OFH Porting

[YoYo_4G63]

Porting the hole of the ofh, i think i've went to far down
So i'll be ok leaving it like that or i mess up the ofh?

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[RamenPride]

Looks like you took too much off in general.... I think the general consensus is to make a "D" shape at the top of the opening and leave the sides alone. Then again, each car is different.

 

[Timechg]

Here is one of the original posts:

http://www.dsmtuners.com/forums/stroker-tech/224606-porting-oil-relief-hole-no-balance-shafts-2.html

Judging from yours, I don't think it looks that far off from what was done in the previous posts. However, you want to make sure you aren't taking material off the gasket surface (it looks like you nicked the bottom edge).

 

[YoYo_4G63]

I did the "D" shape this is my second attempt :/ because the engine have high oil pressure yet.

Btw mines looks same as this one.....

http://www.dsmtuners.com/forums/151091335-post58.html

But now with the piston in there and that gap (on my picture) I'ts worry me

 

[19Eclipse90]

Typically it is the other end that you need to worry about. All that work done near the gasket surface will do practically nothing.

The oil pressure relief valve is a simple spring loaded piston. To reduce the pressure build up, you want the relief valve to do its job quicker than an original setup. The area away from the gasket surface determines the pressure because the piston will need to retract different amounts to allow oil through depending on how the housing has (or has not) been ported. This is why members in the thread you linked to keep showing the bell or D-shaped opening as ideal. Effectively, that increases the cross-sectional area at the point where fluid will flow first allowing the system to regulate the pressure a little better. I suppose it would depend on the high pressure characteristics of your car, but that seems to be the most common approach.

 

[YoYo_4G63]

Ok thank you very much, let's see then how it goes