What "Cam-Heads-Carb" for a street 393w?

Rustang351c · #1 (**permalink**) 10-15-2002, 06:05 AM

Hello,
I'm building a motor for "hot street", and will use a highway gear. I want to motor to have torque all the up, be very streetable, but still have as much top end as I can get. Also want to can the price as low as possible, so I'm going w/ a carb. This is what I've been considering:
PMEracing 393w kit (K.B.pistons,H rods, Scat Crank,$1075)
Edelbrock RPM cam 224/234 @.050 .496/.520 w/ 1.6's
or CompCam#12-246-3 230/236 @.050 .519/.523 w/ 1.6's
or CompCam#12-423-8 224/230 @.050 .535/.544 w/ 1.6's (roller cam)
World Windsor Sr. lites, AFR185's, EdelbrockRPM's or Victor Jr. heads
Edelbrock RPM airgap intake
Holley750 #3310 vac.sec.
Duraspark Ign. / 1 5/8" headers

Is this a matched set? The pistons are dished so the ratio should be @ 10:1 or so.

What "CAM-HEAD-CARB." combination would you use for a "Hot-Street" car?!?

Mr.Fixit · #2 (**permalink**) 10-15-2002, 05:20 PM

this one would be the one I would pick from your list: CompCam#12-423-8 224/230 @.050 .535/.544 w/ 1.6's (roller cam) assuming you have at least 10.25:1 compression
get the lightest pistons and the longest conrods that will fit without putting the wrist pin into the oil rings
I would get the edelbrock rpm heads over the vic jr heads(the vics kill bottom end)
but put a vic jr intake on there with a holley 780-850cfm doublepumper
Get an aluminum flywheel too, otherwise you will wish you had down the road.
These are loose guidlines, better you speak with a local machinest/engine builder who will put it together for you AND stand behind his work. There are a lot of little tricks on these motors, that cannot be fully gone into here.

Jack21 · #3 (**permalink**) 10-15-2002, 05:27 PM

PMERacing kit is good. KB pistons good for warm/hot street pump gas motor. If you're going to be top-ending it a lot, go forged. ARP hardware. FMS billet steel flywheel, and billet steel crank balancer.

Go with CompCams hydraulic roller. 224/230 is good for street, but make sure cam will retrofit early non-roller 351W block. These require smaller base circle lobes to use OEM Ford hydraulic roller lifters. Comp does have a 224/224 retrofit cam, but I like the 224/230 dual pattern better for use with mufflers.

Use the springs that Comp furnishes with the cam, not the springs that come with the heads. Send the springs off to have an oil retentive polymer coating applied before installation. Keeps them cooler, and they last longer.

Check the rocker arm geometry very carefully. You'll likely need a set of custom length pushrods for this.

CompCams makes ProMagnum chromemoly steel roller rocker arms, 1.6 ratio, 7/16" studs. Use these with ARP hardware for street use. Steel rocker arms for street engines.

Look at the AR 205 heads with 2.08/1.60 valves for stroker motors. You have 400 inches to feed, not 350. The AR 205's seem to be made for this, yet only raise the exhaust port 1/8", so your stock headers will fit. The TFS-R head is great, but need custom headers.

Ede performer RPM air gap is OK, but will take longer to warm up on the street. OK for where you live.

Use Holley 750 double pumper or Demon 750 double pumper. Folks are leaning towards Demons as a better, more tuneable carb. Either way, the carb will run too rich when you first bolt it on. Hydraulic rollers pull substantially more vacuum, and you'll have to lean the carb out. Don't put a Holley 3310 on this motor.

Go MSD with ignition chores, vacuum advance street distributor, 6A or 6AL box, and plug wires. If you buy a Duraspark now, you'll only be upgrading it to an MSD later. Come back and we'll tell you how to set it up.

Andy Dunn · #4 (**permalink**) 10-15-2002, 11:10 PM

Hey Rustang, here are a few 393 recipes to throw into the mix

400HP (FORD CRATE-ISH)
http://www.cobralads.com/dyno2000/rustang1.gif

HEADS ........Edelbrock Performer RPM
CAM...........Comp 12-246-3 aka XE274H
MANIFOLD......EdelbrockRPM or RPM Gap
CARB..........750 Holley Avenger

http://www.edelbrock.com/automotive/headford.html
http://www.compcams.com/information/...umber=12-246-3
http://www.edelbrock.com/automotive/man_ford_351w.html
http://www.holley.com/HiOctn/ProdLin...C/0-80670.html

500HP (HOT STREET)
http://www.cobralads.com/dyno2000/rustang2.gif

HEADS........AFR 185
CAM..........Crane 448031
MANIFOLD.....Edelbrock Victor Jr
CARB.........750 Holley Mechanical

http://www.airflowresearch.com/pages/185sbf_strp.htm
http://dab7.cranecams.com/SpecCard/D....asp?PN=448031
http://www.edelbrock.com/automotive/man_ford_351w.html
http://www.holley.com/HiOctn/ProdLin...0-80528-1.html

600HP (RADICAL STREET)
http://www.cobralads.com/dyno2000/rustang3.gif

HEADS........Edelbrock NEW VictorJr CNC
CAM..........Crane 448841
MANIFOLD.....Edelbrock SuperVictor
CARB.........950 Holley

http://www.edelbrock.com/automotive/raceheadford.html
http://dab7.cranecams.com/SpecCard/D....asp?PN=448841
http://www.edelbrock.com/automotive/man_ford_351w.html
http://www.holley.com/HiOctn/ProdLin...0-80496-1.html

550HP (CHILI PEPPER STREET)
http://www.cobralads.com/dyno2000/rustang4.gif

HEADS......Windosr Sr ported By TEA
CAM Comp...35-522-8 aka XE282HR
MANIFOLD...Edelbrock Victor Jr
CARB.......Holley 830 nascar

http://www.fordmuscle.com/archives/2...ow/index.shtml
http://www.compcams.com/information/...umber=35-522-8
http://www.edelbrock.com/automotive/man_ford_351w.html
http://www.holley.com/HiOctn/ProdLin...C/0-80785.html

Just some opinions to follow...take them with a bag of salt

Manifold
I would go with the dual plane RPM manifold with World Sr Lites, GT40, or AFR 165 heads. I would go up to the single plane VicJr with AFR185, VicJr heads, TEA ported World Srs, or AFR 185s.

Carb
vacuum vs mechanical
On a light over-powered cobras with a stick shift, I'd go mechanical secondaries

Carb
religious war edelbrock vs holley vs demon
I have a holley, but my next carb will be a demon. I have seen the dyno live in action, and although the carbs might make identical peak HP, the demon's makes a wider TQ curve. The dyno guys state the same thing and they said they have seen it 100 times. The shape of the bowl on Demons seems to flow the air more efficiently.
http://www.bgfuel.com/demoncarbs/demon_charts.htm

I think all the components you are looking at are great pieces and good mathces. To build an engine from your exact items above, I would go

CAM Comp Comp 12-246-3
HEADS AFR185
Edelbrock RPM Air Gap
Holley 750

I would then try to convince you

to go up from the air gap to the vic jr if you had the hood clearance, and I would try to talk you into the Speed Demon 750

Here are a couple 393 articles for your research
http://www.westechperformance.com/pa...s/75hpmag.html
http://www.trickflow.com/articles/st..._st_2_body.htm
http://www.trickflow.com/articles/st..._st_5_body.htm

hope this stuff was fun

Andy

Excaliber · #5 (**permalink**) 10-15-2002, 11:32 PM

I would say the MSD 6AL over the 6A. 6AL has the rev limiter and I have been known to "float" some valves. Hard to lift when someone is filling up your rear view mirror, lol.

Ernie

Rustang351c · #6 (**permalink**) 10-16-2002, 04:11 AM

Thanks for the info guys. That "Cobralads" site Andy linked to is especially interesting. Check it out. Thanks again.

mkcobra · #7 (**permalink**) 10-21-2002, 07:32 PM

this months issue of HotRod engines, has some very nice 393 stoker info. they used the Ford 392 stroker and got 452 HP and 455 torque on a crate Ford motor, check it out. if you want i will scan and send the mag section.

Jack21 · #8 (**permalink**) 10-21-2002, 08:18 PM

Ford shoots itself in the foot again!

They take a great short block, bolt on a pair of inferior heads (1.93I/1.54E valves) then overcompensate with too much cam for a street engine, and an intake (V. jr) that's essentially top end only. Then try to wow us with peak rather than overall powerband numbers.

You Dyno 2000 guys can try this at home. Buy the Ford 393 short block only. Use an 8 - 10 degree shorter hydraulic roller cam. (224I/234E) Bolt on a "decent" pair of heads from AR, TFS, Ede, etc., with 2.08/1.60 valves (AR 205's come to mind). Use an Ede Performer RPM, or Performer RPM Air Gap with a 750 Holley or Demon. Run the numbers side by side from 2000 - 6000 RPM paying particular attention to the torque curve(s).

It's your money, and your car. You decide. Just be an educated consumer, and don't let peak figures cloud your judgement.

Andy Dunn · #9 (**permalink**) 10-21-2002, 10:38 PM

I'd agree that the vic jr intake is probably not the best match for the stock heads on the ford crate. Certainly peak HP is only one piece of information to compare two engine, but it is a starting point. Here are some additional thoughts

1. Manifolds and RPM
I don't know who started this, but I see this relationship as more of an edelbrock marketing move. Heads are not sold for a specific RPM range and I think it is a little confusing when edelbrock sells manifolds this way. It perhaps an easy system for the public to grasp when really, manifolds "flow". They flow just like heads. I personally think a better approach to engine component selection is to match head flow data to manifold flow data. Too big of manifold on small heads and the engine is flat. Too small of manifold on big heads and you are making the engine breath through a swizzle stick.

2. Manifolds and Flow Data
Its hard to come by but can be found. Here are some sample numbers on edelbrock and Parker intakes....converting all to cfm 28 H2O and averaging the middle and end runners

Performer 200
Torquer 220
Vic Jr 260
Super Vic 320
Parker Funnel Web 305

the Performer RPM was not listed, I am going to take a wild guess and peg it at 210...right between Performer and Torquer

Data was collected from
http://www.jason.fletcher.net/tech/intakes/intakes.htm
http://www.fomoco.com.au/Funnelweb.htm
http://www.rfedd.bigstep.com/generic147.html

and so...if I were putting AFR 205s on an engine, and these peak flow 300 as low as .550 lift, well I sure as shootin would not want the Performer RPM intake since I am starving the heads for air. Likewise, if I was building an engine with AFR165 heads and a medium cam and these heads flow 248 at .550 lift, I would not pick a super vic or parker funnel web intake since that engine is going to be a dog at anything less than wide open throttle.

3. Dual Vs Single intake on a 393 w/ AFR 205s
Here is the chart with a Comp 276HR
http://www.cobralads.com/dyno2000/dual_single1.gif

Here is the area under the curve with the differences highlighted.
http://www.cobralads.com/dyno2000/dual_single5.gif

Green is where the single beats the dual and Yellow is dual beating the single. The single has more total area under the curve. The dual wins the 2000 - 3750 range and the single wins the 3750 - 6500 range. At this point I believe the intake choice is subjective to what a driver is personally looking for. Racing...I would want the green. Bragging rights...I would want the green. Daily driver...I'd probably choose the yellow.

Andy