head gasket what thickness

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champscl

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Aug 23, 2008
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Talked to my machinists today and got some shitty news.. He had to deck my block @.016 removed. It was pretty rusted from sitting so long from the previous owner. My question is what thickness Head gasket do I need Ive got .040 probe pistons forged rods and will be trying to push 450+hp. I want to be able to drive it daily if I had to but thats another story. I want ot keep my compression as even as possible.

Thanks

Champ
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
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Feb 10, 2006
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That is an awful lot to take off :nono:

But, to answer your question it's:
Material removed from the block deck (mm) + material removed from the head deck (mm) + 1.37mm (stock HG thickness compressed).
 

jdub

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Personally, I have little trust in machine shops...you need to check their work.

One other thing to consider is has the head/block decks ever been resurfaced previously. If the block has and you've removed that much more, might want to consider a new block.
 

KicknAsphlt

Occasional Peruser
jdub;1235448 said:
That is an awful lot to take off :nono:

But, to answer your question it's:
Material removed from the block deck (mm) + material removed from the head deck (mm) + 1.37mm (stock HG thickness compressed).

So, in my case (I'm going through a rebuild as well), since I don't know how much was originally taken off of the head (bought it used) I'd take the stock block and head heights and add 1.37mm to it....then, I'd add my current head and block heights to get the current total, and subtract that from the first number, and that should tell me what thickness gasket I'd need...right?
 

jdub

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Feb 10, 2006
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Stock head height = 116mm deck to valve cover surface
Stock block height = 198.5mm deck to main crank saddle

Don't complicate the math...measure your head/block and see where you stand in terms of material already removed. I would not spend a penny on an unknown head until it was hardness tested and checked for flatness across the cam bearing saddles. If it is annealed from an excessive over heat, it is scrap. Ditto if you have a banana shaped head.
 
Oct 11, 2005
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bananaheadcloseupvj2.jpg
 

champscl

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Aug 23, 2008
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North Carolina
Wow this thing blew up, thanks for all the replies I checked with my machinist and he checked all the clearances with the pistons and I'll be going with a 2.0 mm gasket. The block was a stock block and had never had any work done to it. The reason it had to have so much taken off was the guy that I bought it from had it sitting with the head off(Cracked head) for so long that it got rusted and there were some pits in the #2 and #3 cylinder areas. So with the math added up the 2.0 mm should give me plenty of clearance for the probes to run.

Champ
 

87tomanymods

87tomanymods
Oct 25, 2008
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lansdale
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IJ.;1236250 said:
Do you actually know what either of your suggestions does? :nono:
yes actualy IJ i do. deshrouding the valves is the practice of taking away material from the head around the edes that are close to the valve heads . by doing this since you have removed material you are lowering the compresion ratio and improving flow dramaticly.and ccing the head is finding the chamber with the largest volume and taking material away from a that are smaller untill they all match and will lower the comp . another method is sigh,s cylinder head grooving in which you cut grooves into the head that direct flow twords the spark plug. again since your taking material away you lower the comp. many swear by this and have found it to help with detonation far beyond what the small amount of materail would yeild fom comp alone.
 

gaboonviper85

Supramania Contributor
Jan 13, 2008
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87tomanymods;1236566 said:
yes actualy IJ i do. deshrouding the valves is the practice of taking away material from the head around the edes that are close to the valve heads . by doing this since you have removed material you are lowering the compresion ratio and improving flow dramaticly.and ccing the head is finding the chamber with the largest volume and taking material away from a that are smaller untill they all match and will lower the comp . another method is sigh,s cylinder head grooving in which you cut grooves into the head that direct flow twords the spark plug. again since your taking material away you lower the comp. many swear by this and have found it to help with detonation far beyond what the small amount of materail would yeild fom comp alone.


lmfao....dear god

the amout of compression loss from doing that crap would be so minimal that it wouldnt be worth doing.....stop playing video games and start learning....and stop learning from other lansdale ricers bro.
 

wiseco7mgt

dirty mechanic
Aug 12, 2007
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heaps of v8 owners are doing the head grooves and some claim to get more hp from it but no one seems to have any accurate before and after data.
 

87tomanymods

87tomanymods
Oct 25, 2008
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lansdale
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gaboon you are the bigest snake licking dog kissing overinflated foreflushing shit bag doush on this forum if i ever see you in person ill stab you in the neck with a fucking hammer halaluja holy shit wheres the tylenol
 
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