OST-068: Smok'n

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oldeskewltoy
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OST-068: Smok'n

Postby oldeskewltoy » Tue May 05, 2020 5:36 pm

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OST-068 is a smok'n Blacktop, its burning oil.....

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particularly from #4 exhaust valve (wet exhaust port)

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Why is it smoking???

1 too many valve seals........... :( He is lucky that the extra seal didn't cause any damage other then burning some oil

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My client was a little embarrassed, but it was decided he wanted more power anyway, AND besides those seats(2nd photo in post - above), and valves (below)....

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....have seen better days, so I'm building another 20V engine. ;)




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!

allencr
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Re: OST-068: Smok'n

Postby allencr » Sun May 17, 2020 12:05 am

Wow, that's a new one!
If the guide's top isn't normally submerged, extra seal or no seal shouldn't oil it up that much, besides it's only 1 exhaust & isn't going to affect the com. chamber.
Burr on.

allencr
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Re: OST-068: Smok'n

Postby allencr » Sun May 17, 2020 12:07 am

Wow, that's a new one!
If the guide's top isn't normally submerged, extra seal or no seal shouldn't oil it up that much, besides it's only 1 exhaust & isn't going to affect the other or the chamber.
Burr on.
Last edited by jondee86 on Sun May 17, 2020 12:37 am, edited 1 time in total.
Reason: Double post

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oldeskewltoy
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Re: OST-068: Smok'n

Postby oldeskewltoy » Mon Jun 01, 2020 3:22 pm

allencr wrote:Wow, that's a new one!
If the guide's top isn't normally submerged, extra seal or no seal shouldn't oil it up that much, besides it's only 1 exhaust & isn't going to affect the other or the chamber.
Burr on.

bothered client.......


from another forum wrote:So what's the plan for this engine overall?



The plan...

the bottom end of the engine gets a complete rebuild, with new Toyota 81.5mm Blacktop pistons, rings, and new bearings. Additionally the bottom end will get fully balanced. The deck height will be set to provide a squish: minimum of .032" (max of .036").

The head has already (previously) been machined .004", I'll be taking about .004" to drop chamber volume about 1cc from before all machine work.

The chambers in this head are the best I've seen in any of the Blacktop heads I've worked - No chamber work will be needed :thumbs:

Now as nice as the chambers are... some of the ports are not so nice.

poor port alignment (core shift) here

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and here....

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Fixing said poor alignment

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and showing a comparison of 2 intake ports - before and after work

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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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oldeskewltoy
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Re: OST-068: Smok'n

Postby oldeskewltoy » Wed Jun 03, 2020 12:14 pm

3 down........

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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Re: OST-068: Smok'n

Postby oldeskewltoy » Mon Jul 13, 2020 12:46 pm

so... its been a while since I've updated... build is almost finished, just waiting on the new Cometic .036" 20V gasket.





old, and dirty, and look at the pock marks in the exhaust seats


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port work complete - prior to valve job - exhaust seats still pock marked if you look closely

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4 angle(exhaust), along with ground valves with back cut intakes

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a bit closer view

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Head is ready for re-assembled using Supertech springs

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and as always... it requires small tools (tweezers required)

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the bottom end got oversize(81.5mm) pistons, and a complete re-balance

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along with a new MRP oil pan

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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!

allencr
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Joined: Thu Jan 10, 2013 9:59 pm

Re: OST-068: Smok'n

Postby allencr » Wed Jul 15, 2020 11:52 pm

Thanks, looks nice & clean,
Looking at those 3 valves through the intake is always a neat thrill!
Were the other cyls clean & dry & smegma free?

Is there going to be any more finishing/grinding the comb chamber, all the area after the 45, on the 60 to 90 and the ridge around the seat?

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oldeskewltoy
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Re: OST-068: Smok'n

Postby oldeskewltoy » Tue Aug 04, 2020 7:36 am

allencr wrote:
Were the other cyls clean & dry & smegma free?

Is there going to be any more finishing/grinding the comb chamber, all the area after the 45, on the 60 to 90 and the ridge around the seat?


dry for the most part, but far from free of build up.... no more work in the chambers... Blending the angles can improve flow(very small amount), but screwing up the seats by doing it wrong is just bad form. This head now will easily outflow what it flowed before.
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!

allencr
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Re: OST-068: Smok'n

Postby allencr » Sat Aug 08, 2020 6:48 am

OK.
I'd think that big aluminum ridge around the seat would do more then a bit, but I've got 0 flowbench experience and can only go by what looks aerodynamically pretty to my eye.
Thanks.

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oldeskewltoy
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Re: OST-068: Smok'n

Postby oldeskewltoy » Fri Sep 25, 2020 10:40 am

allencr wrote:OK.
I'd think that big aluminum ridge around the seat would do more then a bit, but I've got 0 flowbench experience and can only go by what looks aerodynamically pretty to my eye.
Thanks.

Image


I've done both... when the ridge is bad enough..... I will do a little blending
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!