OST-015: The long and winding road.....

[BOOMEX]

oldeskewltoy I realy like the job you do and the fact that yo are sharing it with us.
For all Thant. Thanks a lot.

But there is some thing that i totally don't understand what is it.

It's This:


Can you explain me please?

Thanks

[Project D]

It's a flow bench test.
http://en.wikipedia.org/wiki/Air_flow_bench

[oldeskewltoy]

BOOMEX Wrote:oldeskewltoy I realy like the job you do and the fact that yo are sharing it with us.
For all Thant. Thanks a lot.

But there is some thing that i totally don't understand what is it.

It's This:


Can you explain me please?

Thanks

Project D Wrote:It's a flow bench test.
http://en.wikipedia.org/wiki/Air_flow_bench

What he said.....

Those are CFM readings taken through a de-carboned head(left column) and a mild port job (right column) They are taken @ 25" of mercury... (common flowbench reading is actually 28") the readings are measured @ different amounts of lift, measured in inches.

[oldeskewltoy]

Moving on to todays work.....


Yesterdays photo of the exhaust port, before and after, was a good example of what I do when it comes to the exhaust ports... kind of shows why I can claim 3 to 10 hp...

With the exhaust gasses no longer having their bend to go around, it is only fair that the intake flow is also eased...



Odd angle... but it shows a lot. Right side of port is about 95% finished, left side is untouched.


more to come

[Project D]

oldeskewltoy do you have ever try to flow bench a head in the opposite way ?
(I mean from the combustion chamber to the intake port)
It would be good to see if the 4AG head and / or your porting have an anti-reversion effect

[oldeskewltoy]

Project D Wrote:oldeskewltoy do you have ever try to flow bench a head in the opposite way ?
(I mean from the combustion chamber to the intake port)
It would be good to see if the 4AG head and / or your porting have an anti-reversion effect

setting up a flow bench to "flow" the reverse of intended isn't excessively hard, after all, the bench is measuring reverse flow when you check exhaust flow - blows out the valves, where checking intakes the flowbench sucks through the valves. From my understanding of anti-reversion, it is most often used in headers. Adding a step up in diameter on a primary pipe for a 4AGE header @ or about 75 - 100mm from the flange is an example of using anti reversion technology.

[oldeskewltoy]

oldeskewltoy Wrote:Odd angle... but it shows a lot.

...... and now it shows even more

[oldeskewltoy]

Below is chamber #4, it has a mis-aligned port to guide/valve seat problem. Note the blue line pretty much bisects the guide boss, note the yellow line pretty much bisects the guide. Because of this mismatch, you get port intrusion (red arrows) This is not uncommon, in fact most ports are not perfectly centered, but some ports are farther off then others - this one is pretty bad, but I've seen worse :eek:




I need to finish exhaust port 4, and get the head off to Loynings for a 3 angle. Once it returns from Loynings, I'll polish and deburr the cam journals.

[oldeskewltoy]

oldeskewltoy Wrote:Once it returns from Loynings, I'll polish and deburr the cam journals.

Oh well, some things don't happen as we expect, I ended up doing the deburring before it went to Loynings, that way they can clean up the de-burring particles.

I de-burred all edges, here is a familiar view, the chambers. The top photo is the pic I took when I opened up the box, the lower shows quite a bit of work performed. Before I get to all the deburring, a quick mention of the chamber deshourding and polishing. As can easily be seen all the chambers have now had the machining "brows" gently removed, and polished area replaces these "brows"



now on to the de-burring work. I've already mentioned when I was doing the chamber work that I removed the burrs from the chamber edges as I worked them. This removes any sharp edges/bits that may cause "ping". Besides the edges in the chamber, all the casting, or machined edges that did have a lip, or sharp edge found themselves less so once I deburred them. Besides the chamber edges, all the oil passages got de-burred, as well as the large breather passage. MOST of the coolant holes I left alone, but the 2 large coolant passages at the back of the head also go a little attention.

I also deburred the top of the head as well... it is far easier to see the differences in this shot



In particular you can see the large crumbling piece of casting flash between cylinders 2 and 3. THAT was a damaged valve just waiting to happen, or possibly a smaller bit could be swallowed by the oil pump and lead to....

Other de-burring up here is around the outside of the bucket cradles, and of course the cam saddles themselves. I'll wait till the head comes back from Loynings to polish the saddles