Cam choice questions, sorry long post

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Tejas

Tejas

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To start with: Sorry for the overly long post but I want to get this right the first time.

I’m looking for some advice from some of you that have a lot more big block Mopar engine building experience than I have.

I’m to the point of buying engine components for my low deck 470” build.

Next month I’m buying a pair of 440 Source Stealth heads, I’m going to have a friend go through them.

He’s going to do some mild porting / port matching, change the valve springs, set the installed height, spring pressures and check everything out.

In order to do that he needs the valve springs I’m gonna use. In order to do that I need to pick a cam.

I have always planned on using a roller hydraulic cam set up because I want it to be a rock solid long term reliable engine because it will be primarily a street car.

I called and spoke to Hughes Engines today and spoke to one of their tech guys and he gave me two recommendations, one a roller hydraulic and one a flat tappet hydraulic.

I gotta admit the flat tappet hydraulic set up is looking good to me just based on cost. The whole set up will be about $1000 cheaper this way.

The Hughes tech guy tried to assure me that everything would be OK as long as I used the recommended oil and break in procedures.

My original goal for the car was to get it to the mid 10’s, now I think it’s too heavy and it doesn’t have the right kind of rear suspension for that.

I’ll be happy with 11’s.

Please give me any recommendations or suggestions you have.



Here’s the car and combo.



1971 Plymouth Duster
Approximately 3400 pounds
Subframe connectors
Mini tubbed
· Mancini XHD rear leaf springs

· Reilly Motorsports rear leaf spring sliders

· 3.91 sure grip B body 8 ¾” rear axle narrowed 12”

· 15”x10” rear rims with 3.5” backspacing, 325/50/15 tires 28” tall 12.8” wide

400 low deck block
440 Source 470 stroker kit
3.915” stroke
4.375” (+.035”) bore
6.535” rod length
Flat top pistons, 10.77 compression ratio with 84cc combustion chambers
440 Source Stealth cylinder heads, mild port and polish
Hughes 1.5 ratio roller rockers and shafts
Offenhauser tunnel ram intake manifold
Two Holley 600 cfm vacuum secondary carburetors
Pro Parts 2” primary and 3.5” collector semi fenderwell headers
727 built to high performance specs
Turbo Action 17805ST torque converter 3400 stall


Here are the two cam recommendations.

HUG HEH5055BL3

HYDRAULIC CAMSHAFT 108º LSA+3

FLAT TAPPET HYDRAULIC / THREE BOLT TIMING GEAR

Camshaft Technical Details

Intake Valve Lift 1.5
Exhaust Valve Lift 1.5
.576"
.593"



Intake Valve Lift 1.6
Exhaust Valve Lift 1.6
.614"
.632"



Intake Duration at .050"
Exhaust Duration at .050"
250°
255°



Lobe Separation Angle
108º



Intake Opening at .050"
Exhaust Opening at .050"
20° BTC
58.5° BBC



Intake Closing at .050"
Exhaust Closing at .050"
50° ABC
16.5° ATC



Min. Suggested Cylinder PSI
200



Sweet Spot RPM
2800 - 6000





AND





HUG HER4652BL

HYD ROLLER CAMSHAFT 110º LSA +3

HYDRAULIC ROLLER / THREE BOLT TIMING GEAR

Hydraulic Roller / Three Bolt Timing Gear



Camshaft Technical Details

Intake Valve Lift 1.5
Exhaust Valve Lift 1.5
.555"
.540"



Intake Valve Lift 1.6
Exhaust Valve Lift 1.6
.592"
.576"



Intake Duration at .050"
Exhaust Duration at .050"
246°
252°



Lobe Separation Angle
110º



Intake Opening at .050"
Exhaust Opening at .050"
16° BTC
59° BBC



Intake Closing at .050"
Exhaust Closing at .050"
50° ABC
13° ATC



Min. Suggested Cylinder PSI




Sweet Spot RPM
2000 - 7000
 
Why Hughes? Do you not want a good cam?
 
Scamp Tramp
Don't know why it came out like that, hopefully I fixed it.

Stroker Scamp
Hughes isn't any good?
What's your suggestion?

Thanks
 
I'm just not a big proponent on Hughes cams. They are fine I am sure, but they are probably some of the fastest rates of lift in a cam out there....and that ain't always a good thing. Can you give me your engine combo in a nutshell without blowin my mind with copy/paste?
 
well it makes sense that you are choosing your cam & springs first.

also you are right the roller lifter setups are $$$$ because you need offset rockers, fancy setup under the timing cover etc etc

up top i would still recommend adjustable roller rockers, but for good ones it's a lot. $550 for hughes i think and the real good ones harland sharp are about $600

since you are running a tunnel ram with dual carbs that's a lot of fuel air...
so i'm guessing you want to peak at 6k+ rpms. your cam choice should match the head flow and intake you are using.

that is a huge intake to be honest. as much cfm as a dominator 4500 carb on an indy intake. you will want 2 1/2" headers and full ported heads and a cam with over .550 lift
that is a ton. if you are going with that kind of lift you definitely need to consider your valve train build.


solid lifters are better for higher RPM's but since you are doing a street engine big block you probably dont want to run much above 6200 anyways; hydraulics will work ok for that but especially if you use rhoades lifters. solids are better in my opinion as they dont have troubles at higher rpm's with pump-up / sticking /etc. solids you need to set your valve lash on a schedule depending on how much you use the car.

so flat solid tappets or flat hydraulic, either or just your personal preference.
 
Sure, see if this works better.

400 block
470 Stroker kit
3.915 stroke
4.375 bore (+.035)
6.535 rod length
Flat top pistons 10.75 cr
Stealth heads with Mild porting / port match
1.5 raito roller rockers. Maybe 1.6?
Offy tunnel ram with two 600 holley vacuum secondaries
Pro Parts 2" headers
Turbo action 10" 3400 stall
3.91 sure grip 8-3/4
28" tall tires
3400 pounds

Shooting for low 11's reliable street car

Thanks
 
Melling HV pump, Milodon 7qt pan, 1/2" pick up, windage tray.
 
your cam choice should match the head flow and intake you are using.
Click to expand...
Best line! My fav to say by the way.


I like to use as much lift as possible without getting into the area where the head flow stalls for my aggressive street, street/strip engines. Milder engines can just have something under .500 with the duration to match the driving RPM /cruise range. If I'm looking to do a sub 11 sec run, perhaps more lift than the head handles, but barley.

Knowing what the head flows is a excellent thing to know when looking for a cam and chasing a E.T.

I think that Duster could use some fiberglass to lighten it up. (3200 or less. Bumpers and hood are a great place to start as well as seats. While 3400 is a little hefty, it should still run well. I do not see a power problem with 11's. Gear ratio wise, yes. 4.30's min. gear. I'd like to use a set of 4.56's for this. (10 sec run)

Both cams are nice. I think I myself would like the roller for the slightly lower RPM band starting point and broad RPM range. Since cost is an issue, I guess the choice is made for you.

My cam choice for a 10 sec run would be something like a duration of 260 intake and a little more exhaust with a tad more lift than the head flows on both sides.

For an 11 sec run, the suggested Hughes Hyd. would do it.
 
I like the short rod combo in this with the tunnel ram. But, I'd go up .5 point in static compression with that intake. As far as the cam goes, I'm not a big fan of hydraulic rollers. Either stay flat tappet hydraulic, or step up to either flat tappet solid or solid roller. I don't run Hughes products for my own reasons. Personally I'd be pushing for a solid flat tappet if you want the best results for minimal spend. Anything around the 250° @ .050 area will make plenty of steam provided the heads are set up properly. As far as hydraulic cams - the Engle K-7HYD, Crane 684571 or Comp XE285HL in that order. As far as solid flat tappets - I like Stroker's recommendation or Crane 681321 or Comp XTQ286S-8 but I'd run the 1.5 rockers with any of them.
 
Survey says!
After much deliberation and a lot of good advise I'm gonna go with a Comp Cams flat tappet hydraulic XE295HL and 1.5 ratio rockers.
.564 lift intake and exhaust with the 1.5's
Duration at .050" is 251 intake and 257 exhaust and a 110 degree lobe separation.
It should be plenty healthy for a 470 stroker and the spring pressures wont be crazy high for a reliable street motor.
Now I need to buy it before I change my mind again!
 
Chevy lobes and a cookie cutter cam grind.....but it will run ok.
 
Actually, the HL series is too fast for the .842 chevy lifter. Not my first choice, but it will make plenty of steam.
 
Tejas said:
Survey says!
After much deliberation and a lot of good advise I'm gonna go with a Comp Cams flat tappet hydraulic XE295HL and 1.5 ratio rockers.
.564 lift intake and exhaust with the 1.5's
Duration at .050" is 251 intake and 257 exhaust and a 110 degree lobe separation.
It should be plenty healthy for a 470 stroker and the spring pressures wont be crazy high for a reliable street motor.
Now I need to buy it before I change my mind again!
Click to expand...

Get the 1.6 rockers for a 600 lift cam, Minus lash, pushrod angles etc....
And fully port the heads....LOL


Have fun, but make that plan and stick to it!!!!!!!!
 
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