i have a 750 speed demon carb and am probably going to change my performer rpm intake to a victor jr and i have 2.02/1.60 200cc/64cc aluminum heads and i have 3:70 gears in my 9 bolt. i am currently making 295rwhp with my melling .480/.480 230/230 cam and looking to change my cam out with something substantially bigger. i dont normally drive the car but once in a while. i looking at the comp cams magnum 305 and use 1.6 rockers which will put the lift at .557 i think. and the adv 253/253 power range 3000-7000 would this put where i need to be?

 

Sounds like it could winner to me as long as youve got the compression and parts to back it up. If not 500 it will be a high 400 number for sure.

 

compression is 10:5 to 1 hyper pistons and stock rods with arp bolts

now someone also just told me that the best cam would be a small @ .050 lift around 220 and large adv duration 300 he said thelow at .050 duration allows more cylinder fill and less bleed off for more compression. and a lift around .550

is this accurate info?

 

Pretty sure it's the opposite....longer advertised duration = slow lazy ramps that bleed off pressure. Shorter advertised duration means more aggressive and modern ramp, ie, better.

 

For a true 500hp out of a 383, with pump gas and a street cam, you will either need really good cylinder heads, or a real aggressive roller cam, I am sure that it is possible with a flat tappet cam, but to keep it streetable I would want a set of AFR heads and a cam no smaller than a 280 advertised duration.

If you already have good heads and want to stick with a flat tappet, I would deffinitely not use a comp magnum cam, they are a very old design and do not have the agressive ramps built into modern designs. I also think that a comp 305 hydraulic cam is a little silly, because by the time the cam hits it power range, your hydraulic lifters are going to pump up, especially considering the higher spring pressures required with a cam that large. I am not saying that is a bad cam, and I am sure plenty of people have made it work, but there are better and more efficien setups out there.

The cam that I would reccomend is a comp extreme energy 290 solid. It has very agressive ramps, and will make a ton more power than your current cam or that magnum you are considering. Along with the new cam I reccomend a set of howards direct lube solid lifters, they have a small hole on the bottom of the lifter to aid in oiling the cam, which will go a long way in preventing flattening a cam lobe. They may be a little more expensive, but it is money well spent, a cam with agressive lobes like this is a good canidate for loseing a lobe, and then you are not just out a cam, but the whole motor needs removed and completely dissasenbled to clean out the metal shavings, a real PITA.

 

Just use the @.050 rating to compare cams, and the adveretised operating range, the bigger the duration, the higher the power band. There are a lot of other variables as well,LSA and ramp design, but we do not need to get into that here.

 

i guess i typed the cam specs that i was looking at a little wrong the adv durartion is 305 and the at .050 is 253/253 and lift is .525/.525 but i also have been hearing about comp cams having problems with wiping out lobes. has anyone else had this problem?

i was told around 108 lsa

 

Every cam company is having trouble with wiping out cam lobes, it is not the cams but the removal of zink from our motor oil due to epa standars. There are things you can do, such as using oil additives like GM EOS or comp break in lube, some people even use diesel oil, and like I reccomended, the Direct lube lifters will go a long way in preventing any trouble.

All of the cam manufacturers have a modern agressive cam line, Comp calls it extrem energy, Lunati calls it Voodoo, and I am not sure about crane. All of these brands of cams will work well, just stay away from the antuiqe designs(AKA Magnum)
This is the cam I would reccomend,http://store.summitracing.com/partde...5&autoview=sku it is a Comp cam, I always reccomend Comp just because I am most familiar with there catalog and have always used there products, but I am sure Crane or Lunati has a comparable cam to this.

 

ok i was also wrong about the magnum label it is a comp cams drag race cam is that a good one? it has a 106 lsa

 

500HP out of a 383 N/A isn't a big deal. This is the engine that I built...

http://www.airflowresearch.com/store/chevy_dyno.php

You can see that it makes 517TQ and 503HP. I had it dyno tuned and it put down 413HP and 430TQ to the rear wheels. The major factor that your are going to have to decide is where you want your power to come in at. Your heads seem to be fairly close to what I have assuming the airflow CFM is similar, then your camshaft will be a big player. I built my engine around the premise that horsepower is a derivitave of torque. Torque and horsepower are always equal at 5252 RPM. With that being said, I wanted to make as much torque at 5200 so the HP would be comparable. The best way to do that is with matched components that promote high port velocity. A dual pattern cam profile will yield you better results, and having it be a roller is more than likely be a must. You are probably going to want to have more lift and a tad bit more duration on the exhaust side to help with scavenging and to make up for the smaller exhaust ports on the head. Using an overall higher lift cam or 1.6 rockers with a single plane manifold will shift your HP curve higher along with your peak power output. That choice will decrease the amount of lower end torque that you will make, but the fact that you are using the stroker crank makes up for some of that loss. Anyway, good luck with your project. Hope you are having fun with it!!!

 

i would like it to peak at and hold somewhere around 5500rpm i have a 6000 rpm rev chip in my 6al box. i also would like to either stay solid or hyd. flat tappet as well. on a budget and i know the retro fit kits arent cheap.

 

For 500 hp out of a 383 on pump gas you will more than likely need to spin it higher than 6000, I am not saying it can not be done, but you would need to have really good heads and more than likely a solid roller cam. The Magnum cams are not bad, but the extreme energy cams are better, if you are going flat tappet then that solid I reccomend should be a good choice, but you will need to spin it 6500 or so, which is probably less rpom than that 305 magnum you were considering.

 

500 huh. Are you just shooting for a number? Is the car getting chassis dyno'd? You won't ever know if the motor is actually making 500 unless you get it on an engine dyno, or you overshoot for the wheel numbers.
If you are making 300 at the wheels with those heads, I doubt you will pick up 140hp with an intake and cam change. AND you don't want to spin it over 6k rpms. You are going to need some kickass heads sir. AFR??

If you wouldn't mind 6500, then go with some less kickass heads with a 215+ intake port.

 

well i am also upgrading my carb from an edelbrock performer 750 to the speed demon 750 i mentioned above so that difference is yet to be noticed and i just broke a rocker stud so that was the last straw so i will be pulling it apart. and i think about 6200 rpm is my limit because i still have stock rods with arp bolts so i dont want to push it too far. i will also be changing my regular rockers to roller rockers. so that will free up a little bit as well. i am changing all the things i went a little cheap on the first time around.

 

 

Those are good flow numbers and you should be able to run very good with those heads, but to make 500 horsepower with a flat tappet cam, under 6000 rpm, you are going to need AFR eliminators.

I think you can build a really powerful motor with those heads, but I would throw your horsepower goals out the window, and just build something that fits your budget, and your goals for streetability and track performance.

If you really want to stay under 6000 rpm, then the cam you have now is about right, you may be able to gain some power with a more agressive lobe profile, but a cam of around 230 advertised duration is about as big as you can go. With a cam in this size, I would reccomend just sticking to a hydraulic, I have heard nothing but good things about the Lunati voodoos, here is one that might work well
http://store.summitracing.com/partde...4&autoview=sku

There are also many other cams near this size that will work well. Use this with a victor jr., some long tube headers, your mechanical secondary carb, some 4.10s, and a good converter and you should be able to break the 11s, without breaking the bank.

 

so what kind of hp should i be looking for? and the cam i have now drops off at 5400 rpm

 

would it be worthwhile for me to pull the heads and have them ported and the have the intake port matched??? since those eliminators have good numbers but are a little pricey and i dont have that kind of money right now

 

I think that the heads you have, and basically your entire long block, should be fine.


I do not have a lot of knowledge of melling cams, but the cam seems real similar to a comp magnum 280, and that cam is good to 6000 rpm, if you are losing power at 5400 now, then you may have other issues, how do you adjust your lifters? What kind of valvesprings do you run? I think that you may have a little more power in your current combo that needs to be sorted out, maybe then you will not even need to buy a lot of new parts to get the performance you expect.

 

i wait until they are down all the way and tighten until no lash and then half of a turn i want about 130+ more hp to the tire which will put me at 425+ rwhp

i just dont think that cam is agressive enough

i also have a 5 speed trans so that cuts a little on loss of hp from the motor to tires

 

I do not understand what you mean by "i wait until they are down all the way and tighten until no lash and then half of a turn" If by that you mean that you wait until the cam is on its base circle, you tighten the rocker until you feel slight resistance on the pushrod, then a half turn more, than you are correct.


That cam is not agressive enough for 425 rwhp, at least not in a 383, but with your stock rods and only wanting to rev to 6200, you just are not going to be able to go with a bigger cam.

The size of the cam determines the peak RPM range, and since horsepower is a factor of tourqe times rpm, then a bigger cam can make more hp, but only IF you spin it at a higher rpm, I could reccomend a cam that will make your 500 hp with your heads , but it will be a radical solid roller that will spin 7000 RPM and require 12 to 1 compression.

Since we already know that you have stock rods, and 6000-6500 is a realistic guidline, a 230 duration at .050 cam is about all that you will be able to run and make good use of.

If you want to keep your compression, your connecting rods and RPM goals, and a flat tappet cam, the only way I can see you even come realisticly close to your goal is a new set of heads, you could have yours ported, but by the time you got them to flow like an AFR eliminator you will have so much time and money in them that you could just buy two pairs of AFR eliminators!

I honestly think you may be being a tad unrealistic with your goals, to gain over 100 hp at the rear wheels is going to take some serious time and money. A 500 horse pump gas small block with a flat tappet hydraulic cam and mild cylinder heads is pretty hard to accomplish, but best of luck with your goals, and keep us posted.

 

How do you plan on driving so you don't blow up that T5? One slightly rough shift at 6000 rpms could trash that trans.

I would do this:
1. change the cam, the one bart suggested is a good one, but the next one higher I think would still be within your rpm range with a stroker. You should pick up some very good power here, considering your heads don't flow very well at low lifts. Right now you are barely using your heads.
2. The vic jr if you plan on spending lots of time above 5000 rpms, I would suggest keeping what you have. Torque is good. Small upper hp gains are worthless on the street.
3. Get a good carb on there.
4. If you're still running the HEI distributor, you probably need a better module.
5. How's your exhaust?

Get er all tuned up good, decide how you feel about it, and then look at how much money you have left.

Don't make a mistake and just shoot for a silly number. You may find that its not what you wanted after all. Make small changes and mold the car into the direction that FEELS right.

 

i have an hei dizzy but it is running of the 6al box and the coil is an hei msd one. and if i blow my t5 than so be it i want a tko trans anyway so when it goes it will be my motivation to go get one. and what cam in particular did you have in mind? bart made 2 suggestions a comp 290s and a voodoo60104. so i dont which you are referring to. i know exhaust will need an upgrade at some point. i have edelbrock tes headers and hooker cat back sys. 3" mandrel bent. and a catco cat from summit. i figure after i get the motor situated i will get different headers. someone suggested dyno dons shorty 1 3/4" and 3 1/2" cat back.

if you are talking about the voodoo 60105 then i think i like that one and use 1.6 rockers and bump the lift up. of all the cams that i have been looking at that was my second choice. so you are saying the performer rpm intake is ok?

 

I do not understand what you mean by "i wait until they are down all the way and tighten until no lash and then half of a turn" If by that you mean that you wait until the cam is on its base circle, you tighten the rocker until you feel slight resistance on the pushrod, then a half turn more, than you are correct.


yes that is what i meant

 

Check into a 4-7 swap cam Summit sells a Comp cams CCA-12-822-14 for $399.95 and the power band is 4,200-7,200 and duration@ .050 is 264/270 and lift is .630/.630. Horsepower on Powerblock used a similar cam on a 406 with 9:1 compression running on87 octane before cam swap it dynoed at 497hp and 500+tq after the swap it pulled 528hp and I forgot to write down tq after . If you can handel the lift I would go with the Comp cam .

 

you cant go by what a TV show said the got from a cam.. they are selling merchandise not HP...

the principle behind a 4/7 swap cam isnt a power increase but to alter the fireing order to more evenly distribute heat and vibration... a small power increase will be realized but not more than 10-15hp would it really be worth the extra money?

 

Yes it is to swap the 4 and 7 for heat ,vibration , and the dyno numbers don't lie the power increase was only 31hp but if you equate $1 per horse power it would be a good buy .

 

Although this cam may get him the power he is after, I do not think he would be able to take advantage of a 4200-7200 cam while shifting at 6000 rpms.

 

bart what do you think about the voodoo 60105 cam with 1.6 rockers? it says it needs 4.11 gears though. would my 3.7 be sufficient until i can get the 4.10's later

 

If he is shifting at 6,000 rpms he should get good performance out of the cam becuse the power drops at the front and rear of the power curve he should be close to the peak of the power band at 6,000 rpms .

 

again you are going by a TV SHOW... not a good source of information! you have no idea about the specs of the original cam or how the previous dyno numbers were attained and again A TV SHOW TRYING TO SELL MERCHANDISE...

 

I don't care if it is a tv show and i didn't write down the original cam specs but it is a great show to watch and get ideas from and all dyno pulls were done on there dyno so the best answer to any question about the cam should be best answered by Comp themselves .

 

Lol, forget the 4-7

The voodoo with 1.6 should do real well.

I think it would be a good idea to do the headers later as well.

 

so does every1 agree with the voodoo 60105. and will it be ok with my 3:70 until i can upgade the rear later my other thing i will have to do is check in my piston valve clearance with the 1.6 rockers so i guess i will have to pull the heads

 

Yes the voodoo will do fine .

 

I have started to post a few times but terminated so here we go with my two cents.

From all the dyno testing we have done I do not believe you will get your goal of 500 hp with those heads and that flow rate. I also don't think an out of the box Victor Jr will allow you to get to those goals.

We have dyno tested motors with heads that flow more than 280CFM and with intake manifolds that flow more than 300cfm. Out best so far is around 460hp at the motor. Next time around with the AFR 195 Comp heads and a bigger cam I think we are going to get that 500hp.

So like was said above get the AFR heads, bigger cam and have the Victor Jr ported to match the heads. Don't forget a good exhaust system. You can't make big power without the rpms. Plan on spinning that thing to 6500 rpm.

By the way check out Orr89RocZ's 383 motor. He is right around 500 hp at the motor with his setup.

 

I have a dyno proven 507 hp @ 6300 and 484 lb ft torque @ 4900 to the crank on my 383. Very streetable too.

Gasket matched only, no porting yet...Dart Pro 1 aluminum heads, 215cc intake, 2.05 valves, stage II. Comp 294s solid lifter cam .525 intake and .525 ex., 1.6 roller rockers, Vic Jr intake, one inch spacer, timing 32 deg holley 750 mech secs, proform main body.

11.1:1 compression, runs on 91 but likes 93.

 

The flow numbers are ok. Run the vic Jr intake.
I love roller cams but if you must stick to flat tappet, i'd run the voodoo mentioned. Thats a nice grind.

You probly can rev that thing to 6500 with arp rod bolts, just make sure the tune is safe and doesnt detonate. I would expect peak over 6000 rpms and hold well to near 6500 where you can shift. Or you can shift at peak, just to be safe.

You'll want to turn atleast 6200 rpm (peak hp) i think to make closer to 400whp or 500 crank. Mines right around 6250 rpm peak but hold well to 6500. 400whp

 

yeah i think that voodoo 60105 will be a good starting point. so you dont think i should try and port the heads at all?

and any ideas on the rear gear ratio for this cam? it says 4.11 and i have 3:70 now but will upgrade later

 

what tire size? I think 4.11's will work ok for that motor with 26" tire and larger.

26" tire will ut you at 6100 rpm at 115mph. if you trap more than that which is near 400whp in a 3450lb raceweight car. Then 3.70's would be nice if you dont want to rev to high or expect higher trap speeds. 115 is 5500 rpm with 3.70s and a 26" tire

 

well i have 26" tires now and will be going a little bigger later but not until i get new rims. so when i change my tires i should bump up my gears?

 

I would get it together and see how it runs first.

 

taller tire will need more gear.

 

gettin it together and running it will be a little way away. just want to get my game plan together which right now includes new valve springs, 1.6 roller rockers, voodoo 60105, maybe vic jr, mighty demon 750, new headers. was thinking of doing some porting and matching intake since i dont want to take it apart twice but i will need to price how much that costs. but i think i might already have enough valve piston clearance so maybe the heads will stay on. so that is my only thing left to figure out whether or not to do.

 

If a cam is designed to make power to 6500 rpms, and you shift it at 6000, then you may be near the peak power, but when you shift gears you will drop well below the peak tourqe, and that is what will slow you down.

I do think that it will still run well with that cam, but he might be able to go one step smaller and not lose any usable power, below 6000 rpm, but gain some tourqe, but either way it will run fine.

You deffinitely want 1.6 rocker arms, as far as price vs. quality, I have always like the Harland sharp.

4.10 gears will work with a manual trans and 26 inch tires, but if you ever do go with an automatic you will have to buy a very good converter, otherwise converter slip may have you overreving at the finish line.

 

I make about 550 to the crank on my 383 setup.

my sig shows everything

 

ok so i found out today that i shouldnt have to pull my heads and check for clearances so they will stay on and no porting will happen if later down the road i can get some things together i will shoot for the afr eliminators. i know they will add some hp, but that will be later. it might take me a little while but i will let everyone know how it turns out and what i end up with.

 

The gear ratio spread wont drop him that far. His torque curve will be pretty flat regardless so if he shifts by 6K instead of 6.5K his ET wont change all that much. I shifted 6K to 6.8K and saw about if not less than a tenth difference. I peak at 6250 but hp is basically flat from 6k to 6500+

 

what crankshaft are u running?...if your running a cast crank i would be careful putting out 500hp on it...

 

I dynoed my 383 yesterday and with a base tune and little timing w/o nitrous it put down 382rwhp and 425rwtq which is about 478hp and 531ft lbs tq at the crank with the following setup:

4bolt main 350 block notched and bored .030 over
Eagle forged one pc rear main crank
Scat forged I-beam rods
Wiseco Pro tru forged flat tops (11:1)
Comp Cams xr282hr10 cam
1.6 Crane Gold roller rockers
AFR 195's heads angle plug
Edelbrock High-Flo TPI base(not ported)
Accel Superram intake
FMS 30lb injectors
ATI Super Damper
Pete Jackson gear drive
SLP 1 3/4" headers

A little more timing and fueling and I should reach 400rwhp. Then I have 150 shot on top of that controlled by NMM just incase I run across one of those new Zr1's. You've heard of those right?