Camshaft for my stock 400 sbc

Well guys, I have a flat lobe on my all original 53,000 mile Caprice wagon. So I am going to do a cam swap this winter. Trying to decide what camshaft to use. I am wanting to keep stock convertor and stock valve springs. However I do want the lumpy sound of a performance engine. Nothing radical just something mild. What has everyone used with good results using basically a stock engine?

 

I had the same issue with my Mopar 360 with a mere 47,000 original miles on it as well. Found a mild Mopar cam online for about $125.00 including shipping. I love it, a decent sounding lope at idle. Performs well and was a breeze to install. Not being a chevy guy I'm not sure what duration and lift to recommend, but the new cam really woke up my 360.+

On a side note I'm not sure how the cam got flattened, the cars original owner was literally a little old lady. I bought the car from her, she was the one and only other owner of my car. She did let her idiot grandson drive it a bit, he managed to bend the hell out of the drivers side rear leaf spring, so who knows how much he beat on her...makes my stomach cramp just thinking about that jackass behind the wheel of my green baby.

 

The specs on my cam were .420 valve lift .050 duration 204 degree int & exh and 110 degree lobe spread.

 

http://www.summitracing.com/parts/sum-k00052/overview/

I ran this one in a '55 Chevy P/U with a stock convertor and I used stock Corvette valve springs for a early 70's since the cams in them had a bit more lift than the trucks and passenger cars of that time and plus I was usually forced to use what left overs my dad had or what I could afford. Don't think I really needed to, I believe the stock springs in the heads were good enough but it sounded and ran great with a 600cfm carb.

I ran that engine for 3 years or so and never had any issues with the valve springs. I also was using the stock 1.5 rocker arm.

 

I used stock valve springs and rockers as well, without issue.

 

1tireman that looks like a good choice. Think that might be my option. And for $134 how could you go wrong!!

 

I put the summit mid range in my poncho and I like it actually had to detune it a tad for the CRAP they sell for fuel now but it sounds lopey not if I properly time it it sounds and runs badd azz!


Gm SBC cams were NOTORIOUS for flattening out at low miles in those years

 

Edelbrock has a package set of intake, cam, lifters and springs if you want to know that works very well together on a stock engine with a few miles on it but I assume this is a late model caprice with efi. They also have a cam that follows along the same grind profile and allows for smog crap and efi. I like the performer package deal. It works quite well and better if you use the whole package. I.E. Cam, lifters, springs and intake manifold. I had the set on my chevy 400 sb and I was very happy with the 345 HP it made with a performer carb. But like all camshafts, the grind depends on your use and what you want to do with it. A big car like wagons with tall rear end gears need some bottom end torque to get em out of the hole and some mid range for cruising. I think the performer package is the best bang for your buck and they'll stand by the product's performance. Either way you decide to go, keep in mind the vehicle's weight, the stall in the torque converter and the rear end gears when you make your choice. If you want a big lumpy cam for the sound of it, you'll give up some in lower rpm performance. There are plenty of cams out there that'll idle smooth and give the power you need/want and might even be smog legal!? The cam is probably the most important piece of equipment in the engine so make a smart choice.
Good luck.
Dave

 

Dave, this is a 1973 Caprice Estate Wagon, 400/400 combo with a stock 2 barrel intake at the moment. I already have the Edelbrock Perfomer intake, 1406 Carb. I am just wanting a little rumble. Not extremely concerned with low end torque or overall performance. The car only gets drove to cruise ins, the drive in and just around town. The only concern I do have is with it idling with the A/C on. Thanks for the input though

 

That's why it's not always a good idea to expect no problems when buying "little old lady's cars." Engine damage/wear occurs during the first few minutes after start-up. Low mileage cars sit a lot and the oil drains off the parts. Cam and lifters are the last parts to get oil when the car is started. Even more so when the car is in a cold weather area. Being constantly started under these conditions, combined with short trips only to church and the hair dresser leads to flat cams.

 

I think my flat cam was caused by me. The car had been sitting the last 7 years and was a non runner when I bought it. I did not remove the distributor and prime the oil system. I suspect the cam was "dry" when it did start. Car ran perfect for the first month, then it has slowly started getting a "miss" and lately it has started the popping back through the carb. And that almost always means flat lobe or lobes on a cam. I knew better, I was just in a hurry. now that is going to bite me in the butt. So lesson is NEVER fire an engine that has been sitting for a long period of time WITHOUT priming the oil system

 

swanny my poncho sat for long periods on and off for years and when I changed out the cam it was fine.


SBC cams had a very very VERY bad problem with this from( I know a lot of old schoolers said the 307 in the late 60's) the 60's and 70's. I would not be surprised if it went bad if you started it every day, They got bad batches of cams and I have changed/seen them in cars with 50,000 mi (on a daily driver) or I do believe less.

I would go 1 step above an RV type grind maybe 2.

 

No matter what cam you choose, be sure to get a good quality oil with adequate levels of Zinc (ZDDP) or you'll get a lot more practice changing that cam out than you'd like. The oil is expensive, but so are cam changes.

From what I've been reading, and what I have in my 429 for when I fire it, Valvoline VR1 Race motor oil has a recommended level for flat-tappet cams. There are others like Joe Gibbs and a couple that escape me at the moment, but they are critical at break-in. It only takes a quick search to find countless horror stories of folks rebuilding their engines and not using a proper oil at break-in, and the lifters grenade on them literally blowing blowing chunks of lifters, cam and block apart.

So best of luck with the upgrade, and get a good oil with plenty of zinc!

 

Brad Penn is another oil with the correct levels. 15-40 diesel oils is what I have been using, But they too are getting lowered levels and will yet again switch.

 

Flat tappet engines really need the protection that the Brad Penn Oils provide, no matter what the engine mileage is.
Be sure and make the investment in a few cases and Wix filters to protect the engine.