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decking a block

Featured Replies

So I bought a engine (short block) has damage to one cylinders has a nick at the top of the piston lip thinking of having it decked but it will be ~.060

 

 

too much?

Would like to hear others reply to this one.  My inexperienced view is that as its on the outside some Devcon would suffice (Plastic welder adhesive). Saving that decking.

If it wasn't into the cylinder liner it wouldn't be that bad. Clean up the very end of the cylinder with a half round file wrapped in 300 grit sandpaper.

Wire brush the heck out of the top of the block with lacquer thinner & then JB Weld epoxy the dents. Gently flat file the excess.

Check the deck with a ground straight edge & feeler gauge to make sure its flat.

Edited by czny

will do, this little hackjob just happens to be at my house lol

  • Author

I also thought about weld and then file it out sand and hone

i almost feel like jb might be better for squareness I.E. effort in  squaring it up after all that heat. i got some jb out there, ill get a move on after my back quits grinding

  • Author

If it can be decked that much I've got a guy to do it and if the side effect is more hp what the hell its like 60$

Will the head bolt be to long?

 

 hi, i want to say that if you shave the deck, you should do both halves to make the engine "equal" on compression side to side,, but most i want to say i saw some head spacer plates for the subaru, i think it was rock auto, basically  they look like a head gasket but solid, .020 if my memory is right,  and were not expensive.. if you can locate those the deck height dimention can get back close.  ( confirmed, rock auto  > subaru >1987 >gl >1.8sohc > engine > cylinder head shim ,, 6 available.) if you deck it might want these.

 i agree the clean and fill aproach others mentioned is worth a try, the head gasket will do the rest , FEL-PRO perma-torque.  that part on the cylinder  liner edge is the main thing.

Edited by ruparts

.016 is the Factory spec on the limit to how much can be taken from the surface.

 

.060 is way too much.

 

Get a different block....they are easy to find.  Sorry Subruise if you are trying to sell that it's toast.......parts block or experiment

  that part on the cylinder  liner edge is the main thing.

 

The cylinder liner does not reacht the top of the block......it's cast into place not pressed.

 

There is a "cap" of aluminium over the top of the iron sleeve about 1/8" thick.....

 

One of the reasons you can't deck them far......that cap gets thinner and becomes a little ribbon of aluminium that soaks with heat and can melt or deform at that point.

  • Author

.016 is the Factory spec on the limit to how much can be taken from the surface.

 

.060 is way too much.

 

Get a different block....they are easy to find.  Sorry Subruise if you are trying to sell that it's toast.......parts block or experiment

my block I bout from someone else he was going to assemble for me

 

very easy to find a block for 250$ I need one for 50$

itll get put together as an experiment, and a reason to use up the stone brand hgs I have sitting around. ill be building another ea82 right next to it w a good block and perma torques. 

The cylinder liner does not reacht the top of the block......it's cast into place not pressed.

 

There is a "cap" of aluminium over the top of the iron sleeve about 1/8" thick.....

 

One of the reasons you can't deck them far......that cap gets thinner and becomes a little ribbon of aluminium that soaks with heat and can melt or deform at that point.

 

 hi,  i did not know that, ,  thank you for the information and the specs to go by if  trying to repair an old block,  see,  old people can learn new stuff !!

+1 on .060 being too much. On top of what G said, it'll move the mounting points for the intake inboard making it very difficult if not impossible to get the intake bolts in. NEVER weld the head surface on an aluminum block unless you have a very experienced welder and a good machine shop. The heat alone can cause cylinder and block warpage you can't fix properly. The block has to be pre-heated, welded, controlled cooled and then checked for squareness and line checked through the cam and crank bores. Pretty sure the cost would be more than $250. If you don't have the money for a block, JB weld the pits as suggested, level everything with 300 grit wet/dry sand paper and a block of wood. Put your heads on and add 5ftlbs to the required torque. JB is tough stuff. It'll hold.

itll get put together as an experiment, and a reason to use up the stone brand hgs I have sitting around. ill be building another ea82 right next to it w a good block and perma torques. 

 

Stone brand are the OE from japanese supplier........WAAAAY better than felpros.....

 

Stones HG sets are what I use all the time.......the come with Factory HG's.......sometimes the cam seals are not quite OE but the HGs always are.

no kidding? and here i thought the felpros were where its at....that must stem from the no required re torque.

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