Issues with shaving .018in off of my head? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 03-25-2014, 08:15 PM   #1
Newb
Thread Starter
 
Join Date: Sep 2011
Location: Bc, Canada
Posts: 3
Total Cats: 0
Default Issues with shaving .018in off of my head?

So for some background information I have a fairly stock '99 miata with 136,000 miles on it. This is the second time Ive rebuilt the engine on this car. In between now and the last time I rebuilt the engine, the engine has become warped, most likely from oil getting into the coolant and causing the hoses to weaken and break causing the engine to overheat a few times.

Now Ive just received my engine back from the shop after getting it machined, and was also given the news that the shop had shaved .018in past spec off my head and .005in off of my block and that I needed to order a .02in spacer to get my engine back under spec and that it would not run if I did not do this, they told me that they had a few Honda engines where they shaved their heads and they had problems running.

So I started doing research to see If our engine's are the same and if it would cause problems with my engine. but so far most to the info I have found has to do with 1.6's or guys that are running e85 and have engine management and such. I understand that it will raise my compression to 10:1 and that I may have to start using 91 octane gas and my timing maybe a bit off but should I have any other problems? or should I be fine and not worry about it and gain a little hp at the same time.

Thanks

Last edited by Reddon; 03-25-2014 at 08:50 PM. Reason: spelling
Reddon is offline   Reply With Quote
Old 03-25-2014, 08:40 PM   #2
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,895
Total Cats: 109
Default

That is way too hard to read. Rewrite your question with proper paragraphs, punctuation etc., and we will be glad to help you.

What you have written does not bode well here.
miata2fast is offline   Reply With Quote
Old 03-25-2014, 10:26 PM   #3
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,357
Total Cats: 1,322
Default

It would be fine if you were talking a good head and decking it .018" to raise compression. If a head requires that large of a shave to eliminate warping, the cam journals are bent too and even if you heat and straighten the entire head, it's likely to simply re-warp as soon as it gets hot again.

Your machinist is an idiot, you should never install a spacer to compensate for a decked head, since it just increases squish clearance and causes other issues. Since he didn't know this, I'm not so sure he knows that you can't deck a heavily warped head. It might be time to find a new head, and it's definitely time to find a new machinist.
Savington is offline   Reply With Quote
Old 03-25-2014, 10:38 PM   #4
Elite Member
iTrader: (4)
 
MartinezA92's Avatar
 
Join Date: Aug 2009
Location: Mountain View, CA
Posts: 1,702
Total Cats: 28
Default

>2014 years after the birth of our lord and savior
>spacers

Agree with needing new machinist.
MartinezA92 is offline   Reply With Quote
Old 03-25-2014, 11:46 PM   #5
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,895
Total Cats: 109
Default

Thank you Reddon for editing your post.

Your question has already been answered. The prices are starting to rise on Miata parts, so the sooner you find one the better.

If you think you will stick around this forum, make an introduction in the Meet and Greet.

Good luck.
miata2fast is offline   Reply With Quote
Old 03-26-2014, 03:03 AM   #6
Newb
Thread Starter
 
Join Date: Sep 2011
Location: Bc, Canada
Posts: 3
Total Cats: 0
Default

Thanks to everyone that has responded I appreciate it.
I forgot to mention that my machinist used a hydraulic press to straightened the head out before shaving it. Would that have fixed it enough so that it will not warp again and should it be fine to put together without the 0.02 shim? I ended up calling my machinist, to ask him some questions and he said everything is will be alright and advised that I should use the shim because he felt that with the head being shaved the timing would be to far off and unable to run and that the compression would be to high.

I did some research on the matter and all I could find is that it would maybe retard the timing 2 degrees at most and have a CR of 10:1. Would that be a huge problem?

Thanks in advance
Reddon is offline   Reply With Quote
Old 03-26-2014, 04:17 AM   #7
Elite Member
iTrader: (4)
 
MartinezA92's Avatar
 
Join Date: Aug 2009
Location: Mountain View, CA
Posts: 1,702
Total Cats: 28
Default

Quote:
Originally Posted by Reddon View Post
I forgot to mention that my machinist used a hydraulic press to straightened the head out before shaving it.
u wot m8? are you serious? isn't this usually used for engines where coming across a new cylinder head is almost impossible, old italian cars, etc.?

i would seriously just pick up a new head.
MartinezA92 is offline   Reply With Quote
Old 03-26-2014, 09:45 AM   #8
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,091
Total Cats: 90
Default

Quote:
Originally Posted by Reddon View Post
I forgot to mention that my machinist used a hydraulic press to straightened the head out before shaving it.
eeeerrrrrr ahhhh... thats not the normal procedure for straightening a warped head...
Leafy is offline   Reply With Quote
Old 03-27-2014, 11:05 PM   #9
Newb
Thread Starter
 
Join Date: Sep 2011
Location: Bc, Canada
Posts: 3
Total Cats: 0
Default

Thanks guys! New head it is then :(
Reddon is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 57 07-19-2017 05:11 PM
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM
Odd Steering issue interestedofold Suspension, Brakes, Drivetrain 5 09-29-2015 02:42 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 12:49 AM.