Swaping out intake manifold

[cobras]

Hi Guys im looking at swaping out my intake manifold on my 351W stroker 392 ford motorsport crate engine, its the 475HP Z head motor with the intake that comes with it, i think its a vic jr,

anyhow the reason im doing the swap is to have a polished or the durashine finnish that edelbrock has, now from the experience you all have here what would be the manifold to get

i wont be doing any 1/4 mile racing and would like to have an increase in hp due to the manifold swap if its possible, so i guess you can say im looking for low end power off the line sort of thing, i was on edelbrocks web site and there are like 5 manifolds, and i have no idea what would be the prime manifold for my motor


any insight on this would be great

[Pete Munroe]

You really need to post all the specs on the engine, but the Edelbrock Jr. is not a restrictive manifold.

Do you want more HP or TORQUE? What are you going to do with the engine...street?...track?...you did say no drags, so I am guessing you want
TORQUE... which would be the Edelbrock Performer RPM dual plane manifold...not the Victor Jr.

I would guess that whether or not the machine work is up to snuff, the parts choices for your crate engine are reasonably compatible...if you want more horsepower and less street friendly manners...change out cams, heads, compression ratio and maybe the Victor is the next step...if you go to the Edelbrock website they have the RPM range for all the manifolds...the Vic Jr. supports a pretty stout cam, heads etc and that combo should work.

If you stay with the Jr. make sure it has been port matched but beyond that you need to know rpm range and other mods required.

Cobra cars are so light, that you can get away with a power band skewed to the top end, but it won't be as driveable in traffic.

I am sure there will be more opinoins on this !

From what you said, I do not think you want MORE HORSE POWER, you want more street-able TORQUE to be fun on the street.

Originally Posted by cobras

Hi Guys im looking at swaping out my intake manifold on my 351W stroker 392 ford motorsport crate engine, its the 475HP Z head motor with the intake that comes with it, i think its a vic jr,

anyhow the reason im doing the swap is to have a polished or the durashine finnish that edelbrock has, now from the experience you all have here what would be the manifold to get

i wont be doing any 1/4 mile racing and would like to have an increase in hp due to the manifold swap if its possible, so i guess you can say im looking for low end power off the line sort of thing, i was on edelbrocks web site and there are like 5 manifolds, and i have no idea what would be the prime manifold for my motor


any insight on this would be great

[cobras]

thanks for the reply

"so I am guessing you want
TORQUE... which would be the Edelbrock Performer RPM dual plane manifold...not the Victor Jr."

so would this manifold give me a loss in hp #s from what i have now, what are the diffrences in a dual plane or a single plane

i would have to say yes to the torque, i dont plan on making any new speed records, i just want it to pull hard off the line and have a good strong pull up through the gears, but also dont want to loose too much HP in doing so


here are the specs from the ford web site



392 cubic inch

475 hp @ 5600 rpm (with headers, and a 750 CFM Holley carburetor not included)

495 lb.-ft. @ 4400 rpm

10:1 compression ratio (nominal)

Forged pistons

Forged steel cap screw connecting rods

Hydraulic roller camshaft, .580" lift intake and .602" lift exhaust, duration at .050" is 232 degrees intake and 240 degrees exhaust

Double roller timing chain set M-6268-A302

Forged steel crankshaft

High-performance T-sump oil pan

MSD billet distributor

Ford Racing aluminum "Z" cylinder heads M-6049-Z304DA with 2.02" intake valves and 1.60" exhaust valves

Roller rocker arms M-6564-F351

Single plane “Victor Jr.” intake manifold M-9424-V351

New heavy-duty 5.8L “Sportsman ” block, oil and water pumps, performance oil pan, steel billet flywheel and high-performance harmonic balancer

[Pete Munroe]

We always have fun changing stuff to be exactly what we want, but for me there is a point of diminshing returns.

There is not much you can do to an engine, beyond spark plugs!...that is easier than swapping out, or replacing gaskets on a intake manifold.

Drive the thing for a year or so...figure out for yourself it it too peaky or undriveable...

Leave the frick'en thing as it is and spend your time/money somewhere else...late on, if it is so important, change it out.

A Cobra is so light that the Vic Jr. manifold on the street is probably of not much consequence...so leave it alone and next year change it out if you need more of something...you are not sure which way you want to go...leave it alone...you can change it in an afternoon...

Have fun by not being obsessive about the way it "looks" or to get performance you can't describe or specify.

Not meant to be critical, just take the easy route...a manifold is an afternoon and another $150 ...for what?

Have fun and drive the car for a season or two.

Pete

[dlang14]

Originally Posted by cobras

"so I am guessing you want
TORQUE... which would be the Edelbrock Performer RPM dual plane manifold...not the Victor Jr."

so would this manifold give me a loss in hp #s from what i have now, what are the diffrences in a dual plane or a single plane

i would have to say yes to the torque, i dont plan on making any new speed records, i just want it to pull hard off the line and have a good strong pull up through the gears, but also dont want to loose too much HP in doing so

Sounds like Performer RPM or Air Gap RPM would be the way to go. On my Roush 427R motor (351w) I went with the Performer RPM over the Victor Jr. Roush didnt have dyno numbers on the air-gap so that was harder to compare and I didnt look at it closely

It is true that the performer RPM will lose peak horsepower compared to the victor jr, but at lower RPM bands it makes more horse and torque. If I remember the cut over on the Roush dyno sheets was at 4800rpms, and if you compared the average from 3K-6K the performer RPM made better average hp and tq. These numbers will be different on your motor but it should still give you a relevant data point. Good luck and have fun!

[Three Peaks]

The Vic Jr. Manifold is a single plane design, more suited to high rpm running and lousy at low end performance and probably has lousy street manners.

A good dual plane manifold like the Air Gap, Weiand Stealth, or one of the cheaper copies will give you more low end with a slight drop off at the higher rpm's you're probably not getting into anyway.

I don't know if the Weiand Stealth is available from the factory this way, but I bought a used one with the Endurashine finish on it and it is really nice.

Bob

[cobras]

thanks for the replys,

[cobras]

thanks for the replys,

pete.. i know what yr saying about drive the car and enjoy it, its just the intake looks a little shi*y with all other parts being polished or chromed, and as you say an afternoon of work and some new gaskets, its not such a big deal to do it

three peaks... so does this endurashine look good compared to a polished piece?


i just figured for the amount of time and what it costs to buy and replace the manifold with a polished / endurashine one it will make the engine look a 100 times better, i guess ill look into the dual plane air gap.


anyone else have any insight on this

[zrayr]

you might also want to consider the Cobra Hi Rise dual plane manifold. Blue Thunder makes a good reproduction that flows better than the original. Again, as stated above, you won't be needing the maximum HP manifold, and the Cobra Hi Rise has a good balance between torque & HP.

Z. Ray

[Three Peaks]

Mine looks better than polishing, I think. It's actually a ceramic coating like sidepipes get and looks about the same.

Bob

[Frank Messina]

Sorry if this is a little late but that is a terrific combination just as it sits. Putting a dual plane anything on it will just kill it and when it's all said and done you'll be kicking yourself for messing it up. What trans and rear end gear ratio do you have? You may want to look at a gear change instead to let the engine get up into the torque band a little sooner, although with max torque happening at 4400 RPMs you should be getting a strong pull from about 2200RPMs.
Frank

[terry lee]

__________________

'66 GT-350
Original Drivetrain, Sheet-Metal, Interior, & Paint

Z.Ray,

That looks like my old '66 GT 350,
Do you have any records on the previous owners? Mine was bought in Milw., Wisconsin from Northwestern Ford in Oct. 1966. I sold it in 1970, and it went to NC. Lost track of it after that.

TL