440 Cam Suggestions

[69 Charger Mark]

If there is nothing wrong with the short block, don't waste your money. If you want to add some meaningful power on the cheap, put a good set of heads on it.

Good heads are in the future but not today. I'm looking at that Trickflow upper end kit but it's going to have to take a back seat for now as putting on basically a whole rear clip from AMD is going to do a number on my wallet. The sheet metal has already been purchased. Just waiting on the paint guy.

 

[69 Charger Mark]

From the original post, I was thinking he wants to take the the engine out for paint and "freshen" the engine using a different cam, and put the engine back in the car for a short time. Later on when new heads can be afforded, to do a complete engine rebuild to work with the new heads?

Yes, you've nailed it exactly! Thanks --------------- Mark.

 

[Curiousyellow71]

The voodoo are mopar based grinds for mopars larger .904 lifters. Comp cams xe are for a chevy smaller .842 lifter. Comp has some mopar grinds but most of them have more duration then you need. One difference between the voodoo and the xe is the way the valve shuts. Voodoo is more gradual...xe slams them down hard. Voodoo has more area under the curve and more lift....which is the benefit of running mopar grinds. Howard's, bullet and even the old MP cams have grinds that are mopar specific. We don't always run mopar grinds but it depends what your goals are. Stock heads your not going to gain much past .500 lift.

 

[69 Charger Mark]

Curiousyellow71 great input. thanks for the insight and I'll definitely check them out.

 

[69 Charger Mark]

The voodoo are mopar based grinds for mopars larger .904 lifters. Comp cams xe are for a chevy smaller .842 lifter. Comp has some mopar grinds but most of them have more duration then you need. One difference between the voodoo and the xe is the way the valve shuts. Voodoo is more gradual...xe slams then down hard. Voodoo has more area under the curve and more lift....which is the benefit of running mopar grinds. Howard's, bullet and even the old MP cams have grinds that are mopar specific. We don't always run mopar grinds but it depends what your goals are. Stock heads your not going to gain much past .500 lift.

I think I settled on this one. https://www.lunatipower.com/cam-k-kit-chr-b-v271h10.html

 

[451Mopar]

I think I settled on this one. https://www.lunatipower.com/cam-k-kit-chr-b-v271h10.html

That is a good choice. The kit photo is a bit generic. The Voodoo cams use a 3-bolt timing chain which I prefer over the single bolt.

 

[wyrmrider]

kit has the 703 cam
Part #10230703K.
is that best? for his compression and gears with a 4 speed?

 

[cryplydog]

I really like the comp xs268s and the xs274s. You would have to use adj. rockers. I use trend H-13 solids. good luck 69

 

[451Mopar]

kit has the 703 cam
Part #10230703K.
is that best? for his compression and gears with a 4 speed?

The cam could use a but more compression ratio, the cam is supposed to be installed with a 106 ICL which helps.
I would use a 0.020" head gasket. Not sure how much he plans to do to the heads because they will be replaced in the future, but milling for compression would help too (or just get aftermarket heads with smaller combustion chambers?)

Doing some quick calculations, compression ratio s/b around 8.8:1 with the assumptions that the flat top piston is -0.092" below the deck, 0.020" head gasket, and 89cc head chamber volume. Using advertised 268 duration with ICL at 106, the intake should close at 60 degrees after BDC, making the effective (dynamic) compression right about 7:1 (7.03:1). Depending on air pressure, I think cranking cylinder pressure s/b about 130-135 psi?

 

[wyrmrider]

in that case I'd use the 702 cam

 

[451Mopar]

in that case I'd use the 702 cam

I have used that 702 cam in a stock compression 400 with a 10" converter and it worked good.
I haven't personally used the 703 cam, but with 440" displacement I think it will be fine, plus the tighter LSA (more overlap) should make the car really fun in the mid/upper RPMs working with the headers and single plane intake and large carb. Nothing on the engine appears to be setup for low RPM grunt. Likely dial in a bunch of initial advance, and work on the carb transition circuit so the engine is not lean at tip-in.

 

[Curiousyellow71]

The cam could use a but more compression ratio, the cam is supposed to be installed with a 106 ICL which helps.
I would use a 0.020" head gasket. Not sure how much he plans to do to the heads because they will be replaced in the future, but milling for compression would help too (or just get aftermarket heads with smaller combustion chambers?)

Doing some quick calculations, compression ratio s/b around 8.8:1 with the assumptions that the flat top piston is -0.092" below the deck, 0.020" head gasket, and 89cc head chamber volume. Using advertised 268 duration with ICL at 106, the intake should close at 60 degrees after BDC, making the effective (dynamic) compression right about 7:1 (7.03:1). Depending on air pressure, I think cranking cylinder pressure s/b about 130-135 psi?

Those number look like a 1970 440 or maybe a aftermarket piston? Hard to say what a 50 year old car has for pistons? We have a rerung std 70 440 and it is in that .080-.090 range. A 68-69 should have a taller 2.03ish piston and should be in the mid to lower 9s...68-69 should be .045-.060 down the deck. I agree a .020 gasket is a good idea. Should be a good fit for the 703 with the 1 7/8 headers and short single plane. The extra overlap should be more powerful then the 702.

 

[wyrmrider]

703 more powerful but less driveable than 702
match the cam to the compression
He has a street dominator not a single plane intake
and he has a carb like already
KISS
702 is better match unless you start changing everything
it's bigger than the 274 comp he was looking at where it counts and just a little shorter on the seat to work with existing pistons
703 is a BUNCH bigger than the 274 comp dutation, lift ,area under the curve

 

[forphorty]

703 more powerful but less driveable than 702
match the cam to the compression
He has a street dominator not a single plane intake
and he has a carb like already
KISS
702 is better match unless you start changing everything
it's bigger than the 274 comp he was looking at where it counts and just a little shorter on the seat to work with existing pistons
703 is a BUNCH bigger than the 274 comp dutation, lift ,area under the curve

Street Dominator is a single plane intake. 703 is a small cam to me, but I like hot rods. To be honest though, I can't say what daily driving a big cammed clutch car would be like. All my cars have torqueflites.

 

[wyrmrider]

i said above pm ajform/s at forabodiesonly
he has the experience with 4 speeds
sorry about the manifold
i was just responding to two above posts
703 is not a big cam but is with his compression and gears that's imho

 

[69 Charger Mark]

i said above pm ajform/s at forabodiesonly
he has the experience with 4 speeds
sorry about the manifold
i was just responding to two above posts
703 is not a big cam but is with his compression and gears that's imho

Hey wyrmrider the 703 is for my 69 Charger. Cam selection is like a dark science to me and I really appreciate everyone's opinion and / or prior experience in this area. Before I spend the $500 for the cam kit I'd like to make sure I get it right. Just curious as to why do you think the 703 would be too much cam for my stock flat tops, assuming that's what's in there. Do you think it will load up at idle? Also I'm not sure how my 3.55 gear set effects the cam. I'm guessing it has to do with building RPM's quicker than say a 3.23 and not taking full advantage of the cam grind? Lastly I talked the the Lunati tech rep, told him everything I had on the car and the 703 is what he came back with. Appreciate the feedback of so many mopar guys. Thanks. ------------- Mark.

 

[wyrmrider]

did you pm ajform/s?
he can explain it better than I can
I'm thinking how to go slow over a speed bump or stuck in traffic with a stick and 703
I'm thinking your compression is low 9s not 10

 

[69 Charger Mark]

did you pm ajform/s?
he can explain it better than I can
I'm thinking how to go slow over a speed bump or stuck in traffic with a stick and 703
I'm thinking your compression is low 9s not 10

No but I'll do that right now. Thanks ----------- Mark.

 

[451Mopar]

Hey wyrmrider the 703 is for my 69 Charger. Cam selection is like a dark science to me and I really appreciate everyone's opinion and / or prior experience in this area. Before I spend the $500 for the cam kit I'd like to make sure I get it right. Just curious as to why do you think the 703 would be too much cam for my stock flat tops, assuming that's what's in there. Do you think it will load up at idle? Also I'm not sure how my 3.55 gear set effects the cam. I'm guessing it has to do with building RPM's quicker than say a 3.23 and not taking full advantage of the cam grind? Lastly I talked the the Lunati tech rep, told him everything I had on the car and the 703 is what he came back with. Appreciate the feedback of so many mopar guys. Thanks. ------------- Mark.

There is too much advertising BS in the cam catalogs. All the choices are a compromise. It really comes down to preference.
The smaller cam will be slightly better below 3,000 RPM, If you have a 2.66:1 first gear, 3.55:1 rear gear and 27" tall tires, so below 25 MPH (in first gear), and if most of your driving is below 3,000 RPM (70 MPH in 4th gear) use the smaller cam.
The Engine simulator makes look like the smaller cam gives about 4 more HP (about 14 ft/lbs of torque @ 1,500 RPM) from idle to 2500 RPM.
The larger cam has more power and torque above 3,000 RPM, but it does not look like a drastic amount, about an extra 15 Hp @ 5,000 RPM.
This is assuming the heads are stock, unported. The stock heads are the limiting factor, much more than the compression.
The smaller cam would be easier to tune because it has much less overlap (smoother idle.)

 

[Curiousyellow71]

The 702 has a wider 112 lsa and less duration then a 703... but both the 702 and 703 have the very similiar power bands because they open the exhaust and close the intake valve within a few degrees of each other. The 703 duration increase mainly shows up in the overlap. The extra overlap is helpful to make more power with the scavenging done with headers. I wouldn't want to give up the top end hp of 703 to gain it on the bottom unless I was towing. LOL