14mm theories

R

RXT

New member
Ok, forgive me if this is in the wrong forum…. but for the past couple of years, I've been casually researching the 14mm pump head swap in that ever present quest for greater hp, without having to resort to an expensive P-pump swap. I've read numerous times about the potential for failure of the 14mm, but as of yet, I'm not sure why they could fail or if that problem has ever been fully resolved. As far as I understand it, am I correct to say that the rotor on these has been known to seize resulting in catastrophic failure. Is this correct?

The reason I bring this up is, it kinda dawned on me one day when I had to give my dog about 15 ml of medicine that I had to "inject" into her mouth with a large 35 ml syringe. While I was cleaning it, I noticed that if I filled the syringe with a little water, say 10 ml, I could forcefully squeeze it out very quickly, but when I filled the syringe to 35 ml and tried to squeeze it out just as quickly, I noticed two things. First, it took longer to squeeze out the water, and second, it took much more pressure to squeeze out the water quickly…Thats when it dawned on me that, maybe this is what is causing the 14mm head to fail. When you have a much larger rotor/plunger, the pressure it takes (provided by the cam plate) to push the larger volume of fuel, in the same period of time is causing the equivalent of hydrolock. If I had the strength to squeeze out a full 35 ml in the same time it takes to squeeze out that same 10 ml, I would have either exploded the plastic tube or bend the plunger. The only way to squeeze out a greater volume of water, in a shorter time with less pressure was to enlarge the hole. Am I on to something here? Or am I way off base and have no stinkin' clue as to what I'm talk about?

Ed
 
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Your on target I think. I’ve been down that road before with rotary pumps, roosamaster not the Bosch though. They are designed very differently so I don’t know if this applies or not. When we used a .450 roosamaster coupled with factory sized lines and relatively small injectors (5x14-16sih), you could seize a head up quickly. We moved to a .450 roosa with .120 lines and 5x25 dual feeds and ran the same pump for 8 years. But the pump also had some modifications to allow fuel to leave in a more timely fashion.

I think for the 14mm pumps quality is an issue now. As far as I know there is only 1 manufacture of 14mm heads, and from what I’ve heard their QC department is lacking.

I too run a stock 12mm VE pump on a tractor of mine. I’m out of fuel, but changing to an A-pump or p-pump is very time consuming and costly. I’ve wondered about the 14mm head, but I’m not gonna buy something that may junk itself in a short time
 
I believe Schied recommends larger lines and a minimum injector size with their 14mm pump. They also pin the timing to make it live longer.(which takes away the biggest advantage of the Ve over pee, dynamic timing)

In a tractor application, I think it would be much happier. Especially if it’s never going to see above 2500 rpm.

You say “expensive p pump swap”. You could be into a pee pump swap very very cheap.
Step 1: buy a running pee pump motor - $1500
Step 2: swap entire motor
Step 3: sell your running Ve motor - $1200

Now you’re $300+ some bits and pieces you may replace like gaskets and such during the swap.

Or you spend excessive amounts of money on a 14mm pump, lines, injectors, just to grenade it making 500hp.

I’m VE to the death, but if I really cared about making more than 500hp, I’d just pee swap it.

Just my .02
 
Didn’t Austin ace take his 9/16” pump down the bush tracks at 4K for many years?? Hurt feelings on the streets and it finally died a happy death after many miles? Didn’t he have a really good supply system and a fuel cooler??...


Fondler.... GTFO with your logic!
 
j.fondler said:
I believe Schied recommends larger lines and a minimum injector size with their 14mm pump. They also pin the timing to make it live longer.(which takes away the biggest advantage of the Ve over pee, dynamic timing)

In a tractor application, I think it would be much happier. Especially if it’s never going to see above 2500 rpm.

You say “expensive p pump swap”. You could be into a pee pump swap very very cheap.
Step 1: buy a running pee pump motor - $1500
Step 2: swap entire motor
Step 3: sell your running Ve motor - $1200

Now you’re $300+ some bits and pieces you may replace like gaskets and such during the swap.

Or you spend excessive amounts of money on a 14mm pump, lines, injectors, just to grenade it making 500hp.

I’m VE to the death, but if I really cared about making more than 500hp, I’d just pee swap it.

Just my .02
Click to expand...

Our tractor ran 4k+ rpm (no tach) for many years on the same rotary. I run my little 4 cylinder VE at 3500
 
mfsuper90 said:
Our tractor ran 4k+ rpm (no tach) for many years on the same rotary. I run my little 4 cylinder VE at 3500
Click to expand...

Sorry, I wasn’t thinking pulling tractor, i was thinking actual work/farm tractor. Sorry man, I’m just a dumb farm boy, lol.
 
j.fondler said:
You say “expensive p pump swap”. You could be into a pee pump swap very very cheap.
Step 1: buy a running pee pump motor - $1500
Step 2: swap entire motor
Step 3: sell your running Ve motor - $1200
Click to expand...

Ok, thats a great rebuttal to my comment, and I would completely agree under the existing options…..but that wasn't exactly the point of this topic.

I'm thinking, maybe 14mm is too much. Maybe 13mm would be a better diameter (We know that size works in the VP44 pump and it's capable of greater power, if the pute doesn't fry first)

Maybe 15mm with a shorter stroke than a 12mm head would work better.

Is the metallurgy so piss poor with the 14mm rotor that it's always going to fail? Or can it be improved?

Ed
 
I think the 14mm failure deal is the same as the china turbo scenario, some last, some don't, and it's all in the clearances. KTA back when he had his made sold around 50 of them without hardly any failures. There are a few Rocken Tech ones that are alive out there, but again, how many do you want to buy? I've thought of trying one out for kicks to see what happens.
 
Has anyone experimented with additional fuel flow to the vane pump?

Seems to me the front bottom ‘lug’ (threaded hole) on the VE could be used as a 2nd feed directly into vane pump if one were to cut into the feed passage

I understand feeding high pressure fuel directly into shutoff port, but for a DD application id personally like to stay away from complicating things too much
 

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There was a thread on here with someone using a hydraulic pump to feed more into the ve. Was a ve 24v engine.
 
smokinVE said:
Didn’t Austin ace take his 9/16” pump down the bush tracks at 4K for many years?? Hurt feelings on the streets and it finally died a happy death after many miles? Didn’t he have a really good supply system and a fuel cooler??...


Fondler.... GTFO with your logic!
Click to expand...

Austin recently just came out to California and helped throw a 14mm ve on my truck. He daily drove his, drag raced, sled pulled and dynoed his 14mm ve all over the place and drove it to every event for years. His pump lasted a long time and talking to him about it he did not seem disappointed that it finally seized. And from what I understand he never went with the fuel cooler and just ran high fuel pressure through a single port. I personally don’t think a fuel cooler is needed until you are either running a race fuel cell or your tank low to the point where the returning fuel doesn’t have enough time/fuel in the tank to displace the heat and cool it down.
 
jlbayes said:
There was a thread on here with someone using a hydraulic pump to feed more into the ve. Was a ve 24v engine.
Click to expand...

You're speaking of "Turboram", out of Stryker, Ohio.
Saw Nicks set-up once, interesting to say the least.

You better be force feeding it as much as the case will take, because it certainly can't, and won't, pull adequate fuel any other way.

Mark.
 
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