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Old 08-18-2007, 05:13 PM   #1
mxpunk
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Default knicked gasket surface

Is this gonna be a problem for me? Im thinking its gonna lead to a blown headgasket sooner or later since the engine will be seeing boost..

Unfortunetly the knock goes into the cylinder too, a tiny bit.

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Last edited by mxpunk; 08-18-2007 at 05:23 PM.
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Old 08-18-2007, 05:24 PM   #2
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It's pretty small.......I wouldn't worry about it.

Curious to see more experienced members thoughts tho.
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Old 08-18-2007, 09:41 PM   #3
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The actual head gasket is outside that point, or close to it. I personally wouldnt worry about it. But I have a bad reputation for being a cheap ass punk.
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Old 08-18-2007, 10:08 PM   #4
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I wouldn't worry about it either.





disclaimer: But like reddevil I am a cheap bastard too. I reuse headbolts.
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Old 08-19-2007, 03:21 AM   #5
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You can see where it falls in relationship to how the gasket seats... look at the markings from the old HG.

You should be A-okay.
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Old 08-19-2007, 10:58 AM   #6
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Yes, I am a cheap ass too! lol

Thanks guys. I think I might of knicked it cleaning the surface with a gasket scraper and a razor blade (gotta be more careful)
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Old 08-19-2007, 11:49 PM   #7
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That's not a problem unless the underside has been gouged out underneath.
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Old 08-20-2007, 04:31 PM   #8
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You mean the outer part of the cylinder, the water jacket?
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Old 08-20-2007, 09:14 PM   #9
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make sure that there isnt any kind of a burr on the gasket surface or cylinder wall. use a fine file to smooth it out.


~Josh~
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Old 08-21-2007, 04:10 PM   #10
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^ yeah its pretty smooth, i ran my finger over it last night but i still think i might hit it with a file gently..
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Old 09-15-2007, 09:45 PM   #11
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if theres a knick on the outer part do u guys think im gonna have problems?

i wasnt paying attention when i was cleaning this **** up and got sloppy..i feel like an idiot!

would a silicone gasket work with this? i dont want to be dealing with head gasket problems

help!!

Last edited by mxpunk; 09-15-2007 at 10:18 PM.
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Old 09-16-2007, 08:22 AM   #12
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got another picture?
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Old 09-16-2007, 08:37 AM   #13
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Sharp egdes have the potential to create hot spots which may make that cylinder more likely to detonate. I'm not sure if that knick would result in that, though.
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Old 09-16-2007, 11:18 AM   #14
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here they are :: stabs self in the eye :: .. lol






what should i do now?!
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Old 09-16-2007, 11:51 AM   #15
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Do you have a machine shop in the area? You can have them deck the surface .003-.005 of an inch, and that should clear it up, or try using a large flat stone with a fine grit, and possibly add a 280-320 lapping compound, slowly and carefully make small circular motion over the entire surface, then when you are done use a feeler gage and straight edge, and make sure you have no valleys.
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Old 09-16-2007, 12:05 PM   #16
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That knick goes into the cooling jacket so your only worry is to keep the wet stuff out of the burning stuff.

Clean it off so there is no burrs sticking up above the surface. Clean the groove with acetone, and put a dab of JB weld on it, then wipe it smooth with a flat object. After it sets Gently smooth it off with 400 grit sand paper if you have any lumps sticking up above the surface. (if you do the wipe off carefully with an absolutely flat object it should be very close to perfectly flat) If it is a smooth surface the gasket should be happy.

Larry
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Old 09-16-2007, 01:09 PM   #17
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Quote:
Originally Posted by bearpaws1973 View Post
Do you have a machine shop in the area? You can have them deck the surface .003-.005 of an inch, and that should clear it up, or try using a large flat stone with a fine grit, and possibly add a 280-320 lapping compound, slowly and carefully make small circular motion over the entire surface, then when you are done use a feeler gage and straight edge, and make sure you have no valleys.
yes i do..but like all that work will cost more then the block itself

Quote:
Originally Posted by hotrod View Post
That knick goes into the cooling jacket so your only worry is to keep the wet stuff out of the burning stuff.

Clean it off so there is no burrs sticking up above the surface. Clean the groove with acetone, and put a dab of JB weld on it, then wipe it smooth with a flat object. After it sets Gently smooth it off with 400 grit sand paper if you have any lumps sticking up above the surface. (if you do the wipe off carefully with an absolutely flat object it should be very close to perfectly flat) If it is a smooth surface the gasket should be happy.

Larry
i may try this..thanks
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Old 09-16-2007, 01:11 PM   #18
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When I clean off the heads and the cylinders I use 220 grit paper on an orbital sander. Takes about 2 seconds to clean up and it barely removes any material.

With your recent luck I'd head to a machinist to get that fixed. You may find yourself in a bigger hole trying to fill and sand that flat.
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Old 09-16-2007, 07:21 PM   #19
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^ yeah you're right...im just concerned that the compression will be off alittle and make things weird..dammit!
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Old 09-17-2007, 11:09 AM   #20
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I did my math for compression on sti block and wrx heads, so it may not match, but the #'s I came up with looked about .2 cr for ever .01 of an inch, so 3-5 thousandths sould be less than .1 on the cr (If my #'s are off someone please correct me, cause I just decked my heads and have them on my block!) I like the jb weld idea, give it a try.
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Old 09-17-2007, 02:02 PM   #21
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Don't worry about that small of a change in CR, .002-005 inch off the deck height would hardly be measurable if you CC'd the engine.

Larry
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Old 09-17-2007, 03:05 PM   #22
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Quote:
Originally Posted by LiquidForce View Post
disclaimer: But like reddevil I am a cheap bastard too. I reuse headbolts.
blasphemy!

you mean you don't automatically jump on the ARP bandwagon??!?

your block is gonna assplode dude.


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Old 09-17-2007, 07:20 PM   #23
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thanks guyys
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Old 09-17-2007, 08:51 PM   #24
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Quote:
Originally Posted by hotrod View Post
Don't worry about that small of a change in CR, .002-005 inch off the deck height would hardly be measurable if you CC'd the engine.

Larry
Hey Larry.. at what point does the piston to head clearance become an issue?
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Old 09-18-2007, 02:54 AM   #25
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Quote:
Hey Larry.. at what point does the piston to head clearance become an issue?
You should always check it when the build is done, but quench is about .039 as I recall so a couple thousandths should not get you in trouble on most builds. There is always a chance you have a cylinder where you have a tall piston, a long rod and a long stroke all in the same hole. That sort of tolerance stack up can get you in trouble using all stock parts on occasion.

I don't think I would be comfortable with less than 0.32-035 quench depending on plans for high rpm.

Larry
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