I am planning on building a high reving 350 (7-7.5k) so i will have a moter ready if i blow the 305. I can get a set for free but dont really know anything about vortecs. Will they flow well enough to rev that high wile making somewhere around 500 hp with maby a 150 shot on top of that??

thx for any help

 

Go to the engine tech board.

 

Srry


Could a Mod plz move this to the right board.

 

will they work? yes.

will they maximize the potential of your engine? nope.

The vortec heads are EXCELLENT budget street heads (fully assembled from summit for $259 a piece). If you're planning on pushing that much power don't cheap on anything. You'll be sorry. I'm planning on using vortecs on my next build and i'll be pushing about 400 rwhp N/A. No plans for spray.

 

Why do you want to spin it that high in the first place? Those heads wont match any cam that will want to work up in those ranges.

 

400rwhp from vortec heads are a rare combination.

 

not really.

mine won't be stock either. They'll be ported to the max and with bigger valves.

 

yea...400 should be easy according to HotRod... 350 engine xe262h cam, vortec heads, 750holly carb. 414hp or something like that... i can honestly say im nowhere near that point.

 

414hp at the crank....he was talking about at the rear wheels.

 

I really don't like the "high reving" craze thats been going on. Why spin a motor to 7500RPM when you could make more or the same HP at a lower RPM? Lower RPMs = more streetable/useable power and easier on parts. The baddest unported/stock valved Vortec headed car I know of runs 11.60's on motor @ 3500lb race weight and he shifts it at 5500RPM... Thats gotta be close to 460HP at the crank

Really reconsider as to why you want to rev high... Whats the benefit when you can make enough power to go 11.60's N/A all under 6000RPM?

 

i'll be using ported vortecs with an edelbrock rpm manifold, carb, xr276 cam (1.6 rockers) ran through a built t-5 to a posi 4.10 rear.

i'm hoping for high 11s at around 420-430 at the crank.

 

If your building an engine that revs to 7k, you obviously going to used forged pistons. Forged Interals are not cheap, so why put so-so heads on an already expensive motor? Go with some Trickflows, AFR, Dart.. just stay away from Edelbrock heads.

 

yea...and im also no where near that point either.

 

You didn't mention that.

 

Any more info on this? Such as the rest of the car's set up? trap speed? cubes? anything?

 

400, stock crank 20/20, stock rods, KB hypercraptastic pistons gives around 10.8:1 but runs fine on 93 octane. 062 Vortecs with just the usual mods to make them work but no porting/cleaning and stock valves, Comp XS282 (244/252 @ 050, .520/.540, 110LSA), Super Victor intake, 750 Mighty Demon, junkyard HEI with 32* of timing, 1 5/8" headers, 2 1/2" pipes with cheapo mufflers

As for the car it weighs an honest 3500lbs. Rear gear is 3.42, tires are 26" tall ET Radials, and the convertor hes running is the same as in my car 9.5" Art Carr that stalls around 4000RPM. Best ET so far has been 11.6x @ 114mph N/A with a 1.62? 60ft and in the high 10's @ 122mph on a 125 shot.

Still a lot of things that could be improved to make this car faster... I think its good for atleast an 11.50

 

400 cubes and solid cam w/ 250+* of dur., I'd hope that thing would be closer to 10's. But that does explain the 11.6x @ 114. Thanks for the info.

 

true he would go alot faster with better heads. It looks like everything in his combo was picked well but he had to go with cheap heads until he could afford good ones.

that's my biggest attraction to vortecs, cheap performance. I'll be going with a smaller cam than that, but with lower gears, a stick and worked heads.

 

If your going to build a 'Vortec' based motor, it will essentially be an L31 (Vortec 350 used in trucks), Add a cam and some other go fast goodies to that and voila, it's a ZZ4 crate motor which only makes about 320 or so rwhp, granted it doesn't rev to 7k, but with vortec heads you wont see much past 5500 anyway.

 

What's your basis for saying "You won't see much past 5500" ?

I know several guys that shift at around 6200-6500 with vortecs. One of them is on this site. And it DEFINETLY keeps pulling past 5500.

You also have to remember that the ZZ4 cam is an extremely mild cam. it's a 208/221 @ .50 w/ 1.5RR, .474/.510, IIRC. You'll have to double check that, it's just from memory. It's retarded to compare that cam to a competant aftermarket cam.

 

With better heads I'm sure it'd be closer to 10's N/A... Its still very impressive for a low budget street motor with a set of untouched "truck heads" in a heavy car... I dont think the cam is big at all for a 400... It doesnt idle real nasty and he only shifts it at 5500RPM. If you can drive 50 miles one way to track, bust off 11.60's NA and 10's on nitrous then drive 50 miles back and go out cruising all night with a bunch of used junk parts thats quite a feat. Most guys going that fast have more money into their heads than my friend has into his entire motor.

 

Seeing as I am one of the original "vortec guys", I will say that they are an excellent cylinder head for a budget build.

That said, Urban you will almost certainly will not see 400 horsepower at the tires out of them naturally aspirated. My best pass was a 12.28 @ 111.85 naturally aspirated before I pulled it apart, in a car that weighed 3100 pounds without driver.

The best thing about Vortec cylinder heads is that they make power everywhere. They will give you a great flat torque curve and decent horsepower, but they are not a cylinder head that needs to be shifted above 5500 rpm. With my setup, I could shift my car at 5500 and 6000 and still run identical ET's and mphs because it wasn't making any more power at 6000 rpm than it was at 5500. With more displacement and compression, you will hit that rpm wall earlier.

The cars that are running fast with vortec heads are doing so because they are making great power everywhere, not because they are making outrageous peak numbers like the LS1 folks. I would bet your 88IROC350TPI's friend isn't making much more than 425'ish horsepower with the 406, but is making well over 500 ft lbs of torque across his powerband. That is what is giving him such a spectacular ET for such a low mph. I would bet he could shift his car at 4500 rpm and still run the same numbers because he is making good torque across the board.

I am sorry, but it irritates me when people are building an engine and advertise what they are going to make at the rear wheels.

A. You have no clue what you are going to lose through the transmission, converter and rearend until you dyno it.

B. Rear wheel dynos with a loose converter are misleading.

C. Every rear wheel dyno is different, so are the numbers. It is pointless to compare rear wheel numbers unless they were extracted from the same machine and run by the same technician on the same day.

D. You don't race on a chassis dyno.

Engine dyno is the way to go, it is easier to tune with the engine out of the car, and any unforseen problems can easily be fixed while the motor is still out.

If you want to make "400 rwhp", I don't think that the vortecs are the head to do it with.

If you want a fast street car on a budget and aren't concerned with numbers, I would go with the vortecs.

 

you're also running a very small cam in your motor, in fact that cam is small for a well worked 305. pop a XE274 with a 3000-3500 stall and watch that combo come alive.