Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Go Back   Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum > General > Tech Talk > S Chassis

S Chassis Technical discussion related to the S Chassis such as the S12, S13, S14, and S15.


Reply
 
Thread Tools Display Modes
Old 02-07-2015, 07:38 AM   #1
Z_on_TE37's
 
Join Date: Nov 2014
Location: Ohio
Age: 30
Posts: 3
Trader Rating: (1)
Z_on_TE37's is an unknown quantity at this point
Feedback Score: 1 reviews
Sr20det cracks in head

I just dropped off my sr20det at the machine shop to get some machining done for my engine build. As he was looking over the head he noticed two hairline cracks starting at the spark plug holes going towards the valve seats. Does anyone have any first hand knowledge on whether this is common and safe to run or if it's going to end up as bad news. I can't find anything other than one post about the same topic and that wasn't helpful. Please help me out here guys!
Z_on_TE37's is offline   Reply With Quote
Sponsored Links
Old 02-07-2015, 07:48 AM   #2
angel mkiv
Zilvia Addict
 
angel mkiv's Avatar
 
Join Date: Sep 2009
Location: Seattle, wa
Posts: 727
Trader Rating: (4)
angel mkiv is an unknown quantity at this point
Feedback Score: 4 reviews
Ask them how much it is to repair it then look online for another..choose the cheapest route.and no I don't think this is pretty common on sr20's.definitly something that needs to get repaired
__________________
Instagram username:angelmkiv
angel mkiv is offline   Reply With Quote
Old 02-07-2015, 08:07 AM   #3
jr_ss
Post Whore!
 
Join Date: Dec 2005
Location: Pa
Posts: 6,409
Trader Rating: (35)
jr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond repute
Feedback Score: 35 reviews
Send a message via AIM to jr_ss
Did your machine shop magnaflux or pressure check it? If they have and that's how the crack/s were found, I suggest replacing the head. Cracks are no joke and are difficult to completely repair. Start with a fresh head but this is uncommon on SR's.
__________________
*My SR20VET* Does your VTC gear rattle in your S14/15 SR? PM me.
jr_ss is offline   Reply With Quote
Old 02-07-2015, 08:28 AM   #4
ANDY black s13
Zilvia Member
 
Join Date: Mar 2012
Location: erith kent england
Age: 56
Posts: 153
Trader Rating: (0)
ANDY black s13 is an unknown quantity at this point
Feedback Score: 0 reviews
I got a spare SR20 bent cam head for spares hardware shims rocker lifters etc
the head was scrap (I knew that and why it so cheap) as each plug hole has cracks from the plug holes spreading across the chambers
Story goes that my head cracked because the ignition amp go too hot and melted
and the plugs went into hyper spark mode (or something really weird happened)
the cracks are really deep and its not repairable as there will multiple cracks you can't see, the cracks can spread through the plug hole threads to the plug seat
Severe overheating will cause the cracks as well,either case its scrap
I know SR bits are dearer in the US but repair costs would far exceed another head imo
ANDY black s13 is offline   Reply With Quote
Old 02-07-2015, 09:50 AM   #5
slideslidegnarslide
Zilvia FREAK!
 
Join Date: Mar 2010
Location: philly area
Age: 34
Posts: 1,408
Trader Rating: (29)
slideslidegnarslide is an unknown quantity at this point
Feedback Score: 29 reviews
Yeah I'm sure you can pick up an empty head or a stock head for 100-200 bucks. Just do that and you won't have to worry
slideslidegnarslide is offline   Reply With Quote
Old 02-07-2015, 11:02 AM   #6
ANDY black s13
Zilvia Member
 
Join Date: Mar 2012
Location: erith kent england
Age: 56
Posts: 153
Trader Rating: (0)
ANDY black s13 is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by slideslidegnarslide View Post
Yeah I'm sure you can pick up an empty head or a stock head for 100-200 bucks. Just do that and you won't have to worry

If you go that route (which is probs the best)
you have to make sure the cam caps are all there for the head your getting
the cam caps are line bored to each head,so using caps from another head will
cause the cams to bind at the very least or seize solid
IMO a bare head with no cam caps is as scrap as the cracked head you have atm
another set of caps could be re-line bored,
but chance cam bearing clearance would be too large
and its not a cheap thing to get done properly
so factor in that cost beforehand
ANDY black s13 is offline   Reply With Quote
Old 02-09-2015, 04:36 PM   #7
Z_on_TE37's
 
Join Date: Nov 2014
Location: Ohio
Age: 30
Posts: 3
Trader Rating: (1)
Z_on_TE37's is an unknown quantity at this point
Feedback Score: 1 reviews
Thank you all for your input. I'm glad you were willing to help me!
Z_on_TE37's is offline   Reply With Quote
Old 02-10-2015, 11:41 PM   #8
joe3180
Zilvia Junkie
 
Join Date: Aug 2005
Location: 909 california
Posts: 356
Trader Rating: (11)
joe3180 is an unknown quantity at this point
Feedback Score: 11 reviews
It happened on mine. When my head was dropped off to get decked they found the crack. I guess you can say lucky for me that they repaired it before asking me, so I got the job done for free. I would have just went out to get a replacement. It is repairable tho....or at least mine was. don't know how bad yours is.
joe3180 is offline   Reply With Quote
Old 02-11-2015, 08:20 AM   #9
TheRealSy90
Post Whore!
 
TheRealSy90's Avatar
 
Join Date: Mar 2009
Location: Maricopa, AZ
Age: 33
Posts: 7,721
Trader Rating: (10)
TheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant futureTheRealSy90 has a brilliant future
Feedback Score: 10 reviews
Pulled a head off of a friends sr20 to replace the head gasket as he had overheated the engine, every chamber had a crack from the spark plug hole out towards the valve openings. May be more common than we think.
__________________
Quote:
Originally Posted by crimsonrockett View Post
Such a good signature.
TheRealSy90 is offline   Reply With Quote
Old 02-11-2015, 10:38 AM   #10
jr_ss
Post Whore!
 
Join Date: Dec 2005
Location: Pa
Posts: 6,409
Trader Rating: (35)
jr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond reputejr_ss has a reputation beyond repute
Feedback Score: 35 reviews
Send a message via AIM to jr_ss
If you overheated the engine, of course there are going to be issues. I think it all depends on how much it is overheated.
__________________
*My SR20VET* Does your VTC gear rattle in your S14/15 SR? PM me.
jr_ss is offline   Reply With Quote
Reply

Bookmarks

Tags
crack, head, sr20det


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 10:50 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
vB.Sponsors
Copyright ? 1998 - 2022, Zilvia.net