Engine experts, Oil pump and pressure Options

[r_towle]

I’m going to build a flat 8.
Not asking to debate this, but it’s the premise of my current research.

In the only successful motor built like this, in Brazil in the 70s or 80s, they had issues getting oil at sufficient pressure to the crank/valves furthest away from the pump.

So, I have two ideas.
If you look at the 911, there is an external oil feed pumping oil into the valve train.
I’m thinking of something like that, but not sure how to route it, or the right place to inject oil ….maybe at the beginning of the second case….or the other end and feed it backwards.

Or
I could enlarge the internal oil galley in the first motor to increase volume.

I expect I will need to find the highest volume pump I can.
I assume different pressure relief valves.
I assume eternal oil cooler and filter.


The rest of the architecture looks fairly straight forward.
I need help, experience, and some hotrod thinking on the oil issue.

[technicalninja]

If I was building a POC (proof of concept) engine I'd simplify the oil system routing by taking it external and running a dedicated dry sump system.

These are commonly driven by a small gilmer belt and are stacked units.

I've seen dry sump pumps with 2 pressure sections and 5 scavenge sections.

You can set up whatever you wish and change stuff around easily if needed.

The only downside is added complexity of the external lines and the overall cost.

Building a flat eight out of two different engines will be harder than building a H8 case (billet aluminum would be my choice) in the first place.

I would expect this to be an expensive endeavor.

Far more expensive than buying a 3.6 and a 915 gear box...

Far more expensive than adapting a Ferrari V8...

Far more expensive than fitting a twin turbo Bently W12 and PDK...

Would definitely be at or above the same level of WOW as the above.

I bet a custom H8 crank would be 50K from a reputable crank builder if you could find one that would try.

It would still be very neat to see someone do this.

Water pumper or air cooled?

NA or boosted?

What vehicle do you plan on installing this in?