[Harold Cox]

Basically Im concerned about performance.

I have a zz4 long block I could use but I was hoping for more from a 406.

Wasn’t that impressed with the zz4.



So here is what I have for the 406 build.

Heads? I have a nice set of 461's with 64cc chambers, 2.02/1.60 in good shape with hardened seats and drilled for 400 steam holes with screw in studs. Not the 461X

But Im concerned that they may not allow enough air in and out and that with the 64 cc chamber I may be pushing my CR for 93 octane.



I would like to use the parts I have simply because of economics but if its not going to perform then I need to make changes.



I could spring for a set of heads…Not vortec please. Something aftermarket.



Heres a list of what I have

406

Bore:4.125

12.5 cc dish piston

5.7 eagle rods with apr blots

Stock crank

Dual-plane performer intake

750 double pumper

Double timing chain and gears

Rotating assembly balanced.

Block has not been decked





Summit Racing Part Number:CCA-CL12-239-3
Hydraulic flat tappet

Duration 262/270

Lobe separation: 111 deg.

RPM Range:1,300-5,600

Intake Valve Lift 0.462 in.

Exhaust Valve Lift 0.480 in.

But I have a few sets of 1.6 / 1.5 roller rockers if needed.

Grind Number:CS X4 262H-11



Im curious about the torque and horsepower with this set up and the performance I can expect.



Built power glide

3:36 10 bolt

1966 Chevelle



Thanks.

 

[Moosecountry]

those parts might net 360 hp?

 

[johnsongrass1]

Not enough details.......We need more details......All the details please
What are you wanting from this thing?
Is this a GM block?
I wouldn't use that Summit Brand cam. Too big of a risk.
Budget?

 

[Harold Cox]

Not enough details.......We need more details......All the details please
What are you wanting from this thing?
Is this a GM block?
I wouldn't use that Summit Brand cam. Too big of a risk.
Budget?

I would like much stronger performance than the stock 283. I've just always heard they provided incredible torque and roasted tires
Ok.
Yes GM block (509 Casting)
Ok I'll try to find out what the risk is on the cam.
Yes Budget. So far I'm 1500.00. Haven't purchased anything other than gaskets and bolts from shop. Rest came from local guys trading around.

Thanks.

 

[Harold Cox]

those parts might net 360 hp?

Thats not bad but do you think it would be the heads holding it back?

 

[johnsongrass1]

90 percent of the power is in the heads...
Do you have the block machined yet?
What parts do you have now so I know what you need to buy.

 

[Moosecountry]

I posted more information in your other thread (cannot find it). You need heads that flow at least 230 cfm but 250 plus would be better. The intake needs to be the "RPM" version or better. a 750 cfm on a dual plane is small for a 406.
When you choose you camshaft a 6000 rpm peak power rating will be in the 5400 rpm range for a 406. NOTE; I said peak power not max rpm. The headers will depend on the other parts you choose. When you get into the 450 hp range you might consider moving up from 1 5/8 primaries to 1 3/4" long tube headers.
If you insist on using a hydraulic flat tappet cam then stay conservative. Roller or pressure lubed solids are better choices.

 

[BogiesAnnex1]

I‘d like to understand what about a ZZ4 you find disappointing?

Your 406 build sounds weak and lacking mostly in heads and cam.

Weird because the ZZ4 has a fairly mild cam with very good heads. My first shot would be a better roller in the ZZ. I be looking at a street cam that times similar to the LT4HOT with 1.6 rockers to max out the lift and a dual row roller drive which might require you to grind a bit off the main oil passage where it projects into the timing case to get backside cam gear clearance.

Unless this is a real race car I certainly wouldn’t screw around with a Powerglide especially with a 3.36 rear axle. The tranny and axle ratio are all wrong for decent street performance. Your in a place where you need a much larger engine or a tranny with more gears or a lot more final drive ratio.

Bogie

 

[Harold Cox]

I posted more information in your other thread (cannot find it). You need heads that flow at least 230 cfm but 250 plus would be better. The intake needs to be the "RPM" version or better. a 750 cfm on a dual plane is small for a 406.
When you choose you camshaft a 6000 rpm peak power rating will be in the 5400 rpm range for a 406. NOTE; I said peak power not max rpm. The headers will depend on the other parts you choose. When you get into the 450 hp range you might consider moving up from 1 5/8 primaries to 1 3/4" long tube headers.
If you insist on using a hydraulic flat tappet cam then stay conservative. Roller or pressure lubed solids are better choices.

Awesome info. Thanks!

 

[ericnova72]

Are you willing to run a solid falt tappet cam?
Don't say "too much maintenance", because with modern tight lash cams, and modern pushrods, springs, full roller rocker arms, ARP rocker studs and polylock rocker nuts you could drive it as a daily and only adjust the rocker arms 1 to 2 times a year.....and rarely find anything more than .002-.003" loose.
It's not like the "good old days" of muscle cars with stock pushrods, stock rockers, stock rocker nuts running factory solid lifter cams where you were under the valvecovers all the time adjusting it if you drove it hard very much.
Modern valvetrains and solid cams work really well for the budget guys who don't want to spend to go hydro roller.

Cam and heads are your major power killers in the current build plan.

Cam is going to act 500 rpm smaller than described, because the catalog listing is based off using it in the most commonly built SBC, the 350. the 400's cubic inches just suck up duration like a sponge compared to a 327 0r 350....so keep that in mind while cam hunting.
I'd add at least 10° more if staying hydraulic flat, and 20-25° more if solid flat tappet(solids look bigger on paper but it takes 12° to 15° of duration lost to taking up the lash ramps).
A solid cam with 236-242° duration @.050, around .520-.540" valve lift would make really solid midrange torque.

An old schoo; choice that still works would be the LT-1 350/370hp stock solid cam....would put you at the 410-420 hp range on your heads.
Lots of mild circle track tight lash solids out there too that make great street/strip cams.

Your current heads, if they have had a decent bowl blending and light port cleanup can get you to 430ish HP and 475 ft lbs torque but beyond that you are going to need aftermarket heads or some serious professional port work on the 461 castings.

The 3.36 and Powerglide can work as long as you don't skimp on the torque converter....you are probably looking at minimum $650 converter to get the job done. Custom built for the car, not off the shelf junk. likely a 8" to 9.5" diameter, higher stall rating than you are probably expecting but built "tight" so that it drives nicely, lkely between 3300-3800 stall when you jump on it.
if you are really serious about maximium launch, then 3800-4500 stall, built tight. You'll be all grins.

 

[Harold Cox]

Everything I listed.

Are you willing to run a solid falt tappet cam?
Don't say "too much maintenance", because with modern tight lash cams, and modern pushrods, springs, full roller rocker arms, ARP rocker studs and polylock rocker nuts you could drive it as a daily and only adjust the rocker arms 1 to 2 times a year.....and rarely find anything more than .002-.003" loose.
It's not like the "good old days" of muscle cars with stock pushrods, stock rockers, stock rocker nuts running factory solid lifter cams where you were under the valvecovers all the time adjusting it if you drove it hard very much.
Modern valvetrains and solid cams work really well for the budget guys who don't want to spend to go hydro roller.

Cam and heads are your major power killers in the current build plan.

Cam is going to act 500 rpm smaller than described, because the catalog listing is based off using it in the most commonly built SBC, the 350. the 400's cubic inches just suck up duration like a sponge compared to a 327 0r 350....so keep that in mind while cam hunting.
I'd add at least 10° more if staying hydraulic flat, and 20-25° more if solid flat tappet(solids look bigger on paper but it takes 12° to 15° of duration lost to taking up the lash ramps).
A solid cam with 236-242° duration @.050, around .520-.540" valve lift would make really solid midrange torque.

An old schoo; choice that still works would be the LT-1 350/370hp stock solid cam....would put you at the 410-420 hp range on your heads.
Lots of mild circle track tight lash solids out there too that make great street/strip cams.

Your current heads, if they have had a decent bowl blending and light port cleanup can get you to 430ish HP and 475 ft lbs torque but beyond that you are going to need aftermarket heads or some serious professional port work on the 461 castings.

The 3.36 and Powerglide can work as long as you don't skimp on the torque converter....you are probably looking at minimum $650 converter to get the job done. Custom built for the car, not off the shelf junk. likely a 8" to 9.5" diameter, higher stall rating than you are probably expecting but built "tight" so that it drives nicely, lkely between 3300-3800 stall when you jump on it.
if you are really serious about maximium launch, then 3800-4500 stall, built tight. You'll be all grins.

Awesome information! Thanks. Considering all you said.