Dart BBC CNC 380's

[SupStk]

Just got my hands on a set and run 'em over the bench. To say I'm disappointed would be an understatement.

Top numbers on the intakes are 393.9 @ .850 with very little gain from .700 to .950. At .450 to .550 it goes stagnet and starts moving again @.600.

The exhaust side marched steadily along up to the top number of 324 @ .950.

My bench is a JKM 600, I was using a 4.625 adaptor, 3/4 radiused intake and no pipe on exhaust.

My questions: Are these numbers inline with your tests? Is my bench suspect at the higher flow numbers?

My goal of 1100 HP on a 565 using these heads appear unrealistic despite what Dart claims.

[double r]

Did you check out

http://www.raceflowdevelopment.com/RFD- ... victor.htm

I am sure Curtis will weigh in here but it's a conventional head supports up to 1200hp. He also has the dart 380's and can probably tell you a whole bunch about them.

I just post this as I am interested in what heads you do end up with for your application. Maybe you will end up with a race style head for this. Let us know what you end up doing to achieve your goal. Thanks...

[bigjoe1]

There is NO WAY in hell you can make 1000 Hp, let alone 1100. Dont hold your breath. You need way more head than that, I wouls figure your good for 900-950 tops.


JOE SHERMAN RACING ENGINES

[Ed-vancedEngines]

If you aleady now own them, there can be a light at the end of that dark tunnel. Curtis can wake them up for you.

We just had similar disappoints with a new Brodix 15 deg SB Head and the bench tests were way off from claims. Sent to Curtis Boggs http://www.raceflowdevelopment.com And he woke them up big time at a reasonable price. Now they are far better than Brodix claimed and that was verified on a local bench here in this area. We checked them local becuase we were angle milling and wanted to see if angle milling hurt any on airflow. It stayed much the same. But two flow benches hundreds of miles apart agreed on the intake numbers.

Can you say truth in advertising. Curtis heads do what his flow sheet tells you they do. They also make power.

Check the thread about the streetable 622 that blew up on us a couple of weeks ago. It is about subject of factory oil filter adapters. The heads on that engine are the RFD Edlebrock 24 degree. I forgot. This is the ones we tested agin, It was not the SB ones. It was the Edlebrock 24 deg RFD CNC that is so super.

Ed

[SupStk]

There is NO WAY in hell you can make 1000 Hp, let alone 1100. Dont hold your breath. You need way more head than that, I wouls figure your good for 900-950 tops.


JOE SHERMAN RACING ENGINES

Don't try to encourage me Mr Sherman. Didn't figure they would support 900 if my flow data is accurate. Talked to John at Dart at length about these heads before ordering. He told me I'd have no problem making 1100+ if the rest of the engine was done right

Thanks Ed, Unfortunately we OWN 'em. i did see your previous post on the 622. Guess a call to Curtis wouldn't hurt.

[Keith Morganstein]

There is NO WAY in hell you can make 1000 Hp, let alone 1100. Dont hold your breath. You need way more head than that, I wouls figure your good for 900-950 tops.


JOE SHERMAN RACING ENGINES

Don't try to encourage me Mr Sherman. Didn't figure they would support 900 if my flow data is accurate. Talked to John at Dart at length about these heads before ordering. He told me I'd have no problem making 1100+ if the rest of the engine was done right

Thanks Ed, Unfortunately we OWN 'em. i did see your previous post on the 622. Guess a call to Curtis wouldn't hurt.

Dart claims 420/330 for the Pro 2 CNC head.

Did you talk to Dart with your findings?

[Mark R]

Monty, you have a PM.

[double r]

I have a solution for you. No I don't work for them. Just thought I would post what their combos are for getting that kind of hp is...

RM Conventional headed 565 with dart 355's is 950+hp but the others are all race heads.

565 Big Chief / 1000hp

18º Pro 1

or

12º Raptor All Aluminum 565ci / 1,100hp

or from steve schmidt

565 "The Terminator" Drag Racing Engine - 1150 HP
12* profiler heads.

I am sure curtis could get you close with conventional heads also...

[TOP38]

Just got my hands on a set and run 'em over the bench. To say I'm disappointed would be an understatement.

Top numbers on the intakes are 393.9 @ .850 with very little gain from .700 to .950. At .450 to .550 it goes stagnet and starts moving again @.600.

The exhaust side marched steadily along up to the top number of 324 @ .950.

My bench is a JKM 600, I was using a 4.625 adaptor, 3/4 radiused intake and no pipe on exhaust.

My questions: Are these numbers inline with your tests? Is my bench suspect at the higher flow numbers?

My goal of 1100 HP on a 565 using these heads appear unrealistic despite what Dart claims.

Have you done anything to the heads??? What valve sizes? How's the transition from the valve job to the cnc port work? Probably needs work here!! With a little tlc in this critcal area you will see some reasonable gains,, @.900 lift on a 4.500 bore I'm just shy of 410 CFM, same head on a 4.600 bore should add anywhere from 10 to 20 cfm which would put them right were dart says... I would recomend a 2.325 or 2.35 intake valve also, not the 2.300,,,

As for power,, 1100 HP from any convential head is one nice piece and just doesn't happen by chance. I have a friend going to the dyno in 2 weeks, 582 w/these heads, bracket deal, looking for and honest 1000 HP.. Also another racer I know, don't have all the details but I know there's nothing out of the box with his heads,, Brodix Head Hunters,, 582 that made over 1100 HP.. Performance on track supports this number too....

Lots going on in the BBC convential heads these days!!! You got Dart, brodix, eldelbrock, and others all battling to be top dog.. Good for us racers...

Big Joe, there are a number of 355 pro one headed BBC that flow 415 cfm and are knocking on the door of 1000 HP in bracket form,, at least from my bench,, these heads may flow 440 on others though..

As for who to talk to at dart on these, speak to tony.

Hope this helps.

[cboggs]

Well, ..

now I know why my ears where ringing, .. someone was talking about me, ..

The dart 380 cnc is actually a very nice head, Tony and the guys at dart
did a nice job. It's got nice velocity profiles, good cross section, and will make
more power then the flow bench might suggest. I wouldn't get too upset yet.

can they be improved, .. well yes, but any cnc head can be improved with
some hand work and TLC. The cross section in the port will support
a 2.35" intake valve and a fairly aggressive valve job,..

On my bench they go about 410 cfm at max, .. and have a fair average
between .4" to .8" lift. They will go 440+ with a good VJ and a 2.35" valve.

I'm yet to see 1100 from them, actually 1100 from a cast single 4
big block is much tougher then it may seem, it takes a great head as
well as a very well ported intake.

There are very few BBC heads with a 2.3" valve claiming flow over 425 cfm
that will hit much over 400-410 on my bench. It takes an aggressive valve job, ..
some careful hand blending and a 2.35" valve to get much over 430 cfm
with good mid lift numbers and still keep airspeed.

Ed, didn't you make like 950 or 980 with that street 622?

Top38, is that you Al ?

Curtis

[TOP38]

Well, ..

now I know why my ears where ringing, .. someone was talking about me, ..

The dart 380 cnc is actually a very nice head, Tony and the guys at dart
did a nice job. It's got nice velocity profiles, good cross section, and will make
more power then the flow bench might suggest. I wouldn't get too upset yet.

can they be improved, .. well yes, but any cnc head can be improved with
some hand work and TLC. The cross section in the port will support
a 2.35" intake valve and a fairly aggressive valve job,..

On my bench they go about 410 cfm at max, .. and have a fair average
between .4" to .8" lift. They will go 440+ with a good VJ and a 2.35" valve.

I'm yet to see 1100 from them, actually 1100 from a cast single 4
big block is much tougher then it may seem, it takes a great head as
well as a very well ported intake.

There are very few BBC heads with a 2.3" valve claiming flow over 425 cfm
that will hit much over 400-410 on my bench. It takes an aggressive valve job, ..
some careful hand blending and a 2.35" valve to get much over 430 cfm
with good mid lift numbers and still keep airspeed.

Ed, didn't you make like 950 or 980 with that street 622?

Top38, is that you Al ?

Curtis

My cover is blown!

[SupStk]

Thanks to all who replied! Maybe things aren't as bleak as I imagined. I want to make a few comments and will try answering those who asked questions.

My first concern was about the accuracy of the flow bench. I've noticed in the past this bench is direction sensitive when testing intakes. If flipping the head so the intake port faces toward the back numbers will be different than when the intake is facing me when testing. Also with big heads I always come up short on flow numbers. Tests up to the 350-360 CFM range are fairly consistant with other benches I've compaired it to.

Another concern I had with the CNC380's is sluggish increase in the .450-.550 range. For example #1 intake is; 287.6@.400, 332.3@.450, check this out...323.6@.500, 340.8@.550, 352.5@.600

Keith, I haven't talked to Dart yet. Wanted to get feedback first from others that have worked with this head and compare numbers.

Mark R. Thanks for the warning and other info. That was who I'm intending to call for the cam. They worked with us on a 581 alky motor with 355 Darts.

double r, I'm aware of RM 565HR and the advertised 975HP, IIRC Darren posted they have angle milled Dart 355's. I was originally was going to run the oval heads on this engine but John discouraged me saying they were going to be a PITA for intake fitment and said the 380's would do all the ovals would without the hassle.

Top38, I've blended the seat transition area after my first test although it wasn't too bad to begin with. Other than that, the heads are the way they came from the box. Still have the 2.300 and 1.880 valves. I've noticed all the SSR's have a noticeable ledge, probably from the cutter transistion working the valve side and switching to the port side.

cboggs, The motor is going together with (2) 4500's. Don't know if the Dart tunnel ram will stay on. The 1100HP isn't carved in stone for what we need. Since it was on the table, thought I'd pursue it. How aggressive VJ.... 55 degree? By the way you look good in the flowbench ads...

[cboggs]

Flow bench ads, awww, .. now you know how ugly I am, ..

I use a 50* seat, .. 65, 75 and 82, .. oval shaped throat, ..

I just finished a set today with a 2.3" valve and my VJ that went
435 @ .900" on my bench, .. 396 before, ..

Curtis

[Talisman]

Flow bench ads, awww, .. now you know how ugly I am, ..

I use a 50* seat, .. 65, 75 and 82, .. oval shaped throat, ..

I just finished a set today with a 2.3" valve and my VJ that went
435 @ .900" on my bench, .. 396 before, ..

Curtis

I'd sure like to have a set of heads like that

Tom F.

[double r]

I am still trying to learn about what makes a good cylinder head so will be interested to see what hp you make.

What are the dart 360 or 370 heads? are they similar to what you have? I noticed this at RM site buried in the cylinder head section.

Dart 360 Beast 2 makes 1025hp @ 8100rpm on a 522cid engine with cast single 4 barrel!

UPDATE,, Dart Beast 2 makes 1100+hp @ 7800rpm on a 572 engine with cast single 4 barrel!

These are conventional heads, so maybe your goal is not that far off especially with the tunnel ram.