[1034]

Hello folks, I came across this website dedicated to Challengers by mistake doing a web search for the above topic. I spent some time here and it's nice to see a webforum dedicated to the Challenger.

I've had my 70 Challenger for about 6 years now, and it's been sitting in my various garages the whole time. I am now ready to semi resto/customize this car now starting with a full paint strip to metal and yanking out the 440 and rebuilding it.

I need advice on a hot street 440 build up. I'm going to throw out some items/desires and see what you guys think.
These are some of the directions I wanted to go, totally open to critisism as I have never built an old muscle car era engine.

I plan on using an Edlebrock RPM performer intake, unknown 750-800 carb, possibly Holley possible Speed Demon, I plan on buying a set of Edlebrock 84 cc closed chamber heads and using 2.14/1.81 combo valves, As far as compression ration, I will run cat pee California gas (91) but I do have access to a gas station that sells 100 octane at the pump so I was thinking 10:1-10.5:1, should I go higher?

I have been told Keith Black pistons are a good choice, now as far as camshaft is concerned, this is where i'm hung up, I want a good match for the head/intake but I also want a wicked cam idle, I love me some lumpity lump. What camshaft do you guys recommend? I want it on the wild side but not to far out of the range of usefulness, I hoped to use a 2000-2700 RPM stall as this car will be like Tim's car mostly street, but be able to be somewhat of a daily driver/cruiser with reliability and some track time.

Here is a link that is 56K death, broadband required of a 69 Road Runner with a bitchin' sounding 440 and is pretty much the lump sound I am looking for, maybe a little more radical, any trained ears can tell me what this cam sounds like as far as specs? http://www.deadendcruisers.com/videos/datteln2004.wmv


I'm torn between the Hughes cams and Comp cams, leaning more towards Hughes cams. Also I want to use gear drives, does Hughes make a 3 pin cam? Now as far as hydrolic/roller/solid, I am lost, I would probably want to run 1.5 roller rockers for some free horespower.

Does a lumpy idle/street capable/3 pin cam for gear drives exist that can be used with rollers?

I would like to be in the high 12's maybe 11's on juice, I will probably go 3.55/3.73/3.91 out back, here are some pics of the beast before the resto

[fbernard]

There's a cam from Mopar Performance (P4120663 if I remember correctly. It's easy to find, it's the only cam with .590 lift in the MP line-up) that's a pretty good example of a streetable power cam. A friend of mine has one in a 500ci Challenger that ran mid-9s at Santa Pod this July. It's not a street car anymore, but it used to be, and with the same engine (with the current gear ration and spool, street is no longer an option).
The engine hasn't been taken apart for 4 years.
Back when it was still used on the road (with trips to Santa Pod starting from Paris, a 1000 mile round trip), it used to get 14mpg. It was making mid-10s back then (with ported B1 heads, 3.5 inch exhaust). I got less mpg with my stock 440-6pack convertible!

It's a mechanical camshaft, though, so it requires adjustable valvetrain (which you should use, anyway, if you plan to build a powerful engine).

If you want to stick to a hydraulic camshaft, you'll find loads of good ones too, but it's not that easy to find 3-bolt hydraulic cams. And the gear drive is really noisy (you will hear it above the engine noise, whatever cam you choose).

You may use roller rockers with any camshaft (you'll have to use adjsutable roller rockers with a mechanical camshaft, but you'll need a roller camshaft if you want to use roller lifters. Roller cams are the most expensive kind, but they give the highest lift and most aggressive cam profiles.

I don't know if roller camshafts are really streetable in the long run, I've only heard horror stories about the lifters failing after a short time. Get some real-life info from someone who uses one before getting one of those.

Be careful about the noise also, an engine that's mechanically "streetable" may be really tiring when you drive it more than 15 minutes...

I have a Challenger with a 306/306 mechanical cam, 4speed/Indy heads/headers/full 3-inch low-restriction TTI setup, and NO ONE rides with me twice. I'm not talking about girls or relatives! No one, even Mopar fans, consider taking a 3-hour trip in my car.
Ear protectors don't do shit. Cell phones are useless.
Killing the engine when I stop for gas sounds like a gift from Heaven.
It's real fun to drive, though. And it' will be even better with the stroker kit and 3.23 rear end (a 4.10's in now)


Don't go too high on compression, it won't change much performance-wise on the street (it may be worth 70HP if you're aiming for 650HP with a killer roller cam, though).
Better keep it around 10, and use more Nitrous on the strip. That way, you can still use lousy fuel and enough timing advance on the street.

You may want to have those heads ported, ported Edelbrocks can do wonders.
You may need to replace your rods if you plan to rev above 6000 for any length of time though (and choose the valve springs carefully also).

[dave-r]

Stay clear of roller cams.

Look at the spec of my engine in the members cars section. My car runs high 11s with this combo. With the headers uncorked it sounds as lumpy as most of the race only cars in the fire-up road with me.
If you want something milder go one or two steps milder on the cam.

The compression you are aiming for sounds OK to me and will work well with a slightly milder cam than mine.
Don't bother with a gear drive. They are more hassle than they are worth.

Use either 1.5 or 1.6:1 roller tip rockers. The 1.6 will give you more lift and lift rate.

[1034]

Thanks guys, Dave, your specs are pretty much spot on as far as what I want. It will take me some time to get into the 11's but even high 12's would be respectable for a street car, I think I'm going to use your specs as a guideline when I build up. Should I stay with the hydrolic cam you had or go with the solid one you are currently using since I doubt I'll be going above 6000 RPM and won't need any power there after.

Instaed of a six pack I would rather go with a single quad, what would you recomend size I go? 750? 800?

[Tim]

An 850 Holley double- pumper is a good compromise for this sort of engine spec.

Or, if money allows, a similar- sized Demon carb.

If you go for the Holley, you'll need to do some setting up to get it to work correctly with a bigger cam. I think the new Demon's come with some adjustability built in?

[dave-r]

My car runs high 11s with the old hydraulic cam. It will go faster with the solid.
I would use a hydraulic one step smaller than mine if you want easy high to mid 12s.

If you will not be going over 6000rpm a 750cfm carb will be big enough. The Demon carbs are a touch on the expensive side but are very adjustable and pretty cool.

[fbernard]

Instaed of a six pack I would rather go with a single quad, what would you recomend size I go? 750? 800?

Forget the six-pack, it's awfully expensive in every way. It's the best way to run rich on cylinders 3 to 6 and lean on 1, 2, 7, and 8.

Since you don't plan on going above 6000 RPM, a 750 Holley (or Demon) would be just right. You may go 800cfm if you take an Edelbrock AVS, they have comparatively smaller primaries, whereas the difference in venturi size between primaries and secondaries is not that big on Holleys.

A vacuum secondary with small primaries is the best way to get mpg, easy tuning, and reliability. When you floor it, the vacuum will draw the secondaries open as needed. You may tune even that simply by changing springs on Holleys (don't know about Edelbrocks). Holley has a nice quick-change diaphragm housing for that now (a set of springs for the road, a set of springs for the strip, and 5 minutes to change them).

An Air-fuel ratio gauge (a real, wide-band one) can be useful to do the fine-tuning (It gets very useful if you choose a mechanical secondaries, four-corner idle nightmare). It's not really necessary if you get a 'simple' vacuum actuated carb. And the power won't be very much different.

Just like the roller cam and gear drive, think of four-corner carbs as race parts. Don't get one unless you plan to become a carb expert or you have one handy.


I'm a Holley guy myself, but you can check the AVS here, on a big-block Mopar setup :

http://popularhotrodding.com/tech/0403phr_carb/

You can read the "Vacuum secondaries" section on that page if you want more info :

http://www.bob2000.com/carb.htm

[dave-r]

Forget the six-pack, it's awfully expensive in every way. It's the best way to run rich on cylinders 3 to 6 and lean on 1, 2, 7, and 8.

The six pack is a damn good intake that still produces more or the same power than any dual plane and many single plane manifolds out there up to 6500rpm.

However I agree that it is expensive and tricky to tune to perfection particularly if the engine is no longer stock.

I also agree that the mixture can vary from cylinder to cylinder a lot but not on all the cylinders you mention and this is more at idle than anything else. At idle I find the mixtures go all over the place from cylinder to cylinder particularly if the throttle has just been used a lot.

I think the problem could be that fuel pools in the upper level of the intake and runs down into #5 in particular but also some of the others. Any fuel pooling in the lower level sits there in a sump and slowly evaporates into the cylinders fed from there.

I find long runs where the throttle has not been moved around much produces quite an even plug colour from cylinder to cylinder.

I have wondered if a small raised damn at the entrance of each runner on the upper level would help stop fuel running down there? As you have to do on the Weiand tunnel ram version of the six pack manifold?

But I agree that unless you like messing with carbs and spilling fuel over your engine it is better to stick with a 4bbl.

[fbernard]

The six pack is a damn good intake that still produces more or the same power than any dual plane and many single plane manifolds out there up to 6500rpm.

Sure it is (it wasn't popular in 69 and 70 for no reason), with anything between 350 and 1350 cfm right when you need them!
But the tuning is a bit of a nightmare (plus, my carbs were last rebuilt in 1992, it may be time for some taking apart again).

I'll be taking the six-pack apart (though not entirely) soon, some parts are on the way. With a fresh set of plugs, and a little testing, maybe I'll be able to tune the carbs right.
Right now, the center cylinders are too rich, and the #6 plug is really fouled up.

I rarely use it in WOT mode though (the convertible is a nice cruiser, I now have the 4 speed R/T SE for 'real' fun), and I guess the mixture distribution is messed up in some way. I'm looking with curisiosity towards the Promax setup with adjustable idle on outboard carbs, thinking those might even out fuel distribution in the outer cylinders (then again, fresh gaskets, proper jetting, and an afternoon with a timing light and vacuum gauge should point me in the right direction).

[dave-r]

You can adjust the idle mixture on the outboard carbs (as I am sure you know) on six packs fitted to 1969-1972 mopars. The carbs I have came from a Jensen built in 1973 and has no idle circuits in the outer carbs.

Having an adjustable air bleed on the outers would be very handy for use with bigger camshafts instead of having to drill holes in the throttle blades.

These might be good if they will make a Chrysler version;
http://www.barrygrant.com/news/articles ... t_004.aspx