So you want to stroke your stock 360 M

[Oldiron440]

Just adding stroke to a stock Magnum

 

[Duke5A]

Ha, I just watched that prior to coming over here! That would make an awesome truck engine, but they didn't mention anything about the almost 11:1 compression on iron heads and that absolute broom stick of a cam shaft. I would expect it to ping like crazy. What do you think?

 

[jasperjacko]

I'll bet his cranking cylinder pressure is up there.

 

[Aspen500]

Some of those "street" engines I see built on TV make me wonder where they expect to get gas to actually run it on the street. Our one and only station with 110 at the pump, closed about 4 years ago. Technically it was "off road only" since it was leaded and and not road taxed but, they always did like Sgt. Schulz and "I see nothing, I know nothing!" if someone pumped it directly into the tank of a street car, instead of a race car on a trailer or gas can. lol It was about 1/4 mile (conveniently enough) from my house and I miss that place............

 

[Oldiron440]

E-85

 

[M_Body_Coupe]

Weeellllll.....DCR is your "friend"!!!

Head on over to (Wallace Racing: Dynamic Compression Ratio Calculator) and armed with your cam's IVC event you will get a pretty good idea what your actual DCR will be.

The word on the street is that about 8.5 on 91 octane pump gas is about the max...

 

[Oldiron440]

Depends on the head, I've ran 9.5 on E10 without problems.

 

[Aspen500]

E-85

Well, that's different. Finding E85 is then the sticking point. No where near as bad as finding race fuel but still........................At least in this area, stations with E85 are in the minority. Maybe 1 out of every 25 stations carry it.

I'm running 10.5 cr on 91 ethanol free premium (which can be found at every station) with reworked closed chamber 413 heads, but that's right on the edge of spark knock on hot days. Do not know my cranking pressure however, other than it takes a lot of grunt to turn the engine with a breaker bar. A compression stroke is very obvious, lol.

I should shut up until I can get the video to play and actually watch it. All I get is a circle going around and around for ever.

 

[M_Body_Coupe]

...I should shut up until I can get the video to play and actually watch it. All I get is a circle going around and around for ever.

Here is the screenshot of the end result!

 

[Aspen500]

Pretty darn respectable, especially the torque.

Still only a spinning circle on the video. Can't wait until TDS fiber optic comes down my street and I can actually get an internet connection that runs faster than 0.3 mbps..............

 

[Oldiron440]

I got hooked up with fiber optic last summer, I guess I was looking for and improvement of some sort. My grandsons Xbox is still glitchy.

 

[Duke5A]

I'm coming up with 9.8:1 DCR if I'm doing this right.

Duration @0.050" Lift: 192 intake, 198 exhaust
Lobe Lift: .284" intake, .279" exhaust
Lobe Separation Angle: 111
Intake Centerline: 115
Static Compression: 10.73:1

EDIT:

The calculator wants advertised duration and not at .050". The above is wrong. Anyone know what the advertised number is on a factory Magnum roller cam? I think it's supposed to be measured from .006".

 

[M_Body_Coupe]

I'm coming up with 9.8:1 DCR if I'm doing this right.

Duration @0.050" Lift: 192 intake, 198 exhaust
Lobe Lift: .284" intake, .279" exhaust
Lobe Separation Angle: 111
Intake Centerline: 115
Static Compression: 10.73:1

EDIT:

The calculator wants advertised duration and not at .050". The above is wrong. Anyone know what the advertised number is on a factory Magnum roller cam? I think it's supposed to be measured from .006".

Umm, in my Blueprint spreadsheet I left this note:

(GoFast uses IVC @0.050, while Wallace requires IVC @0.050+15 or 25 but produces PSI projection)

1) try GoFast here => The static and dynamic compression ratio calculator

2) you can use this GoFast calculator to convert your duration @0.050" to valve vents => Convert .006 valve timing event numbers to .050 numbers

 

[Aspen500]

Never knew about that calculator. For the heck of it, I entered my numbers and come up with static cr 10.47:1 and dynamic of 8.89:1 Static comes to about what I thought it was but the more important number is the dynamic which is right on the edge for 91 octane fuel. Works for me!

 

[M_Body_Coupe]

Never knew about that calculator. For the heck of it, I entered my numbers and come up with static cr 10.47:1 and dynamic of 8.89:1 Static comes to about what I thought it was but the more important number is the dynamic which is right on the edge for 91 octane fuel. Works for me!

The calculations were almost spot on for my old Hughes HEL3844 (238/244 @0.050") hydraulic flat tappet that was in the 360 motor. I had a DCR of 8.72 with a cranking PSI of 182 on a static CR of 10.5.

In real life, my cranking PSI was about 185-190.

 

[Aspen500]

Now I'm going to have to screw a gauge in and check my cranking PSI, for simple curiosity if nothing else. Just for the heck of it, I want to do a dynamic test with the engine running for comparison. In the end, it's the dynamic numbers that are the most important for everything.

 

[Oldiron440]

If you were actually going to run that small block a cam with more lift and duration @050 around 225 to 230 and a center line of 110 would help fill those cylinders and move peek power up in rpm range.
The E85 thing is a geographic thing because I have it local,10 miles west a15 miles east.

 

[AJ/FormS]

At first they say it is a stock 5.9M
Then on tear-down they find that the bearings are Not stock so they say the engine is a rebuilt. Ok fine, but no mention of whether the cam is stock or not. To their credit, the measured it.
Their cam measures ;
192/198@.050 and 111/-4 with lobe lift of .284/.279ex rated lifts
of .454/.446 @ 1.6 arms
That is NOT the specs I have for a stocker.
The stock specs are very hard to find, and I cannot say if what I have found over the years is accurate, but the general consensus I have is this;
182/194@.050 and 250/264/110-9 advertised and lifts of
of .411/.430 @1.6arms I cannot say if this is accurate or not.

So then; lets stack this up. I'm gonna arbitrarily gross up their .050s to comport with aftermarket type .050specs, by adding 53* to the intake and 55 to the exhaust. It may be a lil conservative/ IDK
so; first theirs, then my assumed to be stock specs.
245int/122.5comp/136.5power/253 exh/27overlap/ Ica of 57.5 (theirs)
250int/ 116 comp/ 127 power/ 264exh/ 37overlap/ Ica of 64* (stock)
in both cases, these cams are heavily retarded, I'm guessing to shed pressure, but could be for EGR, etc.
Lets correct them both to split overlap; and I get;
245 int/128comp/121power/253exh/27overlap/Ica of 52 (theirs)
250/int/128comp/115power/264exh/37overlap/Ica of 52 (stock
That's more like it; now you can compare them.
The overlaps are very small.
A stock 318LA is 20*, the 360-2bbl is around 32*, the 340 was 44*

Jus saying; not trying to pick a fight.

 

[Oldiron440]

They are not arguing stock, stock, stock, they put up whatever it is and showed you what more stroke will do. Mopar doesn't have a stock standard on any one part or assembly they have used in the last 50 years.
What a moron.

 

[Duke5A]

Compression aside, look at that graph. The peaks numbers aren't nearly as eye opening as that sheer amount of torque from low rpm all the across.

This is where stroker motors shine. I don't think I'll ever build another stock displacement engine.