Discuss my 440 500+hp project

[Uncle Don]

need some opinions from you engine guru's...been there done that fellas etc.

purchased a 67 440 block with a set of 906 iron heads. all original, stock bore, pistons, rods, etc...but basically going to try and use the rods and pistons and keep it stock bore if i can, somewhat small cam because i will eventually put air back on it as its a factory air car with everything there.

i haven't taken it to the machine shop yet so before i do just kinda wanting to get a good idea of my project direction...

is it even possible to get 500+hp and 500+tq out of a stock bore 440 with 906 heads? and run on pump gas? doing a good port and polish on the heads? etc...good cam.

the machine shop will also dyno the engine before im done...and this is a very reputal speed shop around this area...so no worries there.

parts to do this? opinions?

my goal is around 500hp and 500tq with air, drive to cruises, track, grocery, with wife and kids.....am i on crack?:black_eye:

 

[1969 charger rt]

good luck

 

[jusglazin]

I dont believe 906 heads are original to a 67 HP block, shouldnt they be 915's?

 

[Uncle Don]

no there not the original heads to the engine but the block and the heads have never had any work done to them...sorry should have cleared that up...and it is a 68 block...double checked sorry...either way all stock...

 

[beezee]

Uncle Don, I would build a quench motor using today,s modern cylinder heads and pistons.

 

[Uncle Don]

"quench motor" explain...??

 

[Polara Pat]

Anything's possible I guess but it probably won't be overly streetable when you're done. You're iron heads will also be a lot lighter after all the material that will need to come out of them to make them flow. This is probably a bad example but our 0.30 over, 906 head race wagon (3600 # with me in it) goes 11.40s in the quarter so probably makes better than 500hp, though we've never dyno'd it. We always call it a stock motor but could never survive on the street and is full of goodies.
I don't think setting a hp goal is such a good idea. Just build the best, tightest 440 that will start on cold mornings and idle in traffic.
Just my $.02

 

[Uncle Don]

point well taken. im sure id be happy with anything over 400hp...but i can dream right? my dad has a stock bore 440 with great 906 heads(worked over) 509 cam, stock pistons, rods, good intake and carb and runs 7.00's 1/8th and 11.40ish 1/4, but thats in a 2850lb car....so i would think it would be close to 400hp...and ive got to beat dad! haha...not really but i know the potential is there for some good hp numbers with right combo and still drive it...with air.

 

[beezee]

Ideal quench is the distance of .040" to .055 " piston to head clearance making a near 0 deck piston and modern aluminum closed chamber cylinder heads ideal for an engine build for more complete combustion and far less chance of detonation.http://www.dodgecharger.com/forum/index.php/topic,20368.0.html

 

[q-ship]

My suggestion is to forget about HP numbers and go for torque.

You can easily get 500+ Ft. Lbs. of torque at low RPM's out of decent 440 rebuild (which is much more satisfying and fun), vs. Higher HP, but skittish manners with all the extra cost/hassle items such as higher stall torque converters, low rear gears, etc.

You can easily get 500 Ft. Lbs at very low RPM's, and about 430 HP out of a stock headed reasonable compression (9:1 to maybe 9.2:1), non quench 440.

For the street, especially with A/C, "less is more".

I know it sounds counter productive, but having " been there, done that" for decades, a street torque monster will impress you (and passengers) much more then a genuine 12 second strip car, and can be done for about half of a high HP motor, and get excellent gas millage in the process.

You will also be amazed at how many true race cars you can embarrass through an intersection, or other short bursts, plus you get the benefit of being able to drive long distances without worrying about octane or elevation differences.

just my 2 cents anyway.

 

[beezee]

This is what your looking for in the way of a good 440 build using what you have.
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=5994666&Main=5993644

 

[Uncle Don]

nice read there...all good comments...

so lets say my car weighs about 3700lbs with me in it....
3.23 gear, good 727 with a 2500-3000 converter, sticky tire....good headers and exhaust, if i built a streetable mild 440, and wanted to run say.....11.50's to 12.00's...how doable is that with 440, 906 heads....would i be easier to just put aluminum heads on it or can i get by with 3 angle valve job, basic intake port match etc...on steel 906's....budget build kinda thing??? im up for trying new cam designs out....dad wants me to use the good ol 484 purple.:yes:

 

[Uncle Don]

i guess in a nut shell if i wanted a 11 sec car at 3700lbs how much hp or torque would that require?

 

[Al K]

If I could...I'd make this thread "sticky";I'm looking at the same situation,and I'm sure I'm not alone. Could be an education to be had here.

 

[Meep-Meep]

If I may add to the good points listed so far...Building an engine for a specific application must take into account car weight, gearing delivered to the pavement (including tires), stall speed for auto and proposed use of vehicle and RPM range. You can't have it all and anything you do will be a compromise somewhere. Shooting for high HP numbers means more cam overlap and later intake valve closing to increase high RPM breathing. Compression ratio must also be elevated because of the later intake valve closing point so you can preserve cylinder pressure. Deeper gearing to keep the engine in the power band is recommended.

I'm a firm believer in quench as a way to squeeze the A/F mixture toward the spark plug where combustion must always initiate. Taking steps to eliminate possible hot spots is also good. Proper combustion chamber design will allow you to run some decent compression without detonating and/or having the timing advanced to some crazy level. More compression = better thermal efficiency and is also required when running a big cam. Higher continuous RPM also requires better bottom end components to prevent failure. It's a catch 22.

Closed chamber heads allow for good quench while increasing the compression ratio without having to add ridiculous pop up pistons. A fast burning chamber will require less advance. A quench dome piston with a 906 head mimics a closed chamber head by filling the void of the chamber opposite the spark plug. It's a good idea. If compression is increased but not done properly, you end up with having to run more advance and increase your chances of detonation. Likewise, lowering compression by just adding volume I think is being less than optimal.

Torque is a good thing and is what ultimately moves you, but you need the HP component to feel like something is happening. The trick is to make the most average power in the RPM range that you will spend the most time in. Design around that.

The shorter 108 CL cams tend to produce very high torque numbers over a shorter RPM band and at higher RPM's and require deeper gears and looser converters. The longer CL cams spread the torque out over a broader RPM range for better overall drivability. My guess is you will head for around a 112 deg CL cam.

Real world example: My 68 RR weighed 3700 lbs as raced and went 12.65 @ 107 with 4.88 gears, a 26" slick and not enough converter. Using a calculation to get applied HP I got 370. I ran pump 92 with the full 38 deg advance at maybe 2200 RPM (don't remember exactly). The engine is a 383 with stock valve pocket ported 915 heads, a .528" DC cam, torker with Holley 750 vac secondary and 1-7/8" Hookers open. Pistons are forged and at zero deck. This combo was very drivable and passed the CA emissions test when I increased the valve lash and installed a factory AVS on a DP4B intake. I have built similar engines all based around minimal exotic parts with 9-10:1 compression and had great results.

Hope this helps.

 

[Herr_Poopschitz]

For reference: HP = (197.65 x Race Weight) / (ET^3)

If I remember correctly, this is for avg horsepower through the 1/4 mile in an efficient chassis.

Torque is simply a force. Horsepower is a function of torque over time, and therefore what accelerates a car.

Forget about engine theories for now.

The most important thing that no one's asked is: What's the budget? Don't focus too much on horsepower #'s derived from dynamometers - they can be manipulated and don't equate to how a car will accelerate.

Street manners will be something to be considered after the above is answered.

One other quick comment - by the time you rebuild the 906's and have any porting done to them (I'm assuming you aren't doing it yourself), you could be really close to picking up a set of modern aftermarket aluminum heads, ie, Performer RPM's.

 

[383man]

My car is just what you want to build. I built my 63 to run high 11's on pump gas and be very streetable which it is. Its run a best of 11.49 @ 116 and it weighs just over 3700 lbs. I figure its making right about 500 hp give or take a few. It is a mild 440 I built with the stock bottom end and KB quench pad pistons so I have quench with the 906 open chamber heads. Its 10.0 comp and with 38 total timing it runs great on 92 pump and no ping. Has the MP .557 cam with the Holley SD intake and a 850 DP. I use a 9.5 Dynamic converter and a reverse manual v/b. 4.30's out back with a 30 x 9 tire. I just drove it the 180 mile round trip to Carlisle over a week ago. I drive it everywhere including to the track when I race it. I also added a 6 point rollbar and frame connectors. You could actually build a stronger more streetable eng very easy. I plan to build a stronger eng later with aluminum heads and maybe a stroker kit. I also plan to use closed chamber heads and a zero deck flattop piston for good quench. Thats what I would do if you have the cash. Build a nice 440 but stroke it to about 500 cubes or more as it dont cost much more and then use good ported aluminum heads and build good quench in the eng. You could have a cam custom grinded and you will have a nice streetable car that could run low 11's very easy. You would have a much stronger eng then mine is so it could run easy 11's. Use a nice converter and gears in the 3.91 to 4.10 area depending on how tall a tire you use. Ron

 

[383man]

My 440/426 Maxie looking eng. Ron

 

[Uncle Don]

absolutely love your car. and yes this is what im looking for....mid to low 11's and drive it on a weekend trip...out in town, etc....awesome. i love the look of your car also, that is the look i wanted for my 66 but some how ended up with my 17's i have on it now....thanks for posting.

 

[Dennis H]

440 30 over 850 Demon Edelbrock Performer TTI 9.5:1 Pump 91 Comp Cam 1/2 inch fuel lines elec fuel pump MSD 500 RWHP Dyno.

Drive to Reno/Vegas. 14" Cooper Cobras, Keisler TKO 5 speed, ClassicAutoAir. Sweet street smoke on demand. Reliable. Pro Touring baloney. It is the best my wallet could provide. My favorite car. I have 3. 06 Charger Daytona and an 09 Challenger Track-Pack. I'd rather drive and flog the old 440 Coronet anytime.

When we die, the kids will sell everything. Nobody cares. Drive it. Enjoy it.