1badzee

iTrader: (12)

http://www.gmhightechperformance.com...ade/index.html

Not bad I guess. 460hp (at the crank) with a 355, as-cast DART PRO1 heads and a mild cam (similar to cc467). Just thought I'd share. Enjoy

ss.slp.ls1

iTrader: (36)

Thanks for posting, nice find.

ss.slp.ls1

iTrader: (36)

For comparison purposes...does anyone have flow sheets for Ai 200cc ported stock heads or LE2 ported stock heads?

PNYKLR-TA

iTrader: (1)

damn nice! and they say its 180CC but when measured the ports are closer to 190CC IIRC

1badzee

iTrader: (12)

Yep, GM high tech and Advanced Induction both found the intake ports to be 190cc and not the advertised 180cc.. Why DART would advertise them as 180's is beyond me..

1badzee

iTrader: (12)

I've read somewhere that the off-the shelf DART heads flow between LE1's and LE2's. Not bad for as-cast heads ey?

FASTFATBOY

iTrader: (23)

If you were gonna use them "as cast" I dont see why you wouldnt just go with a Ai or LE deal, seems much simpler.

ss.slp.ls1

iTrader: (36)

Well I would definitely port them. Does anyone know what the compression ratio would be if you bolted a set of these on unmilled?

Grr

iTrader: (2)

god you guys and your pushing AI and LE stuff. Not everyone wants a crappy stock casting, some of us want new stuff, and they are pretty cheap, and if you need to buy LE3s to outflow them, they are a whole lot cheaper

1badzee

iTrader: (12)

x2..

My old factory heads were warped beyond belief so I purchased the DART PRO1 heads and just threw them on. Didn't have money at the time for porting. Lloyd Elliot will surely be getting his hands on these in the mere future when I can afford it.

As for compression ratio, with 0.029 headgaskets, mine is 11.1-2:1 (someone did the math for me i forgot what it was exactly)

zigroid

iTrader: (22)

it has an electric water pump, no other accessories, ported intake manifold, and tuned with an aftermarket ECU. engine would probably make 380 rwhp with accessories and through a 6 speed/10 bolt. color me unimpressed.

1badzee

iTrader: (12)

For unported heads and a mild cam.. I think that's impressive as hell.

James Montigny

iTrader: (13)

Mine were the same way, 190 before porting ... 211 when complete.
As-cast, the 180s do not outflow the stage2 heads you get from LE or AI, (257@ .500 VS ~265)
but Dart now offers CNC-ported 200 and 215cc versions which do seem
to flow pretty good. I'm curious to see how they perform on an engine.

Dart had a little bit of info on their site.
http://www.dartheads.com/download_file.php?pvk=309
I think I remember seeing flow numbers on the 215s somewhere.
Something like 290cfm@.650 IIRC.

robsquikz28

iTrader: (246)

damn nice heads and flow charts for Darts

zigroid

iTrader: (22)

that combo has no accessories and an electric water pump. that is a considerable amount of power unlocked right there that shouldn't be attributed to the heads, along with a ported intake, a 58mm throttle body, and an aftermarket ECU. I bet a set of LE1 heads would outperform them. my stock heads with a valve job and some bowl work that I paid $300 for laid down 390 rwhp through an unlocked big stall automatic, maxing out the injectors. that engine is not maxing out the injectors, so Im pretty sure my engine makes more power too and my heads aren't even on par with LE1 heads.

I just think if that engine was in an actual car with a full accessory drive the numbers wouldn't be all that impressive.

ss.slp.ls1

iTrader: (36)

Well don't they have before an after numbers with tuning and with the rest of the set up the same?

Advanced Induction

iTrader: (2)

Guys, buying flow numbers is like buying a particular color vehicle because it looks faster. A steady state test at 28" is not representative of a running engine. Moreover, data from different test setups is incomparable at best. More often than not, unqualified comparisons of incomparable data are completely misleading. This is not a logical means of cylinder head selection in our experience. Find someone who has met your goals and emulate their setup.

These are the #'s we saw on the fixturing & setup we use for the GM LT1's. You may attempt to draw comparisons between the reported flow numbers, though it is largely fruitless.


Dart is not alone. This is common in the industry. Another good example of why stated data should be considered marketing info & not indicative of performance potential.

David/FastFatBoy is correct. I won't speak for others, but we have gone 9's @ 139 NA at 34XXlb and up to 157mph at near 3700lb (street toy) with our 200cc CNC'd GM head & unwelded GM LT1 intakes. There is nothing inherently wrong with the factory castings for most applications. The results from a ported GM, Dart, TFS, etc. are more a function of the quality/level of work applied than characteristics of the base casting. In other words, the highest end work applied to a factory casting has been proven time and time again to outrun entry level work applied to castings that had more potential in them.

Here is a link to a test we did with Ellwein when these heads were first released. If you care to read it, data is provided: http://www.impalassforum.com/vBullet...72&postcount=1

Those results in and of themselves don't mean much because without multiple data points we have no basis for comparison. So, for comparisons sake there was another Ellwein 383 tested that afternoon. It had our 215cc TFS heads with a very mild SR and a GM manifold. It used the same shortblock, had less compression, and was up right at 100hp over the Dart headed engine. Yes there was more money in it, but that is an immense difference. Approximately a 20% vs. 50% gain over a stock long-block. It is unlikely the engine with our top-end cost 2.5x more from Karl in total.

If you have an unmolested set of GM LT cores then you are set for most builds. If not, then we're fortunate that Dart, AFR, TFS, etc. are producing LT castings for us at reasonable prices. Obviously, a casting with more potential will outperform a GM head, but only if your application and budget supports the associated parts & labor required to utilize that potential.

Hope that helps more than it hurts. Take care

ss.slp.ls1

iTrader: (36)

Truer words were never spoken.

1badzee

iTrader: (12)

Only accessory I have turning with the crank is the alternator. 390whp with what kind of cam? I don't know why you are bashing the DART heads, also do realize this was their first LT1 head - their other ones they're coming/came out with flow extremely well, and are still priced cheap. You argument holds no purpose in this thread because this wasn't a thread intended to see if ported factory heads can outflow as-cast DART heads, because everyone knows they can. It was just a freakin article I found and I thought I'd share lol. If you don't have the money to buy DART heads, just stick to your factory castings. Sure I could have gotten away with another set of factory heads but I was in a complete rush because the car was my daily and I couldn't find any stock heads anywhere, and Murrays (local speed shop) had these heads in stock at the time.

BizZzatch350

iTrader: (33)

I went with the Dart 200s and had them ported by LME. I can always sell my good stock heads that are on the car now and that takes away some of the intial cost to go with these heads.