World Products vs. Dart Heads
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World Products vs. Dart Heads
I'm involved with an eligibility question that I need some advice on. There are two aftermarket SBC cylinder heads under consideration, the World Products S/R and the Dart Iron Eagle. Both would be cast iron, straight plug heads, with porting and combustion chamber modifications allowed. Are there real performance differences between the two? If so, why? Any comparisons on the internet? Thanks in advance.
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-The SR heads are street replacement heads and they are not too bad compared to the older SBC stock heads.
-BUT--the Iron Eagles are 100% performance and race bred pieces with the main intentions of being used on wide open throttle race engines.
-The SBC SR heads that I have seen flow about 191 CFM at .500" lift as they come stock, and then about 222 with a mild porting job.
-The Iron Eagles I've seen flow about 266 out of the box and 287 with a mild port job.
-The Iron Eagles come with intake port sizes from 180CC to as large as 230CC's where the SR heads are small probably 166 to 175 range.
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-The exhaust flow on stock SR's is about 126CFM at .500" lift, then about 181 with a mild port job, and the exhaust on the Iron Eagles is about 169 stock and 195 with a mild port job.
-BUT--the Iron Eagles are 100% performance and race bred pieces with the main intentions of being used on wide open throttle race engines.
-The SBC SR heads that I have seen flow about 191 CFM at .500" lift as they come stock, and then about 222 with a mild porting job.
-The Iron Eagles I've seen flow about 266 out of the box and 287 with a mild port job.
-The Iron Eagles come with intake port sizes from 180CC to as large as 230CC's where the SR heads are small probably 166 to 175 range.
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-The exhaust flow on stock SR's is about 126CFM at .500" lift, then about 181 with a mild port job, and the exhaust on the Iron Eagles is about 169 stock and 195 with a mild port job.
Thanks for the replies. What differences are there in the combustion chambers? The Dart is purported to have more a "heart shaped" chamber, whereas the SR heads are said to more closely resemble the OEM style. Is that correct?? Is there a performance advantage in the Dart combustion chamber design??
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The SR heads are like Bill said more like older GM heads, they make a good replacement head. The World Products Motown 220 head would make a better comparison to the Dart Iron Eagle. Take a look at the new Dart Plantinum Series iron head. They say they flow 10% better than the Iron Eagles and they are only about fifty bucks more ! Alot cheaper than sending the Iron Eagles to the shop to get the same results.
Honestly, it is quite a difference between the two heads. I was going to build an engine using some S/R heads I had laying around for a *very* low buck DIRT racing engine. What stopped me was the water passages around the spark plug side of the head. Normally you could plug holes to angle mill, but the S/R heads water passages diverge under the deck surface. They are available in 67cc and manufacturer says you can only mill I think .020" off the deck. Iron Eagles are available w/ 49cc chamber, which has obvious advantages in a flat-top piston class.
Ended up buying Iron Eagles (small 180cc to be legal for class.) Nice heads! As previously mentioned, they have bronze valve guides vs. iron. Also the factory valve job was at least 5 angles on intake and 2 or 3 plus radius on exhaust with some "bowl hogging" vs. stock type valve job on S/R. No flow bench or flow data, but they look better....
Nova John
PS I just read this and it looks like I'm trying to sell these heads. No affliation with anyone, just my $.02
Ended up buying Iron Eagles (small 180cc to be legal for class.) Nice heads! As previously mentioned, they have bronze valve guides vs. iron. Also the factory valve job was at least 5 angles on intake and 2 or 3 plus radius on exhaust with some "bowl hogging" vs. stock type valve job on S/R. No flow bench or flow data, but they look better....
Nova John
PS I just read this and it looks like I'm trying to sell these heads. No affliation with anyone, just my $.02
Dart also makes an iron head that's 165cc's with the std OE style chamber and iron cast in guides, like the World S/R head, and is available in a 1.60/2.02 or 1.50/1.94 version.
we have a class in one of the local dirt series that allows the use of either the Dart or World OE type head, or an OE open chamber head. all must use the 1.50/1.94 valve sizes.
Pro Action/Top Line also has an OE replacement head like this.
we have a class in one of the local dirt series that allows the use of either the Dart or World OE type head, or an OE open chamber head. all must use the 1.50/1.94 valve sizes.
Pro Action/Top Line also has an OE replacement head like this.