4AG head porting - OST-030: a case in point

[oldeskewltoy]

Valves @ full lift...

Exhaust....




Intake...

Fully assembled... now whats left is setting the valve clearances, and getting it back to my client.

Its packaged back in its case.... with the latch zip tied down...


I heated the end of my punch a bit so I could get it to impress into the ziptie.

All that is left on this is shipping back to my client....

[oldeskewltoy]

All that is left on this is shipping back to my client....

Why I insist on insuring the finished product for its shipment back to it's owner......





I've been told the head itself did not sustain any damage... but this shows significant intrusion.... so when I say the insurance adds $20, or $30 to the return shipping cost...

its just to COVER YOUR ASSets.

[terryo]

some before/after flow data would be interesting

[oldeskewltoy]

some before/after flow data would be interesting

That would cost my clients a significant amount extra....

The modifications I do to 4AG heads have all been proven/flowed before....

flowbench testing for my head work....

http://i79.photobucket.com/albums/j1...eandafter2.jpg

http://i79.photobucket.com/albums/j1...psf34f0bef.jpg

http://i79.photobucket.com/albums/j1...ps2c3ecb9a.jpg

[dnegative]

By carefully surfacing the cam cap "feet" we can get this dimesion closer to the center of the specification

Wouldn't that make it out of round?
I thought if you needed to set cam clearances you generally machined all the caps, tunnel bored and align honed it and re shimmed all the valves.

[oldeskewltoy]

Wouldn't that make it out of round?
I thought if you needed to set cam clearances you generally machined all the caps, tunnel bored and align honed it and re shimmed all the valves.

depends on how much you remove... a few thousandths of an inch... no big deal, much more... then it should be machined

[love ke70]

Wouldn't that make it out of round?
I thought if you needed to set cam clearances you generally machined all the caps, tunnel bored and align honed it and re shimmed all the valves.

That was my exact thought, surely the cam is now running with more clearance one side than the other or even trying to flex to suit its opening?

[oldeskewltoy]

That was my exact thought, surely the cam is now running with more clearance one side than the other or even trying to flex to suit its opening?

sometimes we forget the forces involved... the head itself typically gets less wear because the principle force on the caps is from the valve springs. So, unless serious damage has occurred, the head gets less wear then the caps get. The wear on the cap would be slightly off center, but well within the area between the cap bolt holes... again if damage is severe you toss the head, but in this case the correction works fine. The engine runs quite well, the client is very satisfied.

[love ke70]

that makes alot of sense.