entropy
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posted March 28, 2007 01:19 AM
down on hp - perhaps there was a reason...
did a leakdown test this morning and found 50-45-55-70%
3 cyl had exhaust and 1 w/intake hissing like a pissed off cat.
brand newly built head w/ big intakes and busa buckets... grrrrrrrrrrrrrrrrrr
Thanks to TimChin for being persistent about doing the leakdown. good call, Tim!
BUT, no worries.
Andy @ Metric in Houston is getting a mojo head machine this week and will be giving head jobs real soon. 
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Wideout
Expert Class
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posted March 28, 2007 04:09 AM
Good news man.
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zrxdean
Needs a job
Posts: 2225
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posted March 28, 2007 05:33 AM
Arrrrgh. What happened? Thought this was the 'low CR' tuneup?
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ninja12
Needs a job
Posts: 3310
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posted March 28, 2007 05:53 AM
Did you let the new girls (valves) connect with them big studs(pistons)?
Check your clearances, Maybe the new valves are seating in an getting tight.
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entropy
Moderator
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posted March 28, 2007 06:16 AM
The VTP was close on intake (.041) but plenty of clearance on exhaust(.090), and the exhaust is where i heard most of the hissing.
And, there is no indication at all of the valves touching the pistons (girls making foreplay with the studs).
yep, this is the lo CR motor, but Noonan has help on the way, and i should be back to 15.4+ on the next build.
He is taking .020" outa the pockets and piling it on the crown for more margin.
The the valves started leaking????
Maybe bad from the git-go??
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aliveagain
Needs a life
Posts: 5033
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posted March 28, 2007 07:58 AM
when is the last time you checked the valve guides?
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entropy
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posted March 28, 2007 08:39 AM
quote:
when is the last time you checked the valve guides?
brand new guides, brand new seats, brand new valves, or so i was told
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MadMike
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posted March 28, 2007 09:34 AM
quote:
when is the last time you checked the valve guides?
ummmm are you supposed to do this?
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Y2KZX12R
Needs a job
CompetitionCNC.com
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posted March 28, 2007 11:11 AM
Karl, ask who did your valve job if they vacuum tested the valve sealing? If the seats are cut on a machine that isnt SUPER ridgid you can get chatter while cutting. This chatter causes a scalloped effect and will cause a very poor seat seal. This would be spotted instantly with a vacuum checker.
Or, possably the valves got bent while checking the valve to piston clearance? That nice checking tool has a lot of leverage which can be a double edge sword. Thats why i was saying to use 1 finger on the lever for checking. the tool i use is about 8" long and i use 1 finger. After several times with one finger you get the feal for repeatability and can get consistant results.
Another possability like pete said is guides. But if there all new then all should be cool there.
I would vacuum check the valves and then check the valves for concentricity and wobble.
Also check the stem to guide clearance.
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entropy
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posted March 28, 2007 01:16 PM
Jim,
thanks for the tips!!
I really doubt it is related to the VTP measurements because i only did that on #1 int and exhaust valves.
My plan is to take the head to Andy and have him "fix it", I'm not sending it anywhere no mo!
The chatter is an interesting thought, and we ought to be able to see it, eh?
anyway, i am just glad that i did the leak down and found the issue.
Thanks again
Karl
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NOX
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posted March 28, 2007 02:17 PM
I love it when Karl has problems, keeps me from wanting to go BIG.............,
Good luck Karl, we all wish you the best.........
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MadMike
Moderator
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posted March 28, 2007 02:21 PM
I dont think tweaked valves would have lived through the Texas Mile weekend. well not in my motor anyway with the luck I have... LOL..
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Wideout
Expert Class
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posted March 28, 2007 02:37 PM
I was disturbed why you had lost hp prior to the Mile...so I'm just glad you're on to something (thanks to Tim).
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osti33
Needs a job
Posts: 2973
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posted March 28, 2007 03:23 PM
quote:
did a leakdown test this morning and found 50-45-55-70%
3 cyl had exhaust and 1 w/intake hissing like a pissed off cat.
brand newly built head w/ big intakes and busa buckets... grrrrrrrrrrrrrrrrrr
Thanks to TimChin for being persistent about doing the leakdown. good call, Tim!
BUT, no worries.
Andy @ Metric in Houston is getting a mojo head machine this week and will be giving head jobs real soon.
EEK!! That sucks man. Glad you found something. Keep us posted on the new head. 
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TRNorBRN6001
Needs a job
Posts: 2021
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posted March 28, 2007 03:25 PM
Sabotage I Say !!!!!!
Those Garage Barbies just can't keep their hands off your engine!
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ninja12
Needs a job
Posts: 3310
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posted March 29, 2007 07:55 AM
what did the clearances look like?
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entropy
Moderator
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posted March 29, 2007 08:12 AM
quote:
what did the clearances look like?
G,
i will CLOSELY look for VTP and piston head interference tomorrow.
on 1st inspection, it SEEMS that VTP is OK, no apparent contact; but that some pistons MIGHT have been tapping (slightly) the head.
I wanna take pix of everything with carbon on, then clean it off and look for collision evidence.
The .030" quench I ran on the last build is pretty tight for a stroker, even w/Carrillos...
This is fun stuff.
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