OST-054: 3 rib with snap

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oldeskewltoy
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OST-054: 3 rib with snap

Postby oldeskewltoy » Wed Jan 09, 2019 3:17 pm

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OST-054's owner is "local" (no shipping). The first head he brought to me, back in early December, had seen an "attempt" at changing the squish pads :cry: He had bought the head a few years ago as the one he would build - he wasn't too happy once I showed him the flaw

At this time I'd like to STRONGLY recommend that if you "try" to port a head, and you don't know what you are doing... STOP. In the past 3 years I've bought 3 heads that had to be scrapped because of very poor "attempts"..... that ruined the casting :evil: If you are going to try... just make sure that head isn't sold on.......


So my client disassembles his engine to get me his current head... and it too has seen a hand inside it. On this one it wasn't "fatal"..... the roof of the port has seen some "work"... along with a lot of "smoothing" inside the exhaust port.

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This type of work (tapering port roof) I try to reserve for ITB equipped heads to try and and match the angle of the ITB adapter. In this case some care was used by the previous "porter" so that this head could be re-used.

disassembled, prior to cleaning

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This head has been machined once as well

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more to come.... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

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User avatar
oldeskewltoy
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Posts: 1818
Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Fri Jan 11, 2019 3:36 pm

from another forum wrote:what should the head size be if it hasn't been machined before?

116mm


work begins..... #4 on the left...

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Oh... as the title states... this is a 3 rib, and my client manage to find a set of high comp TVIS pistons 13103-16030, the same pistons I used in OST-050.

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His short block is being built at a local machine shop - with my technical assistance.


more to come..... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

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oldeskewltoy
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Posts: 1818
Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Sat Jan 12, 2019 1:47 pm

oldeskewltoy wrote:

work begins..... #4 on the left...

Image



from another forum wrote:Short turns look beautiful.




and #3 and #2

Image


more to come..... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

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oldeskewltoy
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Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Mon Jan 14, 2019 2:06 pm

Image


Intake side finished... on to the exhaust side and the chambers....


more to come.... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

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oldeskewltoy
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Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Wed Jan 16, 2019 10:10 am

oldeskewltoy wrote:
on to the exhaust side




3 down so far.....

Image


more to come.... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

User avatar
oldeskewltoy
Club4AG MASTER
Posts: 1818
Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Thu Jan 17, 2019 4:47 pm

oldeskewltoy wrote:3 down so far.....

Image




and now the exhaust side is done.....

Image




and from a slightly different perspective...

Image




Next is getting the chambers deshrouded.....




more to come..... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

User avatar
oldeskewltoy
Club4AG MASTER
Posts: 1818
Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Tue Jan 22, 2019 9:09 am

oldeskewltoy wrote:
Next is getting the chambers deshrouded.....



simple progression photo....

Image



and a little before and after before it gets its 3 angle

Image


more to come... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

User avatar
oldeskewltoy
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Posts: 1818
Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Mon Jan 28, 2019 9:00 am

Image


the head is back... briefly... so I can check and set chamber volumes....

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Now it is back @ the machine shop about to get .016" taken off to set the chamber volumes @ 35cc. A 35cc chamber, along with the proper squish should net my client a static compression ratio of about 11.0:1.


Mix in a set of Cat cams 252/222 8.5mm lift cams, and this engine should pull (make power) to low/mid 8000s


more to come..... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

User avatar
oldeskewltoy
Club4AG MASTER
Posts: 1818
Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Wed Feb 06, 2019 7:36 am

Chambers down to 35cc, ready for re-assembly. Cams are Cat cams 252/222 8.5mm lift.

Image


more to come..... :D
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

User avatar
oldeskewltoy
Club4AG MASTER
Posts: 1818
Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Sun Feb 10, 2019 12:28 pm

14 of the 16 valves came in too tight for my shim bank (.001" variance from .110"-.125"), so I brought them back to the machine shop to get tipped (shortened) so they would be in my shim banks shim range.

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As you can see the valves got tipped by different amounts, from as little as .003", to a "big" .012".


Final assembly will have all the intake valves with a clearance of .008"(0.203mm), and all the exhausts clearances at .009"(0.228mm).
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

User avatar
oldeskewltoy
Club4AG MASTER
Posts: 1818
Joined: Wed Jan 09, 2013 4:44 pm
Location: Portland, Oregon

Re: OST-054: 3 rib with snap

Postby oldeskewltoy » Wed Feb 13, 2019 8:05 am

from another forum wrote:As many heads that you rebuild, take 25 minutes and make a holding fixture from small section of angle iron, that will bolt on to your bench grinder. As long as you set the valve stem square to a fine grit wheel, you can easily remove a couple thou by hand at a time. Just have a container of water handy for cooling the valve stem be measurement checks. Sure is better, then waiting on a machine shop, so you can finish the head assembly. davew



If tipping was the only thing I needed, something along those lines would work... but I've been thinking it might be time for my next equipment upgrade. My last significant change was switching from Dremels (yes plural - I used up about 6) to the Foredom 1/6hp SP hanging motor, and hand tools.

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I been thinking it might be time for my own valve grinding machine.

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This would allow me to do some experiments on valve back cut angles, along with precisely tipping the valves. Now, a new kwik way will run me about $7000. I might find a good used one for about $4000-$5000. The keys are the stones, and the chuck - the chuck needs to be accurate to .0005" :shock:
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

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