I got to wondering just what the limit is for these heads? Lets allow a high lift (.680 if it will fit?) solid roller cam, lng valves and 1.7 rockers, tunnelram, 14/1 compression, 408 cubes, vacuum pump, thin rings, a center weighted crank to give some life to the stock block, added bottom end support of some kind, fully ported EQ318b heads, build the short block with as light a rotating assembly as is reasonable. My guess would be 675 hp.
Max horsepower with EQ heads?
- Thread starter gregsdart
- Start date
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Coffee&Cars
Well-Known Member
IMO. You want big power but your choking it with the heads. That's a street replacement head. Not a racing head. To really make that kind of power (675 hp) your going to need at least 350 cfm of flow on the intake. With what you have it will fall off around 6200 rpm. It dosen't matter how high you lift it. If you lift it past the maximum point of flow the flow falls off. Your looking at around 520-550 hp IMO.
yellow rose
Overnight Sensation
I agree to a point with coffee and cars but think the power will be higher. Extreme parts with a limited head. It may still produce a good level of power. In this theoretical engine build, not that it would matter, but, the power band would be very narrow.
Let’s skip total lift. Walk right into duration and install a solid roller with [email protected] intake. (Or larger, you find the cam to install) The head will allow only so much pass through into the engine at (walking backwards) what ever lift it can take. This is where the calculations begin.
Then there is always N02 & pressure to push it further..... but ... we’re talking a N/A engine.
Don’t worry Greg, AJ will be here soon to tell you how crazy you are and to use a 10-1 engine w/a dual plane and a XE 268 cam shortly.
LMAO!!!
Let’s skip total lift. Walk right into duration and install a solid roller with [email protected] intake. (Or larger, you find the cam to install) The head will allow only so much pass through into the engine at (walking backwards) what ever lift it can take. This is where the calculations begin.
Then there is always N02 & pressure to push it further..... but ... we’re talking a N/A engine.
Don’t worry Greg, AJ will be here soon to tell you how crazy you are and to use a 10-1 engine w/a dual plane and a XE 268 cam shortly.
LMAO!!!
yellow rose
Overnight Sensation
Wow. I'm not smart enough to get from Ing to long. Guess I need to read closer to context.
yellow rose
Overnight Sensation
Missing the "o". Damn. Got it now it was an l not an I.
I need a nap.
I need a nap.
My 10/1 compression 408 made 504 hp with a dual plane intake and a hydraulic roller. Add compression , Race roller cam and a tunnelram, plus other power adding tricks, and that says there is a lot more hp available IMHO than 550. A good rule of thumb is, if you have a well designed head, 2.4 hp per cfm you are using is reachable. My 528 wedge has pushed a 3065 lb car to 8.70s at 153 in 1600 da air, with a net .730 lift cam, which reachs about 370 cfm of flow on the heads. You need at least 885 hp according to dragtimes calculater, ON THAT DAY , not dyno hp. That works out to almost 2.4 hp per cfm. So IMHO a head that will flow 280 cfm, which i think they can reach fully ported(?) considering my bowl ported EQs went 272 at .600 , ought to be able to go 625 plus or more, which is only 2.2 hp per cfm.
Actually I put a Comp muthr thumpr with .556 intake lift, 235/249/107 duration cam in it, not terribly radical.
Part of the reason I posted this is I have raced big blocks with poor heads for many (42) years, and curiosity got to me about these heads.
There wern't any really good head options in the 70s for racing a 440.
It also occured to me that someone like me (retired) that really hurts thier race motor might need to look at a cheap alternative in order to keep on racing.
There wern't any really good head options in the 70s for racing a 440.
It also occured to me that someone like me (retired) that really hurts thier race motor might need to look at a cheap alternative in order to keep on racing.
moper
Well-Known Member
A lightened center balanced cfrank, and heads that weigh more than factory castings... And some re-engineering to get long valves and decent springs in them. Win win? LOL.
It's pretty easy math: 2.3hp/cfm given the racey stuff. What do they flow at .600?
It's pretty easy math: 2.3hp/cfm given the racey stuff. What do they flow at .600?
Sometimes an expensive crank is cheaper than a broken block. Earlier i mentioned the EQs might go 280 cfm maxed out. Mine flowed 272 at .600 with 2.02s and a bowl port.
360duster
Well-Known Member
Hi, i think these heads can go around 300 cfm if treated right. If i remember correctly Jim LaRoy did a set that flowed this much....Imm´s cnc version of the Indy X-Head was somewhere around 295 between .600 and .700" Lift - but no longer available. I think around 600 HP is possible NA, but not 675. The Victor head would be a good choice.
Michael
Michael
RAMM
Well-Known Member
Totally agree with this line of thinking.
As far as flow goes yes--I built a 469 ci with Edelbrocks(298.5 cfm) = 680 hp =2.278 hp/cfm. (which makes me wonder whats so great about the Trickflows?) My best effort EQ's went 301-304 cfm. Observed a best of 581 hp @ 417 ci @ 10.5 comp . J.Rob
And nether were a max effort build IIRC.
MOPAROFFICIAL
Oogliboogli
What port volume do you end up at with 300 cfm with an eq?
RAMM, that 417 build should give us some idea of possible gains, with changes to a tunnelram, big cam, and a much higher compression ratio? Care to share the specs on that build?
RAMM
Well-Known Member
SKMFX Budget Small Block - Popular Hot Rodding Magazine
Its all in the link-except that a carb was way better for the average score and if I had of been smart I would have slapped a legal RPM-Air-Gap on it and ran a carb. J.Rob
Some guesses on my part on a full on bracket build; Use EQ heads ported. With 2.08/ 1.60 valves. 408 cubes.
Depending on if the valvetrain can be made (at a reasonable cost!) To tolerate a solid roller with enough duration to run 7,200 rpm, I would try a cam of about 270/284/110 @ .050 to compliment the 14/1 compression i would shoot for. My choice of lsa is based off Vizards chart, which predicts a 107 with high compression, then add 3 degrees lsa to compensate for the 14 extra degrees exhaust duration to keep the same overlap as a single pattern 270 @ .050 cam. A tunnelram with a pair of 750s on top, or in my case, since i already have a system, a hat injector on methanol. Stepped headers ( 13\4 to 1 7/8?). Run a 6200 stall converter for starters, shift at 7,000.
My guess is a motor like this will make 650 plus hp. Comparing it to RAMM's 417 build,The cam may move the torque peak up 1,000 rpm? Compression ought to be worth a 4 percent power increase, the tunnelram ought to make 30 hp more than a single four.
In my 65 Dart drag car it would weigh about 2980 with me in it, and if my power prediction is close, it would run 9.80 to 9.90. I would have to short shift it to leave the fire suit at home!
Depending on if the valvetrain can be made (at a reasonable cost!) To tolerate a solid roller with enough duration to run 7,200 rpm, I would try a cam of about 270/284/110 @ .050 to compliment the 14/1 compression i would shoot for. My choice of lsa is based off Vizards chart, which predicts a 107 with high compression, then add 3 degrees lsa to compensate for the 14 extra degrees exhaust duration to keep the same overlap as a single pattern 270 @ .050 cam. A tunnelram with a pair of 750s on top, or in my case, since i already have a system, a hat injector on methanol. Stepped headers ( 13\4 to 1 7/8?). Run a 6200 stall converter for starters, shift at 7,000.
My guess is a motor like this will make 650 plus hp. Comparing it to RAMM's 417 build,The cam may move the torque peak up 1,000 rpm? Compression ought to be worth a 4 percent power increase, the tunnelram ought to make 30 hp more than a single four.
In my 65 Dart drag car it would weigh about 2980 with me in it, and if my power prediction is close, it would run 9.80 to 9.90. I would have to short shift it to leave the fire suit at home!
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Well, I like that idea.
*I think* I’d go to the next size tube on the headers though. But then again, I haven’t “Been there.”
*I think* I’d go to the next size tube on the headers though. But then again, I haven’t “Been there.”
Wouldah, couldah, shouldah.............Hummm. You think there is enough cross sectional area to take 408" to 7,200 rpm and make any power with the EQ heads? I stretched it to my limit to get 629 HP from the LAX heads with standard off-set rockers at 6,300 rpm.
Somebody build it. Let's see, huh? You bet I would try it. No guarantees though. Send me $10,000 to start the heads.
I think you would need to solid plug the pushrod holes, offset drill the plugs, cut out the pinch entirely, cut the stud mount bosses shorter and grind out the boss material completely from the port inside. Then design a shaft rocker system mount, for offset rockers, with what you have remaining of the stud boss threads.
Or buy a Victor heads because it would be cheaper.
Somebody build it. Let's see, huh? You bet I would try it. No guarantees though. Send me $10,000 to start the heads.
I think you would need to solid plug the pushrod holes, offset drill the plugs, cut out the pinch entirely, cut the stud mount bosses shorter and grind out the boss material completely from the port inside. Then design a shaft rocker system mount, for offset rockers, with what you have remaining of the stud boss threads.
Or buy a Victor heads because it would be cheaper.
Starting to sound like a W2 a bit....
Well yea, DUH! LMAO!!! Have you seen a set up close yet?
moper
Well-Known Member
Along IQs lines... I "think", it might be better with a 3.58 or 3.31 stroke crank and more rpm. The EQ heads are good - but I'm not sure with the long stroke they will make the real big numbers. Come close, probably, but I think if you want high side of 650 it's just not doable without basically recreating the head. Which sort of defeats the purpose.
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