Looking for suggestions on 406 top end.

[BigRedMachine]

As of right now I have a complete bottom end for a 406. Looking to make about 450hp give or take on the motor. not trying to really go higher then 6000-6200rpm. Im looking for suggestions on a top end that will get me there.

Right now I have 4.155 bore with Stock 76cc 1.94/1.5 valved heads with a .480/.480 lift hydraulic cam, 1.60 roller rockers, 750cfm carb, edelbrock performer intake. Pistons have a .500"dome (-7.8cc) which is supposed to yield 13.4:1 compression with a 64cc head. Im assuming that with the 76cc head they are floating at around 11:1(correct me if im wrong).

Just looking to see about what I might have power wise right now and what I should change ie: heads, cam, intake, etc??? Also prefer to stay pump gas and streetable if possible.

Thanks in advance for any help given.

[BMSRACINGENGINES]

Here's a proven combo from a customers car.
10.1 406
Motown 220 heads
Crane 119651 Hyd. roller
Team g Intake 830dp
11.20's @3200lbs
10.40's w/150 shot
goes thru the traps at 6800
very steetable combo

[BigRedMachine]

I wanted to stay lower then 6800 RPM. More like under 6400. I only have a cast crank, studded 2 bolt with I beams and Forged pistons.

[Turbo chevelle]

I wanted to stay lower then 6800 RPM. More like under 6400. I only have a cast crank, studded 2 bolt with I beams and Forged pistons.

Ahh, screw it Marc .... whats an extra 400 rpms anyways ??? LMAO
Use a different rear gear ratio to lower the top end rpm or change the tires to a different diameter.

lots of options for you.

[BigRedMachine]

Im no worrie about being able to lower trap rpm and what not. What im getting at is that Im not trying to make all of my power at 6500+ rpm, because I will never use it.

[adamsvega]

if you have no plans on pushing it past 450h/p then your heads and cam can be conservative big dual plane open 1" spacer and 750 carb .
a bigger hydraulic cam and a small runner 265-275 cfm head at .600 will make you a torgue happy fellow
thats brodix t1 /dart conquest1 /old 215 afr and a comp 280xfi grind on 110 lca if any plans for nos use 113 lca adv. 5 deg.
at 11-1 and pump gas ya need a alum. head other wise a dart 2 steel head would be the best $$$ .
the bigger cost of the alum will save money when ya want to ramp it up latter and the old afr215 has alot of future potential with out killing your combo now

the afr 11-1 406 and that cam pushed a street chevelle into mid 11's on motor
not preaching but justa fact from 1990's
we got 406 motor we ran with a short .500 rule 280 tight lash solid roller dirt set up on 108 lca and ported dart 2(cfm 275) and a team g with devider dyno at 500 h/p 490 ft.











1

[BigRedMachine]

How well would a 292H cam work with a set of aluminum 200cc RHS heads or 195 AFR's and a victor Jr. I know it might make a little bit more power then I was looking for, but thats ok.

[adamsvega]

the bigger the duration the higher it wants to spin for power . if you over cam and under gear you will have a 12 sec. car!!!
what lca and ramp is the 292h on. with a wide lca or long ramp you will build alittle more where ya want it in mid but it will be down on total power .

[adamsvega]

.501 292/244 110 lca with 1.6 rockers and 195 afr
should get ya 2 440+ h/p and 450 tq but your power band is 4500-5500

[BigRedMachine]

I wound up getting a really nice set of done up 292 cast heads, and im going to use the 292H cam with it and a Victor Jr. intake. and 750 cfm double pumper. Compression is going to be a bit high with the 60cc chambers they are shaved down to, but im just going to break down and use the 110 octane

[adamsvega]

your going for the 292cam and head special huh?
the best worked 292 heads flow around 260(unless they look like beer cans uncle ronnie) so your rpm restriction will be golden and lotsa tq. down low . dont over gear/converter it .
the 292 cam( if it is the same as i mentioned above) shows your gas req. wont be as bad as ya think .your over lap will act as egr down low and cruising will be ok but dont jump on it with out 100 in the tank . your a perfect candidate for e-85 or mixed pump/ race.
just do 2 gal. of c-16 to 5 gal. 92 pump gas that will get ya over he 100 mark
ya get a % of lead needed for your heads and because the mix is leaded and unleaded it goes up 1.5 higher than you would think

good luck .
if ya can find a performer rpm or like manifold and a spacer give it a try you dont want top end above 6000 anyway

[BigRedMachine]

Yeah thats the route im going. Seems to be the best bang for buck for me right now and it should get me exactly where I want. The heads are from notyetS10 on here. His buddy 1badimport on here took them to Rich Maitre and said they were some of the best done 292's he's ever seen. Said the Exhaust side is obviously a little restriced but the porting on the intake side is excellant.


Thanks for you help adam, and do you think that will push me to the 440-450HP range with that high compression and all?

[adamsvega]

how much comp./chamber volume will ya have with gasket and your pistons ? if they are angle plug "turbo" small chamber and you got big ports (170+)2.02 1.60 valves and were gm perf. over the counter only
we beer can thin ported a set of these and had good luck with em on 350 roller motors buzzing 8k!!!
at 11-1 depending your head flow and exhaust about 425hp (240cfm@500/185@300)
with 1 3/4 headers and good 2.5"+pipes

[BigRedMachine]

Hes claiming flow numbers in 280's+. I dont know how accurate that is, but they also have 2.02/1.6's for valves.

Cylinder head chambers are at 60cc. Piston Dome Height is at 0.500in with a -7.80 Piston Head Volume. Head Gaskets are 8.9cc compressed thickness.

Going through 3" or 2.5" dumped before the axle from 1 5/8 headers

All of these compression calculators are giving me anywhere from 11.80-12.13 compression with those numbers I listed. The Jegs listing is saying 13.4:1 with a 64cc head, which I think is way off.

[BigRedMachine]

Anyone???