manifold polishing tips wanted
- Thread starter speedy
- Start date
Unless you've done other mods to your engine you are unlikely to notice much difference with a polished manifold (exhaust I presume).
Have a look at the head, it will typcially be rough cast with seams,burrs and other imperfections. A lot can be done to improve this with a high speed tool and grinding wheel like a dremil. However it is possible to overdo it and really stuff your engines airflow completely.
You also need to get all the tiny metal fragments of the engine when you have finished if you decide to do this "on the car". It is best to remove the head, get it properly ported and polished and the most important step is to get a 3 or 5 angle valve job done. Skimming the head will also increase the compression ratio a bit and also help to increase performance.
Have a look at the head, it will typcially be rough cast with seams,burrs and other imperfections. A lot can be done to improve this with a high speed tool and grinding wheel like a dremil. However it is possible to overdo it and really stuff your engines airflow completely.
You also need to get all the tiny metal fragments of the engine when you have finished if you decide to do this "on the car". It is best to remove the head, get it properly ported and polished and the most important step is to get a 3 or 5 angle valve job done. Skimming the head will also increase the compression ratio a bit and also help to increase performance.
Last edited:
pikey motorsports
Track Warrior
as said, your better off doing the head as opposed to the exhaust manifold. although by all means do this too!
on something like a cordoba, the manifolds are pretty good from factory, so a port n polished head coupled with a 4-2-1 manifold and stainless would give you a nice gain over factory standard.
problem is, your port and polish wont be as good as a specialists, and you will still need the valves done, head skimmed etc. by the time you price up what it would cost you may as well buy an ABF engine for 150bhp straight out the box.
on something like a cordoba, the manifolds are pretty good from factory, so a port n polished head coupled with a 4-2-1 manifold and stainless would give you a nice gain over factory standard.
problem is, your port and polish wont be as good as a specialists, and you will still need the valves done, head skimmed etc. by the time you price up what it would cost you may as well buy an ABF engine for 150bhp straight out the box.
MasterAuron
Very Senior Member
Skimming the head will RAISE the compression ratio Waynne. Even some so called "specialists" can't flow a head properly, what makes you think you can?
pikey motorsports
Track Warrior
Doing it properly is an art, doing a basic DIY P&P is within anyones reach so long as they take their time and dont go overboard.
Well spotted MA, I was having a mad moment there, I've corrected my post.
(NB: Lower compression will generally do nothing for performance unless you were planning to add forced induction.
)
I agree just matching the manfolds to head ports can be well out just take it easy best still is to pratice on a old head ive cut old heads up before just to find the wall thickness.
Last edited:
Similar threads
Similar threads
