406 sbc build, need cam recommendations, scat crank, scat I beam rods 5.7, je srp 22cc inverted dome, heads 220 runners, 2.08 intake 160 exh , cc roller rockers 1104 7/16 studs, crower offset solid roller lifters, brodix hv intake same specs as super victor, 930 hp carb, this is going in a 2000 trans am 350 turbo 3500 stall, 373 rear gears, thanks in advance guys. The chambers in the heads are 74 cc
This is a pump gas street an strip deal

 

288hr always works great in a 406.. Large stroke big inch small blocks don't like to rev without a LOT of camshaft, so keep that in mind. Powerband is always 500+ rpm lower then advertised cam specs.

I'm running an nx276hr13 but I was running a blower on my 412. Pulls until 5500 to give you an idea.

-- Joe

 

Probably want a custom for that deal being a solid roller. Pump gas street car get a low impact/tight lash type deal. But other options exist.

comp 12-771-8 or 12-772-8 run good. My buddy i believe ran the 772 In his 406 that has a miniram intake on it, efi car. Ran high 10’s naturally aspirated and 9’s on some nitrous. Its streetable. But your compression will be more like 9:1 and thats not ideal, might want to go with the smaller cam.

You’ll have to check what springs you have and make sure they match the cam specs. You need the right pressure and lift capacity while keeping it closer to bind at max lift to extend life and valvetrain control

you could run a hyd roller in it with solid lifters with low lash as long as the lobe design is ok for it

 

Ok I'll check those out, Thanks for the insight...

 

What 220 heads are you running? Need to know the specs on the valve springs also as Orr pointed out.

Has the block been decked and what thickness head gasket. Compression could be as low as 8.4:1.

 

The heads are rhs, I'm gonna replace springs when I decide what cam I'll be using..

 

I'm gonna be replacing the 22cc inverted dome for flat tops, anyone interested in the inverted pistons, this bottom end is a balanced setup...how much of an issue with changing pistons

 

If you can get them near same weight you shouldnt need a rebalance. Whoever balanced it may beable to tell you what specs are and what weights could be used

 

Thanks for the advice orr, gonna go with flat tops an that cam you suggested comp 12-771-8, I want to thank all that chimed In......

 

I knew the compression was on the low side, I thought maybe with the right cam I could make it work, with all I spent no since compromising now,

 

Id also run 1.6 rockers atleast on intake side if ya can

 

Has the deck been blocked? What head gaskets? Trying to determine if it’s closer to 8.5 or 9:1.

 

Yes the blocks been decked 0.20. haven't bought head gaskets yet

 

0.020

 

Sorry, I missed the post about changing pistons. Those SRP 22cc dish pistons are pretty light. Finding a decently priced flat-top to match their weight might be challenging. However, if you want a naturally aspirated engine, the flat tops are a much better option with your combustion chamber size.

With the flat-tops, your combination will be very similar to one of the engines I did R&D on for a series of shop engines, but using Iron Eagle 215 heads with a little clean up in the pocket area. I’d expect, even if box stock, based on flow numbers I’ve seen, your 220 RHS heads would probably flow a little better. Pistons (compression), cam, and intake varied depending on race or pump gas and whether it was used more on the strip or the street.

Pump gas (10.2:1) more strip than street, a custom grind 252/256 -106 cam using 1.6 rockers for a gross .648/.600 lift was the go-to cam. Holley Strip Dominator single plane, at least an 850 carb, and long tube 1.75” headers with at least a dual 3” mandrel bent exhaust and high-flow (near zero-loss) mufflers were required. A good flowing exhaust is extremely important when dealing with tighter lobe spreads. For a 3rd Gen F-body, 1.75” long tubes and a single 4” exhaust is needed. It also needed a minimum of a true (not rated) 3200 stall speed converter. Idled at 1,200 rpm and brakes worked pretty good in normal stopping conditions – not so good if you had to make two hard back to back stops. Based on test vehicle’s ETs and speed, it was making around 540 crank HP

Pump gas more street than strip, same lobes (duration and lift), but cut on a 110 spread. The best overall intake for this combination, if not running more than a 150 shot of nitrous, was the big Brodix dual plane and a 1” Street Sweeper carb spacer. This would work well for folks that already were running 1.625” long tubes and a good 2.5” dual exhaust, or a good single 3.5” if an F-body. It idled around 1,000 rpm and brakes worked fairly well on a second, back to back, hard stop. For folks driving it more than a weekend cruiser and running less than, or wanted to run less than a 3200 stall, I’d back off a few degrees duration to better match the stall speed – a 242/248-110 solid roller was the smallest cam I’d spec for this particular series.

Hope that helps.

 

Do you have advertised/seat to seat specs for those cams?
What ICL would you have installed them at?

 

This was over 20 years ago and the documentation is stowed away in the attic or I'd verify it. However, I'm fairly certain the 252/256 cam was 285/289 advertised - 106 lobe spread installed with a 102IC and 110EC for more strip than street. If more street than strip, I'd top off the engine with the big dual plane intake and spacer, using the same lobes cut on a 110 spread installed with a 104IC and 116EC.

I didn't install very many of the 242/248-110 solid rollers - it really wasn't enough difference in power compared to a solid flat tappet to justify the price difference - just a little better vacuum and better response for the lower stall speed converters. However, I'm pretty sure the 248 lobe was advertised at 281 degrees. These were all custom grind Lunati lobes from the same family, so I'd assume the 242 lobe was probably 275 advertised (although the 242 lobe wasn't listed in their master lobe catalog). On this smaller cam, I'd install the intake center at 106 (110 lobe spread +4 advanced).