Helix cams

[Fishin Guide]

what pump are you running FG.

It's a 12Valve lift pump, but not from a Dodge application.



Dave

 

[Fishin Guide]

If and when a 12v mechanical pump fails, would an aux electric pump be able to pass fuel, i. e. , can fuel be pumped through a broken mechanical pump? How does a mechanical pump fail (rare I suppose)?



I've been interested in a mechanical fuel pump setup but went to the trouble of adding a pusher pump with filter some time ago. A couple of years ago there was a lot of interest in the pusher and it has some benefits. I have a gauge that tells me if the primary filter is too restrictive (30micron), a heater, auto bypass valve, easy access for maintenance, etc. I also control the pusher with a switch and ended up leaving it off most of the time because of talk that I might be damaging the VP with too much pressure. Who knows! I was getting about 17psi with the pusher and was thinking of getting a lower pressure Carter to reduce the pressure. But like Fishin Guide said, besides the 12v fuel pump, there are the performance benefits of the cam. Seems like the way to go, but I'd rather not give up the pusher - would seem like a nice emergency fallback if it could pump through a failed 12v pump.

If the mechanical pump fails, you will not be pumping fuel through it. Well, depending on how it failed.



The mechanical pumps are very reliable. Even when pumping trash fuel. You could retain your AUX setup and runt he lines up into a -6AN tee. I would prefer to have a manual valve on the electric side so that pump would not see any pressure. Or put a flow restrictor in. I am not a fan of the restrictors, but they will work.



There are very few parts to fail in the mechanical system. Some pumps are rebuildable, and with simple hand tools, it could have a new piston assy. in about 10 minutes. There's no "lever" like in a traditional V-8 setup, just a shoe on the end of a piston that rides on the cam lobe. On the outboard side of that piston is a spring. So, the cam pushes the piston out to the drivers side, the spring pushes back. BTW, the fuel pressure comes from the piston bore and stroke of the pump body/ piston and spring pressure.



I bought a rebuild kit for mine and put it under the seat. In another 250K miles, I may rebuild it for something to do. Best $8 I ever spent!



Dave

 

[JCutter]

So you didnt use the dodge lift pump. Which one did you use. What part #. Did you get it from Napa, auto zone, ect.



Sorry for all the questions but thats why im trying to get the right pump the first time. Ive already got a regulator from my holy blue setup if it will work.





Thanks Jeremie

 

[Fishin Guide]

So you didnt use the dodge lift pump. Which one did you use. What part #. Did you get it from Napa, auto zone, ect.



Sorry for all the questions but thats why im trying to get the right pump the first time. Ive already got a regulator from my holy blue setup if it will work.





Thanks Jeremie

Unfortunately, I have agreed to not disclose the part number of my pump as it was one used in the test phases of the fueling setup.



I would thing Rip would have access to the new part#.



Dave

 

[SRadke]

Is it the piston style pump that replaced the diaphram style that was used in the first gens? These are very commond and we're replaced several in tractors with them. If that's the one you're using a good counter guy at a cummins retailer will be able to find it for you.



-Scott

 

[Vaughn MacKenzie]

I have heard of a number of 12-valve guys going over 300,000 miles and still having their original lift pump (94-up trucks at least). Some have lasted far longer than that. Failures are pretty much a non-issue. I replaced mine around 370k, but there was nothing wrong with it. Going to the 12v lift pump setup on a 24 valve makes a pusher pump pointless.



Vaughn

 

[Fishin Guide]

Is it the piston style pump that replaced the diaphram style that was used in the first gens? These are very commond and we're replaced several in tractors with them. If that's the one you're using a good counter guy at a cummins retailer will be able to find it for you.



-Scott

It is a piston pump. But it is not a replacement for any Dodge pump. At least mine is not.



Dave

 

[GiesJ]

TTT - Fishin Guide - how's that cam treating you?? I am interested to hear if you have gone to new springs?? (and why or why not)? If I remember you were thinking about twins and springs eventually. I read somewhere that it is a real good idea to do springs with the H2. Just trying to figure out what to do and when, when the $ tree is in bloom...

Thanks,

j

 

[Fishin Guide]

TTT - Fishin Guide - how's that cam treating you?? I am interested to hear if you have gone to new springs?? (and why or why not)? If I remember you were thinking about twins and springs eventually. I read somewhere that it is a real good idea to do springs with the H2. Just trying to figure out what to do and when, when the $ tree is in bloom...

Thanks,

j

The cam has been working great. Still no complaints with EGTs or spool. I have added twins. And most guys that drive my truck are pretty impressed.



In fact, we are going to swap to the new bolt on gear design a I plan to raise power just a tad.



Also, the mechanical pump just continues to tick away like the day it wass installed. So, I am very happy.



I have not done springs yet. I have tried to determine if any valve float was going on, and so far, it's still up in the air. However, I do feel that it is a prudent move to do the springs and I am planning to do so.



Dave

 

[GiesJ]

I have tried to determine if any valve float was going on, and so far, it's still up in the air.

Probably a question to demonstrate my ignorance - how do you determine if you have any float? If one does not have float (and what would or would not cause this, individual engine tolerances?) can they run the stock springs? I still really don't understand the benefit of these springs. Can someone dumb it down for me?

 

[Fishin Guide]

If you have ever been in a car that has had valve float, you would know in a second. But, there's also float that is less noticeable. Either kind can and will hinder power production. The biggest downside is the possibility of the valve and the piston trying to share the same space.



The expensive springs keep the valve train in "contact" with the cam. As long as they do thier job, the valve cannot hit the piston. All things being equal. Also, the more expensive springs can tolerate more lift before they bind. Coil bind and float are the reasons to swap springs.



Dave