Hf oil pump question

[Duane]

I have a he oil pump purchased many years ago from mopar performance, made by melling.in this pump the rotor was pinned to the center drive shaft with a roll pin.
I recently purchased this same pump, but directly from Melling and in this pump the rotor is not pinned. Can anyone explain why this new pump is not pinned. Is one better or more reliable than the other?

Thanks

Duane

 

[krazykuda]

Cost reduction... Less parts to assemble, less labor cost to produce the part...

As far as which one is more dependable, it depends on how they fit the rotor to the shaft and how well they control the process & quality...

 

[Duane]

Cost reduction... Less parts to assemble, less labor cost to produce the part...

As far as which one is more dependable, it depends on how they fit the rotor to the shaft and how well they control the process & quality...

I have access to an EDM machine at work. Do you feel I should add a pin to the assembly for reliability?

 

[krazykuda]

I have access to an EDM machine at work. Do you feel I should add a pin to the assembly for reliability?

If you have one that would work under those conditions, it couldn't hurt...

 

[middleagecrisis]

Melling redesigned their Chevrolet oil pump a few years ago and removed material from the pump body, which resulted in broken housings and all the related problems that came with it. Not sure if they did this too all their pumps or just the Chevy drawings. It's since been corrected. I'm sure that change was somehow related to a cost savings for them, certainly not for whoever used that redesigned pump and had an engine failure. You would think that reliability would be a prime consideration in the designing of automotive parts, but our hobby is filled with glaring examples of manufacturers saving a few cents on the product, but costing the user an engine or expensive repairs. Think of soft cam cores, shoddy Chinese made crap that doesn't fit or work correctly, etc. We need to spread the word on good products and bad, and buy accordingly. Now I'll get off my soap box and answer your question. The gear is probably pressed on, since I doubt it was machined, or cast. as one piece. If you have the ability to pin the gear, I would.

 

[krazykuda]

I'm sure that change was somehow related to a cost savings for them, certainly not for whoever used that redesigned pump and had an engine failure. You would think that reliability would be a prime consideration in the designing of automotive parts, but our hobby is filled with glaring examples of manufacturers saving a few cents on the product, but costing the user an engine or expensive repairs. Think of soft cam cores, shoddy Chinese made crap that doesn't fit or work correctly, etc. We need to spread the word on good products and bad, and buy accordingly. Now I'll get off my soap box and answer your question. The gear is probably pressed on, since I doubt it was machined, or cast. as one piece. If you have the ability to pin the gear, I would.

You hit the nail on the head there....

 

[sireland67]

Also tear the pump apart and d-burr it.