Cam

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Adrien

Member
I have been tossing around the idea of putting a mild cam in my engine. I have a 6.4l 392 v8. Has anyone done this?
 
Thanks for the link and info. I've several different things when it comes to replacing the cam. Do you have to replace the lifters, timing gears and oil pump at the same time? I plan on having a local engine shop here install the cam, just curious as to whether or not I should pay them to do the lifters and what not. I know the engine well need to be tuned after a cam install, and I honestly do not know exactly what needs to be done to this engine afterwards. I don't want a shop to take me to the bank.
 
My Scout with a 345 is running the comp 252 cam, headers and a 4bbl 392 manifold. I like it and Robert is right about loosing a bit off the bottom end. The split cam he recommended would be a notch above the comp 252 and is a good choice for the IH sv engines due to the restricted exhaust ports.

Yes on the new lifters and depends on the cam gears. If your old gears are good no reason to replace them, however if the cam bearings have spun plan on needing gears. Mine did and the tops of several teeth were broken off. The comp cam comes as a kit with cam, lifters and gears for $500.

What's your plans for the 392?
 
fdchappie said:
my Scout with a 345 is running the comp 252 cam, headers and a 4bbl 392 manifold. I like it and Robert is right about loosing a bit off the bottom end. The split cam he recommended would be a notch above the comp 252 and is a good choice for the IH sv engines due to the restricted exhaust ports.

Yes on the new lifters and depends on the cam gears. If your old gears are good no reason to replace them, however if the cam bearings have spun plan on needing gears. Mine did and the tops of several teeth were broken off. The comp cam comes as a kit with cam, lifters and gears for $500.

What's your plans for the 392?
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Thanks!! My plan is to get the max performance out of the engine without changing to much. I am thinking the cam, lifters and oil pump. Tune it right and she will rumble down the street and shake at the stop lights :lol:
 
With open headers it's hard to tell how much cam that is. The comp 252 is a bit lopey until it warms up.
 
adrien said:
thanks for the link and info. I've several different things when it comes to replacing the cam. Do you have to replace the lifters, timing gears and oil pump at the same time? I plan on having a local engine shop here install the cam, Just curious as to whether or not I should pay them to do the lifters and what not. I know the engine well need to be tuned after a cam install, and I honestly do not know exactly what needs to be done to this engine afterwards. I don't want a shop to take me to the bank.
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This is a huge red flag to me. When you deal with a low compression engine and couple that with a duration increase, you absolutely must degree the cam. You must be sure that they set the intake lobe cl of the cam I recommended to 106 degrees.
Failure to do that will destroy manifold vacuum at isle and kill bottom end.
If these steps cannot be guaranteed, leave the stock cam in it.

The other caveat is whether or not you have a flat top piston engine of the contoured pistons. The later can run into piston to valve clearance issues when advancing the cam.
 
The red flag really applies regardless of who installs the cam, but having someone out side your control increases the risk exponentially.
 
I think what Robert is suggesting is to make sure whomever you have install the new camshaft be experienced in it and already know to degree the new cam upon installation.
 
ihpartsjeff said:
I think what Robert is suggesting is to make sure whomever you have install the new camshaft be experienced in it and already know to degree the new cam upon installation.
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I'm gonna have to research that. Find out what the specs should be and what not.
 
Robert kenney said:
I would especially on a 392.
Now you must understand that even with the smallest cam, you will move the peak hp up in the rpm range about 400 rpm. This means a slight softening of off idle snap but a satisfying seat of the pants pull to 4000- 4200. I recommend this cam.
http://www.IHPartsAmerica.com/store...product_code=isky-190125-26&category_code=cal
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When I needed to replace the camshaft (and cam bearings) in my 304 about 10 years ago, I ended up using a stock grind. I didn't want to change the hp/tq curves from stock, as my Scout's set up allows me to cruise at 60-65 mph at peak torque (2600 rpm). My 304 rarely sees much over 3k rpm.
 
I have a 345 in a 1970 1200d. Stock.
Am going to rebuild over this winter.
Flat top pistons.
With the split duration cam recommended would degreeing the cam to 106 be recommended?
With that cam would I need to upgrade valve springs?

Thanks in advance.
J
 
There are a couple of dual pattern/split duration options. Specifically which cam?
There are some variables to consider beyond a stock 345. I would absolutely recommend checking the cam timing regardless of the cam being installed.

I do recommend valve springs of a known operating range. Stockers are designed (one can assume) for the oem cam. Beyond that we can not say.
 
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