Thread: Dart Iron Eagle Heads

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Have a chance to get a set of Iron Eagle heads, $500.00 used, don't know if there 165cc or 180cc. Looks like 2.02 intake valves which should be 180cc, plus they have dual springs, 72cc chambers.
My question is are they good for a 400 sbc to get 400 HP. 165cc or180cc????
Thanks for any help. Jack

I would say the 180 heads would get your 400 sbc to 400 hp, but the 165's would probably not breathe well enough to get you there.

I'm not impressed with the Dart Iron Eagle 165 or 180 heads. A respected member on another forum has flowed the 180's out of the box at 205 to 210 cfm, only marginally better than production double hump heads. Stock GM Vortec L31's with 1.94"/1.50" valves flow better than either.
L31 flow...
0.100" 70 48
0.200" 139 101
0.300" 190 129
0.400" 227 140
0.500" 239 147
If I were going to use Iron Eagles, I would use at least 200cc runners even on a 350 motor.
If you're on a budget, go to the boneyard and buy a set of casting number 12558062 Vortecs from a '96-'98 Chevy truck with 5700 Vortec motor. Get the rail rockers and valve covers at the same time. Look for a hacksaw blade casting design on the end of the heads. Make a deal with the boneyard operator that you can bring 'em back to exchange them for another set if you find 'em cracked. Take 'em home and disassemble 'em. Take 'em to an automotive machine shop and have 'em magnafluxed for cracks. If they're ok, have the valves and seats touched up and install new seals. Have the shop drill 'em for steam holes....
http://www.gregsengine.com/350to400.htm
Install CompCams beehive spring #26918, retainer #787 and steel locks #601. They will install with no machine work and allow at least 0.550" lift. These springs install at 1.800" installed height with 130# on-seat pressure.

Use KB168 Keith Black hyper pistons (22cc D-cup) with 5.7" rods. (I just love it when I get to type D-cup and enjoy the euphoric recall associated with it). The stack will measure 9.008". Cut the block decks for a block deck height of 9.014" (0.006" piston deck height). Use Fel-Pro #FEL1014 head gaskets
(0.039" compressed thickness with steam holes). This will allow a squish of 0.045" and a static compression ratio of 9.8:1.

Use an Edelbrock Performer RPM Vortec or RPM Vortec Air Gap intake manifold with 750-800 vacuum secondaries carb. If automatic, 2500 stall converter with 3.50-3.80 gear. 1 3/4" long tube, equal-length headers.

Compcams 12-326-4 hydraulic flat tappet cam. 286/286, 236/236, 0.490"/0.490" with stock Vortec 1.5 rail rockers, 106/114/110, installed straight up. Dynamic compression ratio 8.21:1.

RPM HP TQ
2000 153 401
2500 193 405
3000 245 429
3500 304 457
4000 354 465
4500 390 455
5000 414 435
5500 386 369
In excess of 400 ft/lbs of torque from 1900 to 5200. Nice.

Very nice Tech........Thanks for the info, looks like some thing I can use on my pick me up. Thanks

I concur with Techinspector -

You can get good Vortec heads from Patriot on eBay for $500. They're the Real McCoy with 2.02/1.60 valves, 3/8" studs, guide plates, etc.. And they're brand new with a warranty..

Check out this link:
http://cgi.ebay.com/ebaymotors/Patri...1%7C240%3A1308



Regards,
Glenn

Glenn, thanks for posting these heads. They look excellent for the money and the flow figures are impressive. These heads will give up a little on the low end compared to L31's, but make up for it with a strong top end. I kept everything the same on the Dynosim, just changed the heads. They have the same 64cc chambers as the L31's, so all the static and dynamic compression ratios remain the same. These heads will accept the conventional RPM manifold instead of the Vortec RPM, so a builder would be able to save a little money there.
RPM HP TQ
2000 149 393
2500 189 396
3000 242 424
3500 308 462
4000 370 485
4500 420 490
5000 459 482
5500 472 451
6000 461 404
6500 405 327
These heads, with the same cam, make 400 ft/lbs from 2600-6100, so the power is moved up by about 700-800 rpm's over the L31 heads. This is an interesting excercise to show the difference in cylinder head flow and the resultant power that can be extracted. With an auto trans, you might expect to have to move up to a 2800-3200 stall converter.

Jack60, this combo should reeeeeaaaalllly roast the hides in a stick-shift 'Vette.

Well I'm buying the heads, if there not good for the 400, I have a 327 and a 283 I could use them on.
I'm fixing a 55 Cameo for my daughter so I don't need a ton of HP. Stock it had a 265 [that I don't have], so a good running 283 or 327 should be good for the truck.
Thanks for the help, I'll buy a better set of heads for the 400 when I start that build.

My Vette has a 350, with Brodix track ones, scorpion roller rockers, MSD, TKO 600, 450 HP and goes down the road and track just fine.