408c cam spec advice

Hey Toby,

Welcome back, is this another build to keep you busy during long winter nights?

Have you touched base with Dan Jones? He has built a number of 408's that people are really happy with and probably give you a really good custom grind spec.

Julian

Hi Julian,
Yes another Pantera build, but now I'm in FL so the nights are not as long and the weather is much warmer.

I did email Dan a couple of times but I think he is quite busy on another project and haven't heard back from him in a while so I thought I would post to the forum.

What are the expectations for the engine & car's performance, use of the car, etc? Is drivability important, or is this all about an impressive dyno sheet?

Toby,

Congratulations on the move to warmer climes, I keep toying with the idea myself, made easier by having been laid off last October.

Here's a post from Dan on the specs for Mike Drew's 408C. I think most of the 408's Dan's built have been very similar, it seems to be a proven combination now.

http://pantera.infopop.cc/eve/...50045562/m/994102665


Julian

Hello George,

I am looking for a streetable engine. An impressive Dyno sheet is cool but not if you can't have fun driving around town. I drive the car to shows, take the wife to dinner, and plan some occasional track time.

Toby,

I replied last night, with links to some of Dan's 408 specs, but the post got stalled for review for some reason.

A keeper this time, that's good to hear!

Julian

Julian, I look forward to seeing some of Dans specs when the post shows up. Researching, I found lots of 408 cam specs but non with an IR EFI setup.

Ah, I'm not sure how many would be an IR EFI setup.

Did you move the business to FL or retire?

Sold the company and now retired. I'm 15 mins north of the Daytona Speedway. Looking forward to getting the Pantera on the track soon. Maybe I can get out on the track Sunday, lol.

Here's three suggestions, none of the cams are "off the shelf", they would require being custom ground.

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On the mild side a cam spec would be the standard spec I suggest even for the 351C

112° ATDC intake lobe MATHEMATIC centerline
117° BTDC exhaust lobe MATHEMATIC centerline

VALVE EVENTS BASED ON ADVERTISED DURATION
EVO = 80° BBDC
IVO = 26° BTDC
(Overlap = 52°)
EVC = 26° ATDC
IVC = 70° ABDC

DURATION:
276°/286° advertised duration (measured at 0.006” tappet lift)
222°/232° duration at 0.050"

HARVEY CRANE’S INDICATORS:
54°/54°hydraulic intensity
Overlap at 0.050” = less than zero
Lobe separation angle = 114.5°

LIFT
(recommended minimum):
0.323"/0.323" lobe lift
0.559”/0.559” theoretical (gross) valve lift
0.550”/0.550” net valve lift
(recommended maximum):
0.352"/0.352" lobe lift
0.609”/0.609” theoretical (gross) valve lift
0.600”/0.600” net valve lift

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In the middle we have this

112° ATDC intake lobe MATHEMATIC centerline
117° BTDC exhaust lobe MATHEMATIC centerline

VALVE EVENTS BASED ON ADVERTISED DURATION
EVO = 84° BBDC
IVO = 30° BTDC
(Overlap = 60°)
EVC = 30° ATDC
IVC = 74° ABDC

DURATION:
284°/294° advertised duration (measured at 0.006” tappet lift)
230°/240° duration at 0.050"

HARVEY CRANE’S INDICATORS:
54°/54°hydraulic intensity
Overlap at 0.050” = 6°
Lobe separation angle = 114.5°

LIFT (NO CHANGE)
(recommended minimum):
0.323"/0.323" lobe lift
0.559”/0.559” theoretical (gross) valve lift
0.550”/0.550” net valve lift
(recommended maximum):
0.352"/0.352" lobe lift
0.609”/0.609” theoretical (gross) valve lift
0.600”/0.600” net valve lift

---

On the wilder side, the max "streetable" spec for a 408 would look like this:

109° ATDC intake lobe MATHEMATIC centerline
119° BTDC exhaust lobe MATHEMATIC centerline

VALVE EVENTS BASED ON ADVERTISED DURATION
EVO = 86° BBDC
IVO = 38° BTDC
(Overlap = 66°)
EVC = 28° ATDC
IVC = 76° ABDC

DURATION:
294°/294° advertised duration (measured at 0.006” tappet lift)
240°/240° duration at 0.050"

HARVEY CRANE’S INDICATORS:
54°/54°hydraulic intensity
Overlap at 0.050” = 12°
Lobe separation angle = 114°

LIFT (NO CHANGE)
(recommended minimum):
0.323"/0.323" lobe lift
0.559”/0.559” theoretical (gross) valve lift
0.550”/0.550” net valve lift
(recommended maximum):
0.352"/0.352" lobe lift
0.609”/0.609” theoretical (gross) valve lift
0.600”/0.600” net valve lift

George, Thank you very much for your recommendations. Do you have a preference on a cam grinder?

Re-posting links to Dan's builds, as first post didn't get through;

Mike Drew's build;

http://pantera.infopop.cc/eve/...50045562/m/994102665

One built with EFI in mind;

http://pantera.infopop.cc/eve/...50045562/m/994102665

Julian

You can contact comp cams directly. They will take all your data and make a cam for you. It's actually not a big deal to do so.

quote:

You can contact comp cams directly. They will take all your data and make a cam for you. It's actually not a big deal to do so.

That's rich! They'll take your money and make a cam for you alright! Just not with any regard for your goals or desires!

Probably depends on who you get on the phone over there, but when I called to talk to one of their "cam specialists" about grinding a cam Dan Jones spec'd for, he kept insisting that I needed a BIGGER cam (bigger than George's "wilder side" recommendation above). Despite my repetitive questions as to "why" and "how will it impact idle quality and driveability" he just kept telling me I needed .620-.630" lift and lots of duration (240+) or I "wouldn't be happy with it!" No other explanation at all! We had discussed my goals (I wanted more power than stock, torque in the 390-420 ft.lb. range from 2500-5500 RPM, no monster lumpy idle, and maintaining street driveability was my #1 priority) but he had no concern for my goals and made no effort to explain how his recommendations were going to satisfy those goals.

Needless to say, I took my specs from Dan Jones to a reputable cam grinder.

quote:

Originally posted by toby7777:

... Do you have a preference on a cam grinder ...

Bullet Cams, they're in Arkansas. When you custom order a roller cam make sure to specify a cam core that will be compatible with a steel distributor gear; you don't want to have to resort to using a bronze gear or a composite gear. Composite gears may be OK, I just don't know anything about them. I prefer to be conservative, play it safe, spec the cam and all parts to last a long time.

Tell me what spec you're interested in and how much lift and I'll pick a pair of lobes from their catalog for you to specify.

George,

I'm all in for wild with the .609 gross lift.

Thank you for your help.

That cam is a single pattern cam, it uses the same lobe for intake and exhaust. Bullet has a lobe that is damn near spot-on:

HR294/350

That's 294° advertised duration, 240° duration at 0.050", 0.3500" lobe lift. The lobe is rated "CRA" which means it has a conventional nose, its suited for "big block" valve train (large valves, high ratio rocker arms), and it has asymmetrical ramps.

So specify that lobe (HR294/350) for both intake and exhaust, specify a 109° "mathematic" intake lobe centerline and 119° "mathematic" exhaust lobe centerline. Specify a cam core that's compatible with Crane's steel distributor gear.

Since these lobes are asymmetrical the point of highest valve lift shall occur about 4 degrees earlier than the mathematic centerline. Bullet will have to provide the specifics.

quote:

Originally posted by toby7777: I am looking for a streetable engine. An impressive Dyno sheet is cool but not if you can't have fun driving around town. I drive the car to shows, take the wife to dinner, and plan some occasional track time.

quote:

Originally posted by toby7777: I'm all in for wild with the .609 gross lift. Thank you for your help.

Not sure what you’re really after between the range of grocery getter and wild but if you are interested in the higher end of street performance yet still prefer hydro-roller, and considering the overall investment already required in the build as you describe it, and if you already plan to build a custom exhaust on top of that, I’d suggest you give serious consideration to adding a set of high port or aftermarket 335 series heads to your build. It would be a small to modest incremental increase to the overall build cost and yield some real all around benefits (apologies in advance to all C purists).

The exhaust port performance and possibly combustion chamber configuration (depending upon the aftermarket head) will change the cam selection criteria but also enhance the build potential. Check out this spec of Dan and build by Dave. The cam was a custom hydraulic roller from Steve Demos using DM238HR intake lobes and DM242HR exhaust lobes. Specs are 238/242 degrees duration @ 0.050", 0.620"/0.621" lift (with 1.73:1 ratio rockers), 110 degrees LSA, installed on a 109 ICL. Also of note is the cam core, the cam was ground on a SADI (Selectively Austempered Ductile Iron) core so the MSD cast iron distributor gear could be retained. The cam may be one of the best I’ve seen for the performance/street compromise….truly impressive build from the bench stats. I’d really like to have driven it.

On the IR EFI, if it’s just the look you’re after, you will pay a very high premium for that look as opposed to just a purpose built 4-barrel. There is a ton of supporting overhead necessary to add the EFI conversion let alone IR….such as the fuel delivery system, ECU, wiring looms, sensors, etc not to mention the tuning. If you yourself are not someone who likes to tune, you will likely have something that very few people other than who built it (and many times not even them) can manage it afterward.

A properly selected four barrel will just work every time you insert the key and there are lots of accomplished 4-barrel experts if ever needed. –Just my 2 cents.

Best,
Kelly

Hi Kelly,

A lot of great info. I already have half of the EFI stuff on the shelf so I'll stick with that route. I hadn't heard of Demos cams before. I just went to their website. He seems like a great cam guy.

Thanks, Toby

quote:

Originally posted by George P:

quote:

Originally posted by toby7777:

... Do you have a preference on a cam grinder ...

Bullet Cams, they're in Arkansas. When you custom order a roller cam make sure to specify a cam core that will be compatible with a steel distributor gear; you don't want to have to resort to using a bronze gear or a composite gear. Composite gears may be OK, I just don't know anything about them. I prefer to be conservative, play it safe, spec the cam and all parts to last a long time.

Tell me what spec you're interested in and how much lift and I'll pick a pair of lobes from their catalog for you to specify.

I agree. I recently spoke with a person at Bullet cams about having a cam ground with a core that would be compatible with a steel gear and he felt that it wouldn't be a problem. The other two options might be okay, just not sure how long either will last after some of the posts that I have read.

Another company to check out is Mike Jones Cams. He and David Vizard had a competition on selecting a cam for a motor for Throttle Performance who has entered some of their motors in the Engine Masters Challenge. They both arrived at the same cam specs for that motor, so the competition was a draw. He offers a Billet 1050 steel cam that is compatible with std. distributor gears.

As far a Demos cams, I have heard of them on the 351c forum. Steve Demos used to work at Reed Cams.

My 403 Stroker with CHI 208cc heads and single plane manifold has a custom roller with 248INT/254EX @ .50, .630 lift, 108deg lobe separation. 11.5 comp. Idles at 800rpm with a nice lump. A little soft on the very bottom (who cares its a manual!!) but ramps up, pulls hard and revs to the moon.

Toby,
The 408 in my 72 Pantera was built by McKeown Motorsport with CHI 225 heads and manifold and 11:1 compression and is similar to what you’re contemplating. It was patterned after one Mark did for the Engine Masters annual competition. The solid roller cam is his own design and specs out at 248 INT/254 EX @ .50 lift, 671/681 lift and 110 degree lobe separation. The engine dyno’s out with average flywheel horsepower and torque of 614 and 544 respectively with 681 peak horsepower. It has a heavy lope at idle and is about as radical as I would go in a street car. I only do gentle, rolling starts as I fear for the life of my ZF with 345 rear tires especially now that I know the ZF is only rated at 325ft-lbs input max torque!

FYI, due to "lash" a 240° hydraulic tappet lobe and a 248° solid tappet lobe are going to make peak horsepower at basically the same piston speed (rpm).

This is Comp cams P/N 32-541-8 I thought it was a 284 but it's a 290. I only have 358 c.i and 10.2 comp... I drive the car every day and this car surprises many, many people. I have quite a few scalps w/this ol' car....

https://www.youtube.com/watch?v=nic5OQCFCus

Hi Paul, Cool video on You Tube. Sounds real good. I went with A Bullet cam. Unfortunately they are 3 weeks out on custom grinds!
Your somewhere here in Central FL? I'm in Flagler Beach.

Yeah, I'm about an hour north of Tampa.