351W Game Plan

[Guest]

[joerberg]

I'm going to build a 351W to mate with a four speed and go into a '67 Fairlane. It won't be a stroker - 351 cubes.

Heads - RHS Pro Action with 64 cc chambers and 180 cc runners
Block - Stock
Lifters - hydraulic roller
Cam - Ford Performance B303
Intake - Edelbrock Performer Air Gap with Edelbrock 800 cfm carb
Rockers - roller - make undetermined
Pistons - Undetermined but looking to keep compression ratio under 10:1

I'm open to thoughts on this combination and estimates of how much hp it's going to make. I'm concerned that the 800 cfm carb may be too much for this engine.

[juiced coupe]

Unless you already own the heads, cam, and carb, I'd consider other options.

Since you haven't bought pistons yet, I'd strongly consider using Trick Flow Twisted Wedge heads. Even the standard 170 cc head would be plenty. Don't let the "170" cc fool you, they are one of the best heads available in that size area.

The cam, a B303? On a Windsor, seriously? Regardless of head choice, there are better cam options available. Hell, a custom billet roller can be had for under $400. I know that sounds like a lot compared to a $200 cam, but its worth every penny.

I don't care for Edelbrock carbs. The size wouldn't bother me, I just think that they are garbage. Since you are using a manual transmission, I'd put a Holley 750 Double Pumper (not a dual line, vacuum secondary!) it.

[joerberg]

Coupe,

I had read some articles about the Ford "Alphabet Cams" and also read where a lot of people recommended them for SBF applications. Weren't they designed for the SBF?  Exactly what is it in the specifications for this cam that you dislike and what numbers would you like to see?  What do you folks think about 61cc Trick Flow Twisted Wedge heads with 170cc runners?  I'd like to keep the CR under 10:1 so I'd need a 12 cc dished piston for these heads.

[347HO]

I know you will be very satisfied with a cam "ground" specifically to match your engine, transmission combination and application.  You only have to be truthful when giving the specs of your entire car and application.

I have quite a collection of cylinder heads...
The TFS brands consistently required less work to optimize and work very well right out of the box.

My RHS pro action 215's gave me the most drama and head ache.

The more exotic stuff (Yates c3 and other cant valve family...) needed way more attention to detail per application.

I personally haven't heard someone complain, running a single plain intake on their street car/truck (well matched and tuned) yet.

Good luck with your project!

[juiced coupe]

Weren't they designed for the SBF?  Exactly what is it in the specifications for this cam that you dislike and what numbers would you like to see?

No. Actually, it is a very old generic grind from Crane. On top of that, it is ground on a very cheap core.

I've had a couple of them. I would only recommend them for lift limited applications. And even then, it would be more of a "maybe".

[69 Merc]

I know you will be very satisfied with a cam "ground" specifically to match your engine, transmission combination and application.  You only have to be truthful when giving the specs of your entire car and application.

I personally haven't heard someone complain, running a single plain intake on their street car/truck (well matched and tuned) yet.

Good luck with your project!

            

[joerberg]

I'd like the car to have decent street manners while making a good amount of hp from the low to mid range.  I want a good sounding idle but not so rough it barely stays running.  So, can someone tell me what it is about this cam that's wrong and what specs I should be looking for?

How are the single plane intakes for low to mid range power?  I thought they were more for high end power?  Also, I researched the Trick Flow heads and will probably go with them.

[juiced coupe]

So, can someone tell me what it is about this cam that's wrong and what specs I should be looking for?

Whats wrong with it? The grind is ancient. The lobes are very soft. It is a single pattern. Its ground on a cheap core.

I'd be looking for something in the upper 220° (@ 0.050") on the intake, mid 230° on the exhaust, lift in the. 570-.600 area, and a 108-110°LS. But thats just me guessing.

Any decent shelf cam will be $275-340. Custom SADI cams run ~$340 and custom billet cams are $380-390.

With the custom, they will take all aspects of your engine, car, and expectations into account when setting the events.

How are the single plane intakes for low to mid range power?  I thought they were more for high end power?

With a correctly designed cam, they can be successfully used on lower rpm engines and still maintain good upper rpm power.

Buy for a true street car, I'd stick with the Air-Gap. For a all around car, its hard to beat.

[joerberg]

Thank you.  That's helpful information.

[z-adamson]

Buy for a true street car, I'd stick with the Air-Gap. For a all around car, its hard to beat.

My 347 came with an air gap and I swapped it out quickly.

I found that a hot manifold was much better for a "true street" application. MPG, driveability when cold etc. improved greatly with a hot intake manifold.

[juiced coupe]

Buy for a true street car, I'd stick with the Air-Gap. For a all around car, its hard to beat.

My 347 came with an air gap and I swapped it out quickly.

I found that a hot manifold was much better for a "true street" application. MPG, driveability when cold etc. improved greatly with a hot intake manifold.

By "true street", I was referring to a car that is more street than strip. I wasn't referring to anything remotely close to a daily driver. I based that on this:

I'd like the car to have decent street manners while making a good amount of hp from the low to mid range.  I want a good sounding idle but not so rough it barely stays running.

In your case, I think your choice better suited its intended purpose. But IMHO, your van has very little in common with a choppy idleing, four speed muscle car.

In his case, I believe that the advantages that the Air-Gap off over a standard RPM are worth its minor inconveniences. Unlike the 302 version, the 351 Air-Gap offers a good bit more performance potential compared to the standard version.

[joerberg]

Looking at intake manifolds brings up some questions.  There's really not much for specs on these things other than an rpm range.  Right now I'm thinking of getting an Edelbrock 7521 Performer RPM Air Gap for my 351W build.  This is based on recommendations and not evaluating any data or specs.  So other than experience and advice how do you shop for an intake to insure it's a proper application? 

[knucklefux]

it's all about the combo, and choosing parts that will work well together.  an air gap will work pretty good on a mild 351, but will hamstring a 400+ inch stroker.  would a vic jr be a little better at higher rpm?  certainly.  but with the rest of the parts you're choosing (mainly the heads) you'd have more to lose going to a vic jr.

now, if you were going with 225cc+ high ports (or other higher performance heads) you'd be crazy to use an air gap and even a vic jr might be a bad choice.   

when figuring these things out it's best practice to either take the advice of an engine builder that you trust, or find someone who has already met the performance goals that you're after and mimic their build.

[juiced coupe]

it's all about the combo, and choosing parts that will work well together. 

This.

The arbitrary rpm ratings assigned to many performance parts are nearly useless.

So other than experience and advice how do you shop for an intake to insure it's a proper application? 

Experience definitely helps, and evaluating the intended application. But I'll lay out what I see.

You said that you wanted decent street manners and a good (but not radical) idle. Its going into a smaller sized muscle car with a  four speed, with I'd assume gearing in the 3.50:1 area. Based on this, I'd assume that this will be a "fair weather" and not something that will often see your daily commute.

So, my reasons for choosing the Air-Gap are:

While the standard RPM fits all the criteria of this, it ultimately gives up top end power to the Air-Gap. And while you want the low/mid range power, I seriously doubt that you want to just give up top end power.

The only advantage that the standard RPM might have is on cold startup. The design of the intake will get heat into it quicker, promoting fuel vaporization. Meaning, the cold idle will settle out a little quicker. After the engine is up to temperature, the intake design is just pumping extra heat into the incoming charge. This could also make heat soaking the carb more likely during warmer weather or extended cruising.

The Victor Jr can be made to work decently well for this application, I just don't see the justification. A properly designed cam could offset the low end losses, but I doubt that this engine will ever see enough rpm to take advantage of the VJ.

[joerberg]

Juiced, you're right, this will be a "Fair Weather" driver.  I doubt I'll put more than 2,000 miles per year on it and never in the winter.  Also, while high rpm power isn't my major concern it'll certainly see some high rpm's.  And I was thinking around 3.5:1 gears. 

I appreciate the advice from both you guys but that's my point  As a newbie I have to depend on advice from veterans like you guys because I can't find any data or meaningful specs on intakes.  I'm a retired engineer and I'm used to looking at numbers to help make decisions.  I've got a chance to get an Edelbrock 75214 for a good price and based on your responses I think I'll get it. 

I'm going to hold off on a cam selection until I've nailed down the information on the rest of the car and then have one ground for me.  A number of people have recommended that and it's not really that expensive.

Thanks.