How do think this cam will behave in 408 ?

[mbaird]

My block is in the shop getting a 4” assembly and I am curious as to how the 4” stroke will change its performance characteristics. In my 360 it had a bit of a lopey idle and great midrange. Not so much on the high end but I think that was due to valvetrain issues . Compression will be around 9.9 and I want to use a factory lock up TC (2500ish stall) that came with the 46 rh that is going in the car 3.55 rear gears

Heads are IMM ported EQs and intake is an Airgap RPM . 1 5/8 Dougs headers .
Plan is to have a really strong street driver .

 

[Kern Dog]

That is a very mild cam for 408 cubes.
The MP crate 360 380HP mill used a cam with over .500 lift....You're less than that with 48 more inches to feed. This will really limit high rpm HP and make the engine run out of breath by 5000 rpms.

 

[496 polara]

Looks like you advanced it more for the 360. I wouldn't do that with the 408. It should be responsive as hell and have truckloads of torque with decent HP for the cam size. You have it so run it. 10 more degrees of duration would make it another animal and still be plenty street able.

 

[mbaird]

That is a very mild cam for 408 cubes.
The MP crate 360 380HP mill used a cam with over .500 lift....You're less than that with 48 more inches to feed. This will really limit high rpm HP and make the engine run out of breath by 5000 rpms.

I have 1.7 HS rockers . Lift is around .550+

 

[PRH]

Looks good to me.

 

[Kern Dog]

Well, it sure will make some torque.

 

[fishmens67]

Perfect for a sweet driver, toned down just enough with the added stroke and put the power in the lower RPM.

 

[RustyRatRod]

That's really very mild for a 4" stroke motor. It oughtta run like a cheetah on cocaine down low.

 

[mbaird]

It would boil my little 215/70-14 Michelins with 2.76 gears behind the 360 . Now with 3.55s , a 46rh I think it will be stout ! I have set of 15x7” steeliies being powder coated that I will put some bigger tires on .
Carb is an AVS 800

 

[AJ/FormS]

I ran a cam very much like that 223/230/110@.050 in my 11.3 Scr 367.
Of the three cams she has run, that one is still my favorite.
I ran it straight up, because at 11.3 Scr, she already had 195psi CCP
I ran mine with a clutch and 3.55s....... usually, but she handled any gears.
You'll be fine with a 2500TC.
But, IDK how she'll like 65=1890 rpm in overdrive. (I ended up at 75=1850) , so with the right tune, you should be fine.

 

[Bewy]

Should have a near smooth idle.

 

[harrisonm]

I would personally use a bigger cam. Even with 1.7 rockers, that is a pretty mild cam for a 408. I look at it this way. Why go to the extra expense of building a 408 if you plan to put a fairly mild cam in it. I am not suggesting that you put a huge cam in it that would shake your fenders, but again, why build a 408 that will be milder than it could be?

 

[mbaird]

I would personally use a bigger cam. Even with 1.7 rockers, that is a pretty mild cam for a 408. I look at it this way. Why go to the extra expense of building a 408 if you plan to put a fairly mild cam in it. I am not suggesting that you put a huge cam in it that would shake your fenders, but again, why build a 408 that will be milder than it could be?

I have my 4sp Swinger with a 408 ,ported W2s and a solid roller for a ripper . Just looking for a mild mannered driver with a butt load of torque in the Barracuda.

 

[mbaird]

I ran a cam very much like that 223/230/110@.050 in my 11.3 Scr 367.
Of the three cams she has run, that one is still my favorite.
I ran it straight up, because at 11.3 Scr, she already had 195psi CCP
I ran mine with a clutch and 3.55s....... usually, but she handled any gears.
You'll be fine with a 2500TC.
But, IDK how she'll like 65=1890 rpm in overdrive. (I ended up at 75=1850) , so with the right tune, you should be fine.

I have a few sets of 3.91s if the 3.55s don’t like the cruise rpms.

 

[Demonx2]

I have my 4sp Swinger with a 408 ,ported W2s and a solid roller for a ripper . Just looking for a mild mannered driver with a butt load of torque in the Barracuda.

View attachment 1716403930

Well given this, you already know what a torque monster a 408 is. So this new one will be all the more a torque monster with that smallish cam. Strokers eat duration for breakfast! It will incinerate the tires but run out of breath early. For the street, that should be fine.

In the avatar's 408, it's a 251/255@ 050 and I'd tell you I would add 10 more degrees at 050 if I did it again. But it idles "appropriately" (rough!) and has a 5000 stall TC, probably not what you're wanting in this 2nd 408 of yours.

(BTW...BEAUTIFUL car!! )

 

[mbaird]

Well given this, you already know what a torque monster a 408 is. So this new one will be all the more a torque monster with that smallish cam. Strokers eat duration for breakfast! It will incinerate the tires but run out of breath early. For the street, that should be fine.

In the avatar's 408, it's a 251/255@ 050 and I'd tell you I would add 10 more degrees at 050 if I did it again. But it idles "appropriately" (rough!) and has a 5000 stall TC, probably not what you're wanting in this 2nd 408 of yours.

(BTW...BEAUTIFUL car!! )

Thanks ! The Dart has a 246/250 on a 108 with .648 lift . I can feel the pulses in 1st at lower rpms a little now ( more when towing my bike ! Lol ) and I do have a larger roller on the shelf but that would make the 4sp pretty jumpy off idle at prking lot speeds . Might throw it in to go racing just for fun but the car should run low 11s now and wouldn’t pass tech if I run mid 10s

 

[mopowers]

@mbaird - Is that cam a reground stock core? I'm curious what valve springs Oregon spec'd for that cam. I recently ended up going about a step larger for my 408 build (231/236, .544/.555 on a 110). When I called Oregon about a potential regrind, Ken said he wouldn't go past 110 lbs seat and 300 open valve spring pressures. That seemed soft for a performance cam, so I ended up going with a new SADI core vs a regrind just to be safe.

 

[TT5.9mag]

That cam in 408 inches will be a tire fryer.

 

[mbaird]

@mbaird - Is that cam a reground stock core? I'm curious what valve springs Oregon spec'd for that cam. I recently ended up going about a step larger for my 408 build (231/236, .544/.555 on a 110). When I called Oregon about a potential regrind, Ken said he wouldn't go past 110 lbs seat and 300 open valve spring pressures. That seemed soft for a performance cam, so I ended up going with a new SADI core vs a regrind just to be safe.

I don’t recall if he gave me a recommendation but Brian @ IMM told me the beehive springs he installed should work fine . Never measured the pressures.
I have had some issues with the engine cutting out over 5k though . I am assuming its valve train related .

 

[Demonx2]

Thanks ! The Dart has a 246/250 on a 108 with .648 lift . I can feel the pulses in 1st at lower rpms a little now ( more when towing my bike ! Lol ) and I do have a larger roller on the shelf but that would make the 4sp pretty jumpy off idle at prking lot speeds . Might throw it in to go racing just for fun but the car should run low 11s now and wouldn’t pass tech if I run mid 10s

Ported W2's should definitely put you into the 10's. I've got mild Eddie's and have gone 11.05 so your better heads and a bigger yet cam and BOOM...10 sec poster for sure!

 

[mbaird]

Ported W2's should definitely put you into the 10's. I've got mild Eddie's and have gone 11.05 so your better heads and a bigger yet cam and BOOM...10 sec poster for sure!

It Dynoed at 493 hp and 488 torque . But #7 cylinder afr was really whacko . Figured out later that I screwed the pooch adjusting valves and #7 was way loose . Im figuring 525 hp and 500 torques . Not sure that will get me into the 10s. W2s like lots of compression and lots of duration . Neither of which I have . I could install .029 Cometics and my bigger cam but that would make it tuff to street drive with the 4 speed.
And I have a 4.30 spool for racing .

 

[Demonx2]

I suspect your current power is higher than your estimates. Mine qualifies as a "tractor motor" as I generally shift and stripe it at 6200 rpm. I hesitate to say (and it's all I'll say as I look at the et slips instead) but my 408 was north of 500 #-ft. Your combo likely does better than mine hence my projection.

 

[harrisonm]

I have my 4sp Swinger with a 408 ,ported W2s and a solid roller for a ripper . Just looking for a mild mannered driver with a butt load of torque in the Barracuda.

View attachment 1716403930

Gotcha. It will have a buttload of torque!

 

[RustyRatRod]

It'll be fine. Look at all the large cube engines from the factory that had lesser cams.

 

[273]

It'll be fine. Look at all the large cube engines from the factory that had lesser cams.

100%

The factory wasn't generally looking to use rpm to gain, so they added around 20 ish cid at a time to gain the next step in performance.