Methods to measure

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Well-known member
Feb 19, 2015
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My Car
71 fastback
Looking for methods to measure and correct my intake manifold fitment on my 408 C.
my block has been decked to 0.014'' deck clearance and heads have been shaved 0.008''
lntake face of cylinder heads have not been re-machined, I need to how much material (should) be removed from the intake sides and china walls.
More importantly I am looking for a way to measure my current fit and be able to determine if my Edelbrock Torker is also a little warped.
Chuck, I got the calculation from Wallace, but there is still a lot of Gray area, what thickness of gasket does it assume? and if I had my manifold cut, how would one go about checking the fit ?
I was thinking about laying a continuous piece of solder at both the top and bottom of the ports as well as the front and rear of the block and gently torque to spec and read the solder thickness to see what it measures up to and if it is fairly even across the board.
I am kind of expecting the lower portion of the port to be over crushing my gasket, causing failure.
my solution could be as easy as making my own thinner gaskets.
Yes, a lot of grey on this one. How much was the bock decked, were the heads milled, has the intake been cut
, is the piston pin height the same as stock, etc. Various gasket thickness are available from Fel-Pro, Dana (Victor Reintz), Mahle, Mr. Gasket, SCE. Do you have a borescope (endoscope)? if so, pick a gasket, line the roof of the port with the roof of the gasket and tape it to the head. Set the intake in place and snug 2 bolts on each side. Put the borescope down a couple of intake runners to see how the head and intake roofs line up. If they are very close to lining up, and the china wall has a decent (.060 for RTV seal), and a feeler gauge check at the top and bottom of the port yields very close results, you are good. If the roof of the intake is too high you need a thinner intake gasket, or the intake needs to be cut. Which brings us back to, "how much"? I've been here a few times. In the end I had a machinist, I trusted, and asked him to cut it 2/3 of what he thought it needed. Only had to cut one twice. if the roof is too low, a thicker gasket is needed. This rambling comment my not be of any help, apologies.
As to the warped intake situation, BHJ makes a gauge to check this, a bit spendy. A clean up cut on the intake will reveal warpage. As always a VERY good machinist is your best friend. I hope you get it sorted with minimal drama and expense. Chuck
I think it is .022” off the port sides of the intake and .031” off the China wall sides of the manifold. That is what I am coming up with some right triangle math using .008” off the heads and .014” off the deck.
Block was decked 0.021'' which left me with 0.014'' deck clearence.
Heads were cut 0.008'' and my combustion chamber volume supports that they have only been cut once.
head gaskets are 0.040'' compressed.
So 0.029'' off the top total, most of my reading says this should be ok, but twice now I have got an oily #4 spark plug, each time it has initially stayed clean after a gasket change.
I do have a scope, problem is the Edelbrock Torker has smaller ports than the 4 v's intake ports
(designed that way) although the top of the ports should be a close match.
I never considered the roof of the port could be too high.
Heck ,on the center cylinders no scope should be needed, just a good light.
perhaps a more carefull look is in order and nothing says I have to use .060'' thick gaskets.
Thanks Bentworker,
I trust your trig.
What I don't understand is what thickness intake gasket is that based on ?
haven't measured, but I would be willing to bet that the OEM bathtub gaskets are only about .020'' at best.
Just wondering if a thinner gasket might solve the issue.
Chuck,, I do know a very good machinist, just don't know if he has the right type of milling equipment to do a skinny on an intake manifold.