Getting ready to start on a 383. It'll be 9:1 compression ratio. Cam will be hydraulic roller, .458/.458 on lift, duration will be intake 206, exhaust 210.
Which aluminum heads would you suggest for $1000-$1200, also what size for the intake runners? I was thinking 180cc. This is going in a truck so I want it to be a torque monster...
I think you are really shorting your self on the cam especially if you are going to shell out the cash for a roller. WIth those numbers you might as well save yourself 500 bones and run a flat tappet.
Lots of people have had good experience with the 200cc heads from summit, they come fully assembled for 995.00 or so.
Well, I ran it on Comp Cams Camquest, and true it only made 355 HP, but it made 465 ft/lbs of torque at 2500 rpm which is right where I need it for a truck.
I wrote this thread just for this reason. In my opinion, this is the best torque motor that will run on junk pump fuel. Everyone gripes about the cost of AFR heads, but if you don't start with the best heads, everything else is compromised. http://www.hotrodders.com/forum/pump-gas-street-motor-134146.html#post935777
Ran Camquest with the numbers for Brodix IK 180's with the above mentioned cam and got these numbers: 403 HP at 5000 rpm, 476 ft/lbs at 3500 rpm.
The torque peaks at 3500 rpm, but it still looks like it has about 470 ft/lbs at 2500 rpm. I think I'm good to go, now I just gotta scrape the cash together...
Well, I ran it on Comp Cams Camquest, and true it only made 355 HP, but it made 465 ft/lbs of torque at 2500 rpm which is right where I need it for a truck.
I got better numbers than that with a 383 that had 305 heads and an xe268h cam. (granted the heads were ported and flowed 165cc's) it made 375 hp and 475 ft/lbs at 4500 rpm, which isn't out of your trucks rpm range. I think you are going to hate driving something that peaks at 2500 rpm.
All I am saying is that you don't need to spend all that money for a roller cam for such a mild profile.
I wrote this thread just for this reason. In my opinion, this is the best torque motor that will run on junk pump fuel. Everyone gripes about the cost of AFR heads, but if you don't start with the best heads, everything else is compromised. http://www.hotrodders.com/forum/pump-gas-street-motor-134146.html#post935777
I agree that the best place to start is the right heads, but don't believe all the hype about AFRs. They sound good on paper, but all of their port designs are based on pretty ancient small block ports. They CNC them with a very poorly controlled machine on software from 1995. Their flow numbers are inflated, and even if they flowed as much as they said they did, they aren't very impressive numbers given the port sizes.
you can port factory heads by hand that flow much better than AFRs and do it with less port volume. I'm going with AI (www.advancedinduction.com) for my LT1 heads because their 185cc CNC head blows AFRs 195cc head out of the water on the dyno and the strip. Flow is great, but its easy to fudge, and the proof is on the dyno and the track.
For a long time, Impala SS guys went straight for AFR heads. Then it started being noticed that guys with factory castings that they ported in their kitchen were starting to blow the doors off AFR heads. Further investigation led me to cancel an order I had with AFR. Great company, fine heads, but I don't trust their advertised claims. I have nothing against AFR; they're fine heads, but if you're going to put $1500 into heads, I'd go with something better than AFR.
That motor sounds just right for a warmed over set of vortec heads. Especially if cash is one of your primary concerns. So there not aluminum big deal its a truck.
That motor sounds just right for a warmed over set of vortec heads. Especially if cash is one of your primary concerns. So there not aluminum big deal its a truck.
Do yourself a favor and really research flow numbers; not just peak numbers, but mid and low lift numbers. I fully respect and support the "nothing's too good for my vehicle" standpoint, but many heads just fall short of the prize.
Many of the aftermarket heads (Brodix, Dart, Trick Flow) are cast with the racer in mind. They are designed to fit in race classes where a "stock" head is required, but they're cast with extra meat for porting and deck rigidity. In many cases the "street" offerings from these aftermarket companies don't flow as well as a stock iron vortec. They're designed with the racer in mind who will port the snot ouf of them and expect the decks to seal in a brutal race.
Just my 2 cents... look at total flow as an average throughout the lift range. I agree... with your cam choice, Vortecs would rock. So... if you're looking to invest in excellent aluminum heads and aren't worried about spending money on the "right" heads, how about the aluminum big-port vortec heads? They are a bigger (but similar) port than the stock iron vortecs, but keep the same high-quench vortec combustion chambers.
Getting ready to start on a 383. It'll be 9:1 compression ratio. Cam will be hydraulic roller, .458/.458 on lift, duration will be intake 206, exhaust 210.
Which aluminum heads would you suggest for $1000-$1200, also what size for the intake runners? I was thinking 180cc. This is going in a truck so I want it to be a torque monster...
I am running a 383 with 195cc TF heads, CC XE 274 hydraulic flat tappet cam, 10.3 static CR on 89 octane in a 3300# vehicle, 3.36 RA ratio/4 speed. More torque than I can use with street tires.
I managed to get a copy of Desktop Dyno. I'm thinking about going with: .487/.495 lift, 212/218 duration. Which theoretically is 386 HP at 5000 rpm, and 437 ft/lbs of torque at 4000 rpm.
Camquest was giving me overly inflated numbers.
They aren't technically Vortecs, but they use a larger (210cc) version of the vortec port, the vortec chambers, and have bolt holes for both early and vortec intakes. The 210 cc runners are too big for your cam, but many aftermarket ports will be.
If you're really looking for torque down low but want to go aluminum, try some L98 TPI heads. You might have to port them a bit for the flow you want, but they're cheap and readily available.
I think you are really shorting your self on the cam especially if you are going to shell out the cash for a roller. WIth those numbers you might as well save yourself 500 bones and run a flat tappet.
Lots of people have had good experience with the 200cc heads from summit, they come fully assembled for 995.00 or so.
I'm slightly confused isn't a flat tappet the one that you normally only want to use in high RPM race situations where rollers do not perform well and mainteance is already constantly done in between racing so adjusting the mechanical lifters every so often isn't a big deal? I thought the rollers were better for street low/mid power.
Check out Scoggins and Dickey parts, they used to offer a Vortec head package (intake, gaskets, etc.), I haven't checked in a while but would think it is still offered. The price of their packages was less than the amount that I spent on my heads alone. I was building a 406 for my mud truck and my goal and thinking was similar to yours. Looking back I wish I would have went with the Vortec, saving money and still getting good results, maybe next time. I always choose a cam after deciding on heads, drivetrain, tire size, etc. Good luck.
I'd love some Vortecs cause they're a bargain, but the valves are too small, and they're lift limited to .450". By the time I got them machined for bigger valves, screw in studs, and bigger springs I might as well have gone for something else...
I'd love some Vortecs cause they're a bargain, but the valves are too small, and they're lift limited to .450". By the time I got them machined for bigger valves, screw in studs, and bigger springs I might as well have gone for something else...
Don't worry about valve size. Focus on flow. If a head flows what you need, who cares if the valves are the size of a dime?
Stock iron vortecs are limited to .470" lift. Since you have to buy aftermarket springs for any type of performance cam, all it takes is a set of springs that will allow .550" lift. You don't spend any more, but you get .550" lift without machining anything.
check out competition products head improvement kits, they come with everything needed and can be purchased for less than 175$$ I thought their kit was well put together and a helpful staff. After that a good port and polish I think You would be pleased. I think a lot of times people don't give GM heads a FAIR shake. My machinist is flowing good numbers from a lot of ported and polished rebuilt heads, he's the one who started this debate with me and finally convinced me after showing me some numbers. Price vs Flow, bare Vortecs I've seen for as little as 200 a set. I will see if I can pick up his numbers next time I'm at his shop in 3 or 4 days. I agree on the L98 head they are a performance bargin for a street motor. This is a picture of mine before the port and polish. I will update pics as soon as I get the heads back
Don't worry about valve size. Focus on flow. If a head flows what you need, who cares if the valves are the size of a dime?
Stock iron vortecs are limited to .470" lift. Since you have to buy aftermarket springs for any type of performance cam, all it takes is a set of springs that will allow .550" lift. You don't spend any more, but you get .550" lift without machining anything.
I'm actually running .552" lift in my boat's vortec (.345 at the cam, 1.6 rockers) and it sees frequent 5300 rpms for long periods. I still have plenty of safe clearance from the retainer to the seal.
I'm not disagreeing with you tom... maybe mine is an exception, but I've never heard about interference with the .550" kits.
I'm slightly confused isn't a flat tappet the one that you normally only want to use in high RPM race situations where rollers do not perform well and mainteance is already constantly done in between racing so adjusting the mechanical lifters every so often isn't a big deal? I thought the rollers were better for street low/mid power.
It depends on which flat tappet you are talking about, mechanical flat tappets are for what you said. Hydraulic flat tappet are for the everyday cams. Rollers are good at any RPM, hydraulic rollers are suited better for more aggressive street applications where you don't want to sacrifice low or high rpm driveability and solid rollers are for serious engines that see high rpms.
This is just generally speaking there are exceptions.
This is why one must look to Summit, for their VORTEC ZZ5. Talk to your machinist about doing a set of the VORTEC heads this same way. An assembled pair of 8060's prolly runs 600 bucks. Or, just buy 'em bare and put somebody to work.
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