Well I am getting closer to February which is when the motor will be built. I am wondering what type of intake do I really need for the 406?

My goal is for a realtively mild 406 with heads in the 200-215CC range. I would like to see a minimum of 300RWHP but am hjoping for @ 350RWHP

Is the ASM runner / base TPI setup going to be a major restriction, is 5200 RPM the max for this setup?

Or is the Mini or Super Ram going to be that much better for a car that will have a max RPM of 6500 due to the stock 400 crank? I woul assume that max HP/TQ will occur @ 5800 RPM.

I have not ruled out machining a new plenum for the Stealth Ram but sort of dont want to creat problems by making an unknown setup.



[Modified by ld85, 1:49 PM 12/30/2002]

 

You would love the TPI. The midrange torque is so fabulous with those things that they are a pleasure to drive on the street. However, 406 cubic inches will definitely be pushing it. I can easily get 5200 rpm with 355 cubic inches on my IROC driver, and maybe just a little beyond. And my 221 degree @ 0.05 cam (Iskendarian) is perfectly matched to the rpm range of the TPI. All I did was port the upper plenum just behind the throttle body (very important, there is a big mass of unnecessary aluminum that blocks airflow there), and port match the lower plenum to the heads. If you use an '87 or older TPI, the center bolts will match the older style small block heads. Otherwise, get the heads to match if it's 88 or newer TPI.

You have 51 more cubic inches than me, so I don't think you'll see 5200 rpm. You might see 5000, maybe 4800, so make sure to get a cam profile that will maximize things within that range.
Your torque will be very big block-like with a TPI on a 406.

IF you get the enlarged passage plenums and runner tubes, and larger throttle body, then I believe you will probably be able to get 5500 rpm. But that's a lot of investment for just an extra 500-700 rpm. You be the judge.

Otherwise, a TPIS miniram or the new Holley Stealth FI would work well. I really love the looks and performance of the Stealth set up, and that would be my first choice with a 406, especially if you want some high rpm.

The TPIS is plug and play, but the Stealth needs to be set up with a lap top computer. So once again, you be the judge.
If you need assistance with Dyno 2000, I would be very happy to help you. Just pick out some cams you'd like me to try, and I'll do the rest.

 

in all honestly one of the first things to think about would be the intake system not last you should have built the whole motor around which system you were going to use to optimise it for the most power if you are trying to go 6500 rpm long runners are out and so is a super ram so the only thing left is mini ram and stealth ram with along more gear to go with that its a whole combination not just throw some parts together :cheers:

 

Well since I have bought nothing but the block and crank I can still do what needs to be done. I had planned all along on modding a Stealth Ram to fit on the motor which I know is good to the 6K RPM range. But since there have been a couple of Super rams and Minrams come up for sale close to the overall Stealth Ram cost I wondered. With my 3:07 gears I doubt the car will see 6000 RPM too often. But the 5200 RPM is just not going to be high enough of RPM for this motor. I understood tha tthe motor should be designed around where it spends most of its time in the RPM range so I agree with the intake choice issue. Regardless there are 3 potential choices for an intake. My quesion was bascially can a TPI flow enough to get higher than the 5200 RPM range.

I am working from the bottom up and staying within the life of the crank and the 4+3 tranny which will be an occassional max of 6500 RPM, and working in the RPM band that I will drive the motor, so different strokes, I think they say!





[Modified by ld85, 7:53 PM 12/30/2002]

 

if you got to 5200 rpm out of large runners on a 406 i would be surprise if you got more than 5700-5800 rpm out of the super ram i would be surprised i have a 244 at 50 600 lift solid roller cam with afrs and dont pull more than 5600 5700rpm its done no more power i shift at 5200 5400 rpm its done and thats with a large solid roller cam and good heads if you are shooting for 6000+ rpm you will have to go mini ram the stealth ram has no background on a larger motor like the 406 i know because i was on vacation in bowling green last july and did a tour of the holly plant and talked to the two guys that did the r&d and dyno time on the stealth ram and had no real numbers what it would do on a large motor like a 383 or bigger they did all there testing on a 350 ci motor i talked to these guys at some lenghth and got no awnswears so with out hard numbers on a larger motor i think its a gamble at best :cheers:

 

Before my SC-with a 406, headers, 23deg trick flow heads(not ported). Intake=edelbrock base port matched to heads and runners; siam. runners with stock plenum, but plenum port matched to 58mm TB and to the runners. Cam=flat tappet hyd. 226/222 at .050 .494 lift with 1.6 roller rockers on a 114lsa.
With the above combo it would pull to about 5200/5300rpm and then it was all over....
Then changed to a SR without any further port matching...and then it would honestly pull to 5800rpm.
And :iagree: if you want more rpm than that, you're going to have to look at something else.

 

Drive it, thank you for this information. Your information is very useful. I have never built a motor like this before. So this helps me to understand where the RPM range is.

What CC were your heads? 190CC-200CC? Did you get any dyno info?

 

From the web!

Combo 70 comes from pages 29-31 the 2000 edition of Petersen's Hot Rod Camaros.

This engine is a 406 cu. in. version that is to be put in Mark Stielow's "Thrasher" 1969 Camaro. The build uses some impressive parts such as a roller cam, a Cola crank, and CNC'd Edelbrock Victor Jr. aluminum heads. The roller cam is pretty stout, and the lift seems huge with the 1.6:1 rockers; however, the EFI helps this engine to still be streetable. Note that the HP peak is at 6000 rpm, while the torque peak is at a low 4000 and 4100 rpm. This torque peak is only at 67-68% of the peak power rpm. Most engines have peaks that are closer, with the torque peak occuring at 75-80% of the HP peak rpm. Perhaps the EFI is the reason for this.
Displacement: 406 cu. in.
Induction: Accel EFI
Heads: Edelbrock Victor Jr. CNC
Camshaft: Crane hydraulic roller, with 286/294° of duration, 236/244° of duration @ 0.050 in. of lift, and 0.525/0.579 in. of lift (Corrected valve lift with 1.6:1 rockers is 0.560/0.579 in.)
Rockers: Crane 1.6:1
Headers: Hedman 1 5/8 in.
Pistons: Wiseco forged aluminum
Rods: Trick Flow 6 in.
Crank: Cola
Distributor: Accel
Comp. Ratio: ?

MAX HP: 460 @ 6000 :eek:
MAX Torque: 450 @ 4000 and 4100

 

im not harping on you id85 but that combo if thats at the motor looks preety weak it looks like a lot of mis matched parts now if it said 550-600 hp at 6000rpm and 450-500 ft lbs at 3500-4500rpm now i would say do that motor but that one you quoted would be hard pressed to break in to the 11s :cheers:

 

Have a nice winter, I may be back in the spring.

 

You did not mention your cam size which is very important when matching to long runner intakes, but I'LL give you a combo on a friends Vette I built.It's a 406 steel crank, rods, and forged pistons, hydrualic roller cam (comp cams) 230-236 112 LC , AFR 190cc heads mild porting , DFI computer, 36lbs injectors, Hooker 1 3/4 headers, the comp ratio is about 11.5:1 , evans coolant and careful tuning helps us run this high on pump gas. The intake is not exactly what we wanted to use but availability was a problem at the time. We have a fully ported stock lower (very restrictive), ported and shortened Super Ram runners to increase top-end and a Super Ram plenum with 1000cfm throttle body. Many would think the cam was to big for the long runner of the Super Ram intake but the added duration helped soften the low-end, matched to the internally shortened runners and helped relieve cylinder pressure with our 11.5:1 cr. It all worked out great! 350rwhp @ 5200rpm and 500ftlbs of torque @ 3200rpm this equates to 440hp and 500ftlbs of torque!
There are about 50horses lost in the lower intake! The right intake would be a big mouth or accel unit with full extrude hone and then finished of with some hand porting. But idealy the best intake would be a modified single plane carb style intake( for those who don't mind some linkage and fuel line modifications) it loses very little low-end if any when compared to the long runners and the top-end is much better especially on big inch motors .
good luck! P.S. We went 12.00 @112mph on the first pass drag radials and 3.08:1 gears with a th400 and Dana 36. easy 11 sec car!

 

Forgot to mention the single plane intake conversion is also alot cheaper than those long runner intakes available. about $1000.00 cheaper! good luck!

 

If you only want 300 to 350 horse at the wheels how fast do you want to go ???

I can't see why you want to take it up to anywhere near 6500 rpm

I'M running mid 12's with my 350 ltr motor and i only see 5200 rpm max

I think you would be happy with a superram or even an aftermarket ltr setup but if you are spending the money i would go for the S/RAM.

Corky runs low 11's with a S/R 406 you have said before you only wanted to run 13.0 flat you could do that with a 406 and the std ltr setup but it won't rev well above 4600 rpm

I agree with Corky decide how fast you want to go and build a motor to suit that. Tell us how fast you want to go and we can tell you what to use :yesnod: :yesnod: :yesnod: :yesnod: :yesnod: :yesnod: :yesnod:

:cheers: