Valve to piston Clearances

[Mang]

Have searched but I cant find.
Anyone got an figure - I am running Wiseco 810s with standard valves

thanks

[Dirck]

Mang, I'll wager Tack has the answer. As you know, adjustable cam sprockets are required to set clearances.
Minimum clearance WILL NEVER be found at top dead center (always before or after).
This mindset has destroyed many engines.

[tack1000]

I know this is not what you asked but I'm sure I have the valve to piston set as well. I'll have a look once I get home.

http://www.750turbo.com/forum/viewtopic.php?f=9&t=11218

Have a look a the vid at the end.

[Mang]

Thanks Jeff

[tack1000]

Sorry chap can't find the doc I'm after. I might just have to re-run it.

[tack1000]

Mang

Just a point on the Wiseco Pistons.

The exhaust valve pocket is not quite big enough.
I've seen (not on all) on a few re-builds that the exhaust valve just clips the edge of the pockets.
Even after it had been checked with soft solder method that it had the correct clearance.
It would be worth IMHO removing a small amount of the leading edge in a crescent shape both down and across the pocket starting with 1mm in the middle.
I'm not sure if I've explained it very well so I'll pop a photo up to show you what I mean.

[Charlie @ Evergreen]

Machinist clearance the valves for .040 with 1mm larger exhaust valves installed.

Sure the same is required for std valves..the 1mm valves clayed showed only about .015 !!
[/url[URL=http://s792.photobucket.com/user/evergreenturbo/media/84e1e035-b330-45c0-a2e8-b788eb25c6fc_zpsrqm7n4of.jpg.html]

[Dirck]

[tack1000]

So you can see the effect when the valve clips the piston here.

[Dirck]

810 build pocket reliefs for 1mm up-sized zorsty valves align just beyond interference impressions in Tack's photo.
So many have installed the 810 Kit as a drop-in with standard OEM valves in place as it was designed to be.

*****Are we saying that the pistons need alterations before installing on an engine equipped with standard valves?????

[David de Botton]

You guys are saying that the Wiseco 810 kit is a serious problem ?
You definitely cannot rebore and assemble without getting valve pockets milled / relieved ?

Concerned as I have a bore kit still in the box

[Dirck]

David, In retrospect, for those running 810, initial mild run-in interference knock may go undetected and subside soon thereafter.
Scoping seems advisable.

[Charlie @ Evergreen]

Sorry if there was a misunderstanding on the Piston to Valve Clearances David. Complete post indicates they were machined for oversize valves. Stockers no worries

Machinist clearance the valves for .040 with 1mm larger exhaust valves installed.

Sure the same clearance is required for std valves..the 1mm valves clayed showed only about .015 !!
[/url[URL=http://s792.photobucket.com/user/evergreenturbo/media/84e1e035-b330-45c0-a2e8-b788eb25c6fc_zpsrqm7n4of.jpg.html]

[Turbo Pete]

Might still give mine a tickle just to be sure!

[Dirck]

Wise if you're toying with clock-able cam gears and degree wheel to squeeze out that last elusive pony.
Otherwise, wouldn't mar W's well engineered factory form.