Starting 408 build - thoughts or suggestions?

[Texasdoc]

Any recommendations or comments on intakes for a 408? I would like to keep it street drivable without having to keep it above 4000k to get any power. I understand that the stroker kit will give me more power down low. But I'm not sure what else to look for.

The cam I'm considering is:
Hydraulic roller
Advertised Duration: 280/288
Duration at 050: 228/236
Lift: .565/.565
LSA/ICL: 112/106

I can barely squeeze the Airgap under my hood but have to use a 1inch tall 11 inch diameter air cleaner. I'm not sure if that is enough flow for the 408. So I am considering going with a different (shorter) intake. Performer RPM, Weiand Stealth? The Vic Jr is a single plane which I've heard are less tolerant on the street.

Any comments?

[Dimis]

Originally Posted by Texasdoc

The Vic Jr is a single plane which I've heard are less tolerant on the street.

Any comments?

Brent would know best, but with the extra cubes and a light car, I take with a grain of salt the perceived negative effects of a single plane on the street.
Particularly if your rear end is on the taller side.

Sounds like your going to have a fun project on hand.

Enjoy,

[blykins]

Originally Posted by Texasdoc

Any recommendations or comments on intakes for a 408? I would like to keep it street drivable without having to keep it above 4000k to get any power. I understand that the stroker kit will give me more power down low. But I'm not sure what else to look for.

The cam I'm considering is:
Hydraulic roller
Advertised Duration: 280/288
Duration at 050: 228/236
Lift: .565/.565
LSA/ICL: 112/106

I can barely squeeze the Airgap under my hood but have to use a 1inch tall 11 inch diameter air cleaner. I'm not sure if that is enough flow for the 408. So I am considering going with a different (shorter) intake. Performer RPM, Weiand Stealth? The Vic Jr is a single plane which I've heard are less tolerant on the street.

Any comments?

Didn't I recommend a cam for you? Unless you want a pickup truck hp and torque curve, the duration is too short on that cam, and I would run more lift.

Rpm air gap or victor jr either one would work just fine.

[Texasdoc]

Originally Posted by blykins

Unless you want a pickup truck hp and torque curve,

I don't even know what that means...

Thanks, tho. I talked to a few builders and custom cam manufacturers. They thought this cam would make the engine a little more street friendly. I can always change it later if needed. I'll go with the AirGap since I know it fits.

I'll call you when I'm ready for the AFR heads. It will likely be a few months.

[blykins]

Originally Posted by Texasdoc

I don't even know what that means...

Thanks, tho. I talked to a few builders and custom cam manufacturers. They thought this cam would make the engine a little more street friendly. I can always change it later if needed. I'll go with the AirGap since I know it fits.

I'll call you when I'm ready for the AFR heads. It will likely be a few months.

It means that the engine would be more suitable for a truck with that cam.

You can not read or listen to the advice that a cam manufacturer gives you about a camshaft. I promise that I've built more 408 Windsors than any cam hotline operator.

I'm sorry for sounding a little crass, but I'm coming off of a weekend blessed with a stomach virus, so I'm not in the best of moods.

Anyway, I've built a whole lot of 408's, from pickup truck engines to race engines. The cam that you picked is way short on duration, and will probably peak somewhere around 4800-5000 rpm.

If that's what you want, then that's great, but IMO a performance engine should not be that short winded (but does not have to be radical either).

The last 408W that I did used a set of Trick Flow 11R heads, a Victor Jr. intake and a cam with about 12° more duration. It peaked at 5600 rpm, had a very flat torque curve, but still sounded and performed nicely, making about 510 hp.

I also built a 408W using a similar cam to the one you picked, for a guy's pickup truck that he was using to tow a car hauler. It peaked at about 4800 and made about 390 hp.

The biggest mistake that people make when searching for cams is that they read the description under the cam specs, "Power range from x rpm to x rpm". That may be true, but it's only true for one specific engine size, and it's usually the smallest size in the engine family. What they don't tell you is that a 408 needs a LOT more cam than a 351, and that even changes depending on the cylinder head and other parts of the build.

[Mark O'Neal]

Originally Posted by Texasdoc

I don't even know what that means...

Thanks, tho. I talked to a few builders and custom cam manufacturers. They thought this cam would make the engine a little more street friendly. I can always change it later if needed. I'll go with the AirGap since I know it fits.

I'll call you when I'm ready for the AFR heads. It will likely be a few months.

You can use more duration with that 112 lobe separation and not sacrifice driveability. Something in the 235/245 range would be about right.


Also, that manifold will give you a better average horsepower, but you will sacrifice peak horsepower.

The last Engine Masters we did with a 408 we got 635 average with a dual plane, and 690 with a single plane. But, since we were racing dynos, after all......