H.P guess

[nicks diner]

Just finished up my truck and it runs very strong with a built 406. Im thinking bout getting it dynoed soon but was curious what you all think. I will list the mods as best as I can and thanks.
406 forged gm crank 4 bolt main arp
5.7 Eagle hrods
1.6 comp roller rockers
K.B forged flat top pistons, around 11.5 to 1 on the high side
Dart aluminum 200 cc with a mild port
Hydraulic roller comp cam,intake 533 exhaust 519 duration@50 243 257 107 lsa.
Hooker pro comp ceramic 1 3/4 out 2 1/2 Black Widow exhaust (amazing sound by the way)
Msd 6al
150 shot NOS with digital retard
holley 750 double bumper pro built
AIR Gap intake
I think timing is set at 28.
posi 3.5 gears.

I can try and answer questions the best I can but im basically curious what this combo will net me.

[Blue Rat]

That .050 an CR sounds high too me for a street engine. But still seems like a well thought out engine. Who designed the camshaft?

450 HP.

[nicks diner]

Originally Posted by Blue Rat

That .050 an CR sounds high too me for a street engine. But still seems like a well thought out engine. Who designed the camshaft?

450 HP.

All I know on that is that it's a custom ground Comp cam. I wanted it lumpy and that's what I got. By that way stall converter is 3000 and Trans is th350.
Thanks

[moggey01]

alot of variables such as ring package ,type of hone , etc. left out. ummm 460 -520. Dynos vary also.

[nicks diner]

Originally Posted by moggey01

alot of variables such as ring package ,type of hone , etc. left out. ummm 460 -520. Dynos vary also.

Yeah I left a few things out that I'm not sure of. Was hoping for 500 without the spray. Any suggestions or input would be appreciated. By the way I do run 100 octane.

[HemiChallenger71]

Check your cranking compression. You more than likely will be fine on pump 93. That cam has a ton of overlap. The low lift kind of makes me scratch my head. Sounds like a comp thumpr grind.

My guess on motor is 440/450hp 500ft.lbs. at the crank. I also think on the hose it will pick up less than 150hp because of the camshaft.

In the truck my guess is 330hp 420ft.lbs. at the wheels N/A and 450/550 on the hose.

Keep this thread updated with your results!

[nicks diner]

So you're saying my cam is costing me power? Sounds amazing and feels strong. Any suggestions on my setup ?

[Blue Rat]

http://competitioncams.carshopinc.co...90485/12-602-8

[GASoline71]

Building for sound is what the Thumpr line of cams is all about. Nothing but sound at idle. Huge amounts of overlap with a narrow LSA is costing you power.

Gary

[nicks diner]

Originally Posted by GASoline71

Building for sound is what the Thumpr line of cams is all about. Nothing but sound at idle. Huge amounts of overlap with a narrow LSA is costing you power.



Gary

Intresting, I've seen very good Dyno #s in the mid and upper range with that roller cam,I know they got a bad rap when they first came out with the flat tappet but I guess it is what it is. Figure the bottle can always make up for it and something else to change later. Ty

[HemiChallenger71]

Its a N/A cam not really designed to work well with nitrous. Not that it cant work or wont.

How are your power brakes?

Yes you can always try another cam. The nice part is you can re-use everything you have an just change the cam and valve springs (depending on whats in there now). I think there is a lot on the table depending on the heads. What exact 200cc dart heads do you have? There are several.

[cableguy0]

I agree with everyone else. The only thing that cam is going to do well is make noise. Your leaving a ton of power on the table. Low lift and high duration doesn't do a lot for you. With a 200cc and 400 cubic inches I would want to be .575-.600 lift and in the mid 240's@.050 duration to have a screamer. The nitrous will help but there is only so much you can do without air flow.

[Marv D]

Originally Posted by cableguy0

I agree with everyone else. The only thing that cam is going to do well is make noise. Your leaving a ton of power on the table. Low lift and high duration doesn't do a lot for you. With a 200cc and 400 cubic inches I would want to be .575-.600 lift and in the mid 240's@.050 duration to have a screamer. The nitrous will help but there is only so much you can do without air flow.

DITTO

Short duration HUGE lift is the current trend in custom cams,

Which Dart aluminum heads?

You have an issue with retro hydraulic rollers in trying to get lift up 'huge' and not have oil band / exposure problems when you step over the .43ish tappet lift. So getting lift up becomes a function of how much you want to spend on a rocker system. You 'can get' 1.8:1 shaft rockers for whatever head you have... but they start costing more than the head casting themselves at some point.

I'll be slightly more generous than some,, I think you may have 450-460 at the flywheel.

At the chassis dyno your going to be sorely disappointed in the number.

[nicks diner]

Dart shp 64 cc
had my 03 cobra set up at steeda,they did stock dyno runs at 335 at the wheels. After intake exhaust and pully changes upper and lower hit 405 at the wheels. My current set up would kill my cobra so I'm kinda confused. I am going with afr 220 aluminum in a week or

[Marv D]

Be aware, Afr advertises "accepts stock valve train components" and that is absolutely true! But 'accepts' and "has correct valvetrain geometry" is two worlds apart here. Crower, Jessel T&D,, everybody has a package of offset shaft rockers to specifically make the 220 / 227 heads 'tits-up' correct. The .45\.1 offset corrected the early 220's, and I believe is still the correct # for the current 220\227 offerings. This is the Crowers I used on the set of 220's in the 66. You can see by the pushrod vs valve tip here how far they moved the intake to accommodate the 2.08 intakes, and make the port work so well as it does.

Do NOT misinterpret that,, AFR is a really REALLY nice head and when they advertise a flow # its not some inflated BS pie in the sky number,, I've had 4 sets of AFR's on my personal motors and have built more than a few (both street and race) motors using their heads. Every set I had on a reputable flow bench come back within 1-2% of advertised. Tony guarantees that 2% out of the box and has never let me down.

Only thing I'll say is if your changing heads,, get rid of that cam and get something more appropriate to the 406, more appropriate to racing, and more appropriate to the giggle gas. That is,,, unless your looking for a street machine that will only see the track as a novelty.

all that said..
Those SHP heads are really not a bad head. I think 200cc is small for a 400" motor that you are taking racing, but with a retro-hydraulic roller that is never going to see the high side of 6000rpm they should make a kick-az street motor. Cubic inches makes torque and the 400 is next to end of the road for cubic inches in a small block. Except for the goofy duration I think the motor 'as is' will make really good streetable torque from around 2800-5500. (where we spend 99% of the street driving time anyways)
But too many things are working against you up high to make impressive horsepower numbers.
Remember horsepower is nothing but a calculation of torque and RPM. And you have to make good torque above 5252 RPM to have 'good' HP numbers. I think that is going to be the issue that makes the numbers disappointing. Everything in the combination is working against high RPM's

The 750 carb is absolutely MINIMAL for a 406 spinning 6800-7000 rpm
The cam has been discussed
If the block is stock deck you have 10.9:1 compression,, if it was zero decked, you have 11.6:1

EXCEPT,, many MANY of the KB flat top pistons have a dramatically reduced compression height. If those pistons are in the hole 0.060" , and a 0.050" gasket, and the stock 0.025" deck,, you could have as little as 9.1:1,,, or as high as 12.3:1 if everything is built to minimize quench.

There is a LOT of unknowns here and (DO NOT TAKE THIS AS A SLAM) from what I see is a nice combination of 'whos who' from the parts catalog,, but not really a well thought out combination intended to make power for the race track.

The chassis dyno is very subject to way too many things that can sway the number. If you want a real world measure of what is in this,, take it to the track and FLOG IT,, lets see what is really in it.

[nicks diner]

Makes sense and I also know I can't just slap a pair of afr and be done with it. But your right it pulls very hard to the Rev limiter wich I have set at 6000. Brakes work good and street manners are surprisingly excellent. To be honest I doubt my truck will see the track anytime soon. Much appreciated input thank you.

[HemiChallenger71]

If you like the way it runs and drives then dont mess with it.
6500 is more than safe on the limiter, I'd put the limiter at 7000 and shift at 6500 if it were me.

I ask about the power brakes because I doubt that camshaft pulls more than 10in.hg at idle and a lot of those small boosters dont work unless theres 12-13" hg. You may not actually really have any power brakes is what im saying. Worth a look into.

[nicks diner]

Would a vacuum canister help?

[slotard]

If you end up replacing the cam with one designed to make power you might consider going solid roller. With modern materials, solid roller cams shouldn't require valve adjustment very often.

[nicks diner]

I was just curious bout what you all thought and I definitely learned bout what it takes to get it at the track and I'm probably a little short on the higher rpm range . Quick story I have a customer and also feed the corvette club here in Orlando twice a month. 2010 zo6(not a member but my neighbor ) and we played around from a 20 mph roll (no cars around ) and I held 2 car lengths and pulling (no spray) on him till he shut down at a pretty good pace. I'm thinking maybe this cam and set up will surprise a few more on the street. the thing that impresses me the most is how well it hooks up,much better than my pos 03,wheel hopping , 33k super whatever cobra. Anyways thanks for the input and love my Chevy and this forum.

[imjeff]

I would invest in a dyno tune. Often times the cheapest HP available. Then you'll know the HP and, more importantly, the optimal timing so you don't puke the motor. It's hard to detect ping with a healthy exhaust.

Jeff

[nicks diner]

Definitely, local shop here has a mustang dyno which is conservative and more precise. I will post the sheet when I get this done. Thank you

[dubds10]

Ever get this done? Interested to see what numbers you were putting to the rubber.

[nicks diner]

Actually put a brand new AED carb on 3 weeks ago and it is an amazing difference. The shop I was gonna do the dyno pulls on was closed for a month on vacation so waiting on them. Keep you posted when I finally get it there.

[flips72]

cant wait to see the numbers on this, hope you are surprised in a good way sounds like a lot of fun. I`m also running a 406 , dart pro1 215 runners and 626 lift solid roller, victor jr with a 750 demon worked by stealth racing, don't have a clue what kind of power it makes but with a 150 shot on 275 radials it has went 6.98 in the 1/8, so I think you will be happy with your set up.