Horsepower change?

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gregsdart

gregsdart

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If you go to" 8.80s, sneaking up on it" post, the description of my 65 Dart with 550 cubes , 440-1 heads, 926 dyno"d hp ran 8.80 runs with some issues will fill in some details.
On to my question. I made a few changes and am curious what guys think hp will change.
List of changes-
DLC COATED .205 wall PISTON PINS
replaced .180. Wall Manley pins.
Went to 7.1 hbeam long rods , had 6.86. Hbeams in it before.
New slightly lighter pistons from Gibtech
Same L2L coating
Thinner rings had .043, .043, 3-16
Went to .036- .036-3mm
Got rid of gear drive (milodon) went to belt drive.
Had a vacuum pump but never got vacuum
Above 3 inch on dyno. Plan to run 12 to 15 inch vac if possible.
The big change-- replaced Megablock with
New BMP Aluminum block.
Crank is the same Crower with center counter weights. I hope this will limit any horsepower loss due to the change to the aluminum block. That thought is based on the fact that the better Crower center weighted crank drastically reduced cap walk in the megablock with identical tuneup. Also ford Coyote aluminum blocks and I believe LS aluminum motors run them.
So, thoughts on loss or gains?
 
Whewww! SMOKING! I'm unqualified to answer that, but with my limited knowledge, sounds like you took a Lil weight/ drag off the reciprocating mass. I'm sure it's not in vain. With that said, THAT'S A RAGING MOPAR!!!!!!!
 
Are you running that on methanol? I don’t foresee any loss of power. How much weight is that aluminum block worth?
 
What did the rod ratio end up at? You didn’t gain anything with the belt drive. The block will cost 15-20 hp. Ring deal will suffer even though you did a nice upgrade on the ring pack.
 
Methanol for fuel. Rod ratio is now 1.64541
The megablock weighed 248, al block 144 for a 104 lb difference.
 
I’ll say it’s about even hp wise. The ring pack and lighter top end parts will help it rpm quicker but as @Rat Bastid said ring seal will tell the tale. It will be faster though from the weight savings.
 
gregsdart said:
Methanol for fuel. Rod ratio is now 1.64541
The megablock weighed 248, al block 144 for a 104 lb difference.
Click to expand...

So you gained some on rod ratio. That’s a good thing. Still not sold that the weight loss will make up for ring seal. Are you going back to the dyno?
 
I talked to Wilson manifolds today about the 3x intake. They think it could help to rework the plenum. I asked about POTENTIAL HP gains knowing that there is no way to know results with mechanical injection. He said MAYBE 20 TO 25 HP GAINS due to fixing the plenum area.
The DLC coated pins ought to help. Vacuum won't hurt them.
I assume i may see 20 hp just from higher vacuum.
 
gregsdart said:
I talked to Wilson manifolds today about the 3x intake. They think it could help to rework the plenum. I asked about POTENTIAL HP gains knowing that there is no way to know results with mechanical injection. He said MAYBE 20 TO 25 HP GAINS due to fixing the plenum area.
The DLC coated pins ought to help. Vacuum won't hurt them.
I assume i may see 20 hp just from higher vacuum.
Click to expand...

Yes and yes. Even though you’ll have a relatively dry intake, the cloverleaf top is a power loser. It been awhile since I’ve ad my hands on one of those intakes but I’m pretty sure there are two dividers that have a hook at the end of them and that needs to be squared up. I also remember the dividers protruding quite a bit into the plenum. If that’s the case you should shorten all the dividers up some too. More vacuum with your ring pack will certainly make more power. Why was the vacuum so low on the dyno?
 
I take it by dry intake you’re using a Ron’s injection system or the like. I’m curious if you’ve you talked to your cam grinder (I’m assuming that you’ve got a custom grind at this level!) about retarding or advancing cam timing or regrinding it with the change in rod ratio. Or is it so far past the point of diminishing returns it doesn’t make any difference?
 
Garrett Ellison said:
I take it by dry intake you’re using a Ron’s injection system or the like. I’m curious if you’ve you talked to your cam grinder (I’m assuming that you’ve got a custom grind at this level!) about retarding or advancing cam timing or regrinding it with the change in rod ratio. Or is it so far past the point of diminishing returns it doesn’t make any difference?
Click to expand...
Probably beyond my scope of comprehension but I’d say that is an excellent question.
 
**** Greg, may have to ask John force !
You got way bigger "big boy pants" than I .
 
I do know what would make a bigger gain than all this other stuff. Go to Spud Miller’s nitro notes and look at the 20% tune. I promise if done correctly you won’t be worrying about a power loss! :rofl:
 
BTW, that is very bad advice if you don’t have aluminum rods in your engine.
 
Low vacuum may have been a rear main seal .
For the cam, any regrind would probably cost performance somewhere. This cam is a specialy ground inverted flank cam from Mike Jones. Due to it being on a stock core it is about as high a lift lobe as can be put on it. Also I follow the thinking of Reher-Morison, that rod ratio has little effect In most cases.
 
gregsdart said:
Low vacuum may have been a rear main seal .
For the cam, any regrind would probably cost performance somewhere. This cam is a specialy ground inverted flank cam from Mike Jones. Due to it being on a stock core it is about as high a lift lobe as can be put on it. Also I follow the thinking of Reher-Morison, that rod ratio has little effect In most cases.
Click to expand...


That’s why I asked about the R/S ratio. You start getting above 1.8 with good heads and it will start hurting power.
 
Update;
Going to 572-13 cnc385 heads. Also step 2 1/8 to 2 1/4 to merge collecters for headers from 2 1/8 to 4 inch collecters headers. I figure the two changes give me a shot at an honest 1,000 hp or more. Add that to a weight reduction to 2890 race weight, and it may go sub 8.50s?
 
gregsdart said:
Update;
Going to 572-13 cnc385 heads. Also step 2 1/8 to 2 1/4 to merge collecters for headers from 2 1/8 to 4 inch collecters headers. I figure the two changes give me a shot at an honest 1,000 hp or more. Add that to a weight reduction to 2890 race weight, and it may go sub 8.50s?
Click to expand...
Bad *** !
 
So you ran 8.80s on the old 926hp setup at what race weight? Are you considering a gear change and/or converter change at this point? Might be worth a thought with the weight loss and more power. If it makes an honest 1000hp or more I’d say there is likely 3 tenths in it.
 
gregsdart said:
Update;
Going to 572-13 cnc385 heads. Also step 2 1/8 to 2 1/4 to merge collecters for headers from 2 1/8 to 4 inch collecters headers. I figure the two changes give me a shot at an honest 1,000 hp or more. Add that to a weight reduction to 2890 race weight, and it may go sub 8.50s?
Click to expand...
All of this I am assuming is "on the motor".
 
Greg you are making enough steam that you really need to think about 50/50 or even 48/52 weight distribution to control the chassis.
 
New AL block is 105 lb lighter. Lithium battery took off another 25 lb for 130 total, all up front.
Aluminum blocks are argued by some to show less hp, due to ring seal and heat disapation.
Weight distribution is about as good as i can do without adding forward ballast. If i can't get it to hook i may have to go back to a heavier battery or add ballast. I hope to run solid 8.50 in the heat, 3500 da. We will see. All normally aspirated, though if i come up short i could run M5. That fuel is worth a solid tenth ET.
 
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