how are you going to make more hp with 12valves over 24valves

12extra valves means more airflow which means cooler egts which inturn can add more fuel to make more power and i only have 1700 in my p-pump conversion. that i performed last week. runs awesome love it

havnt updated my sig

 

Just because it has 24 valves instead of 12 doesn't mean it flows more. There is a lot more to flow testing turbocharged engines than most have done. The 12v head will flow as much if not more than the 24v head. For a long time I too thought that the 24v head was the clearcut winner but it just ain't that easy. If the 24v head was better don't you think you would see all the high HP guys doing it? I am not knocking anything here its just my $.02 worth.

Glad you are happy with your setup. Most guys seem to be happy with the conversion, I loved mine but for all the wrong reasons.

Doug

 

Did you do your P-pump swap or did you have Piers do your swap? The information you're giving us conflicts with what I was told by Piers and several other shops who have done the swap.

Good point but not my reason for swapping. I'm doing it because the 24V engine I bought didn't have any of the electronics included. I sold the VP44 and used that cash to buy a complete '96 215hp Cummins with a bad shortblock. I kept the parts I needed, sold some of the pieces off of the bad engine and still ended up with enough cash to pay for the P-pump conversion lines and then some. It was much cheaper than finding a harness and all the electronics then trying to make them all work in my Ford. The P-pump conversion just simplifies my swap AND gains some reliability. I don't see how I can go wrong.

How long do the VP44's in the 900hp trucks last when you drive them on a the street regularly? How are their street manners?



Why is that a problem when 12V trucks typically get better MPG?

Quote:

Originally Posted by Jetpilot

worse driveability
custom parts

A set of $375 lines? Is that it for the only custom parts for the conversion?

Quote:

Originally Posted by Jetpilot

dollars for the conversion

It was cheaper for me to convert to a P-pump. As far as I know, you're the only person that spent 10K to put an inline pump on their truck. Why didn't you just buy a 12V?

[QUOTE=Jetpilot]did I mention driveability [QUOTE]

What's wrong with everyone's driveability? You're the only person talking about driveability issues. What are the issues and why do you think causes them?

Here's the bottom line. Talk about how the spray pattern from the 24V nozzle position sucks. Talk about how the dish in the pistons is a better design on the 12V. Talk about ANYTHING and back it up with facts. Hell, just give an opinion on what you think goes on inside the engine.

You made some specific statements and I asked you to clarifiy them and you didn't.

 

Remember that a 900HP 24v can be turned down to less than 600 at the flip of a switch. A 12v can be turned down to a point by using a valet switch, but at that HP level, I don't know how far! Look in my sig for the difference between valet and full fuel at 1/3 that power. I don't think the difference is linear, either

And at any given power level, the drivealbility "out of the box" WILL be better with the 24v. the P-pump take a bit of tuning to get it to act the way you want, make the power you want, and get the mileage you want, etc. The 24v's are, good or bad, "plug and play."

I was thinking about the conversion to P-pump 24v a while back when I thought my engine was toast. Some very knowledgeable people talked me out of it in my certain situation. Way too finicky for someone else to get behind the wheel of my truck, and it come back in one piece. As much as I hate it, other people do have a need to use my truck from time to time

IMHO,
Chris

 

WOW,

Sorry I offended folks..... I was just offering my experience in owning a p-pumped 24v. I will try and answer a few of your questions. PDR did the actual conversion, I did the tuning. When I left their shop the truck was putting down around 500-550 RWHP. With some tuning different turbos and a little squeeze the truck was making right at 900RWHP. The trucks driving manners were not great. Tons of smoke, not a lot of low end HP but boy did it run good on the topend! I couldn't tow anything with it and I got tons of soot everywhere especially the interior.

Now as for VP's some last some crap out fast.... My old truck ran in excess of 750RWHP for over 60K with no issues. My truck now needed to have the pump replaced before 30K. As far as street manners I can tow our horse trailer all over with my current setup (only around 8K loaded) but its street manners are great. It drives much better than my p-pumped 24v truck did. It isn't quite as strong on the topend but its getting close. That being said I also had to replace a p-pump on the DD p-pumped 24v truck that was less than 20K on it. The replacement pump only lasted about 200 miles before needing replaced. It now has another pump on it with about 1K miles and is running strong. The p-pump is much more reliable than the VP but it is not indestructable.

As for why didn't I just buy a 12v, well in looking back that is what I should have done. There are a lot more parts for a 12v to choose from and I feel the truck would have performed better. I was a lot less knowledgeable back then and it sounded like a great idea. Don't get me wrong I loved the truck its just that to me it was not near as useable as what my current VP truck is.

Super4X4Duty,

I am sorry I didn't answer the questions you asked about the injectors earlier. Formula 1 is producing injectors just for p-p-umped 24v trucks, there is a lot more to these injectors than just lowering the pop pressures, they should be a great injector for guys running the p-pumped 24v trucks. I am not at liberty to say what modifications are done to these injectors but they are extensive. As for the "guys" just lowering pop pressures and saying that good, I really don't want to get into names and such. I tried running several 24v injectors on my old truck from stock to some 12 hole models. I tried running modified pop pressure injectors without much difference, but lowering them did smooth the engine out some. I will just say that I wish these injectors were available when I had my truck.

As for custom parts, it might be better said custom setup.... A 12v timing cover needs to be machined, injector lines, spacer for the intake horn, fuel supply system, wiring harness, getting the cruise to work. Things like this make this a one of a kind vehicle, how I do mine might be different than how someone does theirs. This makes it more difficult if you have a "one off" part break somewhere back in the sticks.

If you have any more specific info that I can answer please let me know and I will try and respond. Again sorry if I offended you.

Doug

 

I havnt figured out a way to get the cruise working on mine yet, if u could inlighten me on this one

jake

 

Well first off, you didn't offend me in the least. I appreciate the appology but it's not needed. I would hope this could be a discussion about the pros/cons and pitfalls associated with installing a P-pump on a 24V. You want to share your opinion and your experiences? Great! How about backing up some opinions with reasons why you feel a certain way? My intention was to stir up some answers, not **** people off. I would hope yours was the same. So let's cut to the chase.

What's the reason the P-pumped 24V head/piston/injector setup runs better/worse than a P-pumped 12V head/piston/injector setup? Let's break this down into three areas. Cylinder head. Injectors. Piston design.

According to the person I spoke to at Piers the ported 24V head outflows the ported 12V head by a decent margin. I haven't put the two on a flow bench, but I might do that next month when I'm home just to see for myself. I'd be curious to see the difference between flowing the head with/without the air horn in place. Does the dish setups offer any power differences? Flame travel problems? Of course the 24V piston has to be used with the 24V head.

Now getting to the injectors. If the P-pump 24V conversion does not have the potential to make more power than a 12V, why would Formula 1 or anyone waste their time developing an injector for that setup? So if the problem with the 24V injectors is the only problem, why do they 24V's make good power with a VP44? I have a ton more questions/comments but limited time. I'll be back.

 

This is just my opinion on the matter BUT

The 24v in my opinion has the advantage over the 12v in this area as well---

The 12v has indirect injection which means that the injector sprays the fuel in the cylider at an angle which mean you have a lot better chance at washing the cylinder walls with a 12v, you will also have worse atomization of the fuel.

the 24v has direct injection which means just the opposite, that the fuel is sprayed down directly onto the piston which lessens your chance of cylinder wash and increases atomization of the fuel

JUST MY $.02

Jake

 

Both are Direct injection

Indirect injection is where the fuel is squirted into a pre combustion chamber before entering the combustion chamber



Cylinder wall wash is an issue with both.... If your timing is off . if not the fuel WILL be squirted into the bowl

370's which have a wider pattern than stock 12v injectors can potentially wash the cylinder walls if your timing is low but at 16-19* they seem to leave a spray pattern on a piston that is not too far off from stock


If i remember correctly the 12v uses a 60* injector spray angle and offset bowl on the piston the 24v uses a 90* angle.... and centered bowl maybe a question here would be if the bowl is offset is it detrimental to the explosion process and the rotation of the engine is thier more skirt side load because of the offset bowl leading to friction?

 

Good points. Glad we're starting to think out loud. Now the next question would be... Why would the P-pump have any effects on this in a 24V? Whether the P-pump or the VP44 pump is feeding the 24V, why would this change? Is there actually a huge difference in the way the P-pump delivers the fuel? Does the VP44 have a different charge pressure/volume that is more desirable?

 

The VP has a more even, higher pressure injection. The P-pump needs RPM to get the pressure up where it should be!

Chris

 

I just got mine runnin today and I don't see what all the fuss is about. The truck with my pulling injectors in idles as smooth or smoother that it ever has, it has a little more touchy loud pedal, I believe they must have put the 4000 gsk in it when they rebuilt it cause it revs to 3800. I still have the stock DV's in for the winter and I have never seen the boost guage move so fast cruising down the road when you get after it. I'm going to put the stock injectors in it and put the snowplow on and wait for it to snow

 

??????

What did you do about the cam/lift pump situation
??You revved it to 3800 w/o floating the valves???
Do you have aftermarket springs and retainers
How did you do the machine work on the front cover. or did you machine the head instead????


Jake

 

Did you keep Your tps for the cruise like travis did.
if so how did you mount it

Thanks
Jake

 

Reving an engine (3800 rpm) with no load will produce little boost and no problem for the valve springs. 3800 rpm under full load with high boost the valves would most likely float.

J.R.

Edited by Admin