How do you measure head to intake angle mismatch?
07-20-2017, 12:37 PM
#1
Drifting
Thread Starter
How do you measure head to intake angle mismatch?
I had my intake gaskets slip and basically push out in a couple areas both sides maybe 1/4 inch. Not sure how it happened. So I have the intake off and want to check the angle between intake and head.
Do they make a tool or something to do this?
Do they make a tool or something to do this?
07-20-2017, 12:45 PM
#2
Le Mans Master
you could put some clay on the mating surface(s) then bolt it on, remove and measure the thickness of the clay.
07-20-2017, 04:48 PM
#3
Burning Brakes
You could also get a machinist protractor (used on ebay) or similar (Home Depot etc.) and use the Lifter Valley flat as your reference on head and manifold surface.
07-20-2017, 05:22 PM
#4
Le Mans Master
Set the intake with NO gaskets, start bolts at the ends, and take a flashlight to look at the gap between the intake and china wall and see if there's a difference in the angle between the upper and lower edge of the intake to head interface.
07-20-2017, 06:20 PM
#5
Le Mans Master
Use a feeler gauge to measure the gap.
07-20-2017, 06:23 PM
#6
Drifting
Thread Starter
So to see with flashlight am I shifting the intake forward to see everything. Not sure what you mean? China wall means block fwd wall?
07-20-2017, 09:32 PM
#8
Team Owner
On an episode of Fantomworks they had a later C1 come in it ran fine other than using a bunch of oil. They figured out that it was the mismatch you are talking about.
Do you use a lot of oil? Are the heads and intake stock or aftermarket? How long has the intake been on and when you say your gasket slipped how can you tell it "slipped" and just not crushed out a bit is some places?
Do you use a lot of oil? Are the heads and intake stock or aftermarket? How long has the intake been on and when you say your gasket slipped how can you tell it "slipped" and just not crushed out a bit is some places?
07-21-2017, 10:08 AM
#9
Drifting
Thread Starter
I do use a lot of oil and the intake and heads are aftermarket. I had coolant in the number 8 cylinder which started all this and it appears to be from the intake gasket failure at the water port.
You are right, it could be some kind of crushed out thing but it looks more like some kind of pressure since we aren't talking about a small amount of push out, this is large causing vacuum leaks. Sorry no pics but where you would see maybe 1/8 of the gasket sticking out around the whole intake, mine had 1/4 to 1/2 bulging out in maybe 4 locations. Very strange.
One issue I think is causing this could be blow by past the rings or something. I use breathers but may go back to PVC to lower pressures.
You are right, it could be some kind of crushed out thing but it looks more like some kind of pressure since we aren't talking about a small amount of push out, this is large causing vacuum leaks. Sorry no pics but where you would see maybe 1/8 of the gasket sticking out around the whole intake, mine had 1/4 to 1/2 bulging out in maybe 4 locations. Very strange.
One issue I think is causing this could be blow by past the rings or something. I use breathers but may go back to PVC to lower pressures.
Last edited by Surfer69; 07-21-2017 at 10:09 AM.
07-21-2017, 01:44 PM
#11
Team Owner
Use the approach suggested above by TimAT. If you see that the angle of the intake runner surface is different than the angle of the heads mating surfaces, use a feeler gauge to measure the gap at the widest part. If that gap is larger than .010", you may have to get the intake runners milled to match the heads and then use thicker gaskets so that the bolt holes will still line up.
You can call some 'speed' shops to see if they sell any intake/head gaskets that can absorb some angle mismatch between those parts. Someone may make a 'crush' type gasket that will work and still seal well.
To seal the end rails, you can use the little rubber pieces and some Permatex Ultra Black RTV....OR....you can just use the Permatex U-B alone, if you squeeze out a line of it on each China rail and let it set up a while before installing the intake. With either method, once you have placed the intake in position, install bolts loosely, then tighten to 5 ft-bls and then allow Permatex to cure before final torqueing of bolts.
You can call some 'speed' shops to see if they sell any intake/head gaskets that can absorb some angle mismatch between those parts. Someone may make a 'crush' type gasket that will work and still seal well.
To seal the end rails, you can use the little rubber pieces and some Permatex Ultra Black RTV....OR....you can just use the Permatex U-B alone, if you squeeze out a line of it on each China rail and let it set up a while before installing the intake. With either method, once you have placed the intake in position, install bolts loosely, then tighten to 5 ft-bls and then allow Permatex to cure before final torqueing of bolts.
Last edited by 7T1vette; 07-21-2017 at 01:46 PM.
07-22-2017, 01:59 AM
#13
Team Owner
Eyeball it. If you have a feeler gauge set, hold the gauge shim edgewise so you can eyeball shim thicknesses that appear to be the same dimension as the largest width of that gap. You should be able to get within a couple of thousandths of the actual gap width. Your estimate will be close enough to make the next decision.
07-22-2017, 09:20 PM
#15
Melting Slicks
The China Walls are the Walls on the Block forward and aft that are generally sealed with RTV in modern times. I would get a quality Gasket set both Mr Gasket and GM are good. Then I would just set the Manifold on with the Gaskets skipping the China walls using 4 Bolts in the corners finger tight. At this point it would be nice if the engine was on a engine stand but none the less I would take a good look to see if all the surfaces are Parallel. Are the China Walls extremely close or excessively wide ?