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1G Decked block engine build

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Bryan 93

Proven Member
99
12
Nov 5, 2013
Mentor, Ohio
Hi, so my 1G 6 bolt 4g63 block is getting built. The machine shop had to take 0.010" off the block deck, it wasn't in the greatest condition obviously. I have a rebuilt 2G head with SS stock sized valves to go with it, it has had a minimal amount of material removed from its deck, a few thou at best if my memory serves me well. Both are freshly machined and I was planning on using a Cometic MLS HG.

I have all new front case, timing belt, and oiling components for the block.

I'm assuming degree'ing my cams and a piston to valve measurement is needed. Does anyone have any recommendations that might be commonly overlooked when taking a significant amount of material off the block deck? I hate to overthink it, I'm sure this has been done many times before and this isn't rocket science. I did some research but most everything online is SB Chevy or Ford stuff,not sure how much it relates to a 4g. I am working with my engine builder on this, but am always curious about other's opinions as well, plus I prefer to sound as if I have somewhat of a clue when we converse. Any help is appreciated.

I am thinking a thicker head gasket is probably required, not sure about this yet. Makes sense that if 10+ thou is taken off the decks, a 10+ thou thicker HG should bring things back into spec, is it that simple? I will be running fairly high compression Wiseco HD e85 10.5-1 pistons, with Carillo steel rods.

Thanks for reading,
Bryan
 
Good choice on the rods, provided they are the pro h beams. I am not an engine builder, and I am in a similar scenario myself, but I have read that the gasket thickness can be pretty sensitive to quench area. There was a pretty experienced user on here recently who had a lot of problems with head gaskets and explained how he thought the quench area was to blame for it and a lot of it really made sense and made me look into it further, but unfortunately I am no expert in that field and can't offer much help other than to say research that. As long as you have adjustable cam gears you should be fine regardless of how much is taken off aside from losing the "max" range of adjustability whatever cam's you run would normally allow. Would it be smarter to keep the geometry closer to stock? Yes, but there's a point where you're trading valve clearance for strength in the gasket area. If it were my engine I would rather have the valves closer to the Pistons and a lower cam tuning window than have a weaker gasket area.
 
Yeah they are the pro h beams. I'll be running GSC S2 cams, with adjustable cam gears. The little I've read on quench with the 4G is it really doesn't make much of a difference. Not sure how much truth is in this.
 
You'll probably get more useful replies over on the link forums. There's a hand full of users on here who would know what direction to point you but they rarely give in depth, technical replies. The s2's are not a terribly aggressive cam and i believe that even the fsm says you're good to like .012 removed from the head and block combined, though I think that's more for factory cam timing. I know things are a little different with that high compression, but I wouldn't sweat .01 all that much. Also you seem educated enough to make your own decisions but just to add, many of us wouldn't bother with a cosmetic gasket.
 
Like you said before degree your cams and watch piston to valve clearance.
A thicker head gasket would also be a good idea with that high of compression.
I think your headed in the right direction
 
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