5.7l Mercruiser Camshaft Specs

[Bob & Sue]

Might be building a new engine wanting to know if these are the correct specs for a 5.7L Mercuiser that I found online. The engine block & heads I'm starting out with is a Gen III 6.0L cast iron 4 bolt main with heads ported & polished to an Edelbrock aluminum manifold.

Lobe Lift + .002(0.051)
Exhaust
.300(7.62)
Intake
.287(7.289)
Duration at .050 In. (1.27 mm)

Cam Lift
Exhaust
.294(7.467)
Intake
.307(7.797)

Journal Diameter
1.8682-1.8692(47.440-47.490)

End Play
.011-0.030(0.004-0.0012)

Timing Chain Deflection
[LH Rotation]
.375(9.5) from taut position [total .75(19)

 

[geo737]

Here is some info I found on a camshaft with similar specs you are looking for:

If it is from a Marine 5.7L Vortec the most common cam has the following specs:
PN 14097395 specs = 256/264 Adv. Dur. - 196/206 duration @ .050" with .431"/.451" lift and a 109 LSA.
These are really a very good cam choice and GM used them in the 350 Ramjet and HT383 crate motors.
The 350 Marine cam would be a good one if used with good flowing heads like the Vortecs they were designed for.
Even though they look pretty mild they actually make good power.

Here is some more cam info to help if you are planing to degree the cam- I cant vouch for the accuracy of the specs as they were pulled from a chevelle website:

note that lobes appear to be asymetrical on opening and closing sides. I did not take duration at lash point as that is pretty meaningless but GM says it is 288/308 - lift measured right on spec with .287/.300 lobe lift for about .430 and .450 at the valve.

Open and Close heights .004 .006 .050 .200

Intake Open 20-btdc 17-btdc 7.5-atdc 50-atdc
Intake Close 60-abdc 53-abdc 24-abdc 20-bbdc

Exhaust Open 63-bbdc 60-bbdc 35-bbdc 8-abdc
Exhaust Close 28-atdc 23-atdc 10-btdc 54-btdc



Here are some numbers distilled from the above that you can plug into you cam calculator to get close to the above actual opening and closing points.

.004 = 260/272 109Lc 1 deg ret

.006 = 250/264 108Lc 0 deg straight up

.050 = 196/204 109Lc 3 deg adv

.200 = 110/118 109Lc 4 deg adv

the info is para-phrased. I put this cam in my engine rebuild/re-power and I can say that I am very happy with the performance of our boat. GM refers to the cam as a "RamJet 395". note that the cam is a hydraulic roller design so if your block is newer, it should be equipped to install this type of camshaft. The other info you are looking for should be available in a Mercruiser service manual or a good aftermarket book on how to rebuild a small block chevy