thoughts on bumping up compression

dirttymaxx said:
on a diesel puller i would lower compression,force feed that baby!

street i would up it about 5-10 points,you could do that with head gaskets/mill head.
if you mill the head you need to know your pistion to valve clearnce!!! but it should only need milled about .010 to do that.

my race motor is set up at .005 of clearnce at top dead center,that really really tight!!

i will see if i can find that fourmala.
you could run a smaller bowl in you head/or pistion.
or you could deck the block,inturn this will make the pistion stick out of the block,then that will change your valve to pistion clearnce. unless you destroke the motor. or use a pistion that has a diff rist pin location,thats higher up in the pistion.

hope this helps in some way,theirs more but. . . . it kinda get crazy
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On the cummins milling the head will yield pretty much 0 on compression increase. You have to make the combustion chamber smaller to gain compression.
 
dirttymaxx said:
on a diesel puller i would lower compression,force feed that baby!

street i would up it about 5-10 points,you could do that with head gaskets/mill head.
if you mill the head you need to know your pistion to valve clearnce!!! but it should only need milled about .010 to do that.

my race motor is set up at .005 of clearnce at top dead center,that really really tight!!

i will see if i can find that fourmala.
you could run a smaller bowl in you head/or pistion.
or you could deck the block,inturn this will make the pistion stick out of the block,then that will change your valve to pistion clearnce. unless you destroke the motor. or use a pistion that has a diff rist pin location,thats higher up in the pistion.

hope this helps in some way,theirs more but. . . . it kinda get crazy
Click to expand...





:rolleyes:
 
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How much more compression did them stack add?

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If you move the stacks closer together and point them towards each other does it raise drive pressure?
 
big swole what was that all about? i didnt proof read it lol

say what you will. . . . thats not my truck,i just tune it and fix it! bet you cant say you have made 575-600 on stock charger? got the dyno sheet to prove it!

zstroken:
On the cummins milling the head will yield pretty much 0 on compression increase. You have to make the combustion chamber smaller to gain compression.

yeah your right,kinda went back to my gasser days!
 
dirttymaxx said:
big swole what was that all about? i didnt proof read it lol

say what you will. . . . thats not my truck,i just tune it and fix it! bet you cant say you have made 575-600 on stock charger? got the dyno sheet to prove it!

zstroken:
On the cummins milling the head will yield pretty much 0 on compression increase. You have to make the combustion chamber smaller to gain compression.

yeah your right,kinda went back to my gasser days!
Click to expand...

Lets compare apples to apples, even on stock chargers. :) The '89 5.9 charger isn't the same size as the 2011 twin turbo ford "stock" chargers.
 
well yeah naw ****! but who cares?
i just get tired of all the smart ass comments about the stacks!! so what their big and if you guys really wanna push it,the dodge guys are a hell of a lot worse about stack size. at least they look some what right!


fyi their bull haulers. not stright stacks
 
dirttymaxx said:
well yeah naw ****! but who cares?
i just get tired of all the smart ass comments about the stacks!! so what their big and if you guys really wanna push it,the dodge guys are a hell of a lot worse about stack size. at least they look some what right!


fyi their bull haulers. not stright stacks
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So, the stacks have the :homo: ?
 
I don't even like the bull haulers on semi's where they belong, still fugly as hell.

Actually on the oil pressure, thinking about doing something there, I've been finding the compression side of the rod bearings showing some wear, could be some greed with the timing to however. This is at 15.1, 20-22.1 sounds expensive.
 
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Joesixpack said:
I don't even like the bull haulers on semi's where they belong, still fugly as hell.

Actually on the oil pressure, thinking about doing something there, I've been finding the compression side of the rod bearings showing some wear, could be some greed with the timing to however. This is at 15.1, 20-22.1 sounds expensive.
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yeah, I was thinking with upping the compression you have more, unloaded pressure on things, never mind adding 60psi of air on top of that.
 
Proper torque management with a stand alone would go along way. Were VE is sweet at lower rpm and big boost, keeping the fueling under control. As the rpms go up, and VE suffers the raised compression ratio could be effective.....(and non destructive).
 
it takes 600hp worth of cylinder pressure to make 600 hp. it takes 1,000hp worth of cylinder pressure to make 1,000hp. REGARDLESS of compression ratio.

timing has A LOT to do with when that cylinder pressure happens, whether you are running (for instance) 50 psi at 20:1 or 70 psi at 15:1. (to arrive at the same cylinder pressure)


if you wanted to go ahead and get better mileage and better off boost response then up compression, but be prepared to fix things if your tune is a bit off and you want to go beating on it.

a standalone that lets you control everything would be the way to fly with higher compression for a good street/strip (to 800hp ish) vehicle imho. for all out drag racing or pulling, stick with whats proven, and drop the compression and let the turbos do the work for you.
 
JasonCzerak said:
The wording suggested matching a CR's compression with a 12v. not going above the CR.

Who else is raising compression?
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Sorry I worded it wrong. Your favorite friend Compy bumped it up on one. Said it made 600HP clean. Monster Mike has also bumped up the 24v. So I say with the proper setup on a 12V it would be amazing.

Ron your bumping yours up right?
 
Rumor mill says there is a high compression (> 20:1) 5.9 with three chargers that made big hp on the engine dyno recently. 180 psi boost
 
There are some definite positives with upping compression. The down side is that is a totally different school of though on engine design and it requires different settings on timing and a cam that can bleed off a little bit of compression on the bottom end and then continue gain captured intake flow as rpm rises by closing the intake valve more degrees after BDC. I am glad to see so many people finally playing with different compression ratios stroke and rod length. Making cleaner power should be one of our top priorities if diesel is to hit more of a mainstream audience. We are working with quite a few people upping compression ratio and looking for custom cams to compliment them. THis next race season will change a lot of peoples minds on what the "ideal" way to make power is. In a drag race situation there are lot of benefits.

Zach
 
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