Northstar rebuild: Will style (Page 33/119)
AJxtcman JAN 28, 08:15 PM
I completely forgot to get a picture of the insides of the valve covers to show the metal. I washed them in my spray cabinet parts washer and most of the metal is still in-tacked.
1fastcaddy APR 22, 08:38 PM
bump it up cause my 96 is comming together slowly but surely. Drew

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1985 GT Fastback
Low Original Miles at 41,506!!!
01 Cavalier Z24 16" wheels
KYB shocks
KYB struts with coilovers-coming soon

Will APR 23, 10:50 PM
Got new job, climbing out of debt. I expect to proceed in June timeframe.
Steven Snyder JUN 10, 01:30 AM
Bump!

It's June!
Will JUN 10, 09:40 AM
I've placed an order for 11.5:1 pistons... there goes another G...
AJxtcman JUN 10, 11:20 AM
Hmmmmm.
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I was under the impression that one of the major root causes of all head gasket failure is detonation. I had an 11 to 1 engine with a 4 bolt head that would blow a head gasket every time it detonated!
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This was a cast Iron block and head, V8 with 10 head bolts. I blew 3 head gasket in about 200 miles. The block was true and the head was also. I was working at AC specialties and the only fix for my car was to O-ring the block. I lived in the Start of the Columbia Gorge and the start of the Cascades. I would have a 1000 feet of altitude change in about a mile. I would be climbing a hill and hear a Ping for about 5 seconds or less and that was all it took. I tried FelPro, Victor, and Detroit head gaskets.
A SBC could with stand more detonation because it had more head bolts.
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Good luck.
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How far can you mill the heads with out changing Cam timing?
Will JUN 11, 01:59 PM
The Northstar is not a SBC.

The head bolt threads for a SBC are in the deck surface. They tension, and thus deform, the cylinder walls when tightened. The cylinder wall loading, and thus cylinder wall deformation change throughout the 4 cycles of the engine. The whole structure of the engine just "moves around" a lot compared to a modern engine like, say... a Northstar.

In the Northstar, the headbolt threads are deep in the outer wall of the block. Since it's an open deck block, tension in the outer wall translates to compression on the inner wall. The loading on the bore wall doesn't change much with the various loading conditions of the engine... the block/head interface is much more stable than it is on an older engine like a Chevy. The torque + angle head bolt tightening procedure also yields tighter, more consistent clamp loads than on an older engine.

I'm also going to be using Cometic MLS headgaskets.

LS2's only have 4 bolts per cylinder and they're running 10.9 on a bigger bore than the Northstar, with a more flexible cylinder head. LS7's are running 11:1 on an even bigger bore. I think the comparatively small bore Northstar will be just fine.

Any decking of the heads or block alters cam timing. How much can be figured out by looking at the pitch diameter of the cam sprockets and the amount decked. The cam sprockets get redrilled for cam timing changes anyway... it shouldn't be a problem to have them redrilled to compensate for machining of the block surface.
AJxtcman JUN 11, 07:35 PM
The Engine I was refering to was not a SBC, But when I did reference the SBC it was the say that they did not have the same known head gasket issue.
The engine was a race trim 340 in a race car. 3" tire on the front 10.5" on the rear. plastic side windows the whole bit. 69 dart. I saw the same issue with fords also
I worked at a machine shop that mainly did Chevy work, so flaws of other makes was pointed out.
Will JUN 11, 08:55 PM
I know SBC's have five (and BBC's have 6!), but there are lots of engines with four that hold lots of cylinder pressure (big block Cadillacs, for instance). Hondas and lots of imports have 4 head bolts/cylinder.
AJxtcman JUN 12, 07:28 AM
Honda
They don't blow head gaskets