pbuzick88

Hi there, I am currently building my first small blick to put it in my 1984 camaro. So far I have a 400 short block bored. 040 over to a 408 with keith black pistons, edelbrock hydraulic flat tappet cam .488/.510 lift. 234/.244 duration and stick crank. I am looking fir a set of geads that won't break the bank I have heard about the World Sportsman 200's and am kinda leaning that way.

I am really looking for any input as to which direction to fo from here as far as heads and such thanks for your time and any input is appreciated thanks

355sleeper

iTrader: (4)

Whats your compression ratio? Also that cam will be too small if your wanting 200cc heads

TTOP350

iTrader: (8)

What are you wanting out of your car?

for me the cam is way 2 small and Id look at 235-245 AFRs but you will need offset intake rockers...

pbuzick88

Changing the cam is no big deal I am wanting to build a street strip car more aling the lines of a track car and idk what the compression is gonna be

pbuzick88

Or is there a head set that I can just bolt on for a decent price with what I've got

DeltaElite121

Dart Iron Eagle's you can find used for fairly decent price. I also recommend getting a nice solid flat tappet to match the heads. That's just me, though.

355sleeper

iTrader: (4)

I would say a set of rhs 200s, they can be had for about 1k for the pair new. And cam something in the mid .500 lift or more andsomething like a 235 to 240the int and 245 to 250 exhaust duration

pbuzick88

I have a set of 906 casting vortec heads but they need work and I've heard that the 906 aren't rhat good anyways?

355sleeper

iTrader: (4)

I would only use vortecs on a 350, they would really choke your 400

1gary

Whatever heads you end up with,make sure they are drilled for the steam cooling holes.

If it where me,I would play it on the conservative side and look to get into 180 or 195 cc intake runners with 202's so I could build up more bottom end.It's more fun to have the power output in rpm's I drive in most of the time and your building in a natural attribute of a bigger sbc using the larger intake valve with a somewhat under sized runner to maintain viscosity for a broader low rpm torque output.

LarryL

I use vortec 906 heads on my 400+ sbc setup. I put in 202 164 valves, Ls6 bee hive springs(yellow) ,cut down top of guides and port matched and polished them. Running a hyd.roller cam 240-246 dur. 536 lift 10 to 1 compression. Runs great, idled at 750 ( when auto trans) now 5 speed. She revs to 6800 and pulls all the way. I shift at 7200. I have 3:73 rear. I have 5.7 rods and full float wrist pins. I have had this setup for 10 years never had a problem.

1gary

Larry,my point sir is you certainly do know what you have.But don't know what is missing.The only way to do that would to swap heads,cam and kit.What I suggested you are going to trade off hp for torque.My thinking the torque aspect is more important to street driven vehicles than hp.Just my two cents.

articwhiteZ

iTrader: (56)

maybe im missing somthing with this combo? (fill me in ifso)

7200 rpm? with a lift of 536? and a Dur of 246?
and springs has old has 10 years...
you sure your tach is working?

i run mech rollers and the last time i did a 400+ small block. for over 7000 rpm it was
over 257dur and 645 lift. and springs 2 times what yours are.and comp of 12.5...with AFR 220's..a nice street car eng.... im just asking..cuuuzz..Maybe.. im doing it all wrong.

LarryL

I only drive the car once and a while now ---under 4000 hard miles on engine. When I first built the motor I did not install the LS6 springs, I did that several years later. Was your cam custom ground for your setup, my was.

355sleeper

iTrader: (4)

I really dont see your 400 with vortecs making power past 4500 to 5k rpms. That 170 runner will kill that engines breathing regardless of port work, as the vortecs are pretty well maxed out of the box

1gary

Yepper.A 170cc is too small.180 to 195cc is a good middle ground giving up some top end but building a solid bottom end.

watajob

iTrader: (29)

Viscosity?!

Confuzed1

iTrader: (4)

I'm assuming the .234/.244 duration is at .050 lift correct? I'll assume the people that think that cam is small are thinking that's "advertised" duration?? - not sure.

So, you NEED to figure out what pistons/stroke you have now so you can determine what size chamber heads you'll need so you KNOW what compression you end up with...or else you could end up with a 12.5:1 race gas only type of "street/strip" car. Not too practical for the street side. No one can tell you exactly which heads with the info you provided.

I wouldn't shop for them if I were you unless I know where you want to end up. Which KB pistons?? -21cc inverted dish, domes or what? I wouldn't go over 10 to 10.5:1 max compression to run on pump gas. So figure out what your static and dynamic compression is going to be.

With the cam you have, (in general) it's going to breathe best in the mid-to-upper RPM range. You don't want a small intake runner head for that. 200 to 220cc heads should match up better and make more power.

1gary

I agree with you needing to know the compression ratio to dictate head/cam combos.Where I respectfully disagree is the common trap of bigger is better for intake runners.Yes the power output is better,but at a much higher rpm range.So to match that up is a rear ratio a 4.56 or 5.13's??.Ouch!!!Chase that with refreshing it up twice a season.How about a conservative intake runner and a 202 valve to keep the viscosity up and lower the torque curve??.Then cam it accordingly.Do you care if it falls off at say 5500??.Well yes and no.Mainly used on the street??.Really don't mind that rpm limitation that much and would rather have use of the torque side of it almost off idle.That would plant the flesh to the seat pretty easily.Light the tires up at will with a shade short of 500 lbs or slightly over 500 lbs of torque all below say 4500 rpm.Yeah a bruiser street cruiser crowd favorite at the hot dog stand.

355sleeper

iTrader: (4)

Ill give him the benefit of the doubt and say he was thinking of "velocity"

TTOP350

iTrader: (8)

Small heads choke motors.
I'll gladly give up 10-15lbft of tq under 2500rpm to gain 50 more hp up top.

Confuzed1

iTrader: (4)

I don't believe the OP mentioned what gears he plans to run, but regardless, the COMBINATION of the cam/heads is going to determine where the power band is going to be. With smaller runners with his current cam, yeah he'll get a little better (velocity) in the lower RPM range (more TQ) at the expense of better breathing in the upper. It's a trade off.

The OP didn't say "mostly street"...he said street/strip. He didn't state "mostly" on either, so you can only try to find a combo that works best for both...but it won't be set up perfectly for either unfortunately.

I don't fall for the "bigger is better " analogy on anything...it's the combination of ALL parts that dictate what you need....and remember, this IS a 400 plus cube engine...200cc intake runners are NOT big at all for that engine. I agree with some of what you're saying, but...why put that size of a cam in it, just to choke it in the mid-to upper rpm range with a smallish runner head?? Doesn't make sense to me.

400 small blocks make quite a bit of TQ anyway due to displacement...don't ask me how I know...lol

Confuzed1

iTrader: (4)

...exactly...

1gary

Spell check-spell check??.Well ya knew what I meant to say.

Manic Z

iTrader: (1)

I run RHS 200cc heads on my 383, and they run great. I'd even go one step bigger for a 400ci motor.
And these heads are very affordable.

DeltaElite121

Sizing runners/heads means very little in the overall scheme of things. A bigger head will not "bog" a motor out if the head is well designed and matched to the rest of the components. It might not be optimal in some circumstances, but it WILL work. I personally use 200CC Iron Eagles on my 355 (which are now technically 206's) and I don't have any problems whatsoever. The tradeoffs for going bigger are much better than going smaller if you're wanting to go fast. Also keep in mind there is such a thing as too MUCH velocity (as well as too little); like anything.. more is not better. It's all about balance.

For example: let's say I lost some power down low with my cam.. Who cares? I've got a 4200 stall converter with 3.42's. I'm not going to notice I lost anything unless I'm putting around going to walmart. Even then - I won't really care because I'm not trying to go fast getting there.

In a 400 SBC I'd run a 215cc head minimum.

1gary

It's a proven fact that you can and will move a torque curve based on the size of the intake runner/valve size.The bigger the runner the higher that torque curve will begin and on the other hand the smaller the intake runner you can tailor the torque curve at a lower rpm.So if your running a street vehicle,wouldn't you want a torque curve well on it's way to 500 lbs at say 3500 rpm??.Why would you even care what it produces at 6500 or even 6000??.How often are you going to use that??.

Matched head/cam combo??. Absolutely!!!!!.And certainly the compression ratio being the driving force behind the decisions made.

DeltaElite121

My cam winds to around 6800 so in a DD street/strip car.. I use it frequently, actually. Why limit yourself to 6000 RPM's (or less) when more RPM's = more power (provided the parts support it)? More CFM's also means more potential for power to be made. Combine that with larger cubic inches of displacement and you've got a recipe for something fun. Now making it RELIABLE is a whole other story, but there's no reason to cap yourself out with small cylinder heads.. particularly on a 400 SBC. These motors make more than enough torque down low to justify anything "lost" (most cases you won't even notice it unless you dyno'd the car or heavily mismatched something) in order to make higher RPM power. This doesn't need to be a drag car by any means, but limiting yourself in fear of bogging things out is silly; particularly because that can be avoided completely if the parts are matched well.

There are multiple ways of doing a street car right. There's also just as many ways to doing it wrong, though. I personally don't see the point in building up a motor if you're only going to halfass it and make everything run out of steam before it's even remotely potent. To be fair though, we don't even have enough information on the car to make an educated build.

1gary

Forget hp.Damm old habits die hard huh.Torque is king on the street and the earliest the better.You ant mph'er anyone in street light racing!!!.And that is what hp is = to.Torque is = to ET.The first 60' to 330' saggy bottom ends don't get-er-done.Let alone you needing a high gear ratio/torque convertor to make huge intake runners work as they should adding costs.And these 400's with the goofy stream hole cooling have bores that DO move around alot.We leaked down a number of 400's over the yrs to find your hard pressed to get the same results twice.And those where race version done right with torque plates during the build.Now if this user is going to go over 10.5 in compression,that is a game change.The advantage of a bigger C.I.SBC is you can cam them up more and they are more accepting with good street manners.OK-your saying but it is a 400.Do know what the stock intake runner is on them??.Is a 180cc to 195cc tops a improvement on that??.You bet your treed butt it is.It isn't a limitation,but more over a smart build for the intended use knowing full well the outcome.We have seen and build a number of class winners for 1/8 racing only with torquer engines.In fact my own 383 build is a 9.3 compression under 500 lift hydro roller cam 180cc intake runner with 523lbs of torque at 4525 rpm.Off idle,well really 200 rpm off idle it is well into the 400lbs of torque.All I am doing with a 700R4 to help out abit is a 3.70's gear.Really it don't need anything else.And 90 percent of the time in street light racing I'll tree the hell out of the guy next to me.

Let me convert you.Facts are the higher you in rpm's,the tons more money it costs.It increases the likelihood of breakage.And the chances of losing A whole engine increases everytime you do it.

So you look at this 400 which by the way is .040 over already and was likely not build using torque plates,with the same poor cooling design,being used on the street with what stock rods and really not the best pistons,a cast crank,likely a stock rear end gear ratio.Now I wouldn't suggest in the first place taking that bottom end much over 5500 rpm.Have guys done it??.Sure it's their money and risk,but the guys who haven't following our advise are still enjoying their turn key rides for yrs.So giving the components above,it isn't logical to have him build-up a engine requiring it to rev past the component's capabilities and let alone when again torque is king on the street the earliest the better.

Also,I can't remember how many dozens of hard core heads we have bought and sold over the yrs of doing that.And how many we have used in strictly race applications.None of which would have worked well for the street.