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kinda runnin low on funds with my blown tx-19 build up and was wondering if i could get 700hp outta these heads:
336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports
the tx had a brand spankin new roller mill in it when i bought the boat and the heads are nice oval ports with fresh guides and so on, my blower intake is for rect. port. & what i was thinking is if i can buy a oval blower manifold cheaper than heads this winter if it'll produce 700hp with these heads, a nice blower roller cam, 9.5 to 1 or 10 to 1 compression, dual 850dp's.i'm trying to build a fast cove racer that'll still do 90+, with dominator b-cut, and would like to keep rpm's around 5800-6200rpms.is it possible and what do i need to do as far as compression and cam choices? thanks for any advise.
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For an "on the cheap" deal, use the manafold you have. No! Really! Use a roller of 250+ deg at .050 intake and 260 at .050 exhaust. These heads when properly ported can make 550-600 HP without the blower. The Chevy heads use the same exhaust port for the peanut ports, oval and square ports, that means that your exhaust port ratio to intake flow is good. If you can't make that rig run 90, shoot yourself. For further info call me. TIMINATOR
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For an "on the cheap" deal, use the manafold you have. No! Really! Use a roller of 250+ deg at .050 intake and 260 at .050 exhaust. These heads when properly ported can make 550-600 HP without the blower. The Chevy heads use the same exhaust port for the peanut ports, oval and square ports, that means that your exhaust port ratio to intake flow is good. If you can't make that rig run 90, shoot yourself. For further info call me. TIMINATOR
use the square port intake on the oval port heads? would i be leavin any hp on the table by not just runnin a oval blower intake? thanks timinator for the info
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Use FelPro 1211 gaskets on the square manifold to oval head; bolt it up get it wet. Like Timinator said "if it won't do 90mph" GET OUT OF BOATING!!!!
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95mph is my goal, 100+ would be icing on the cake. so will it run better with the rect. port intake? better than an oval port blower manifold?
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I made 610 hp with a ported set of 049's and a SINGLE 850 annular on a 461ci ,with a solid lift. It always wanted more fuel and air,you should have no problem getting 700 with a blower,but those heads are going to be MAXED after that,and its going to be a torque monster!!!!,the rect intake isnt going to matter cause theres only so much air and fuel those heads are going to flow.
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Sanger's got it right. TIMINATOR
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I had a similar BBC rect port blower (B&M 420) intake with oval port heads this summer. When I would look into the intake it was an awful mismatch in ports but it did work but I really hated it. With a limited budget I figured that aluminum heads were a bit out of my budget. I upgraded to a nice set of iron rect port heads (and a few more cubes) and I anticipate a much better breathing engine.
I just couldn't get the immage out of my mind of seeing those little oval ports bolted to that nice rect port intake.
It worked. Did it work well????????
just my .02
L J
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i pulled the mill yesterday and pulled the heads off today. i guess i'm gonna use these 781's, stick some stainless valves in em and do alittle port work. found an old link that show'd some flow numbers in a "oval vs. rect port" testing. pretty interesting that the oval ports out flow rect. ports on the exhaust side up to 650 lift, intake on oval ports out flow as well.i'm gonna order a cam with no more than 650 lift. it'll have monster torque up to @6k and that's where i'm wantin to build it all. i'll save up next fall and buy some nice brodix heads, change cam. i've gotta overhaul pump, do floor work, carpet, gauges, rewire it my way this yr. on top of mill upgrades.
the guy that sold me the boat swore the mill had no more than 3hrs since a complete rebuild, guy actually was tellin the truth!
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here's the superflow bench flow numbers between rect. and oval ports, good info!
http://www.maliburacing.com/ovalvsrect.htm
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weiand says their manifold is for both oval and rec. ports. just have to use the spec. fel-pro gaskets.
Dan
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weiand says their manifold is for both oval and rec. ports. just have to use the spec. fel-pro gaskets.
Dan
yeah i called them too trying to figure out why jeg's and summit show no listing for one, they told my torque numbers were better with the mismatched set-up. smokinlowrider, aaron has been runnin number like crazy for me and we came up with this set-up:
RPM --- HP -- Tq
2000 - 270 - 709
2500 - 351 - 737
3000 - 433 - 757
3500 - 505 - 757
4000 - 576 - 757
4500 - 642 - 749
5000 - 693 - 727
5500 - 733 - 700
6000 - 751 - 657
6500 - 726 - 588
7000 - 693 - 520
7500 - 654 - 458
575 bbc 10.5 to 1
weiand 6-71 8-9lbs boost
dual 750's
781 heads, ported with 2.19 1.88(may go to a 2.25 i instead)
roller blower cam 252 262 durations 645 lift
well i hope its close cause i'm building it already! if the torque #'s come out close, this tx-19 is gonna be quik outta the hole.i like the matched 700hp and 700ft lbs of torque at @5800, which is where i want to run wot.
aaron, i appreciate the help bro! if ya make the next taylor meet in b.bow, i will get ya shiat faced!
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Ya want port mismatch? How about all of the Ford 460 Marine motors in the 70s and 80s having the small port regular heads and the Cobra-Jet large port intakes on them? That was normally aspirated too. Everyone took off the heads and port matched them and gained usually nothing! TIMINATOR
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Ya want port mismatch? How about all of the Ford 460 Marine motors in the 70s and 80s having the small port regular heads and the Cobra-Jet large port intakes on them? That was normally aspirated too. Everyone took off the heads and port matched them and gained usually nothing! TIMINATOR
nope, just can't afford to buy the heads i want this yr. and i'm not gonna buy some cast rect. ports just to run em 1 season, best thing to do is just run this combo for 1 season, get some brodix or darts next fall. i've still gotta buy pistons,rods, crank, ss valves, pump overhaul kit, shaft and inducer, new carpet, headers recoated, install some tunes this winter. doesn't leave much room for a 2k set of heads for me this yr..
