OST-066: I get all wavy (4AC content)
03-09-2020, 05:24 PM
Post: #1
OST-066: I get all wavy (4AC content)
[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


note the edge of the head is wavy, this is the last iteration of the 4AC head in the USA.


Its difference from its first generational "brother" is MORE substantial, then a Blacktop head is different from a Silvertop head [Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


So why build a 4AC head??? Partially because I haven't done one for a client.... and partially because along with the head, my client included this manifold....




Twin side draft manifold for a 4AC head Huh

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


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
Find all posts by this user
03-09-2020, 05:59 PM
Post: #2
OST-066: I get all wavy (4AC content)
Cool, I've never known of anyone building a 4ac before so it'll be good to see one for a change. I wouldn't even have guessed that there's much that can be done with one.
Find all posts by this user
03-11-2020, 12:36 AM
Post: #3
OST-066: I get all wavy (4AC content)
(03-09-2020 05:59 PM)Power_uP Wrote:  Cool, I've never known of anyone building a 4ac before so it'll be good to see one for a change. I wouldn't even have guessed that there's much that can be done with one.

I was playing around with a 1/2 of a non wavy head about 2 years ago... yes I said half

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]



and gains were made... Huh

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]

But this is a wavy (apka a swirl port) head... and while the intake opening is the same.... nothing else inside the intake port other then the valve seat is the same.....

apka - also possibly known as


but I jump a head ( Angel )..... the client wanted this head, and cam cover, and manifold to look new... so after cleaning, it got tumbled... (zinc shot media)

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


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
Find all posts by this user
03-27-2020, 04:37 PM
Post: #4
OST-066: I get all wavy (4AC content)
The wavy SOHC A head is oddly shaped for sure..... round entry, but NOTHING like the non wavy head, as it immediately changes shape inside the head

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]



port work begins.... First order - DO NO HARM...


setting port size, and blending the port-to-manifold

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


I'll be focusing on removing sharp edges, removing poorly casted areas and blending.

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]

Odd shapes throughout... look at that oddly shaped short radius...


.... at least the exhaust ports are conventional

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


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
Find all posts by this user
03-27-2020, 05:42 PM
Post: #5
OST-066: I get all wavy (4AC content)
I can't wait to see the power increase on this one. It might inspire me to tune the 2E in my car instead of replacing it altogether with a 4E turbo.
Find all posts by this user
03-27-2020, 10:00 PM
Post: #6
OST-066: I get all wavy (4AC content)
By any chance, is your client also known as 84hachi? Dumb question
If I'm correct he does own the exact same manifold on his 4AC powered hachi. Wink

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-066:  I get all wavy (4AC content)]
Visit this user's website Find all posts by this user
03-28-2020, 12:06 AM
Post: #7
OST-066: I get all wavy (4AC content)
(03-27-2020 05:42 PM)Power_uP Wrote:  I can't wait to see the power increase on this one. It might inspire me to tune the 2E in my car instead of replacing it altogether with a 4E turbo.


I will ask... but only a few have shared their dyno plots with me so far.... Most recently... OST-061 - 172 whp Miata 1.8

(03-27-2020 10:00 PM)banpei Wrote:  By any chance, is your client also known as 84hachi? Dumb question
If I'm correct he does own the exact same manifold on his 4AC powered hachi. Wink

That would be Steven, no this isn't his.


2 down.... 2 to go

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]

Dan -

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

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
Find all posts by this user
03-28-2020, 01:41 PM
Post: #8
OST-066: I get all wavy (4AC content)
Dan
Are you doing anything inside the chamber? Looks like both the exhaust and intake could use relief help on the side walls?
Dave W
Find all posts by this user
03-28-2020, 10:22 PM (This post was last modified: 03-28-2020 10:23 PM by banpei.)
Post: #9
OST-066: I get all wavy (4AC content)
(03-28-2020 12:06 AM)oldeskewltoy Wrote:  
(03-27-2020 10:00 PM)banpei Wrote:  By any chance, is your client also known as 84hachi? Dumb question
If I'm correct he does own the exact same manifold on his 4AC powered hachi. Wink
That would be Steven, no this isn't his.
Yes that's him indeed.
But I just rewatched one of his videos and the manifold looks similar in shape and also has similar linkage arms, but it does differ in details. For instance this one appears to have a vacuum plug on one of the intakes.

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-066:  I get all wavy (4AC content)]
Visit this user's website Find all posts by this user
04-02-2020, 06:47 PM
Post: #10
OST-066: I get all wavy (4AC content)
(03-28-2020 01:41 PM)Dave W Wrote:  Dan
Are you doing anything inside the chamber? Looks like both the exhaust and intake could use relief help on the side walls?
Dave W

The exhaust side of chambers 4 and 2 (far left, and 2nd from right in photo below) did get some massaging as they did encroach some on the exhaust valves of those 2 chambers.

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]

On the intake side, I left it alone as the gap from the valves edge to the chamber wall wasn't that tight, as an example here is a small block Ford chamber (Dart 210cc port performance head) the valve - chamber wall fit is tighter

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


This head also required a thread repair chamber 3, it is a timesert. Timesert is the only real way to fix a spark plug hole. Using a helicoil doesn't transfer the heat properly.
[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


A very nice 3 angle valve job....

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]


re-assembly... using Viton rubber valve seals...

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]

... and Sealed Power (VS-813) valve springs - They have a bit more seat pressure, and can accommodate more lift.

[Image: AEU86 AE86 - OST-066:  I get all wavy (4AC content)]

Dan -

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

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
Find all posts by this user


Possibly Related Threads...
Thread Author Replies Views Last Post
  Ivan's coupe [spoiler: things get sticky] Ivan141 501 341,164 07-22-2020 09:02 PM
Last Post: Mylesmck
  OST-068: Smok'n oldeskewltoy 5 595 07-13-2020 09:47 PM
Last Post: oldeskewltoy
  OST-064: Breathing on a 3 rib oldeskewltoy 15 1,759 04-06-2020 05:37 PM
Last Post: oldeskewltoy
  OST-062: Mixed Breed Autocross Whip oldeskewltoy 18 2,295 01-02-2020 06:31 PM
Last Post: oldeskewltoy
  OST-063: Busy Boy oldeskewltoy 4 884 12-24-2019 01:55 AM
Last Post: oldeskewltoy

Forum Jump:


User(s) browsing this thread: 1 Guest(s)

Contact Us | AEU86 | Return to Top | Return to Content | Lite (Archive) Mode | RSS Syndication