C/R and Cam question
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From: North Central Washington
C/R and Cam question
I am a new member here and I have a question. I am rebuilding a 1968 F250 2x4 with a 390 as a daily driver. I would like to run regular gas, what is it 87 octane. My question is, what compression ratio should I shot for and I'm wondering on ideas for a cam to use.
Thanks Tim
Thanks Tim
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I don't believe I would exceed about 9 or 9.5 to 1 compression. If you are using the Edelbrock aluminum heads (or any other aluminum head) you should be able to get away with another 1/2 point. As far as cam selection, I usually fill out the Comp Cams information sheet, then call them and listen to their recomendation. All the cam companies have the same service, I'm sure. I've just always preferred Comp.
By the way, welcome to FTE !!!!!
By the way, welcome to FTE !!!!!
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FTE Chapter Leader
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From: North Central Washington
Thanks Dave,
I am running stock heads C6AE-R (but I maybe getting a set of rebuilt heads if I can't find anyone to work on the ones I have) and the stock 2V intake manifold. Which brings up another question, is there a chance that my manifold is warped? Over the years this has happened twice the first time it happened a changed heads just because and that worked for awhile. The second time it happened, I added two containers of alum-seal and that seemed to stop it from leaking. What is happening is that I start burning water in the #8 cylinder. Both times I can see that the water was coming from the water port that is in the rear of the head and making its way to the intake port of the #8 Cylinder. It also looks as though I have been sucking oil and air into the #6 cylinder from the valve galley. As I stated earlier this is the second time for the water leak in the same location.
Any ideas
Tim<O
</O
Go Seahawks !!!!<O</O
I am running stock heads C6AE-R (but I maybe getting a set of rebuilt heads if I can't find anyone to work on the ones I have) and the stock 2V intake manifold. Which brings up another question, is there a chance that my manifold is warped? Over the years this has happened twice the first time it happened a changed heads just because and that worked for awhile. The second time it happened, I added two containers of alum-seal and that seemed to stop it from leaking. What is happening is that I start burning water in the #8 cylinder. Both times I can see that the water was coming from the water port that is in the rear of the head and making its way to the intake port of the #8 Cylinder. It also looks as though I have been sucking oil and air into the #6 cylinder from the valve galley. As I stated earlier this is the second time for the water leak in the same location.
Any ideas
Tim<O
</OGo Seahawks !!!!<O
</O
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I'd keep the compression conservative, too, if you plan on running 87 octane. That engine stock had over 10:1 compression, I believe....which means you may have to decide whether to use dished pistons or plan on running a higher octane gas.
Your cam selection will have to do with what rearend gear you're running. The higher gear ratio( numerically) you run, the more duration you can stand. Be realistic as to what rpm range you plan on running because you move your power band up as you go higher with lift and duration.
Your cam selection will have to do with what rearend gear you're running. The higher gear ratio( numerically) you run, the more duration you can stand. Be realistic as to what rpm range you plan on running because you move your power band up as you go higher with lift and duration.
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From: Madison, SD
Chance it could be warped Tim. Clean the mating surface good and lay a metal straight edge on them. See how thick of a feeler gauge you can slide between the surface and the staight edge. Also, check to see if there is a crack or corroded casting around the water crossover ports.
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