Is 528 hp and 591 ft-lbs enough?

[Brickster]

After reading about a bunch of engine combos it seems like we are little off the mark. The engine is a 440 with a 440 source stroker kit. I think the actual displacement is 496. Hyd roller cam from Clay Smith, I don't have the cam card here and don't rememeber the numbers. Stealth heads with a little clean-up, deburning, back cutting the valves, removed a little material around the exhaust valveto help knock the compression down some and help flow. Compression ended up at 10.5. Harland Sharp 1.5 roller rockers. The pistons were set up with a zero deck height. The carb is a 750 speed demon on top of an M1. I think that's it. Anyway the car it's going in is a 73 Charger. 3.90 gear, with a gear vendor an a 28.5" tall rear tire. I think it should be fun enough but did we miss something? I know it's hard without the cam specs.

Brick

[Rolling_Thunder]

I would bet the cam is the hold up - I have not had good luck with Smith cams in the past

[Musicman]

I would say that you are right on the money for that combo
Sure there will always be things that you could do or could have done to produce more power, but I see nothing wrong with this combo myself...

[tan top]

 dyno numbers look good  nice combo ..could  use more fuel though  A/F of  13 , is a bit lean  ...needs to be 12  i'm thinking:Twocents:

[Brickster]

we ended up going up on the jets and back down on the timing to get our best numbers

[firefighter3931]

M1 single plane or M1 dual plane ? Cam specs ? Header size ?

Hard to say if anything is wrong with that combo....more info needed. 

The HP is about right for an unported Stealth head...MFR (Mike) 505 made a little less hp but he is also using a flat tappet (Non-roller) cam.



Ron

[MOPARHOUND!]

The thing that stands out to me is the 750 carb.  If I were looking for more HP with that 496" combo, I'd start by swapping on a 950 HP carb.

[firefighter3931]

The thing that stands out to me is the 750 carb.  If I were looking for more HP with that 496" combo, I'd start by swapping on a 950 HP carb.

Normally i would agree.....but the heads are the bottle neck in this combo. Mike is using a 950DP on his stealth head 505 and it made less hp than this one.

Look at the scfm #'s on the dyno sheet....the engine is only using 629cfm at WOT/MaxHP = 5500 rpm so carb sizing is not the issue. A bigger carb wouldn't change much at all, if anything. 


Ron

[Brickster]

Single plane intake

duration at .050 is 246 degrees, intake and exhaust
lift on both intake and exhaust is .540
in. opens 37
in. closes 77
ex. opens 77
ex. closes 37

I use tti headers on the car but they wouldn't fit on the dyno. The headers we used for the dyno did have smaller primarys. I'll measure them later, seems like they were 1.750

[MOPARHOUND!]

The thing that stands out to me is the 750 carb.  If I were looking for more HP with that 496" combo, I'd start by swapping on a 950 HP carb.

Normally i would agree.....but the heads are the bottle neck in this combo. Mike is using a 950DP on his stealth head 505 and it made less hp than this one.

Look at the scfm #'s on the dyno sheet....the engine is only using 629cfm at WOT/MaxHP = 5500 rpm so carb sizing is not the issue. A bigger carb wouldn't change much at all, if anything. 


Ron

I'd have to disagree.  I would not think a 650 CFM carb would be sufficient.    Is the 629 cfm all it is using, or the max it is being allowed to receive?

[firefighter3931]

The thing that stands out to me is the 750 carb.  If I were looking for more HP with that 496" combo, I'd start by swapping on a 950 HP carb.

Normally i would agree.....but the heads are the bottle neck in this combo. Mike is using a 950DP on his stealth head 505 and it made less hp than this one.

Look at the scfm #'s on the dyno sheet....the engine is only using 629cfm at WOT/MaxHP = 5500 rpm so carb sizing is not the issue. A bigger carb wouldn't change much at all, if anything. 


Ron

I'd have to disagree.  I would not think a 650 CFM carb would be sufficient.    Is the 629 cfm all it is using, or the max it is being allowed to receive?

Well then, you and i can agree to disagree 

Using my own 446 as an example, the engine dyno showed 798cfm of air at 6500 rpm and i was using an 830 cfm Proform carb. When we dyno tested a 950 hp it made slightly better hp (5hp) but pulled no more CFM than the smaller rated carb. The increase was more likely a function of better fuel atomization. 

Dwayne dynoed a customers 13:1 496 and it had a 750 dp'er on it....that engine combo made 660hp. They tried a 950hp with all the bells and whistles and it made less than 5hp more. Hardly worth the $750 investment that he would have had to make for minimal gain....$100/1HP increase is not cost effective. 

The intake tract is not the restriction on this build ; large plenum single plane and 750 cfm carb is more than enough to satisfy the current requirements. Mike's 505 bears this fact out....stock stealth heads with a descent cam and 950 cfm and less power than this one. Of course a different dyno but the builds are more similar than not. 

The Stealth is a 250 cfm head in stock unported configuration. The power is where it should be given those parameters. Compared to the other strokers in the proven combo's section the stealths don't make the same kind of power compared to the Eddy RPM and Mopar 452 aluminum castings....that is reality. Joflaig's RPM headed 512 stroker made ~ 545hp/615tq and General's 496 made 553hp/610tq and both of those engines are using identical heads other than the name stamped on them. Headflow is power....pure and simple 



Ron

[firefighter3931]

Single plane intake

duration at .050 is 246 degrees, intake and exhaust
lift on both intake and exhaust is .540
in. opens 37
in. closes 77
ex. opens 77
ex. closes 37

I use tti headers on the car but they wouldn't fit on the dyno. The headers we used for the dyno did have smaller primarys. I'll measure them later, seems like they were 1.750

The M1 single plane is an excellent manifold....it's not holding the power back. The Stealth Heads are the "cork" in this build and realisticly...it's making the power it should be. 

Personally, i would install this engine in the car and try it out....the huge torque it's making will be loads of fun on the street. If at some point you decide that more power is needed ; pull the heads and send them out for porting. It wouldn't be too difficult to pick up an additional 50hp with headwork alone....nothing else would need changing.



Ron

[idahogrumpy]

   The 10.5 compression 470 I'm involved with just pulled 620 hp. It was pulling some where around 723 cfm at 6450 rpm. This is an Indy 440ez1 headed engine. Solid lifter cam with a 114 lobe separation. I'm working on getting the dyno pulls and exact specs listed soon. My point here is I would agree with Ron, The heads make the big difference in the build.  Kyle

[Brickster]

Personally, i would install this engine in the car and try it out....the huge torque it's making will be loads of fun on the street. If at some point you decide that more power is needed ; pull the heads and send them out for porting. It wouldn't be too difficult to pick up an additional 50hp with headwork alone....nothing else would need changing.



Ron

Thats my plan. To be honest we did think the power would be 550. This car is a street car and will be way more power than we could ever need. The heads did have a little work done but mostly just clean-up and the lock and spring change. Thanks for you imput guys. Check the car out in the link below

http://www.dodgecharger.com/forum/index.php/topic,46656.0.html

[MOPARHOUND!]

The thing that stands out to me is the 750 carb.  If I were looking for more HP with that 496" combo, I'd start by swapping on a 950 HP carb.

Normally i would agree.....but the heads are the bottle neck in this combo. Mike is using a 950DP on his stealth head 505 and it made less hp than this one.

Look at the scfm #'s on the dyno sheet....the engine is only using 629cfm at WOT/MaxHP = 5500 rpm so carb sizing is not the issue. A bigger carb wouldn't change much at all, if anything. 


Ron

I'd have to disagree.  I would not think a 650 CFM carb would be sufficient.    Is the 629 cfm all it is using, or the max it is being allowed to receive?

Well then, you and i can agree to disagree 

Using my own 446 as an example, the engine dyno showed 798cfm of air at 6500 rpm and i was using an 830 cfm Proform carb. When we dyno tested a 950 hp it made slightly better hp (5hp) but pulled no more CFM than the smaller rated carb. The increase was more likely a function of better fuel atomization. 

Dwayne dynoed a customers 13:1 496 and it had a 750 dp'er on it....that engine combo made 660hp. They tried a 950hp with all the bells and whistles and it made less than 5hp more. Hardly worth the $750 investment that he would have had to make for minimal gain....$100/1HP increase is not cost effective. 

The intake tract is not the restriction on this build ; large plenum single plane and 750 cfm carb is more than enough to satisfy the current requirements. Mike's 505 bears this fact out....stock stealth heads with a descent cam and 950 cfm and less power than this one. Of course a different dyno but the builds are more similar than not. 

The Stealth is a 250 cfm head in stock unported configuration. The power is where it should be given those parameters. Compared to the other strokers in the proven combo's section the stealths don't make the same kind of power compared to the Eddy RPM and Mopar 452 aluminum castings....that is reality. Joflaig's RPM headed 512 stroker made ~ 545hp/615tq and General's 496 made 553hp/610tq and both of those engines are using identical heads other than the name stamped on them. Headflow is power....pure and simple 



Ron

Something isn't adding up somewhere.  A 496 with a street/strip cam & aftermarket Stealth heads would make max power with a stock-ish 650 CFM rated carburetor??

It's often been said that you don't bolt stock heads on a stroked 440, or you will end up with a 440 with a big crank that runs like a 440.  If the heads are the problem, the head money would well be invested in a better brand of head for a stroked 440, and the Stealths avoided.

[Musicman]

There are a number of things that could have been done, but who really cares... it's a great street build just the way it is. As Ron stated, dropping on a larger carb would produce a small improvement, but the gain would hardly justify the loss of cash now, not to mention the further loss of cash at the gas pump... it just wouldn't be worth it. Truthfully, it looks like the clean-up work that was done on the heads got them flowing a little better than stock, I would never expect those numbers from a 255 CFM head myself... But then again, it doesn't really take a lot of work to get the Stealth heads flowing better.

[firefighter3931]

Something isn't adding up somewhere.  A 496 with a street/strip cam & aftermarket Stealth heads would make max power with a stock-ish 650 CFM rated carburetor??

It's often been said that you don't bolt stock heads on a stroked 440, or you will end up with a 440 with a big crank that runs like a 440.  If the heads are the problem, the head money would well be invested in a better brand of head for a stroked 440, and the Stealths avoided.

I don't think anyone here is advocating a 650cfm carb for a stroker build but a 750 cfm is certainly not "too small" based on the dyno information. 

The Stealths are not a race head and in stock form will limit power on a stroker build. Depending on what you're looking for out of the car they may be just right or too small. The smallish intake port will limit top end power somewhat but if you want a strong cruiser and plan to run 3.23 gears and a mild/stock torque converter these can be an excellent choice.

The aluminum closed chamber design is perfect to build a tight quench pump gas type build and drop some weight off the nose of the car. Certainly more cost effective than porting OEM iron heads and outfitting all new hardware/machinework. 



Ron

[Brickster]

Something isn't adding up somewhere.  A 496 with a street/strip cam & aftermarket Stealth heads would make max power with a stock-ish 650 CFM rated carburetor??

It's often been said that you don't bolt stock heads on a stroked 440, or you will end up with a 440 with a big crank that runs like a 440.  If the heads are the problem, the head money would well be invested in a better brand of head for a stroked 440, and the Stealths avoided.

I don't think anyone here is advocating a 650cfm carb for a stroker build but a 750 cfm is certainly not "too small" based on the dyno information. 

The Stealths are not a race head and in stock form will limit power on a stroker build. Depending on what you're looking for out of the car they may be just right or too small. The smallish intake port will limit top end power somewhat but if you want a strong cruiser and plan to run 3.23 gears and a mild/stock torque converter these can be an excellent choice.

The aluminum closed chamber design is perfect to build a tight quench pump gas type build and drop some weight off the nose of the car. Certainly more cost effective than porting OEM iron heads and outfitting all new hardware/machinework. 



Ron

I ruined my stock open chamber heads (maby) and the car has 3.91 gear with a gear vendor. Because of the OD I was told I needed a converter with a lock up speed below that of my cruising RPM. We should be driving by Sunday I'll report back by then for sure.

[MOPARHOUND!]

Always interesting to have a good bench racing session Ron.

Brickster, by no means interpret the discussion as highjacking your thread.  I believe those responding have a a shared goal of ferreting out the possibilities that might be causing your 496" 440 stroker combination to underperform, if at all.

I use tti headers on the car but they wouldn't fit on the dyno. The headers we used for the dyno did have smaller primarys. I'll measure them later, seems like they were 1.750

Curious to know if they are in fact 1-3/4".  Hard to blow 500+ horsepower through a header that size, could be one of the issues restricting the combination??  

For comparison, my 496" 440 stroker made 514HP and 589 ft. lb. torque with factory iron "452" heads with 2.14/1.81 valves (the $500 heads from Aeroquip, on special at the MoparNats), and minimal basic port work.  It too had 10.5 to 1 compression, but with horrible quench, the pistons being .020+ down in the hole.  Hydraulic (not a roller) cam spec'd with 1.6 rockers meant 246 @ .050, and .534/.534 lift.  Holley Street Dominator intake with what I believe to have been an 850 DP the builder had on hand at the time.  Headers were believed to be a set of 1-7/8" the builder had as well (long story).  

Been hunting for my dyno print out, but have not found it so far.

Brickster, 514hp and 589 ft lb torque was enough for me.  Wall to wall torque at any speed, 7mph or 70mph. 7000 miles later I bolted on a set of Eddy heads and replaced the factory HP manifolds with a full TTI header/exhaust system.  The car went from hang on to your seat fast, to scary/sick to your stomach/verge of out of control fast.  I destroyed 2 trans mounts, and a driver's side motor mount, and I've never raced the car.  If you haven't upgraded already, contact http://www.engine-swaps.com/ .

[Steve P.]

Ron is right. After looking back at the proven numbers no more is really needed. I fixed my boo boo..  

[Brickster]

We got the engine back in the car over the weekend and took a test drive this evening. Wow, what a difference. It moves out well for a big car. Got a small issue with the valley pan leaking. It is a fabricated style from 440 source, it is going away and a stock style pan/gasket is going back on. I've got a few pics to add soon.

Brick

[firefighter3931]

We got the engine back in the car over the weekend and took a test drive this evening. Wow, what a difference. It moves out well for a big car. Got a small issue with the valley pan leaking. It is a fabricated style from 440 source, it is going away and a stock style pan/gasket is going back on. I've got a few pics to add soon.

Brick

Glad you like it....that's a big bad torque monster you've got there. 

I looked at your link....very nice car ! 



Ron

[aifilaw]

The torque curve is beautifully flat, that's what I like to see, but it peaks late in reference to your bandwidth, I think there's two reasons for that, 1. cam could be slightly better, 2. heads needed another 10-30cfm worth of port work, and it wouldn't take much.

I would have like to see your manifold pressure during the run, if I had to guess I would bet you have some suction static pressure in there.

[Brickster]

Update!

I finally got to the drag strip. We went 13.5 at 106 mph. No traction for all of first gear and a rookie driver (me).