318 cam

65Dart270Sedan said
Having a hard time getting the answer I’m looking for, so I’m going to try this again. I’m building a LA 318 out of a 74 satellite with the most amount of stock parts and cheap mods as possible. I’m new to all this and I don’t have a lot of money to work with . I want to put a cam in this engine and I found a cheap cam on summit racing with 285 duration and 480 lift. What mods will have to be done to make this work? Thank you in advance. Summit Racing SUM-1798 Summit Racing™ Camshafts | Summit Racing this is the cam I’m thinking about getting.

You have not purchased the cam yet. Better take a step back and think about this a bunch. On an engine rebuild you need to define what you want to accomplish as an end result. That is a lot of cam for using as much stock parts from 1974 as possble. Those year engines had low compression and open chambers. Open chamber heads are somewhat prone to detonation as compared to quench heads. Do not choose a cam solely on price. If a cam fits your build specs and will give your expected performance and you get it on sale, good. But purchasing the wrong cam just on price is a lesson in frustration.
Describe on here exactly what you expect for an end result and budget. Then people on here can give relevant advice.
With looking at using as many stock parts as possible, you probably need to look at an "RV" style cam. 210° to 220° @0.050" tappet lift. If your valvespring installed height is aboit 1.800", beehive springs can be used to control spring harmonics. You will need different retainers and probably locks. For valve lift, if you do a little pocket porting and port match, the 0.475" lift at the valve is probably good. Build the engine for 0.525" valve lift to clear the pistons. This way if your cam is a bit less on lift you can later upgrade your rockers for a higher ratio. Intake is more sensitive than exhaust, so you can just replace the intake rockers. Remember you are likely telying on atmospheric pressure to fill the cylinders. The exhaust has give or take 100PSI at EVO pushing the exhaust out. Then the piston on the exhaust stroke is pushing it out.
Careful consideration must be given to the intake and exhaust manifolding. Stick with a dual plane intake for low RPM torque and driveability.

Dartswinger70 said
I have heard in my travels that, with a LA 318 the stock cam is best in terms of economy reliability and power. Stock lift on an LA 318 cam is below .400" I know most wont want to accept that but , I'd bet there is something to it. Without heads, ( and I don't mean ported stock 318 heads, I mean upgrading to a 340 style head with the large ports. ) there really is no need to cam a 318 but that's just my $.02.