Intake Manifold Question

[RPinoski1]

Have a friend that just took .050 off the deck of his block and now the intake manifold doesn't fit. Does anyone have a mathematical formula or simple way to get the amount we need to shave off the intake manifold to fit correctly without having to make 10 trips to the machine shop?

Thanks in advance
Rich Pinoski

[FED 387]

Fel Pro ,,Goodson and several other companies make an angle gauge that will solve your problems---Also if you have a chevy engine get ahold of the Chevy powerbook it will give you the answer to this as well---maybe Adger Smith or one of the other engine builders on here can jump in here too----Comp 387



















fel

[SSDiv6]

Here is your answer:
For intakes that intake serves as a valley cover:


For other intakes:

[Adger Smith]

Way to go SS Div 6. That was good. works ever time as long as no one has cut it before you. I use those very same formulas. Pay close attention to the angle of the head @ the intake surface. Remember it is better to make a couple of trips to a shop than have too much cut off by making a rough guess. I tell customers up front that they might be back for more. You can make a rough guess by looking down the bolt holes & see how much they are off center. You can also measure from the center of the right bank intake bolts to the center of the left bank intake bolts. Then flip your manifold over and measure the bolt holes on it. Then cut the the manifold or head surface the 1/2 difference of the two measurements. Be sure to use bolt holes that are mates. Some maniflods dont have in line bolt patterns. You can also use this same method for a quick check of port alingment.
OK FED, how is that? :~)

[RPinoski1]

I forgot to mention it is a SBC Super Stock engine in the opening post..........

The heads are CC'd and on the engine so we can't touch the head surfaces. The angles between the two surfaces are correct and the front and rear are not touching. The problem is without gaskets the "Victor" manifold sits up too high for the intake ports to line up correctly and the bolt holes have already been enlarged for better alignment. The gasket is a Mr Gasket 101G. It seems everything in the books refers to the head surface removal nothing refers to the deck surface removal.

So I was wondering if someone had "a rule of thumb way" to know how much to shave off the intake if you knew how much you took off the deck? Again the angles between the two surfaces are perfect. I just need to lower the intake so the tops of the ports will line up again.
Before the freshen up everything was port matched and lined up perfect. With the new pistons we had to lower the deck .050. to get the correct piston to head clearence.

I

[SSDiv6]

The same rule applies when you deck the block. Like Adger said, the formula is a guideline, however, it may take a couple of visits to the shop to get it right.

[Adger Smith]

Making the bolt holes larger in the manifold is a crutch & I would have never done that. You loose a good visual starting point for alingment when you get the drill out. If the manifold is milled correctly the bolt holes will be in alignment. Re read my post about measuring across the valley from port to port on the head & then on the manifold.

[FED 387]

maybe measure from the centerline of the crank to the top of the deck to get the measurement of what the deck is currently & compare that to the chevy guidelines as to what the "correct" distance should be ---this will tell you if the block has ever been machined---if it has by comparing the 2 measurements you will be able to determine how much you will need to remove ---also remember that you will want a few "thou" difference between the top of face of the manifold and the bottom of the manifold head match ---the gasket will take up most of this and when the manifold is tightened down it will eliminate any leaks at the head/block/manifold quench point---Right Adger???? Comp 387

[SSDiv6]

If you cut more than required, you can still get thicker gaskets that will make up the excess cut. Some time ago, I purchased a left over Mopar engine built for the IROC series Dodge Daytonas. When I pulled the intake manifold from the W-5 heads, there were four thin gaskets that had been glued together to make up the seal.