416 with Comp Cams XE275HL Hydraulic stick

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67FormulaS_273HiPo_4spd

67FormulaS_273HiPo_4spd

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I have a 340 / 416 I'm screwing together, with the following combo:

* Speedmaster heads that have had the once over by my machinist - valve job, bowl blend, checked guides, under-cut intake valves (flow peaks, intake 265cfm / exhaust 196cfm)
* Diamond dished forged piston (-21.5cc) zero decked
* 340 block punched out 0.030"
* 10.2:1 static compression with 63cc chamber heads
* Either an Edelbrock Victor 340 or MP M1 single plane intake (I have both)
* Holley HP 750cfm double pumper or Holley street-avenger 770cfm (I have both)
* Doug's 1-5/8" long tube headers
* A833 4-speed
* 8-3/4 sure-grip with 3.23 gears

This will never see the track, purely a street driven car (67 Barracuda fastback Formula S) pump gas only car. I want something that's hassle free that makes decent power (450HP / 480TQ) and can cruise long distance relatively well. To this end, I was thinking of using a Comp XE275HL hydraulic flat tappet cam, which will end up with dynamic compression of 8.27:1 and VP of 168 psi.

What do you guys think of this cam choice?

Cam specs below for reference:

CC 20-227-4
Duration @ 0.050" int 231 / exh 237
Lift int 0.525" / exh 0.525"
LSA 110
Intake centreline 106
IVC 63.5
 
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I like the cam, and have one on the shelf. I ended up going with a solid flat tappet a size or two larger for my current build but may use it in a 360 I have or the next 340. Your stroker could probably handle more duration but that should be a pretty nice combo on the street. The one caveat is the hydraulic lifters. I would have the machinist check every one for proper grinding and visually verify that they all spin on the cam lobes in a mockup. Been a lot of motors ruined over the last decade or so, due to improper face grinding on the lifters of multiple brands. My builder had to re-face the Comp SFT lifters I gave him, so it extends to solids as well. Just crappy quality control both by the machining house and the companies putting their name on other people's work.
 
That series of cams make decent power, up to the limiting rpm of the valvetrain……. Which usually ends up being the lifters.
I wouldn’t count on it going much higher than 6k, and if the lifters have a high bleed rate, the springs are stiff, and if you use higher ratio rockers……. It may not even be clean to 6k.
But those issues are kind of true for any Hyd cam…….especially the fast rate stuff.
 
I’m weary of anything hydraulic flat tappet anymore, but even more so with hydraulic lifter quality control as of late. I didn’t see what rockers you were intending on using, but imagine adjustable valve train is in the works. As far as a stock solid lifter cam, this one would be a good choice for your street driver.
DODGE Howards Cams 712362-08 Howards Cams Mechanical Flat Tappet Camshafts | Summit Racing
For flat tappet use in a street car (with probably a lot of idling time), I would be inclined to use EDM direct oil lifters.
DODGE Howards Cams 91718 Howards Cams Direct Lube Extreme-Duty Mechanical Lifters | Summit Racing
Strokers tame down what would appear to be a long duration camshafts pretty handily, I would expect to see the rated power band of 3400 to 7400 shift down to the 2500 to 6500 range, and more likely even lower than that.
 
Thanks for the replies, quality control on flat tappet cams are a real concern, so is the stability of rocker gear at higher RPM.

I have a set of good used hydraulic lifters that I intend to get re-faced for use with that Comp XE275HL cam I'm thinking of using. I also have a nice set of 273 adjustable rockers with lock nuts on the adjusters. Obviously, I'll need to get some push-rods made to suit my needs.
 
Garrett Ellison said:
I’m weary of anything hydraulic flat tappet anymore, but even more so with hydraulic lifter quality control as of late. I didn’t see what rockers you were intending on using, but imagine adjustable valve train is in the works. As far as a stock solid lifter cam, this one would be a good choice for your street driver.
DODGE Howards Cams 712362-08 Howards Cams Mechanical Flat Tappet Camshafts | Summit Racing
For flat tappet use in a street car (with probably a lot of idling time), I would be inclined to use EDM direct oil lifters.
DODGE Howards Cams 91718 Howards Cams Direct Lube Extreme-Duty Mechanical Lifters | Summit Racing
Strokers tame down what would appear to be a long duration camshafts pretty handily, I would expect to see the rated power band of 3400 to 7400 shift down to the 2500 to 6500 range, and more likely even lower than that.
Click to expand...

Garrett, I don't mind the idea of a flat tappet solid stick, I have no issue with going over valve lash once a year.
That Howard's cam though, seems a little too aggressive for what I need.
 
l like that cam choice, and if you have a set of lifters you're confident in that much better. In my opinion your right at the point where the hydraulic cam is reaching its limitations because of the amount of spring that it takes to really control that Cam's velocity. The spring starts to work against the hydraulic mechanism but if you keep RPMs realistic 6200 ish top. I would be confident that cam will be very strong. I don't particularly like that gear ratio with that cam . A 3:55 or 391 would make that cam shine.
 
It still surprises me how much cam and carburetor even a 391 stroker can absorb in a heavy vehicle. In hindsight, that one in particular could have made use of the XE 275HL in place of the XE274H and something closer to 830 cfm than the 750 mighty demon. A higher lift solid with similar .050 but shorter advertised duration numbers would have really made it shine.
 
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Okay after reading the op I realize we're talking about a 416... I like everything about it more now it could take more cam but if you have a good clutch those 323s should match up well.
 
If you want to see something interesting, do a search here for "stroker cam upgrade." You'll find several users with some "large number cams" looking for more performance from a given combination.
 
Sounds like a good street combo.Only change I might would consider would be a dual plane intake with the 3.23 gears. Probably be a lot crisper down low and at part throttle for a STREET car. Depending on your stall speed as well.
Double pumper or vacuum secondary is like blondes or brunettes.They both work as long as you know how to tune them.
 
I built a similar engine over 10 years ago and bought the same Comp Cams cam. I decided to put in a Hughes hydraulic roller instead (228 @50) as recommended by Hughes. It was a great street engine. You could probably go a bit bigger.
 
496 polara said:
Sounds like a good street combo.Only change I might would consider would be a dual plane intake with the 3.23 gears. Probably be a lot crisper down low and at part throttle for a STREET car. Depending on your stall speed as well.
Double pumper or vacuum secondary is like blondes or brunettes.They both work as long as you know how to tune them.
Click to expand...

I agree 496, I had a RPM air-gap but ended up selling it. I think the Victor 340 will work, however an Eddy RPM air-gap would be the cat's-*** on the street.
 
I have the Comp XE268H in my stock displacement (with the exception of a 0.030 overbore) 340. It also has headers, an Eddy Air Gap and an Eddy Thunder series carb. It runs and sounds great. I am right at 375 HP, which is about 1.10 HP per cubic inch. With your extra 76 cubes, I think that cam would be an excellent choice. I'm going to assume that given the 416 displacement with at least 1.10 HP per cube you will be around at least 460HP, and probably more. That is a healthy cam. I am estimating 475 HP.
 
Just to add a bit of a curveball to the discussion, I have a MP 284 / 484 / 108 hydraulic stick in the stash.
Is this something that would work with my combo, or am I wasting my time?

I say this because way back in the day I had a '68 340 with cleaned up X heads, 9.5:1 comp, cast iron intake, Holley 750 vac sec, 1-5/8" long tube headers & MP 484 stick. This thing was in an Australian Charger (A Body) with a 727 & 2500rpm converter, with 3.23 geared rear. A real street hero, such a delight to drive. Great sound and pulled hard for what it was.

Only picture I have of this car

v.jpg
 
A cam that small combined with a single plane intake is not a good match of parts.

I do think it's a good cam for a street driver with the 416. It'll have a little bit of rumble but it will be mild sounding. Just depends on what you're after. If it's a car you're driving more than to cars in coffee, you don't want a hero cam anyway.

My 2c, run that cam in combination with a dual plane intake.

Make sure you get a converter (that actually flashes) in the neighborhood of 3000-3500. Run gears in the 355-373 range. It'll be a ripper.
 
I had a Bullet Racing solid mechanical camshaft in my
340/418" stroker. The duration @050 was around 248/250 with.530 lift. Lobe separation was iirc 108...I had a Victor 340 port matched intake, and a Demon 850 carb. Iron J heads fully ported, with Indy 1.5 roller rockers. It pulled HARD to 6500 all day long in my '72 Duster, and the idle was plain nasty. That cam may be a little much for what you are using your car for though.
Oh I used a 3500 stall converter, and 4.10's in the 8-3/4.
 
superstock64polara said:
Just to add a bit of a curveball to the discussion, I have a MP 284 / 484 / 108 hydraulic stick in the stash.
Is this something that would work with my combo, or am I wasting my time?
Click to expand...
I think that is too small of a cam for your stroker. It would work fine, but you would be giving up a lot of HP.
 
superstock64polara said:
CC 20-227-4
Duration @ 0.050" int 231 / exh 237
Lift int 0.525" / exh 0.525"
LSA 110
Intake centreline 106
IVC 63.5
Click to expand...
Looks pretty good to me mate, if you do run it use good quality lifters not cheap ones. It would be mild enough in a stroker.
If it did end up cranking at 165-170psi, and tuned properly you’d probably be able to run it on 95RON fuel.
 
A few guys have mentioned this might be a better all-round combo on the street with a dual plane intake manifold instead of the Victor 340, I intend to run. Just had a look in the stash of parts and found a nice port matched Weiand Stealth intake. I know that an Eddy RPM air-gap is probably a better choice, but what does everyone think of a Weiand Stealth for my combo?

wnd-8022_lj.jpg
 
The Weiand Stealth manifold would be great on the street. From memory, I think they’re a bit taller than an Eddy RPM? Or slightly longer runners??
 
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