Cutting 160 pump for 13mm p&b's

AHall said:
On a serious note, the average person wouldn't believe that the tiniest scuffing on a plunger often means it gets thrown out. Barely can see discoloration from the polish. I'm sure Seth has a couple pics laying around. The ol fingernail trick doesn't apply to fuel injection.
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This is true.

The only pics I have are on my phone and they aren't clear enough to show the issue.

I guess I should also say that I have no issue with people trying to be innovative or save money, but some short-cuts lead to fiery crashes. Fabricating your own $20 barrel/plunger sets is one of those short cuts.
 
I had heard that the acid in your skin is enough to kill the tolerance.

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CTDYoungGun said:
The fitment spec for barrels and plungers is 80 to 100 millionths. No, that's not a typo.

If you still feel that you can build your own pump and internal components, please post up the process and results so us newbs can learn...
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Most people can't appreciate how close that is. If you had a precision lapped 6061 aluminum ball bearing that was exactly 1" in diameter at 68 deg F. and warmed it to 69deg F. it would measure 1" + 13.1 millionths or 1.0000131.
 
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I see what happened there. My work stops at the 4th zero, lol. I had never heard the tolerance but I knew only Bosch is trusted in general, pretty clear why now.
 
Emery cloth... Feeler guages... Grow up will ya.... Will be reamed out undersized then honed half thou over. From there the DLC guys will take care of it and bring it into what I want. If you all are gonna give such a hard time then fine. Talk amongst yourselves off my thread at least if you have nothing useful.

I'm not trying to shortcut, otherwise I wouldn't bother in the first place and wouldn't be sending my pump out to get components DLC'd.
 
BramanteCummins said:
Emery cloth... Feeler guages... Grow up will ya.... Will be reamed out undersized then honed half thou over. From there the DLC guys will take care of it and bring it into what I want. If you all are gonna give such a hard time then fine. Talk amongst yourselves off my thread at least if you have nothing useful.

I'm not trying to shortcut, otherwise I wouldn't bother in the first place and wouldn't be sending my pump out to get components DLC'd.
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You got it hoss! I'll bow out of this thread since I don't have anything useful to add. :Cheer:

Edit: Before I bow out, don't forget to have those plungers checked for hardness...that may of some importance.
 
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CTDYoungGun said:
You got it hoss! I'll bow out of this thread since I don't have anything useful to add. :Cheer:

Edit: Before I bow out, don't forget to have those plungers checked for hardness...that may of some importance.
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That's certainly going to be important. I'm going to order 150-200 worth in the cheapos and cut them up to check them thoroughly. Everything I can get DLC coated I will. That will ease the load on the surface and also make them less sensitive/prone to wear or damage.
 
BramanteCummins said:
That's certainly going to be important. I'm going to order 150-200 worth in the cheapos and cut them up to check them thoroughly. Everything I can get DLC coated I will. That will ease the load on the surface and also make them less sensitive/prone to wear or damage.
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Spend $600 on Bosch plungers first and save yourself the $200 worth of scrap parts, labor, coating, wasted time.

The only thing I would consider using a $13 plunger for is clearing my toilet.
 
AHall said:
Spend $600 on Bosch plungers first and save yourself the $200 worth of scrap parts, labor, coating, wasted time.

The only thing I would consider using a $13 plunger for is clearing my toilet.
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Any idea on Rocken tech? Theirs are more complete, not so good reveiws on their ve rotor heads but haven't seen anything on plungers. I still intend on the coating however. Just seems like a good thing to do in general.
 
You might get away with them. Less failures. Some swear by them to get into a 13mm pump and save a few bucks. If I were you I would cut costs somewhere else in life (ie less ribeye, more ramen) and go for Bosch. And wouldn't worry about coating. I always like innovative ideas, but it seems unnecessary in this application. Only thing I would consider in a pump is micro polish.

If you do decide to go a different route I wish the best.
 
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AHall said:
You might get away with them. Less failures. Some swear by them to get into a 13mm pump and save a few bucks. If I were you I would cut costs somewhere else in life (ie less ribeye, more ramen) and go for Bosch. And wouldn't worry about coating. I always like innovative ideas, but it seems unnecessary in this application. Only thing I would consider in a pump is micro polish.

If you do decide to go a different route I wish the best.
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To DLC a few fork tubes they quoted me about 30$ a piece. It's well worth to have that low friction and that hard a surface.

I wish I could cut costs more, do the bosch units come with the springs and all the other components needed or is it strictly a plunger and barrel set?
 
What spring are you looking for? P&B kits come with just that.
 
While we're on the topic of pump parts...

How can you tell if a part is "genuine Bosch" prior to purchasing it? Are the Bosch part numbers sufficient or do the knockoff parts have the same numbers?
 
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This is on a Rocken tech plunger. Guy has been doing 1k hp on it for some time now. One of the plungers got stuck, but it was because he sucked the pump dry for too long.
 
DLC coating is a good thing in some applications, I have done several sets. Any amount of coating the plunger will not start into the barrel. With the right tooling you can create the tolerance needed to refit the plunger. You will spend hours and hours refitting hoping the entire time you don't go to far or get it to hot.
 
01PPUMP said:
DLC coating is a good thing in some applications, I have done several sets. Any amount of coating the plunger will not start into the barrel. With the right tooling you can create the tolerance needed to refit the plunger. You will spend hours and hours refitting hoping the entire time you don't go to far or get it to hot.
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This is my worry, after talking with my pump guy I'm very wearing of DLCing them. What he said was bosch uses air to measure the fitment.
 
Maybe the coating wull take up the extra space in the poorly machined chinese barrels.

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