Low Profile SAE Adapter

[MToomey]

Hi folks,
I tried posting over in automotive since it's an SAE spec, but they didn't have much to say. If you know somewhere better to inquire about this, I'm all ears.

I am designing a one-off hydraulic power unit for a custom job at my company. We have the engine on order and the pump picked out, but the engine has an SAE A 4 bolt pattern and the pump has an SAE B two bolt pattern—the big issue being the pilot diameter interference (A is Ø3-1/4" and B is Ø4").
The engine manufacturer is providing a splined hub to adapt from the output of the engine to the input of the pump, leaving up to 5/8" between the mounting faces of the two flanges. Does there exist an adapter that will fit in that space or do I need to draw my own and pay a machine shop to cut two of them for us?

Is this all a moot point because I should use a shaft coupling between them? I'm trying to keep things compact because I don't know yet what else will need to fit here.

 

[TugboatEng]

The pump should have multiple options for flanges. Even if you've already bought the pump you should be able to purchase the bearing housing with the correct flange without having to buy a complete pump.

 

[MToomey]

The pump should have multiple options for flanges. Even if you've already bought the pump you should be able to purchase the bearing housing with the correct flange without having to buy a complete pump.

Tugboat: In this case, Parker reports they only offer that pump with the B flange.

However, I have learned since I posted this that I had been working with the wrong engine and that the bigger engine *does* have a B pattern and pilot.
Crisis averted!