Do you perhaps mean the valve face and seat, as opposed to the 'guide'? We might be using different terminology here, but to me the guide is the part that the stem passes through, and it has nothing to do with the flow.philippeF said:Hello
May you tell me what is the best theorical shape around a valve guide for best flowing in an combustion engine ?
HelloDanger said:Do you perhaps mean the valve face and seat, as opposed to the 'guide'? We might be using different terminology here, but to me the guide is the part that the stem passes through, and it has nothing to do with the flow.
Okay. The only valves that I have personal experience with are in Mopar 'B' heads. The guide barely protrudes into the intake port about (3/16"), and is just a cylindrical extension of the head casting. Ideally, I supposed, it would be flush with the port wall and therefore have no effect at all on the airflow rather than merely very little as is the case now.philippeF said:Hello
i mean in the intake pipe, around the valve guide...
You're welcome. I'm curious about your opinion regarding the intake runner, though. One of the simplest horsepower boosting operations when rebuilding an engine is 'porting and polishing', wherein you grind the port mouths and intake/exhaust runners to an exact dimensional match and smooth out any casting flaws or surface irregularities. The whole point of that is to reduce flow turbulence at the junction. It gives a big power boost for the outlay of a couple of Dremel bits and some emery paper.philippeF said:Thanks, even if i have not the same opinion about polishing intake pipe..