These air cooled Cylinder Heads were never designed to be race heads. They became race heads due to homologation requirements for GT racing. But for the air cooled 962 but Turbo use is different. You can cheat yourself out of a problem with boost.

The short turn is a killer. Not many other heads are so bad. Almost a 90° turn, big valve guide boss and a 8.00 or 9.00mm valve stem. What could be worse.

Its not surprising that 4.0L engines make about the same as the 3.8L RSR engines did. Its all about getting the air to turn without creating a huge eddy effect that stuffs up almost 2/3rds of the port area. The bigger the port the bigger the eddy. Go smaller and the total air flow sucks.

If the port was a straight shot to the back of the Valve, the flow and HP numbers would increase significantly. Just about all engines big or small hit the 400 HP mark and basically stop. More RPM makes little difference but it can help as long as the air volume stays constant some.

The lightweight masses certainly help in spinning the engine faster. That in itself is a great help. If you are air and torque limited, getting into the usable torque quicker will send you down the road quicker too.

We all have to accept what we are given and make the best of it. Expecting a huge number without understanding the issues is where many get caught out.

thanks for the explanation Neil, thats pretty interesting.

You saw these heads in person right? were they not able to somewhat solve this 90 degree turn issue?

By any chance have you seen or have any insights into the other two 4-valve heads producing around 500hp (allegedly)? Singer and robert lintons. I am curious how they solved this.

Hi Neil, that's very interesting. Is there somewhere I can find more information on the build and what the other engine components used are going to be?

Both of these 4V projects have made a complete reversal in specification. I need to keep my mouth shut sometimes, offering idea's to customers.

We are going against the grain with these 2 projects. Going small not big. Not sure what the outcome will be, having to push the limits to achieve any performance. All new componentry and totally into the unknown for me.

Hero or zero I guess.

Neil, you may already know this, but to be sure: In American V8 racing engines, the ports in the heads make a sharper bend than the ports in the Porsche heads. The Porsche ports are almost a straight shot by comparison. One of the tricks head designers and flow bench experts figured out was to get the turn in the port early, and then make sure the last 1/2 inch or more of the port is straight to the back of the valve. SBC Chevy intake ports can be made very efficient this way, even though the damn things look like a bent knuckle.

I have not seen any heads used in racing for sometime that have ports as you suggest.

All of the heads we see have close to no short turn. Just a small one as the port transitions into the chamber. Mostly 4V heads but most of the 2V V8 aftermarket heads we have seen are this was as well.

I need to get out more.

It appears they now have a flat 8 using the same heads and it would appear cylinders...

https://www.instagram.com/p/DPXxouaDJ-w/?hl=en&img_index=1

Based on the somewhat short size it appears to be a 180 degree V rather than a boxer. I had always wondered if you could save 59mm just by using shared crankpins and then optimize here and there to fit 8 cylinders in the same dimensions. Seems Runge has done with swindon