Big Block Chevy Cam Recommendation Anyone?

OK, I'm posting this for a friend who is building a big big block Chevy. He is looking for some cam recommendations.

I'll give you the specifics that he told me. The car is a 1987 Buick Grand National weighing 3500lbs with 28 inch tall tires, 411 gears, and a TH350 with a 3800 stall torque converter. The engine is a 565 cubic inch, with Dart Pro 1 355 heads, 1.7 ratio roller rockers, super victor intake, and a Holley 1050 dominator carb. This car is pretty much for drag racing only, with occasional street use. Any recommendations will be appreciated and considered.

I'm "assuming" he means Dart 360s... (BBC head, 360 CC intake runner)

Before we get to the cam, tell him to discard that TH350. Behind an engine of that much torque, it's not gonna last more than a couple passes. In the heavy car (over 3,000), TH400 is a much better choice than PowerGlide. I wouldn't consider any other automatic transmissions. Maybe a LencoDrive...

For a solid roller in the RPM range that engine wil operate (6,000-7,000), Comp's .440 lobe lift stuff is very good. It will yield right at .750" lift with those rockers. You didn't say what the compression ratio was, so we'll have to "wing it".

10:1 or lower, keep duration under 260 @ .050" lift on the intake side.

10:1 up to about 11.5, make it 272

Over 11.5:1, 278.

Any duration higher will require more RPM than that big boy will "like".

Those are pretty good heads on the intake side, so exhaust should be equal or up to 4 degrees MORE. LSA should be kept around 110 or 108 for a streeter with "race" potential.

I was looking through the Comp catelog, and there isn't really a good one for this combo "off the shelf". Too much weight and/or not enough stall for the stuff they list. They have an extensive lobe library and can "make" you anything you want. The price doesn't change unless you want an oddball journal or base circle or something like that.

Jim

A bit more info on the engine. It's a Dart block 4.60 bore and 4.25 stroke. Dart Pro 1 heads with 355 cc runners CNC'd. The part number for the heads is DRT-19574136. Forged pistons, H-beam rods, 2.30/1.88 valves, 10.25:1 compression.

As for the TH350...he figures it'll split in two, so he is planning on getting a TH400 ready to put in. :smile:

Well, there ya go! We call those heads "360", as that's the nearest runner size. Dart calls them that in their catelogs, too (unless it's something brand new I haven't seen, which is possible...). As they've been CNC-ported, they may have started life as "320s".

Using the .440 lobes, make it 272/276 @ .050" lift, on a 110 LSA. Put the intake lobe at 106 and the exhaust at 114. I don't have a lobe catelog handy, or I'd give you the lobe numbers. Call Comp and ask for Gary. He's very knowledgeable in this area. Tell him Jim from Central Virginia Machine sent you. It won't get you a "deal", but it WILL get you honest service!

Jim

Thanks for the advice Jim. I'll pass the info along to my buddy. I'm sure he's getting itchy to get it all put together and in his Buick.


I knew I shoulda raced him when he had the V6 in it.:banghead:


Thanks again,

Darren