Thread: Cam for 400

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I'm doing a little work to my 400 small block. I'm going to put an edelbrock performer intake on it. I'm debating on what cam to use. I'm thinking one of these two:

Comp Cam
Operating Range: 1300-5600 RPM
Duration Advertised: 262° Intake / 270° Exhaust
Duration @ .050'' Lift: 218° Intake / 224° Exhaust
Valve Lift w/1.5 Rockers: .462'' Intake / .469'' Exhaust
Lobe Separation Angle: 110°

or
Comp Cam
Operating Range: 1600-5800 RPM
Duration Advertised: 268° Intake / 280° Exhaust
Duration @ .050'' Lift: 224° Intake / 230° Exhaust
Valve Lift w/1.5 Rockers: .477'' Intake / .480'' Exhaust
Lobe Separation Angle: 110°

A friend of mine that is a mechanic and professional truck puller suggested I go with the first option since i'm running an auto tranny, but I've got a 400 turbo tranny for it. What do you guys think? they're both the comp extreme energy cam. I'm not trying to build 400 horse, I just wanted to build it up a little over stock since I've got the engine on the stand.

With the big problem of lack of zinc in oil these days, whatever grind you choose I'd suggest getting it as a hydraulic roller. The flat tappet cams just don't seem to live anymore. Friend of mine has to replace his Lunati, less then 4,000 miles on it and losing a couple lobes already......

Remember those cams are probably designed for a 350 so a 400 will tame the cam some. Something with a slight lope in a 350 will idle dead smooth in a 400. 400s need a larger cam to breath through 350 heads. Half a bottle of GM EOS at each oil change is way cheaper than a roller cam conversion. Keep the valvesprings reasonable, break it in right and flat tappets can last.

I had a 400 bored .030 with dished piston, 58cc heads with 2.02"s/194's, my cam was the 58239th cam that UltraDyne ground. cam was a 276/286 at .0045", 221/230 at .050", .454"/.454" valve lift, and 110 LSA. It should be in the engine on a 104° to 106° ATDC ICL--ie, 4 to 6 degrees advanced. It should work with anything between 9:1 to 10.5:1. Power in a 406 should be from just off idle to 6000, with peak around 5200. Idle should be around 750, and there was enough vacuum to work power brakes. I used stardard felpro blue gasket, Q-jet with drilled idle mixture jets and I run 87 octane, with th350 tranny. I ran 87 octane with 36-38 degs timming and had no ping. My cam was a flat tappet and if you use the correct oil (study your oils on which "TO" use, ("Most" diesel oils or farm use oil) and a bottle of GM EOS during break in you'll have no problem!

Mine had a healthy lope to it , with factory torque converter, and a shift kit.

Pat

Thanks everybody!! I still don't know which I'll go with, but thanks for the advice!! I'm definately going to be researching oil and additives more before I break it in.

I don't know how to start a new thread but this is close to my question. I am nearing the wiring installation finish line on my '29 roadster with a SBC 350/700R4/Maverick 8" so I am thinking about my engine break-in. I have filled it with Joe Gibbs break-in oil but it has been over two years since I bolted on the heads. I recall that all the tappets dropped in their bore holes easily except for one. I have adjusted the valves statically with 1.6 ratio roller rockers but I want to play it safe for break in and I will replace the rockers with another set of 1.5 ratio rockers so I will have a chance to look at the tappets and re-oil the pushrods. My plan is to install the 1.5 ratio roller-tip rockers and reset the valves statically along with squirting ZDP oil additive into the lifter holes and the pushrods. My question is how does one get out the tappets? I do not see any way to get the lifter-tappets out. Is there some sort of special hook to pull out the lifter-tappets? If not then I would at least like to spin the tappet-lifters in their bores to check to see if they are free and I think all but maybe one is but I don't want that one tappet-lifter to wipe out the cam lobe under it. I guess you can only spin the lifter at TDC when the rockers are on there but I should be able to spin them with the rockers off? I remember lapping in valves in a flathead '36 Plymouth six with my dad long ago and we used a wooden dowel with a suction cup on the end and spun it between our hands to lap in the valves. Is there some sort of suction cup tool to spin the lifter-tappets in their bore to make sure they are free before startup? A dumb qestion but I don't want to lose the cam.

Don Shillady
Retired Scientist/teen rodder

Should be able to pull them out with your fingers... If they're down in the bore too far you can pull them up carefully with a curved pick hooded under the retaining ring that holds the pusrod cup in the lifter. Last thing to do before you fire it up is pre oil it....Then just hope for the best on the cam break in.... I've given up on flat tappet cams, seen too many wiped out too fast. All rollers for me!!! good luck, should be fine.

If you watch you will see the pushrods spinning--if they are spinning the tappet is spinning

If not, and it happens to be the one your worried about, stop and pull the manifold and check it out more closely

Well I don't want to break the seals on the intake so I will just lower the spring pressure with the 1.5 rockers instead of the 1.6 set and fill the pushrod holes with ZDP additive, as well as the normal pre-oil with reving the pump. If the pushrods don't all spin I will then have to remove the intake and take a close look at that lifter-tappet. Thanks for the helpful comments.

Don Shillady
Retired Scientist/teen rodder

Don if I remember Right your 350-355ci had a Camshaft not much Larger then a Stock 350 Chevy . And your Valve Springs on them 882 Heads were not heavy Seat PSI either . With the right oil and EOS Additive and if you run it 20 Min at 2000 you should have Zero Problems with Camshaft Break in and Life of that Camshaft .

Originally Posted by huntboy3181

I'm doing a little work to my 400 small block. I'm going to put an edelbrock performer intake on it. I'm debating on what cam to use. I'm thinking one of these two:

Comp Cam
Operating Range: 1300-5600 RPM
Duration Advertised: 262° Intake / 270° Exhaust
Duration @ .050'' Lift: 218° Intake / 224° Exhaust
Valve Lift w/1.5 Rockers: .462'' Intake / .469'' Exhaust
Lobe Separation Angle: 110°

or
Comp Cam
Operating Range: 1600-5800 RPM
Duration Advertised: 268° Intake / 280° Exhaust
Duration @ .050'' Lift: 224° Intake / 230° Exhaust
Valve Lift w/1.5 Rockers: .477'' Intake / .480'' Exhaust
Lobe Separation Angle: 110°

A friend of mine that is a mechanic and professional truck puller suggested I go with the first option since i'm running an auto tranny, but I've got a 400 turbo tranny for it. What do you guys think? they're both the comp extreme energy cam. I'm not trying to build 400 horse, I just wanted to build it up a little over stock since I've got the engine on the stand.

What Cylinder Heads and Pistons are you running in this 400 . If it has Stock Cast Pistons and 882 Heads the First camshaft will be Over stock but very Streetable . If you have Stock Valve Springs they need to be Replaced and your at Max on Pressed in Rocker Studs with #1 no Chance in running #2 with out Up-Grade's to your Cylinder Head's and a Bump in C/R . Again this is if that 400 is a Stock Long block ?

I will be going thru this for my 383, 305 series cam. I had the cam treated by comp cams and will run a break in oil with zinc. I will also leave out the inner valve springs for break in.