Head ports , recommendations and BS

[joespanova]

So , if anyone saw my "do I need titanium valves or new heads" post........a little follow up. Some intake SEATS wont stay put.
The titanium valves were suggested to me by Tony Mamo ...he thinks my RPM range might have had the steel valves a little "unmanageable" and hence the seat movement..........who knows........anyway , I bring home my trusty hardness tester ( check for soft heads ) set up for Rockwell B scale and they check anywhere from R40-R50 depending on where you take a sample.So...I'm inconclusive. Brodix says 48-50 for a low. I consider just getting new heads and start looking around....... BES , Brodix , Dart , AFR and a few other sources.
ALL , without exception , stipulate they wouldn't suggest using a 245 head on a 377. Brodix said it'd be a "turd" basically.
The applications for a 245 head are always 406-421 and larger. So , I actually start to consider a 230ish head , CNC'D or otherwise.
Now , here's the thingy........my car at 2975 with me on board runs low 9.30s @144 and change ( 5 speed ) NA. That means its probably making about 700 ( 5.91 1/8th @116 best )
I poured the intake ports for the first time , today..........255 cc's!! The heads only flow 305ish @ 750 on a 4.030 bore fixture ( as checked by Larry Meaux and Chris Howe , Kaases shop )..................sooooo much for head recommendations.
If you take these MFRs as the "gospel" apparently you LEAVE POWER ON THE TABLE. Your question might be "would the car run quicker with a smaller port volume..........unlikely , I was told , in fact peak may well fall of given my RPM range.
I get a hold of Eric Weingartner ( answers phone , returns calls , seems to really know heads ). In my attempt to convince myself its time to buy new.........and believe me , I'm a hard sell so I start askin' stuff :
1) results ( power and performance ) from a REDUCTION in port volume when flow numbers are very similar between 2 heads ( one at LEAST 10 cc larger )
2) the effects of changing combustion chamber shapes ( SHAPE ONLY ) given same volume , same piston dome ( given it clears everything.)
In other words going from a Brodix chamber to a Dart or AFR , given my domes were ordered to work with the Brodix Track 1 head.
So , my conclusion...........don't make decisions based on the MFRs. advice.
I have large heads @ 255cc.......so the car should be a dog.....in fact the opposite is true.
https://www.youtube.com/watch?v=XyIAxOLChc4

[mag2555]

Actually with this new 255 cc info in hand now it's time to #1) find out where the minimum port area is by checking the head and some Manifold runners (hopefully for best performance it's in the head) and #2) if your Manifold atleast has between a 1.5 and 2% expansion rate in port area from the head push rod pinch ( if there's still any there ) to the End of the runner in the Plenum.

I think you can run these same or better numbers with less rpm and port area is linked to this big time!

[Carnut1]

Looks like a nice opportunity to learn to me. Could you post up full combo? Can you have heads flowed with intake , carbs, and air cleaners? Just because the heads flow 305 cfm does not mean they flow that with the whole system connected. The 377 cube combo works really well but that doesn't mean there isn't some still on the table. Is this a n2o combo? As far as airspeed through a port I have always felt it was combo dependent and rpm related. The hotter ls combos are using very big ports and slower airspeeds at the rpm they are running. Randy is using a 240cc intake port on a 420+ cube Chevy at 9000rpm making excellent frame bending power. I have no doubt he is running very high airspeed with a well designed port. Hate to say it but that equals very high "Port Energy". The experts will argue but a bigger lazier port can still produce good port energy numbers and good performance. I remember early 90's I ran my first set of Chevy bowties on a mild street combo. I was expecting it to be a dog until 4000 rpm or so and it was just the opposite. I had read multiple times that head was just too big (especially fully ported) for a street application with 3450lbs, mild gears and and a 2800 stall. So your high winding 377 can use the larger port volume to satisfy cylinder air demand. This is a piece that is rarely discussed. Thanks, Charlie

[6.50camaro]

A quick run of the numbers shows 2.82 avg. csa for 255cc . Plugged into the port limiting velocity formula shows mach index of .59 @8800 if your car falls back 1200 rpm on shift it drops to .51 @7600rpm . I used 5.5 as an arbitrary port centerline lenght ,could be off slightly . And using 4.155 x 3.48 as a bore stroke combination for a 377 sbc .
Not to bad in my book. Dan

[joespanova]

No , this is not NOS combo................I would be ashamed to start this thread if it was. The combo is 14.2-1 377.
https://www.youtube.com/watch?v=tFMkt1GFTtM
I have no idea who the ugly SOB with the timing light was........
The point is , regardless of the head options...........if I'm not using these heads to "exhaustion" ( read that full potential ), I'm skeptical of "potential or promised" gains from any other std port 23 degree head.

[Carnut1]

Wow, that guy is ugly! Carbon copy of my little brother. Good sounding smallblock. If it were me I would be doing up a 260+ cc set of 23 degree heads with welded pinch and offset shaft rockers tit valves and more rpm if the bottom is solid. Thanks, Charlie

[treyrags]

Having a good dual quad tunnel ram setup doesn't hurt..... Love the gear peddling. Very nice.

[Carnut1]

Screenshot_2018-07-29-13-14-12.png

I don't know all the details but something similar to these that match your bore may give you a bit more rpm, top end. Thanks, Charlie

[6.50camaro]

Are these heads a result of your own work . Can you have those heads digitized ? Then you could replicate them as often as needed or even sell a few as GODFATHER heads to offset costs . Just a thought . Dan

[Carnut1]

Are these heads a result of your own work . Can you have those heads digitized ? Then you could replicate them as often as needed or even sell a few as GODFATHER heads to offset costs . Just a thought . Dan

The picture is of Chad's 265cc 23 degree heads.

dart 215.jpg

This is a intake bowl pic of my Dart 215's, About 235cc port between 315-320 cfm @.7". I think my Darts would make less power on this mill at this port volume. The cnc thing may happen, we will see. Thanks, Charlie

[6.50camaro]

Charlie, I have followed your many threads on the progress of your dart heads and admire your work . But the question was really posed to joespanova about digitizing his track 1 heads . Sorry for the confusion. Dan

[joespanova]

Are these heads a result of your own work . Can you have those heads digitized ? Then you could replicate them as often as needed or even sell a few as GODFATHER heads to offset costs . Just a thought . Dan

LOL , no........Chris Howe originally ported them and , back when you could actually GET him to work on heads.......Larry "fiddled" with them a little as well. I'm wondering WHAT they flow on a 4.155 bore fixture....... like everybody else does these days.

[joespanova]

Are these heads a result of your own work . Can you have those heads digitized ? Then you could replicate them as often as needed or even sell a few as GODFATHER heads to offset costs . Just a thought . Dan

The picture is of Chad's 265cc 23 degree heads.dart 215.jpgThis is a intake bowl pic of my Dart 215's, About 235cc port between 315-320 cfm @.7". I think my Darts would make less power on this mill at this port volume. The cnc thing may happen, we will see. Thanks, Charlie

Thats one "tidy bowl"..........

[joespanova]

BTW , if I replace the guides as you suggested Charlie , anyone care to share their thoughts on how well .312 stems survive with lots of spring pressure?
I mean if I'm going to replace all 8 intake guides I may just go from .375 to .312 stems ( weight and flow ? )

[Carnut1]

Charlie, I have followed your many threads on the progress of your dart heads and admire your work . But the question was really posed to joespanova about digitizing his track 1 heads . Sorry for the confusion. Dan

No problem. My state of confusion.