ausmini https://www.ausmini.com/forums/ |
|
Head surface - too late to save? https://www.ausmini.com/forums/viewtopic.php?f=2&t=77119 |
Page 1 of 1 |
Author: | smac [ Sat Jun 09, 2012 4:07 pm ] |
Post subject: | Head surface - too late to save? |
Just dug this out of the cupboard - any one any thoughts on the chances of this being ok after being skimmed and the seats dealt to? I know it's hard to tell via photos but just looking for first impression responses....... ![]() ![]() ![]() |
Author: | drmini in aust [ Sat Jun 09, 2012 4:25 pm ] |
Post subject: | |
Head face will clean up fine, take off .020" or whatever you have to. Original thickness was 2.750", measure it and see where it's at. Smallbore 295 and 202 heads are OK with .070" or so off, the face gets a bit thin beyond this- what with the usual 40-50 years corrosion in there. Yeah I know Vizard says 3mm or more is possible, but these days you will have gasket problems. Most 1275 heads you can take 4mm or more off, no problem. They are heaps thicker. ![]() The valve seats should clean up, if not just fit bigger inlets and unleaded exhaust seats, or bigger exhaust valves too. ![]() |
Author: | smac [ Sat Jun 09, 2012 4:43 pm ] |
Post subject: | |
This is a 295, so where should I be measuring? (i.e. which hole is the thinnest) |
Author: | drmini in aust [ Sat Jun 09, 2012 4:50 pm ] |
Post subject: | |
Measure total head thickness, top to bottom. ~2.750" was stock. |
Author: | smac [ Sat Jun 09, 2012 5:16 pm ] |
Post subject: | |
Well that makes sense. I'm getting 2.75 to 3 decimal places on the ol' electronic callipers. I suspect this head did it's life in the original car and then lived on a shelf, so standard would make sense. Might just be worth getting it cleaned up then. Thanks for the info. |
Author: | drmini in aust [ Sat Jun 09, 2012 6:42 pm ] |
Post subject: | |
I would take .060" off it, because otherwise your C/R will be pitifully low with those big 28.3cc chambers and std dished pistons.. 998 Cooper had D-top (ie, domed) pistons for 9.0:1 with that head, 1098 Spridget had flat tops for 8.9:1 (I think) with same head |
Author: | kiwiinwgtn [ Sat Jun 09, 2012 6:45 pm ] |
Post subject: | |
Give it a soak in water and molasses bath for a week or two. that will clean our any rust in it. make sure its sulfa-ted molasses then get it skimmed and cleaned |
Page 1 of 1 | All times are UTC + 10 hours |
Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |