Cam Swap - 318/5.2L Magnum V8 - '65 Barracuda

-
gwmax65

gwmax65

Magnum V8 Mopar
Joined
May 17, 2013
Messages
120
Reaction score
80
Location
Utah
Want to switch my stock cam out and put an aftermarket cam in a 1996 Dodge 'carbureted' Magnum 318/5.2L V8 that will be making its way into my 1965 Plymouth Barracuda. Shooting for the lopey/thumpy sound, like this Duster has in this video:

[ame="https://www.youtube.com/watch?v=ufRTSVOnmDQ"]Plymouth Duster Hughes Whiplash cam - YouTube[/ame]

I believe I would have to switch my whole valve train up towards a flat-tappet setup to achieve this cam swap, looking for alternatives... Still got a long ways to learn about the define specifics/details of motors measurements and such, got the basics down though! Have experience with small blocks, not rebuilding necessarily, just the typical amateur regasket/reseal/repaint + throw a new timing chain in if needed.

Done a stock 5.2L Magnum Swap into a '65 Valiant 200, and was surprised by the dramatic difference in power vs a stock 2bbl 273. Anyways.. Any help would be greatly appreciated!
 

Attachments

  • IMAG1828.jpg
    39.6 KB · Views: 434
  • IMAG1802_1.jpg
    32.2 KB · Views: 381
  • IMAG1226.jpg
    40.7 KB · Views: 392
  • IMG_2241-edit.jpg
    32.7 KB · Views: 383
Hughes does indeed make a hydraulic roller Whiplash for 5.2 Magnums ( carbed...) Need to add matching springs. Here is their recommended one for carb'd 5.2 Magnum. Read the footnote on the bottom,on widening the lobe centers for drive able idle. The part numbers on springs & retainers,make it a bolt on( not removing heads,from block) situation.

Category : B- Small Block Dodge Magnum : Camshaft


HUG SMR0814ALN-7


SB HYD ROLLER 318 WHIPLASH CAM

WHIPLASH SERIES HYDRAULIC ROLLER CAMSHAFT

$357.41




These hydraulic roller cams are designed to work in carbureted, non computer controlled engines.

Camshaft Technical Details
Intake Valve Lift 1.5
Exhaust Valve Lift 1.5 .480"
.487"

Intake Valve Lift 1.6
Exhaust Valve Lift 1.6 .512"
.520"

Intake Duration at .050"
Exhaust Duration at .050" 208°
214°

Lobe Separation Angle 107º
Intake Centerline 102º
Intake Opening at .050"
Exhaust Opening at .050" 2° BTC
39° BBC

Intake Closing at .050"
Exhaust Closing at .050" 26° ABC
-5° ATC
Sweet Spot: Idle to 5500 RPM
You wanted Whiplash cams for Magnum engines and now we’ve got ‘em! These hydraulic roller cams are designed to work in carbureted, non computer controlled engines.These cams are designed to work with low compression engines only. Stock Magnum engines usually have to much cylinder pressure to use this cam. If you are running stock Magnum compression you should consider one of our cams that is ground on a 110º or 114º LSA. Call us with any questions or concerns before ordering.
Like all of our Whiplash cams these rollers will have very aggressive idle characteristics and accelerate very hard right off the line, no waiting for the RPM to come up. These are new cams, not regrinds and you can use the stock oil pump drive gear. These cams will require our 1110 valve springs and our 1278 retainers. We have a tool, #66784M that will allow you to change valve springs with the heads on the engine. We will sell or rent this tool.
Available for 5.2 and 5.9 engines.

These cams will not produce as much vacuum as the stock cams. At an idle you may need to put both feet on the brake pedal. When driving the vacuum will come up. To increase vacuum you can add an electric vacuum pump or a vacuum reserve canister.

Related Items:
1278 Retainers

1110 Springs (16 required)

I personally would widen the lobe centers myself. For better help,you might add what trans(stick/auto) converter stall(?), rear tire size & rear end gear ratio. You could also call Oregon Cam grinders,who can do a similar grind,a lot cheaper. You will most likely need a custom length pushrod set ( aftermarket cams,usually smaller base circle ground. Hopefully this helps. Do lots of research, ask lots of question s,before you order a single part. Saves money ,in the long run.
 
Honestly, I would not get rid of the roller cam for a flat tappet.
Why down grade?
 
What's with folks thinking they need to do the flat tappet swap in a roller engine lately? I've seen at least 4 people in the last month with this hogwash.

That sh8t has me concerned.. Ever hear of a re-grind? I think information and vendor lists for that need to become a sticky in the magnum swap section.

If you want lumpy, just lean out the idle a/f adjusters using a mild cam and kick down the idle speed. It's not worth the trade off in low and mid range pull. 230 @ .050 max duration.

My cam is a 292 225 @ .050 112 LSA .525 int/ext lift. Cost was $175 reground at bullet cams. Pulls hard.

[ame="https://www.youtube.com/watch?v=J28gourc7KU"]Woods 74' Dart walk. - YouTube[/ame]

Done.
 
Thanks Abodybomber! I never found the foot note you mentioned on their site at the bottom

http://www.hughesengines.com/Index/...el2=V2hpcGxhc2ggSHlkLiBSb2xsZXI=&partid=26251

I noticed they were saying that magnum engines typically have too much cylinder pressure to run this cam... That doesn't make sense to me cause why would they make the cam in the first place and say it's designated to work in a magnum motor?

Anyways, was also wondering, you said I don't have to pull my heads, so unlike a flat tappet setup with solid lifters, am I safe to just use the hydraulic lifters as they are with this new cam? I know a flat tappet/solid lifter setup wears as a set, but didn't know about a hydraulic lifter setup.

Also, would the push rods need to be replaced with different sized ones too?

I don't understand what widening lobe centers means.. Unless you are speaking of the oval shaped cast part in the oil valley center below where the intake would sit, if that has to be opened up more for more travel for the lobes on the camshaft...
 
gwmax65 said:
Thanks Abodybomber! I never found the foot note you mentioned on their site at the bottom

http://www.hughesengines.com/Index/...el2=V2hpcGxhc2ggSHlkLiBSb2xsZXI=&partid=26251

I noticed they were saying that magnum engines typically have too much cylinder pressure to run this cam... That doesn't make sense to me cause why would they make the cam in the first place and say it's designated to work in a magnum motor?

Anyways, was also wondering, you said I don't have to pull my heads, so unlike a flat tappet setup with solid lifters, am I safe to just use the hydraulic lifters as they are with this new cam? I know a flat tappet/solid lifter setup wears as a set, but didn't know about a hydraulic lifter setup.

Also, would the push rods need to be replaced with different sized ones too?

I don't understand what widening lobe centers means.. Unless you are speaking of the oval shaped cast part in the oil valley center below where the intake would sit, if that has to be opened up more for more travel for the lobes on the camshaft...
Click to expand...

I wouldn't worry about the cylinder pressure thing,on that cam with a carb setup. Set your timing curve right,& tune it ( it does take time,on your part,B.T.W...)
Hydraulic rollers ,are actually reusable! Good to go,there mN.
I definitely would do an "adjustable push rod mockup" .. And order a correct length set. Comp Cams, sells a mock up one,for 20 bucks,beats listening to your valvetrain rattle away.( needs lifter preloaded,-.060"-090" in the ballpark.)
Widening the "lobe centers"..
Takes some of your " ratty hot rod idle " away, adds street ability /low end torque ,& mid range drivability (think 1000-4500 rpm range, where. you usually need it most..) Widening it,(110-112-114), makes less mid range, but much easier to tune. (Also why I asked about transmission/converter/rear tire size & gear ratio.) ..
 
PoisonDart74 said:
What's with folks thinking they need to do the flat tappet swap in a roller engine lately? I've seen at least 4 people in the last month with this hogwash.

That sh8t has me concerned.. Ever hear of a re-grind? I think information and vendor lists for that need to become a sticky in the magnum swap section.

If you want lumpy, just lean out the idle a/f adjusters using a mild cam and kick down the idle speed. It's not worth the trade off in low and mid range pull. 230 @ .050 max duration.

My cam is a 292 225 @ .050 112 LSA .525 int/ext lift. Cost was $175 reground at bullet cams. Pulls hard.

Woods 74' Dart walk. - YouTube

Done.
Click to expand...

Listen to him,as well. .. Poison 74 ,did it with hard work mucho, minimum buck spent.....
 
Interesting.

I was also under the impression that Magnum engines were specifically designed to run on 87 octane and had 8 or 8.5:1 compression.

102 IS a kind of crazy centerline.

I've got a roller 318 and a set of magnum heads that I was thinking of mating up.

I'm not real sure what the Mag heads will do the advertized 9.2:1 comp of the 318 roller.
 
The cam specs in post#2 are little different from a factory 340 cam. They just tightened up the LDA and added a bit of lift. Now if they increased the rate of lift, to put more area under the curve, that would explain the springing requirement. That would tighten up the powerband and increase the specific power slightly from the factory 340 cam.So it would, seat-of-the-pants, sound and feel faster. But the early ICA tells the real story.Premium gas, and burning more of it, and I suspect, very little change in ET or MPH.Especially with an automatic, and non-optimum rear gears. But if it's the idle you're after, and are able to tune a timing curve,and don't mind the high cost per mile of gas, there you go.
To me, it's like those guys with fart can mufflers.
I had one cam with a 108LDA. Performance-wise,on the street; it sucked.And that was with everything optimized. I won't be buying another any time soon.
On the street,in a car that gets driven,it's hard to beat a wide powerband, that starts real low, can use a tight TC,and 3.23s or 3.55s, even if that means a sacrifice in specific power. It's nice to have a gear that goes to 50 mph or so,before having to shift. That means 3.55s with a tall tire.It's even nicer to have a combo that puts second gear at or near peak torque when the TC flashes, and at cruising speed.But once again, I digress.Sorry.
 
If you are going to put a new motor in your car you need to think about optimizing the combo for intended use.

Happy with my new combo, 12.32/108.77 1.746 60' running rich at 11.7 thru the trap.
67 Dart 2dr post all steel guessing 3360 full fuel and driver. 2 buckets, small custom dash, squirrel cage fan for comfort and door panels is the basic interior.
360 Magnum roller, 9.3:1 was 8.8:1 from factory with .040 head gasket, OEM magnum heads milled .010, .028 head gasket, stock valves, MP crate motor springs, ported by me at home.
Knockoff airgap, demon 650 DP, Lunati roller steel core custom grind 234/236 .495/.475 lift. 108 LSA/106 ICL Cam was picked to match the street/strip package I wanted. Idles at 11" vac in gear and sounds cool but I always pick a cam for the intended power band.
999 low gear set, TF2 shift kit Lockup circuit disabled, Turbo Action 10" 3200-3400, 3.91 SG, 27in MT drag radial, Mancini SS springs, 8.75 axle moved back .75", battery in trunk.
Car is a blast, very street friendly with 29" street tires and driven 50 to 100 miles to the track.
I'm still messing with optimum A/F ratio and launch rpms. Car also runs great on 89 fuel.

Stock magnum springs are very soft and my installed height was 1.62" The MP springs work great. I cut my guides down to maintain .050" retainer to VG seal clearance.

I could have had my stock cam reground but decided to sell it and have a Lunati Custom roller grind. It was $310 to my door and I was able to reuse the stock pushrods and lifters.
 
Don't put a flat tappet in a motor that doesn't have to have one. It's a huge downgrade from a roller in every way.
 
You must log in or register to reply here.
-

Back
Top