What is the correct/best way to port match the intake to the heads? I never done this, and I could use some help.

thanks

 

Select the gasket that you are going to use, which has holes that are the next size up (larger) than either of the existing ports (heads or manifold). Center the gasket on the head and use "machinists blue dye" to color the metal. Do the same on the manifold ports. Grind the excess material away so as to just blend in the dyed areas.

This way, you don't have to have the heads and manifold done at the same time or by the same people so long as you use the same gasket type/number.

Ah, but then the real trick is to get the head, manifold, and gasket to line up when assembled, because there is some slop here!

Before I do the RTV, I tack the gasket to the heads, aligning the ports as best as possible, and lay the manifold in place. I reach in through the carb opening with a piece of brass wire and "feel" the interface for the best fit. When I am satisfied, I mark the manifold/head so that when I do have the RTV setting up, I can prettly much drop the manifold right on target.

 

1-Have heads pre-mounted on block to be used, with both head
gaskets in place.
2-Use 2 pieces of masking tape or 2 spots of silicone and position
the intake gaskets in place.
3-At this point make sure the intake gaskets (marked R/L) fit the head
ports the way you want them.
4-Lay the intake in place with 4 corner bolts, at this time you'll know
if bolt location is OK.
5-Snug the bolts down, and using a 1/8" drill, drill 4 holes (1 at each
corner) through the intake making sure where you drill you will
hit the gasket (don't drill where there is no gasket below).
6-Let the drill tip go right through the gasket and stop on the head.
Remove the intake and lay the gaskets on the respective
sides as templates, (we use 1/8" "cleco" buttons to mount
the gaskets back on the intake sides) and you can use (2)
1/8" drill bits for alignment. With the gaskets mounted on the
intake, simply scribe out the ports on the intake and "grind away".

By using this method we can literally leave a near perfect "overhang"
(reversion-wall) on the intake runner of .020"/.030"

In simpler terms, the head port is slightly larger than the intake port. It's your choice to line up the port perfectly or leave that "overhang".
The entire procedure takes about 20/30 minutes to achieve and guarantees a "perfect" fit on the final ***'y. This procedure can be done on assembled long blocks that have been running and getting an intake change.
We prefer run the intake port "inside" the head port for anti-reversion only on street engines and not on the “track only" units due to the higher VE of race prepared engines. Thanks, Gary in N.Y.

P.S. There is no other accurate way (that I'm aware of after 38+ years of engine building) to get "perfect" port alignment, period!

 

to gofast,,, reversion-wall does help

 

GOSFAST:

Let me make sure I understand the whole process. After you have ground the intake for matching and are ready for final assembly, do you use the 1/8" alignment holes to get the gasket aligned in the exact same spot on the heads? Do you then use the alignment holes after the manifold gets dropped in place to insure the manifold is lined up perfectly? (The manifold mounting bolts won't position the manifold accurately enough.)

Thanks, Cris

 

Thanks alot. This make sence. Im just a bit worried to drill a hole throue the intake

thanks

 

Hi Chris, you will visually "sight" them on assemby, we do that on all.
Once you finish "laying out" the entire scenario you have no use for the 1/8" holes at that point. They are only used to line-up the gaskets on the intake ports for location. However, be sure to install all the bolts while fitting and "snug" them into place, you don't need to torque them at this point, but they should be in position! After that, the holes do nothing, there's nothing goes in them, they are simply "dadum" (location) points!

Let me expand a little more. When you lay the intake on, if it's possible, look in the carb hole and make certain all is OK. You can do this with most open-plenum intakes, it can't be checked this way with most side-by-side ones. But the gaskets will still "tell" you if the location's OK. Occasionally you will find you can actually "position" the intake front to rear slightly with the bolts in place, before drilling it and the gaskets, as needed. Thanks, Gary in N.Y.

P.S. We've actually been contacted by other shops, ones building race units, about the above procedure. Most are curious about the 1/8" (empty) holes they see left in most of our own intakes!

 

Thanks Gary, nice trick. These alignment holes might also be a great tool on final assembly for dual plane manifolds since you can't look through them to see the gasket position. One might even consider opening up the alignment holes to 1/4" so you could look down the holes as you set the manifold in place.

 

Hi Cris, you pretty much got it! It's actually very important on those dual planes, like you said, you can't see down the ports. This is the only "dead-on" deal that I know. You can't miss with this procedure, no matter what kind of intake/head combo you're putting together. Thanks, Gary in N.Y.

P.S. Sometimes it gets a little tough to make everything clear, but we give it our best shot. As to the drill size, whatever you're comfortable
using is OK. I'll just remind you here though that you are limited sometimes to the gasket area that you have to drill through and the intake manifold. When you do this for living you find sometimes it's not too easy finding 4 good corners on the manifolds. Also, we use the 1/8" drill size because we have "cleco buttons" with pliers for them and they are all that size. The 2 drill bits we use are 6.000" and 12.000" long for easier "reach".

 

Here's a good "how to" grind away.
http://www.valvoline.com/carcare/art...cid=5&scccid=5
Eddie

 

Be careful not to take to much off.

 

Good info here.