The V8 Owners Forum -

ITB fasteners, water hose connector and blanking plate for rear end water hose hole.

Those injectors are quite far away from cylinder head.

I would think that 180 degrees would be plenty. Cool air flows through the intake manifold, unlike, for example, the engine's breather system where hot bypass gases flow. There are unlikely to be any problems.

Cant the TBs towards each other rather than keeping them vertical?


Yes, one possibility to make the intake runner straighter. There is not much space available if the fuel rails are between the tb's. In the final version, the tb's mounting will be modified so that it fits the intake manifold ...

FBW wrote: Sat Apr 11, 2026 8:48 pm
Can the material withstand the expected temperatures permanently?

Material is PA18CF, heat resistance of approximately 180 degrees Celsius.

I've had those BMW itb's for years. I've made one steel intake manifold half and one aluminum one. I wasn't happy with either one. Then I would have had to make another one just like it, it's doable but I have limited time. This 3D printing guy I sent a WhatsApp message to a couple of weeks ago ...

The final product is made of some decent material, I don't know what material. I believe it's some decent stuff. This guy has been making these for a few years and is a car enthusiast himself. I have no doubts about that.

These are just mockups to see what i have to change. Any opinions about injector position? For me it look like fuel is injected straight to long side port wall. Does it disturb air flow? If i flip itb's around fuel is injected allmostish middle to port. Which way is better. Short side radius is too ...

Problem solved. I ordered Harland Sharp roller rockers with 1.65 ratio.
Pushrod end needs to be 5/16
Rocker bodies were out of stock, so those are ready to ship in 6-7 weeks.

472USD+shipping.

minorv8 wrote:I think I still have a set of new steel rockers. I live in Helsinki so if you are interested I can try to find them.

Great I have set of steel rockers from blue box in my shed and set of adjustable pushrods. If yours are some other brand i'm interested.

Thank for other replies also.

How strong are they? i have turned in lathe rocker shaft hole bigger for bronze bush. Assembled with new rocker shafts. First time i did this was twelve something years ago for 3.5 carb engine. Good upgrade in my mind. No problems with 3.5 efi with hurricane cam and stock valve springs after four ...

How deep pistons are at TDC in undecked RV4.6?

In my tophatted 4.6 pistons are 0.2mm above deck at TDC because i want them that way.
Going to use composite gasket so piston
to head clerance is going to be approx 1mm. Am i right?

need4speed wrote:It's definately not the gauge as I've just learned this morning it pressurised so much it blew a hose off!

Faulty radiator cap? Coolant system pressure is limited by radiator cap about 1bar.