Milled intake for decked block versus same intake on undecked block

[Warp6]

Here's the scenario:
I had a "built" engine in my GN - deck height was cut, intake was milled to fit with the decked block. Blew it up.

Now - fresh build with different block with factory deck height. Using intake above.

Hypothetically, couldn't there be some mis-alignment with the intake surface to head surface? Chasing a pressurized crankcase - blowing oil out of dipstick.
I know it could be ring blow-by but trying to rule out everything. I actually forgot about the intake being milled when I put this thing back together. It seems to me the angles could be off. Like more clearance toward either the lower edge of the intake ports than that of the top edge or vice-versa.

 

[earcher1]

your intake will sit too low now probably, depending on how much was milled.the ends of the intake may touch the ends of the block and the bolt holes wont line up. this happened to me as my engine was like your first engine.the gn1's on my engine had been milled and after spending 10 plus hours of porting my intake i discovered that it didnt fit at all. so i had it milled 60 thousands. not sure how you can go back though. maybe a thicker headgasket if its not too much.

 

[turboclam]

I think Champion sells intake spacers for this sort of thing. Goes between the head and intake.

 

[SS502]

Explain "Blew it up".. what was done to block after? As far as rebuild. Sure sounds like blow by to me, but need to know if block was honed or bored? Rods, pistons & rings replaced..more info the better. As far as decking of intake & block, depends how much was done... if only .010-.015.... a thicker gasket would be fine.... Just my 2 cents

 

[SPOOLFOOL2]

With the intake still bolted to the heads, remove the doghouse and look inside with a flashlight. You should be able to see where the intake port meets the head port. If needed, a thicker intake gasket would be my seggestion. NOT head gasket.

Mike Barnard

 

[Warp6]

I didn't realize there was a thicker intake gasket out there. Would someone please elaborate on what's available.

 

[Warp6]

Explain "Blew it up".. what was done to block after? As far as rebuild. Sure sounds like blow by to me, but need to know if block was honed or bored? Rods, pistons & rings replaced..more info the better. As far as decking of intake & block, depends how much was done... if only .010-.015.... a thicker gasket would be fine.... Just my 2 cents

Engine #1 decked - gone
Now running engine #2 - 249" all new reciprocating assembly. Running GN1 heads from engine #1 and factory ported/milled intake from engine #1

 

[SS502]

Still sounds like blow by the rings to me, or a bent rod.

 

[Scott Atk]

Chances are if it bolted up, it's not an issue. Do a compression or leakdown test.

 

[turbofabricator]

Fel-Pro 1200 intake gasket will take up more thickness. I have glued two 1200's together before, too. Need to plug PCV valve if you are using the 1200 gaskets, if you have no oil separator added to the PCV system. The 1200's have no valley pan to keep oil out of the PCV.

 

[EVIL]

If you used the two ( front and rear) rubber strips on the intake and the intake bolt holes lined up then it may be fine.
Do what SPOOLFOOL2 said and remove the doghouse and look inside with a flashlight to see if the runners line up.

D

 

[turbodave231]

Remove rocker arms and up pipe. Pressurize the intake through the throttle body. I use an aluminum puck machined to the right size and a pressure regulator. If you have pressure leaks you will find them...........,and you'll be suprised how many little leaks you find!!