Porting & Polishing Throttle Body etc?

[Byard]

I have always used my trusty Dremel to grind the butterfly valve spindle down and polish the whole intake to allow better airflow.

However I now have a diesel which ofcourse I can't do, but would taking the intake / exhaust manifold off to match them up increase airflow and allow the engine to breath better?

Just curious if it would help, I know it will make very minimal effect if any.

Thanks

[thinfourth2]

If you had a diesel it would have little effect as it should be running lean anyway

[Byard]

Would like to RR it before and after I do it to see if it makes any difference.

[The Black Flash]

Try the Engines and Drivetrain forum.
The general concensus from those that know is that manifolds are made smaller than the head port. The reverse step does not affect flow, but does prevent backflow, and should be retained. It also gives some wiggle room for alignment, unless the manifold is dowled in place, you can't align it perfectly anyway.

[Futuramic]

Byard said:

I have always used my trusty Dremel to grind the butterfly valve spindle down and polish the whole intake to allow better airflow.

However I now have a diesel which ofcourse I can't do, but would taking the intake / exhaust manifold off to match them up increase airflow and allow the engine to breath better?

Just curious if it would help, I know it will make very minimal effect if any.

Thanks

If your diesel has a full pressure turbo setup then the difference will be negligible. In a naturally aspirated engine airflow throught the cylinder head is key to increasing power. On a modern diesel this is largely considered irrelevant as the same effect can be achieved for a fraction of the price by turning the boost up. It doesn't matter, therefore, if the intake path is slightly restricted as adding a few Psi will easily overcome this.

[Byard]

Futuramic said:

If your diesel has a full pressure turbo setup then the difference will be negligible. In a naturally aspirated engine airflow throught the cylinder head is key to increasing power. On a modern diesel this is largely considered irrelevant as the same effect can be achieved for a fraction of the price by turning the boost up. It doesn't matter, therefore, if the intake path is slightly restricted as adding a few Psi will easily overcome this.

How do I add PSI?

[Futuramic]

Uo the boost; nowadays done by computer as turbos generally have an electronic wastegate. Or else fit a hybrid turbo of some kind.