Orange Peel

iTrader: (20)

I had Jason from TSP make me a set of Dart 225's with 2.080/1.60 valves, not milled, equipped with their dual springs, etc.

I had them sent directly to Combination Motorsports to install on my 402 shortblock. I was told there was a flow sheet in the box when they were sent out, Dave at Combination said no flow sheet in the box when he got them yesterday. Ok no biggie, have them flowed for me, and he uses another shop (West Coast Racing), and they have ZERO interest in these heads, they work on Supras, etc, so they flowed them and have no reason to f up the data. They use a brand new Superflow Bench 1020.
But here's the breakdown.....

Test Data:
28" of Water
4.000 bore

Valve lift(Intake Side)-
.100 65.30
.200 134.40
.300 199.50
.400 257.80
.500 292.90
.600 304.60
.700 313.40

Valve Lift(Exhaust Side w/o pipe)
.100 56.30
.200 96.60
.300 135.20
.400 175.20
.500 201.40
.600 219.10
.700 225.40

Valve Lift(Exhaust Side w/pipe, 1 3/4 to 1 7/8 stepped pipe)-
.100 55.60
.200 100.00
.300 142.40
.400 186.10
.500 215.30
.600 234.80
.700 242.80

Now, I'm no expert, but I know there are little differences/variations on flow numbers from bench to bench, but is 26cfm down at .600 in that realm of error? I know flow numbers are probably like dyno numbers, they may perform and flow low, but we'll have to see. I'm not mad, I was just shocked to hear the numbers compared to advertised numbers. As long as they make power I don't care what they flow, I know the bigger valves will help me make power.

I DO NOT want to wait on a new set before this motor goes together, I waited 2 months for these heads, and I NEED my car back together. If I dyno low, then I know why. But this is accurate data, true and not fluffed data, and I trust the flow I got. If I had a flow sheet with the heads I could compare it to this and see what's up, but we don't.

Any opinions on these numbers?

Thanks again Jason for getting me the heads, the parts I needed and sending them where I needed them to go. I know you guys are swamped with orders and I appreciate all you have done for me through this tough time. I hope to make 500+rwhp with my setup, and I hope these heads live up to their reputation.

Patrick G

iTrader: (14)

Good numbers, but they do not raise the bar over existing good aftermarket heads. Certainly not at the level of AFR 225s or ETP heads of similar cross sectional area. They should still make excellent power though.

Orange Peel

iTrader: (20)

But why wouldn't they flow as advertised, what could cause bad flow? Just curious.

1QuickT-A

iTrader: (12)

thats funny..

thats funnier...

iamsickofitall

iTrader: (18)

ask jason to fax or email you your flow sheet - they claim to save them in the computer...then compare it to your results

Orange Peel

iTrader: (20)

I also want to know the final intake volume and the cc of the heads. I already PM'd him, once he gets back to me I will see what he has on file.

Beast96Z

iTrader: (21)

So your saying they were supposed to flow 330 cfm advertised at .600"? I understand flow benches have variations, and the 1020's are a bit stingy, but I think the numbers you got are more in line with what I would expect from a 225 cc head on a 1020 bench. I would have been sceptical of the 330 cfm from the begining. There aren't many heads out there that can achieve that goal with the givin port volume. I know a few say they do, but everyone seems disapointed when the independent results come in. Not that TSP is inflating, because they have always been great to work with, but I have flown a few 320cfm advertised heads, and the results were far worse then what you got, and they were from "reputable" vendors at that. I think your numbers are good for a stingy bench. I say roll with um' and see what happens.

Ksett

If the heads weren't milled the 225 castings are 62 cc's from Dart.

-Joseph-

iTrader: (12)

I remember seeing Jason flow those exact heads with a 4" bore and a good LS1-specific radiused inlet. They flowed 324ish @ .600" lift on our SF600 Flowbench. The flow numbers look in-line at .500" and below, and the exhaust looks right on too.

Orange Peel

iTrader: (20)

I'm saying that TSP posted results for the 225's with smaller valves in the 320+cfm range on their site at .600, mine fall short of that, that's all, this to be exact....

Precision Race Components Stage 2 cnc ported cylinder heads. Fully CNC ported Dart LS1 based cylinder heads!

NEW Dart Cores
2.02 1.60 Valves
Dart Single Springs Rated to .625" Lift
Completely Assembled & Setup To Your Specs!!

Valve Lift Intake
.100" 74
.200" 153
.300" 209
.400" 260
.500" 296
.600" 320
.650" 324


As long as the heads perform, that's what I care about, and I was concerned about the large gap in the cfm range from what they are supposed to do. It could be the bench, it could be that TSP setup the bench different than the other shop, who knows. If they don't make the power, then another head will go on the car and we'll do it again

Orange Peel

iTrader: (20)

It's good to hear they did get flowed, wish the sheet came with them to see it. I think they will do the job, just hope I don't miss some power is all.

Beast96Z

iTrader: (21)

The LS-1 specific radiused inlet may have alot to do with it. That vs. clay could skew the numbers a bit.

cantdrv65

iTrader: (3)

Could be a number of things that would throw flow readings off. In my experience the guys at TSP deliver. My budget PRC LS6 heads have performed well, I hope you get great results as well.

Plum Crazy Rob

iTrader: (3)

Here are independent results on a PRC Dart CNC Stage 2 (2.02 valve). I can't say my buddy is unbiased, because he is a porter and does mucho LT1 / LS1 work, but I did stand there and watch him do it, and no stunts were pulled....

SF600, 28", clay inlet:
Lift Int Adv int
.100 68 74
.200 144 153
.300 207 209
.400 260 260
.500 298 296
.550 312 TBD
.600 315 320
.650 305 324

Only thing I had a problem with here was the .650 number.


Lift Exh (no pipe)
.100 51
.200 92
.300 133
.400 172
.500 200
.600 215

hmmmmm.....looking at Tony Mamo's flow-o-rama (I would ALWAYS ignore ADVERTISED numbers IMHO...), its a good, but not great head.... albeit with a rather large port and somewhat average exhaust flow

Waiting for dyno results from somebody without issues at this point

Oh BTW ...we also flowed an unported Dart 225, which went 313 @ .650, and otherwise matched the published Dart numbers (about 20 cfm down from the intake numbers above, ~more or less)

'hoochie2

See? They don't have to be shiny to kick azz!

383ss

iTrader: (14)

wow, interesting results. I almost got a set of those 2.08 valve heads. kinda glad I didn't at this point. I'll hold out for 240 or 255 ETP's.

1QuickT-A

iTrader: (12)

Thats what I try to tell these newbies all the time.. They think that advertised numbers are 100% correct and always legit. But, as most of us know.. They are called ADVERTISED numbers for a freakin reason.

11 Bravo

iTrader: (3)

I don't know, I think the LS7's are the best heads out. Of course you still have to find an intake and everything else. I haven't yet seen anything about the ETP's that convince me they are better.

Layn_Low_247

iTrader: (1)

Should they have flow sheets for each set of heads? I order some Stage 2 PRC CNC Darts and they didn't come w/ a flow sheet.

Full-Force

iTrader: (11)

I think the PRC Dart heads that are advertised as 320 cfm are 205's. Maybe they end up 225 after porting. The as cast Dart 225 flows like 312 out of the box.