The IR 'Fix'

Sometimes when you use non-standard methods and parts, things do not always go as planned. Such is the case with the IR manifold casting. After a great deal of effort to get this old mechanical injection unit updated to electronic injection, and then starting the car, it was clear that something just was not right. After analyzing, investigation, over analyzing, and then analyzing some more, we developed the following conclusions:

1.) The angle of the intake to head flanges were incorrect by about 1-1.5 degrees, resulting in about a .020 gap at the flange when after the manifold was tightened down and creating leaks.
2.) The manifold was probably made for a raised runner head, so the alignment of the ports was way off, in principal it looked like the manifold was sitting to high in the heads
3.) There was to much clearance in the throttle shafts causing leaking and problems with consistent idling between cylinders.

So here is the fix:

1/2.) Aaron used the Bridgeport Mill to machine the correct angle and remove enough material to drop the manifold deeper into the V of the engine. This required the mounting holes in the manifold to be slotted to allow the bolts to go through the intake holes into the head. Custom intake gaskets were made to get a good seal between the manifold and head.

3.)The throttle shaft bores were bored oversize on the horizontal boring mill, and bushings were inserted, and reamed to fit for the shaft. Due to the length of the shaft, it was split and a coupler machined to provide flow adjustment between the front and rear cylinders.

Seems that the fix was successful, no leaks and I was able to synchronize the flow on each cylinder. Special thanks to Aaron and Dad for all the effort in fixing up the manifold!