How to deck a 4G63 Cast Iron Block

[BogusSVO]

How to Deck a 4G63 Block



The block is a 7bolt 4G63T

The block was brought in to be prepped for rebuild.

It has been Bored and Honed to .020 over std.

Checking the block I found it had .0025 taper from front to back and has water pitting.

I set the block on the machine fixture; the block is on the main saddles.

I make a .0005 pass, Cyl #1 is shorter than Cyl # 4

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I see I have a good level set up side to side, notice the dark low spots around #1 cylinder.
A MLS head gasket will not have had a good sealing surface.

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Pass #2 is a .0015 cut

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Still some pitting at the fire ring of the head gasket.

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One more pass of .0015
The block looks good, and has a good head gasket sealing surface.

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[Lofty]

I enjoy every post of yours! !
now show us head rebuilds

 

[V12 Killa]

I enjoy every post of yours! !
now show us head rebuilds

x2

Keep it coming Bogus

 

[Imback]

If you were in ny i would throw you so much work. I definitely enjoy your posts.

 

[Alex7747]

i wish you could be my machinist . looks great though

 

[BogusSVO]

Thanks all for the compliments!

I post this info in hopes that when you have to have machine work done, you will have a better idea of what to look for, and what questions to ask when you drop of your engine parts at a local machine shop.

 

[G-UNIT]

looks good!

 

[flexnuts02]

Whatever you do I wouldnt bother using sealer spray. Use an MLS to save yourself from machining the deck anymore.

 

[BogusSVO]

http://www.dsmtuners.com/forums/cyl...correction-machining-belt-surfaced-block.html

 

[black97spyder]

Here is my block surface, notice on the far left cylinder There is a dark ring around some of that cylinder. It is pretty hard to see though.

 

[casperfast]

did you just get that back from the machine shop like that? can you feel that ring with your fingernail?. i wouldnt run an mls gasket on that block. the deck surfacing should have removed that.

 

[BogusSVO]

Thats what it looks like to me, that it was decked (Mostly), but they just did not take the last .001 or .002 to finish the job.

 

[DSMReviver]

Looks good Dale! !

 

[SlowSpyder]

Pssshhhh..... No need for some high tech stuff! Where's the large belt sander!!!

 

[black97spyder]

Yeah I got it back from the machine shop like that. He decked it already and told me how much he took off but I don't remember how much he told me.

It was a lot worse from the headgasket biting into the head and block but he got almost all of it out when he decked it. and no I can't feel it with my fingernail.. its just a dark ring basically now or parts of what used to be a ring

 

[pindlepiper]

I am wanting to run a Felpro Permatorque MLS head gasket on my current build. My block and head are at the machine shop right now getting inspected. The machinist stated he used a mill for the heads and a broach for the blocks. The head surface seams extremely smooth and shiny, where the block surface is shiny, you can kind of see the cutting rings on the deck surface. Will this approach be fine to run a MLS head gasket? He said if I wanted he would try and figure out a way to set my block up so he could use his mill on it too.

 

[BogusSVO]

Some broaches can cut for a MLS, but a Broach has 10 to 14 cutter blades, the set up of the blades is critical and a PITA.

Do it is hard to say if it will work or not, untill you can see the finish. Ask too see if he has a block broached that you can look at

 

[pindlepiper]

He did show me a block that he broached. It looked shiny, but you could see the cut marks on the deck. It was pretty smooth, but your finger nail would very lightly feel the cut marks if that makes sense? Should I have him try to set it up on his milling machine that they use for heads?

 

[BogusSVO]

You want it as slick as glass the closer the better.

Also make sure the set up is off the block mains, not the oil pan rail

 

[JacksonAuto]

A broach mill can cut as good or better than a CBN when properly set up. Most shops choose a CBN because they're much faster which reduces labor cost. It all depends on the skill level of the machinist and how much pride he takes in his work.

There are a lot of high-end race shops who are buying up the old Blockmaster machines (made in the 50's and 60's) because they prefer them over the newer CBN stuff.