24v monoterm pistons in 12v?

[WHITExGUY]

As the title mentions, sometime over this winter/next summer i will be starting a new engine build(5.9 12v) for my track/race car. I like the idea of using monotherm's since the rest of the engine will be built completely but sadly they are currently 24v specific, as you already know.

Now i've been doing as much research(google loves me) as i could, gets kind of tiring after only finding 2 helpful posts for every 50 i read. on some forums people say using 24v pistons in a 12v simply wont work due to the different bowl offset's(which completely makes sense). However one past thread started on this site on this very subject stated that it can be done if the correct injector tip/nozzle is used, but never went into detail about what spray angle would be necessary.

So my question is, what sorta of spray angle would be needed to use a 24v piston in a 12v? My mind tells me the narrowest spray angle available. Would this be a correct assumption? Would advancing/retarding timing be helpful/necessary as well?

or will this just simply not work at all unless you do a full 24v head swap.

thank you for any input, sorry if this has been answered already and i simply missed it in my searches.

 

[Smokem]

Depends on which bowl design and the amount of timing be used, many forged pistons used in 12v applications have centered bowls.

 

[SPEAKSUP]

I know it's not monotherm's but I know of two 12V builds using 24V pistons yes they are both 1000+ HP but they work fine.

 

[WHITExGUY]

Depends on which bowl design and the amount of timing be used, many forged pistons used in 12v applications have centered bowls.

That makes sense, i didnt even realize the center bowl on many forged untill i just went back and looked at some of them. :nail:

As for bowl design I wasnt aware they made different designs(didnt research the monotherm pistons themselves as much as i researched 24v pistons in a 12v). Is the design varriance based upon year or compression ratio?

Sorry if this is an easy answer i should know already, my brains twisted from all the pages ive read in the past couple days.

I know it's not monotherm's but I know of two 12V builds using 24V pistons yes they are both 1000+ HP but they work fine.

Thats very comforting as i only plan to make 650-700 with my engine.

 

[ctdiesel99]

That makes sense, i didnt even realize the center bowl on many forged untill i just went back and looked at some of them. :nail:

As for bowl design I wasnt aware they made different designs(didnt research the monotherm pistons themselves as much as i researched 24v pistons in a 12v). Is the design varriance based upon year or compression ratio?

Sorry if this is an easy answer i should know already, my brains twisted from all the pages ive read in the past couple days.





Thats very comforting as i only plan to make 650-700 with my engine.

If that's the case, save your money on running monotherms

 

[YOUNG GUNS15]

If that's the case, save your money on running monotherms

We all know how plans go... They change and all of the sudden we want 300hp over our original goal. Those pistons will last any goal change if e wants more. I like the idea of overbuilding stuff.

 

[longhorn859]

Thats stupid...Yeah, overbuilding to an extent...but monotherms????

 

[ctdiesel99]

We all know how plans go... They change and all of the sudden we want 300hp over our original goal. Those pistons will last any goal change if e wants more. I like the idea of overbuilding stuff.

You do know what a set of monotherms cost right??

I'm all for building for future mods, but as chase said......monotherms? That's a bit of a stretch even for a 900-1000hp 12v imho.

 

[YOUNG GUNS15]

Thats stupid...Yeah, overbuilding to an extent...but monotherms????

where is he going to be in 4 years? he could want 1200hp and monotherms will handle whatever he wants, nitrous, gazillion cc of fuel etc. I say go for it, it wont be such a stupid idea when you break something and really wish you had just done it in the first place.

 

[ctdiesel99]

where is he going to be in 4 years? he could want 1200hp and monotherms will handle whatever he wants, nitrous, gazillion cc of fuel etc. I say go for it, it wont be such a stupid idea when you break something and really wish you had just done it in the first place.

Other modifications/upgrades will need to be addressed in the bottom end when going from 700 to 1200hp other than just pistons.

If he want's to have $6,000 in rods and pistons alone for a 700hp truck so be it, just saying I would save the money for his application and goals

 

[YOUNG GUNS15]

Other modifications/upgrades will need to be addressed in the bottom end when going from 700 to 1200hp other than just pistons.

If he want's to have $6,000 in rods and pistons alone for a 700hp truck so be it, just saying I would save the money for his application and goals

who saves money in diesel hot rodding anyways? LOL

he could spend the money in other places a lot better, yeah i get that. but if he wants them I say go right ahead.

 

[6.4 F-350]

The problem is one thing Leeds to another monotherms leed to billet rods witch leads to blah blah blah. Build smarter not spend more. Sometimes less is more IMHO.

 

[WHITExGUY]

jeeze this took off into the "waste of money" direction quickly....

If that's the case, save your money on running monotherms

Thats stupid...Yeah, overbuilding to an extent...but monotherms????

This build isn't like an over the winter thing. It's going to be at least a year in the making so money really isn't a huge concern.

If you knew half the things this engine will consist of you would understand that going with a different part just because its cheaper would be like building a space shuttle to NASA spec and then using bottle rockets as the main engines.


As for why i want to use monotherm's over a more common aluminum race piston, monotherm's can simply handle way more abuse then an aluminum can over a long period of time. My engine wont see the quick 9-13 second drag car abuse cycles or the frame twisting puller runs. Its going to be in a car revving out for minutes at a time, and i dont want to have to be worrying about melting a piston if i spike a 1600+* egt during one of my runs, or worrying that i might fatigue the pistons and by some act of god it decides to fall apart and then im done for the day or worse year.(highly unlikely? yes. but still possible).

So yes im going off the "build it for 1500+ and worry less at 800 and under" theory.

The problem is one thing Leeds to another monotherms leed to billet rods witch leads to blah blah blah. Build smarter not spend more. Sometimes less is more IMHO.

billet rods are already on my list, along with many other wet dream parts you could possibly think of for an engine handling 1500+.....:rockwoot:



But please lets try not to fall to far off course on the original subject of monotherm pitons in a 12v please, id really enjoy finding out more about this since other websites never really go into full detail, and most say its not doable when clearly it is.

 

[Smokem]

Anodized forged aluminum.

 

[WHITExGUY]

Anodized forged aluminum.

Still straying away from the topic, but please elaborate more.....im assuming hardcoat anodized.

To me putting a coating on something is meerely putting a bandaid on to hide the weakness, once the coating wears off enough weaknesses are exposed and well you can guess were thats going.

 

[Smokem]

If you can wear off anodizing, you are doing something real wrong. This way you can have any piston bowl you desire, from a few different sources.

 

[AHall]

Exactly what is the application. What rpm? You'll be adding some weight to the rotating assem.

 

[WHITExGUY]

If you can wear off anodizing, you are doing something real wrong. This way you can have any piston bowl you desire, from a few different sources.

Sorry i shouldnt have worded that that way at all, just waking up and posting on a forum half asleep isnt the best idea i guess. Dont know exactly were i was going with that myself. Sorry i feel dumb now.

I know hardcoat and other anodizings are very hard to wear off (some cases nearly impossible), obviously one benefit of hardcoat is abrasive resisntance.

But what does hardcoat/anodizing do for heat resistance, i know getting gold or some other thermal protective coating will help. But does it really change the amount of heat soak an object sees that drastically?

Exactly what is the application. What rpm? You'll be adding some weight to the rotating assem.

5-6000rpm so aluminum would be beneficial unless i do some other massive lightening to other components on the rotating assembly.


I would however like to maybe keep this somewhat on topic tho. I understand my application doesnt call for monotherm's but since the info is not out there yet can those who know a thing or two about using 24v pistons in a 12v give some insight to what sorta bowl design/timing/spray angel youd use regardless of what my application is.

 

[kawi600]

Might make more sense to do a 24v ppump conversion if you really want the monotherms.Less grief with timing too, Id imagine. since you dont have to worry about the offset injectors making an elliptical spray.

 

[zstroken]

Issue with the forged pistons is the non steel ring lands.