OST-069: Transformation
11-05-2020, 06:32 PM (This post was last modified: 11-05-2020 06:35 PM by oldeskewltoy.)
Post: #1
OST-069: Transformation
[Image: AEU86 AE86 - OST-069: Transformation]



OST-069 begins its transformation with a cleaning.....

Nasty..... top

[Image: AEU86 AE86 - OST-069: Transformation]



and bottom....

[Image: AEU86 AE86 - OST-069: Transformation]


and while a cleaning gets it suitable for work....

[Image: AEU86 AE86 - OST-069: Transformation]


it is still too nasty to sell... so add another step... tumble it!!

[Image: AEU86 AE86 - OST-069: Transformation]


[Image: AEU86 AE86 - OST-069: Transformation]



more to come.... Hurray!

Dan -

You can |Sad .... OR you can ask for help!!!

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
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11-05-2020, 06:56 PM
Post: #2
OST-069: Transformation
Nice work

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11-07-2020, 10:34 PM (This post was last modified: 11-07-2020 10:35 PM by banpei.)
Post: #3
OST-069: Transformation
Nice cleaning! Thumbs up!
Maybe I have missed this, but you have a big tumble cleaner that are large enough to fit engine heads? Dumb question

1982 - TA60 Carina 4dr sedan - fun cruiser
1983 - AE86 Sprinter Trueno - import project
2013 - Honda Civic sport - daily driver
2004 - AEU86 dot ORG - daily domain

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[Image: AEU86 AE86 - OST-069: Transformation]
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11-12-2020, 11:04 PM
Post: #4
OST-069: Transformation
(11-07-2020 10:34 PM)banpei Wrote:  Maybe I have missed this, but you have a big tumble cleaner that are large enough to fit engine heads? Dumb question

No, one of the machine shops I use has a large "tumbler" - large enough for blocks! The tumbler is partially filled with zinc shot. They close the lid and the head is dragged repeatedly though the zinc shot.



Porting begins.... #1 on the right, had a bit of a step left after the factory machining, I cut this back and smoothed it out. On the left, #2, adjusting the seat and bowl

[Image: AEU86 AE86 - OST-069: Transformation]


I frequently have to "fix" core shift, here is a prime example from the exhaust side

[Image: AEU86 AE86 - OST-069: Transformation]


2 down... 2 to go....

[Image: AEU86 AE86 - OST-069: Transformation]



more to come...... Hurray!

Dan -

You can |Sad .... OR you can ask for help!!!

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
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11-13-2020, 10:48 PM
Post: #5
OST-069: Transformation
(11-12-2020 11:04 PM)oldeskewltoy Wrote:  
(11-07-2020 10:34 PM)banpei Wrote:  Maybe I have missed this, but you have a big tumble cleaner that are large enough to fit engine heads? Dumb question

No, one of the machine shops I use has a large "tumbler" - large enough for blocks! The tumbler is partially filled with zinc shot. They close the lid and the head is dragged repeatedly though the zinc shot.
Nice! Thumbs up!
I was always wondering how you get those heads look like new but now we know your secret. Dodgy

1982 - TA60 Carina 4dr sedan - fun cruiser
1983 - AE86 Sprinter Trueno - import project
2013 - Honda Civic sport - daily driver
2004 - AEU86 dot ORG - daily domain

Support our forum, buy from the AEU86 shop:
[Image: AEU86 AE86 - OST-069: Transformation]
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11-14-2020, 10:50 AM
Post: #6
OST-069: Transformation
Vapour blasting makes for an even nicer looking result.. not too common though.
The tumbler probably gets to hard to reach inside cavities better, but that is as much of a risk as a benefit.

FABRICA MI DIEM, PVNC!
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11-15-2020, 11:07 PM
Post: #7
Photo OST-069: Transformation
I have seen people smooth the valve guides down so they are flush with the IN/EX channel, is there any reason for doing this, or is it overdoing it.?

Restoring my AE86, all the way... Going JDM style Big Grin
http://www.aeu86.org/viewtopic/ae86/p/150463#150463
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11-24-2020, 08:31 PM
Post: #8
OST-069: Transformation
(11-15-2020 11:07 PM)Vaptor Wrote:  I have seen people smooth the valve guides down so they are flush with the IN/EX channel, is there any reason for doing this, or is it overdoing it.?

good question....

I assume you mean something similar to this.....

[Image: AEU86 AE86 - OST-069: Transformation]


the actual 4AGE/ZE valve guide is all of 1.6" long....it holds the 4AG valve stable at valve speeds up to 75 opening/closings per second......

[Image: AEU86 AE86 - OST-069: Transformation]

The more you shorten it, the less stable the valve becomes. Shorten it a little, and it isn't likely to be an issue, shorten it more....???

But how short is too short?? I can't tell you..... for I don't know.


What I do know, is Loynings does use guides on many of their 4AG race engines, while removing the guide boss, they still keep the guides....

[Image: AEU86 AE86 - OST-069: Transformation]




In the same breath... I have shortened guides in one of my head builds... but it wasn't a 4AG... and it wasn't shortening them as much as in the above photo.

I was building a 1GG head, and the guides were longer then the 4AG guides, with similar, or less lift then a 4AG..... so I shortened them

intake....
[Image: AEU86 AE86 - OST-069: Transformation]

exhaust....
[Image: AEU86 AE86 - OST-069: Transformation]





When I port heads I've tried to follow one underlying rule..... "do no harm" Wink

Dan -

You can |Sad .... OR you can ask for help!!!

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
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11-25-2020, 09:49 PM (This post was last modified: 11-25-2020 09:50 PM by Vaptor.)
Post: #9
OST-069: Transformation
Thank you Dan for this deep explanation to my question Smile

First picture was exactly what I was referring to.

With standard Guides length, it can keep the valve stable to a max of 75 opening/closing per sec, so for High RPM with High lift, better keep the Guides to a standard length and not experiment to much, although the Lorring approach looks interesting Love it!

Restoring my AE86, all the way... Going JDM style Big Grin
http://www.aeu86.org/viewtopic/ae86/p/150463#150463
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11-27-2020, 05:26 PM (This post was last modified: 11-27-2020 05:27 PM by oldeskewltoy.)
Post: #10
OST-069: Transformation
(11-25-2020 09:49 PM)Vaptor Wrote:  Thank you Dan for this deep explanation to my question Smile

First picture was exactly what I was referring to.

With standard Guides length, it can keep the valve stable to a max of 75 opening/closing per sec, so for High RPM with High lift, better keep the Guides to a standard length and not experiment to much, although the Lorring approach looks interesting Love it!

be careful about using absolutes - some 4AG engines (Loynings, or Hasselgren) make then to spin upwards of 92 valve oscillation (openings/closings) per second

Dan -

You can |Sad .... OR you can ask for help!!!

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
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