, where you been??

Thanks again
 
What's hilarious? Anyone offering to spend the time to document actual flow changes to any mopar head is thumbs up in my book. Don't have a 318 but this data should be archived for anyone looking to build one, imo.
 
It was "Not including the valve job" just a few minutes with the grinder on the port.
 
80fbody said:
What's hilarious? Anyone offering to spend the time to document actual flow changes to any mopar head is thumbs up in my book. Don't have a 318 but this data should be archived for anyone looking to build one, imo.
Click to expand...

No the showing is great, it shows people facts...like these heads suck for anything other than a 318 or stock 360 emissions

its just watching someone learn that fire burns you...get the burn cream quick.

Anyone who really knows should be asking whats up with the dodging of my questions, does anyone really want to learn here??

Go ahead try and act cool and take 3 steps back, see you at the finish line.
 
You must log in or register to reply here.
-

Back
Top