Do I have to have my block and head "decked" to run a Multi layer steal gasket?

[Turbo_Joe]

Im in the middle of pulling my engine and I want to build it right the first time..I was wanting to use a MLS Cometic or Mitsu headgasket but seems like I read somewhere that to do that I need to deck the head and block. Is that true? If so why? Also what exactly is "decking"? How much should that run at a machine shop in rural Indiana I wonder..thanks

 

[92AWDHX40]

you should take it to a machine shop and they should know what to do, no idea about pricing there call around and ask the shops shouldnt be too much just to deck it, its taking material off with a machine then making sure its flat, there you go call around we couldnt tell you what they charge. thats the best i can tell you its just that simple.

 

[Turbo_Joe]

OK thanks. so basically its like "milling".Except at a minimum level just to put a resurface on the head and block..I need to do that to my head anyway because I need to make sure its not warped. Thanks for the info. I will call my local machine shops in the morning. Now some one said I should use some kind of "copper" spray on the gasket and surfaces..is this true? Thanks again

 

[eurytopic]

From what I understand you need a RA50 or finer flat finish on the block for it to seal properly. There is debate about the copper spray. Personally, I ran a MLS without copper spray and without decking the block (just cleaned it well) before I knew any different and it worked fine for me on a 14B running 15 PSI. I'm not sure if it would have blown with more or not.

 

[VETTE_50_TH]

50 RA is actually pretty rough when it comes to this kinda stuff. When it is milled professionally, they can achieve 10 or less with good equipment. As long as the surfaces are level and clean, you shouldnt have a problem.

 

[Turbo_Joe]

Thanks guys..I plan on running like 28 to 30 psi on E85 so I want to get this right..

 

[9!'clipseDOHC]

Also for them to deck the block all the internals have to come out. If you are already going to have the engine apart them I would get it done.

 

[Turbo_Joe]

Also for them to deck the block all the internals have to come out. If you are already going to have the engine apart them I would get it done.

Yeah, im going down to the bare block..for sure getting this done and going with MLS gasket..thanks guys