Vortec headed 400 truck build up cam and using my heads?

[Chevelle45466]

Vortec headed 400 truck build up cam and using my heads?

I'm building soon a SB 400 to replace my Vortec headed TBI 350. It ran well and lots of folks do 383s in their trucks so why not a 400, I Have the block.

I'll need some cam help.

I all ready have Vortec heads with 2.0 /1.7 or so SS valves bowl work and mild port polish. New springs/ retainers/ locks/ seals. I bought them for a decent price and used them on a 350 in my truck. I all ready have GMPP 1.6 roller rockers that are self aligning and the GMPP TBI Vortec intake was on it. The Vortecs even had the steam holes drilled before. LT Headers and bigger 90lbs injectors and 50mm throttle body.

The 350 spun rods, cam, probably mains to. Makes me sick.

So I pulled my 400 block I bought last summer and it is in line at the machine shop it had all ready been checked for being sound prior to me at the same shop.

Will the Vortecs choke it. My other 400 has Dart Pro 1s 215 ports 64cc with a nice inverted dome, but it is a little higher strung even with w 3000 stall and 3.73s. Pulls hard to 6200+.

If I blow the 400 some day or want to pull it. I made the plan to use the 64cc chambers on a 383/396 SB. More and more common for 64cc heads every where.

I was going with a 9:1 piston with 5.7 rods.

I thought the Vortecs were good to 400-420 HP.

Wouldn't the port velocity help make torque down lower?

In my case it won't see more than 5500. But this truck is heavy.

It will have retro fit hydraulic roller lifters and a decent cam considering it is 4x4 with a 2500 stall 3.73s an a 29-30 inch street tires it will need torque.




CAM selection... remember retro fit hydraulic roller camshaft???

Torque and pulling to 5000-5500 a plus realistically 5K

What is the combo good for number wise???


Help. Please

[gmc406]

I'm not sure what roller cam would work with the 406, because I don't have much experience with roller cams. But, vortec heads would produce bottem end torque like a big block. If your looking for 5500rpm, they'll be just fine.

[H8NURIS]

COMP Cams Xtreme Energy retrofit camshafts.

[Busted Knuckles]

What pistons are you going to use for 9:1? The closest I found were KB 126 with a 30cc reverse dome. One of the car rags did this build and got 525tq and about 450hp. I think those numbers are a bit inflated, but 500tq shouldn't be a problem and they should hold on to around 5000 - 5500 rpm's. I'm doing the exact thing on my '77 Blazer, I'm going to run a hydraulic roller similar to GM's hot cam. It'll pull like a big block, just don't know what it'll do for fuel economy.

[Chevelle45466]

http://www.cnc-motorsports.com/product.asp?ProdID=12518&CtgID=

SKU: KB126

Manufacturer: Keith Black
Mfg part #: KB126

Description:
Keith Black Hypereutectic pistons are a T-6 heat treat piston with the machining features of there new generation forging and utilize the properties of 390 alloy. There are significant advantages with hyper pistons in compression restricted classes. The low conductivity of the alloy and reflective piston top surface lowers oil temperature reduces combustion heat and pressure loss. Tight suggested clearances keep things quiet and reduce oil consumption.

Piston Specifications
Bore Stroke Rod Length Comp/Ht Ring Size Pin Size
4.125 3.750 5.700 1.466 5/64 5/64 3/16 .927

Piston Weight Pin Weight
565g 145g
CR/58cc CR/62cc CR/64cc CR/76
9.6 9.3 9.1 8.3


These should work well. I'm doing a complete rotating assembly from them. Eagle cast but balanced with new balancer/flex plate.

$893.95

CNC-KB126

http://www.cnc-motorsports.com/product.asp?ProdID=20508&CtgID=

CNC External Balanced Performance Kit, SB Chevy 400, 3.750" Crank, 5.7" Rods, 9.1:1 KB Pistons
Our price: $ 893.95

Type: Product
Availability: Available

Qty: Buy now | Add to wishlist | Add to favorites

Ask a question | Email to a friend | Print

SKU: CNC-KB126

Manufacturer: CNC-Motorsports
Mfg part #: CNC-KB126
Bore size
std (add $ 30.00)
.030
.040
.060

Recalculate

Be the first to review this product. Write a review

Description:
CNC-Motorsports Performance Rotating Assembly kit's are hand picked to deliver you reliable performance you can count on with out sacrificing quality, Yet maintain a very affordable price.

Kit Details
# New Eagle Cast Steel Crankshaft
# New Eagle SIR Lightweight Steel I Beam Connecting Rods ( Bushed Fit Pins)
# Keith Black Hypereutectic Pistons
# Performance Piston Ring Set
# Clevite 77 Performance rod and main bearing set
# New Harmonic Balancer and Flexplate will be included
# Rotating Kit's are External Balanced, +/-2 Gram balance on pistons and rods, 1/2 gram or less on crankshaft balance, bobweight balance card included.



Stroke Rod Piston/Pin Weight Dish/Dome CR w/58cc CR w/64cc CR w/76cc Ring Pack Piston Brand
3.750 5.700 565/145g D-Cup 30cc 9.6 9.1 8.3 5/64 5/64 3/16 Keith Black



Compression ratios and piston weights are calculated using 4.155 bore with a .038" thick head gasket.

I remember that the best flowing small block production heads never flowed as well as the production Vortecs.

Sure after market heads flow more larger runners but they beat the heck out of the stock TBI heads and I have them.

Port velocity is also very important not just flow. If I could find a set of 200cc heads dirt cheap I'd jump on it. But even no-names are $700.

I'm looking for some real grunt. So torque numbers are important.

Thanks,
For all the input.
Rob

[H8NURIS]

Check CamQuest by comp cams. You can play around with the different cams to see what kind of torque you can get with your heads at different RPMs. I used it to build my 406.

[Chevelle45466]

If any of you are interested I have pictures of my port work and engine assembly at my web shots page.

http://rides.webshots.com/album/562900897Kwqvqk

I'm wanting to add an external fuel pressure regulator. I bought a cheap import one that was posted on another board or on here had been used. Mounts in the return line. Lines look so small.

Thinking I might as well spend the money on an Aeromotive or Holley AFPR. And use A/N fitting with -6 lines.

Engine should be going in this weekend. Hope to hear it run soon and then See how long the 4L60E will last.:bang:

THe cam I'm using is on a 112 LSA .519 lift duration 217 Intake and .500/221 on the exhaust.

http://good-times.webshots.com/photo/2013217370030004544vdNLcp

[bored&stroked]

Vortecs will work great for this combo. Bigger cubes means more cam can be used without upsetting low end torque. That with the roller cam means you can get to .500" lift pretty easy and thats where the stock vortec port peaks its flow.