I was wondering if someone can help me estimate my motors horsepower and torque with my current setup and the new heads I want to get.

SBC 355 with flat top Hyp. pistons, 462 or 882 76cc 1970's crapy head castings, Weiand duel plane intake, QuadraJet 4 barrel carb, cam specs:
My Cam Specs are the following:
Cam Lift int .295 exh .310
Valve Lift int .443 exh .465
Lobe CTRS int 100 exh 124
Lash Hot Hyd.
Adv Dur int 280 exh 290
.050 Dur int 214 exh 224
Adv timing BTC 39 ABC 61 BBC 88 ATC 22
.050 Timing BTC 7 ABC 27 BBC 56 ATC -12
Also running full length hedders into duels with a H pipe 2.5in exhaust.

What I want to get is a set of the World Products Inc. Sportman II heads: 72cc combustion chamber, 200cc intake runners, and 2.02 intake 1.6 exhaust.

What HP/TQ will I have before and after the head swap. Thanks alot to anyone who takes the time to run it through their dyno software. You rock!!! :hail:

Also running an Edelbrock 50-75-100 N2O kit (not relavent but just makes me smile thinking about it)

 

The numbers seem strange but this is probably a mismatch of parts, seemingly the heads. The World heads doubtless want to see higher rpms and a lumpier cam.

Before: 356 hp and 372 torque

After: 351 hp and 374 torque

Keep in mind that DD2000 give you gross dynomometer figures, not net. Thus you should subtract 25 or 30 hp for your accessories like air conditioning, alternator, water pump, etc., to figure a net hp. This would get you in the neighbourhood of 320 hp net from each engine. I also assumed you would have small tube headers and mufflers, a 9.0:1 compression ratio, and a hydraulic flat tappet cam and lifters.

Now subtract about 65 or 70 hp for drive train loss, and you will have around 250 rear wheel hp.

I would guess this would push a 3rd gen Camaro into the 13s. Maybe 12s with nitrous.

 

I guess Sitting bull!!!!

Did you use desktop dyno?

 

Yes, I did. Do you come up with different numbers?

 

CRAP!
So with my setup it would basically be a waste of money. An upgrade to the most crutial part of an engine and no mo power
"I also assumed you would have small tube headers and mufflers, a 9.0:1 compression ratio, and a hydraulic flat tappet cam and lifters. "
All true but with old heads I would have 8.5:1 new heads I would have 9.0:1 guessing of course.
The reason I went with the smaller cam is because I have a TH350 auto trans and a stock stall converter. I didnt want too much cam to kill my low end torque. What cam could I run to take advantage of the heads while still retaining low end torque? How is my intake, is there one that would be more suited for my setup?
BTW the car is a 79 vette with 3.55:1 rear end ratio and 3600lbs I think.
So with the heads and the "right cam" what #'s will I be making?

 

Them heads HAVE to make more power, it just doesn't make sense. It is going from a 170cc intake runn to 200cc and 1.94/1.50 valves to 2.02/1.6 valves. They just have to make more power I would think. The heads were pretty much the most restictive part of the engine. I cant imagine the cam could be responsible killing any gains from the head swap. Oh well... if so what the hell do I have to do to make it work. What cam should I go with? Still want good low end and mid range.

 

cam
I have been looking at some CAM profiles. Some street/strip ones that offer good mid range are not too far off what mine is as far as lift, lobe seperation, and duration.
The only thing I noticed is that my cam favors the exhaust a bit more, which is fine for the use of nitrous but I'm not on the bottle all that often. What if I went to a 1.6 rocker on the intake? What would my max lift be? Would it help me out? Both cams have 112 lobe seperation
Thanks for all the input.

Example: Crower Cam
Specifications:
* Advertised duration: 286 intake/289 exhaust
* Duration at .050 in. cam lift: 225 intake/230 exhaust
* Gross valve lift: .454 in. intake/.463 in. exhaust
* Lobe separation: 112 degrees
* Power range for level 3 cam: 1,600 to 4,800 rpm
* Power range for level 4 cam: 2,000 to 6,200 rpm
* Recommended compression ratio: 9.5:1 to 11.5:1

Description:
Hot cams from Crower

Chevrolet: 262-400, (except 265) 286/289 advertised duration, Compu-Pro 284HDP, hydraulic, camshaft

Designed as a level 3 cam for 400 engines, this cam is intended for the Hot Street application. This cam offers an extended rpm range with emphasis on the mid-range. Performance rear-end gears, headers, dual exhaust, large cfm carburetor, and performance intake manifold are required.

This cam is also designed as a level 4 cam for 302 and 327 engines and is best suited for Hot Street or Drag Strip situations. This cam exhibits strong mid-range and top-end torque and horsepower. Modifications need to include low rear-end gears, headers, dual exhaust, large cfm carburetor, performance ignition, and increased compression ratio of 11:1.

 

it tends to minmize the hp. Make sure you have the most current flow numbers. Exhausts on the first gen WP heads sucked.

 

How about Dart "Iron Eagle" heads with the same specs?

 

They are World products Sportsman II heads. The "II" i'd assume means second generation. I would be ordering these heads new from Summit, Jegs, ect.

 

here is all the flow data I could find. It only has flow @ .400 lift

World Products Sportsman II Iron
: : Port:201cc
: : Chamber:72cc
: : Valves:2.02/1.60
: : flow@.400 225cfm

Damn Vortec's flow more!

: GM Vortec Iron
: : Chamber:170cc
: : Chamber:64cc
: : Valves:1.94/1.50
: : flow@.400 227cfm

Here is where I got the data. The vortec hold up suprisingly well! They compaire several heads at this site. I was kicking around getting a set of those but was told Darts or Sportsmans would be better. I guess it only shows data @ .400 lift so were not seeing the whole picture. That could explain some things.

http://www.hotrodheaven.com/comments/messages/7303.html

I know the limitations with the Vortecs but with my cam I dont think lift will be a problem. Also any idea what my lift will be with a 1.6 rocker on the intake?
Sorry for all the long a$$ posts

 

This is getting rediculous! Dont mind me, I'm just trying to break a record for the most post in one day! :lala:
Just wanted to post another site with better flow data

http://users.erols.com/srweiss/tablehdc.htm

 

First off I had:

Stock TPI, 355 L98, stock crank and rods, fordged pistons, gear drive, Sportsman II heads, stage 3 shift kit, vigilante converter, edelbrock 1 5/8 headers.

1.88 60' and a 14.2 1/4 mile


I then switched to a single plane fuel injected intake, and 1 3/4 headers and I know run...

1.89 60' and a 13.2 1/4 mile.

And this was with no tuning on the motor and a problem with the Oxygen sensor and ram air.


Make your own decision on how you want to do it..

 

The best advice I could give you is to set aside the engine ideas for a while and get a higher stall torque converter. If you went from stock to, say, 2300 rpm you will shave maybe as much as 4/10 second from the ET. And the car will still be very well mannered for a daily driver.

It just seems like a better expenditure of your money until you hash through the engine design.

 

I think I see what the issue may be.

462 heads are not "smog heads" and run pretty well for hotrodders.

882's are large chamber smog heads.

Changing from 882's (76cc??) to 72cc large intake runner heads, should wake the HP up in the engine.

 

The difficulty with the Sportsman II heads is that they are meant for high revving engines. With such hogged out runners you are not going to get much low rpm torque. They are an all out street head or a racing head. They aren't really meant for a daily driver/medium street car.

 

I think I have the 462 casting on the motor right now (would need to varify) and I have the 882's in the shed that I could throw on.
What promped this whole debate for me was a artical in carcraft which compaired the 462, 882, Vortec (96 and up), and Bow Tie II heads. It was showing how the Vortecs are a good budget head for street applications. The 462's were the worst and the 882's were close to the vortecs. The vortecs even beat the BowTie II's.
So this got me thinking about swapping the heads because I think im running the 462. I could port and polish the 882 and have them on for really cheap but would it be worth it. I was told to get the aftermarket heads to make it worth my while but is that true with my setup?
Todd Sauve sent me a dyno program (thanks) and with higher flowing heads it didnt give me much more power but it did push my power band higer into the rpm range without killing my low end torque.
I am going to get that magazine artical and punch the acutal #'s in from this test and see what I come up with. I will also try some different cam combos. I'll post the flow #'s for everyone just incase other are courious.
Thanks again for everyones help!

 

hey sitting bull is how large is the desktop dyno program?

 

Sitting Bull, would you be willing to trade DD2000 for some other software you might need? I have been wanting to check out that software for some time now. Let me know if your interested and what software you need.

 

Agreed. I run those heads. When I installed them, I expected massive gains. Didn't happen. After a little investigation, I came to the conclusion that they were a mismatch with the rest of the motor. The cam was too mild and I needed more fuel. I'm in the process of rebuilding the motor to match the heads. DD2K is showing 470hp/470tq for the new combo.

 

I disagree....

I was pulling 1.8 60 foot's with these heads and a TPI intake.

Nothing about a high revving motor...

That was all torque....

Then I switched the intake and headers to use "more" o fthe heads and still pull a 1.8 60 foot.

Torque was still there, I just woke up more of the horsepower.

I

 

Well... Is it worth swithching to the 882's then? I already have them and I think it will push out my useable rmp range. I would port and polish them and maybe mill them a touch to bump up the compression. Attached is the 462/882 comparison without estimating any port and polishing and increase in compression from milling. Interestingly if I retard my cam timing it streches out my rmp range too without too much sacrifice to low end. All my lowend losses can be made up for with the nitrous I am going to try to attach a screen print

 

lets try again

 

OK, but tell us what engine and parts you are using, along with tranny, torque converter, rear gears, etc. I'll bet that tells the story of why it is working for you.

 

It all depends on the combo and the gains you're looking for. With ported L98 heads I was turning 12.96 on the motor. When I installed the Sportsman IIs I lost 2 tenths. I have nothing against the heads, I'm still using them. I just think that the 200cc runners are too much for a relatively mild 350. This year they'll be on top of a 10.5:1 383 with a 530/550 Isky cam. That should actually be able to use the heads.

You're running them on a TPI motor. That's all torque anyway. Even if you lost a little, you wouldn't know it. I'm running a carb conversion from TPI. I noticed a loss of torque, and a huge pull from 4000 to 6500.

edit. Here's an accurate flow table for DD2k. http://www.fbody.com/members/Formula91/SporsmanII.flw
Right-click save-as...

 

I took off the TPI and put on a single plane fuel injected intake setup.

I stayed the same 60' so there was no loss of torque from the intake switch and gained a second in the 1/4 mile which means I better utilized the horse power with the new intake setup.

And I agree there are better heads and better things you can do with a head setup and it does help if you match everything up.

I personally will be going to AFR cylinder heads as soon as I get the money saved up.

I justed wanted to comment on my experience with the Sportman II's.