Adding 22 cubes,,, power increase? 528 to 550

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gregsdart

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Since i need a rering and new bearings, i had my 4.15 crank offset ground to 4.315. Bore is 4.5043, had line2line coat the pistons to make up the .0043 needed to clean up the bores. Basic combo was 15.1 to 1 compression, fully ported 440-1 heads, 3x intake, Terminter injection running methanol. Headers are 2 1/8 x 30 x4 inch collecters. Cam is a solid roller, 285 /296/114 @ .050 with .840 net lift after lash intake, .790 exhaust in at 110. I would hope to pick up. Both torque and hp a bit. Best et and mph at 3055 wt was 8.77 at 153 mph before.
 
With .165 thou more stroke u would gain over 3 compression points. I can’t see how u can use the same pistons. Did u go to a shorter rod? Enlighten me. Kim
 
With methanol, adding stroke is the best way to pick up torque by taking advantage of the extended burn time. Was your cam ground custom ground for your present combination? If not, it would be best to have it reground for your new combination. Rod ratio change will change where the opening and closing events need to happen at to get the most out of methanol. But really, wow, what a combination! I don’t remember the exact hp & torque/cubic inch numbers that you should be making in a N/A combination with methanol but when brought to its full potential and multiplied by the extra 22 inches it’s going to be a significant number.
 
Cubic inch has a huge effect on torque but it’s gonna do it a lower rpm which means similar hp as you have.

Cubic inch is gonna allow you to run a little less rpm stall and gear, and may give up some hp to friction, but also may gain hp if your cam and heads like the new rod ratio.
 
With .165 thou more stroke u would gain over 3 compression points. I can’t see how u can use the same pistons. Did u go to a shorter rod? Enlighten me. Kim
Final calculation said an increase of from 15.1 to 15.5 on compression if i keep the unswept volumes the same. If it gets to be more for some reason i can cut the dome down, which currently is about .100 hi and flat. I redid calculations by stroke increase and also by cubic inch increase and came up with slightly higher numbers of 15.7 and 15.73. The originaI compression was calculated way back in 2002 when i put it together for the first time. I don't want to go above 15.5 on advice of a very well known engine builder who said 15.25 to 15.5 was about the best place to be. Higher than that needed more fuel to keep the motor happy which cancels any extra power.
I had 6.965 long hemi H beam rods in it and found a 6.860 H beam with the 2.2 rod bearing. That plus going to a cometic .027 gasket from the .051 gasket before makes it all possible. The piston to head clearance should change by .0015 higher and if things get a little tight i just go up one step in gasket thickness to .030.
 
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I also have a 4.30 gear to put in the dana which would drop launch torque a tad more than the old combo with the 4.56 . i run a 33 inch tall tire and a 2.45 low Torqueflite.
 
The change looks good on paper skimming over the cam specs. I’ll run the numbers later and see what the timing events show. Out of curiosity, what kind of ignition are you running on that?
 
The change looks good on paper skimming over the cam specs. I’ll run the numbers later and see what the timing events show. Out of curiosity, what kind of ignition are you running on that?
thanks in advance! Ignition is a new MSDdigital 7. Plugs at .025 but i can try .022 after a few passes. I wanted to dyno this deal but the piston coatings dictate a very long three time full warmup cycles with total cool down between each cycle. Timing will start at 33 since it ran best at 34 before.
 
thanks in advance! Ignition is a new MSDdigital 7. Plugs at .025 but i can try .022 after a few passes. I wanted to dyno this deal but the piston coatings dictate a very long three time full warmup cycles with total cool down between each cycle. Timing will start at 33 since it ran best at 34 before.

You guys mind explaining that piston coating ? ------Never hears of it !!
 
thanks in advance! Ignition is a new MSDdigital 7. Plugs at .025 but i can try .022 after a few passes. I wanted to dyno this deal but the piston coatings dictate a very long three time full warmup cycles with total cool down between each cycle. Timing will start at 33 since it ran best at 34 before.

So do a long 3 time warmup on the dyno.

In my experience increasing cubic inch via increasing stroke has a far more pronounced increase and effect on power vs. increasing bore size.
 
It may require a little more timing than it did before, the piston will be moving faster away from TDC than it did before with the longer stroke and shorter rod. It will also put more leverage on the crank earlier in the combustion cycle as a side benefit.
 
You guys mind explaining that piston coating ? ------Never hears of it !!
Piston skirt coatings from. Line 2 line are durable like that on modern production pistons. The coatings are also tough enough to allow thicknesses out to .020 (twenty!) over. The coatings are applied thick enough that they reduce piston to wall thickness a lot after run in even. The warm/cool cycles are to get the coating to wear in, absorb oil and take a set so they last. They don't claim any power increase and i suspect that is due to every build being a bit different. Cost me $300 to have them done. Cost goes up as the required thickness goes up.
 
Piston skirt coatings from. Line 2 line are durable like that on modern production pistons. The coatings are also tough enough to allow thicknesses out to .020 (twenty!) over. The coatings are applied thick enough that they reduce piston to wall thickness a lot after run in even. The warm/cool cycles are to get the coating to wear in, absorb oil and take a set so they last. They don't claim any power increase and i suspect that is due to every build being a bit different. Cost me $300 to have them done. Cost goes up as the required thickness goes up.


Right. It's an abradable coating that makes the effective piston to wall clearance about .000 or dang close.

As the engine is run during a relatively short break in period, this coating wears off the piston until the running clearance is established, which is usually tighter than an uncoated piston.

The upshot is this coating allows much tighter piston go wall clearance, making the piston more stable in the bore, and thus, increasing ring seal. The more you can keep the ring belt parallel to the bore surface, the better the ring seal.
 
I know someone who had an issue with that coating. He was running it in a high effort hemi, he would shut it off and it would not restart/turn over. My guess it was just the learning curve.
 
I know someone who had an issue with that coating. He was running it in a high effort hemi, he would shut it off and it would not restart/turn over. My guess it was just the learning curve.

Who's to say the engine was blueprinted properly?
 
I’m confident the motor was put together as intended. That being said he does run some crazy ideas in regards to piston skirts.
 
Right. It's an abradable coating that makes the effective piston to wall clearance about .000 or dang close.

As the engine is run during a relatively short break in period, this coating wears off the piston until the running clearance is established, which is usually tighter than an uncoated piston.

The upshot is this coating allows much tighter piston go wall clearance, making the piston more stable in the bore, and thus, increasing ring seal. The more you can keep the ring belt parallel to the bore surface, the better the ring seal.

Gotcha , but what is it / material ??
 
Who was your cam grinder and what rocker ratio are you running and what are your lash settings?
 
Who was your cam grinder and what rocker ratio are you running and what are your lash settings?
The cam was ground by Mike Jones. It is an inverted flank roller. The lobes are 85510 intake and 89480 exhaust with .867 gross intake lift and ..020 lash. Exhaust is 89480 lobe with .816 gross lift and .020 lash. Specs at .050 are 285/296/114 in at 110. Rockers are Jesel 1.7 ratio. Lobes are .510 and .480. Mikes timing specs on his web sight don't match the ones on the paperwork i got with the cam. The web site states the intake is 289 @ .050 and the exhaust is 302 @ .050. Two emails back to Mike have not gotten a response. Just for shizts and giggles i am going to measure them when i put the motor back together.
 
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I might would check clearances with the cam retarded up to maybe four degrees. But I doubt with those lift rates that it’s going to be “asking” for more camshaft. With the huge ports and valves and fast lift rates it will respond well to the extra piston velocity at TDC and BDC. You should see more significant changes to the fuel curve by changing stroke and rod ratio than would be netted from a 22 cubic inch displacement increase in a larger bore size. Of course, how much more significant is a good yardstick of how well it’s working.
 
From the first install i can retard the cam, but at 110 the intake is under .100 so i could try it retarded from 110.
 
There may be some top end hp available by advancing the cam, and that’s what makes things happen at this level. If the heads still have water in them the heads will become the bottleneck before the camshaft will. It would probably take a set of the solid cast -1 heads wallowed out before the cam becomes the limit here. It’s awfully close to being a blown alcohol grind. I expect there will be a decent change in the e.t. numbers coming out of the recent changes, your displacement is near the limit of what a good 440-1 is able to keep up with. I’m curious as to what aftermarket block and driveline you are containing all this power with, and what the chassis is certified to run at. Definitely got some bragging rights here.
 
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