63 SWC F.I. doghouse

[Rainer S.]

Anybody having a F.I. system restored should be aware of a very important step, before re-installing the unit on the car.
I had my F.I. system "restored" by someone on the east coast.
Installed the unit on the car, got engine running so-so. after shutting down the engine I noticed fuel seeping out around the mounting feet, at the gaskets, after a while.
This indicated to me, that the mounting feet were not sealing properly. (I hand stoned the surfaces, used new gaskets and torqued-up the unit per torque specs at installation).
I removed the F.I. unit, checked it on a surface plate, and sure enough, the mounting feet were all over the place, not in relationship to each other.
I had to dis-assy the unit completely,in order to get the base ready for machining. I have to make a fixture to clamp it to, planning on grinding the mounting surfaces on a Blanchard grinder.
My point is, when you have your unit restored, be sure to include a possible re-surfacing of the mounting pads,(does not have to be grinding-can be milling too, if milling, use a diamond tipped cutter).
(Check the surface, if it needs to be re-qualified, before restoration).

Rainer

[John D.]

Re: 63 SWC F.I. doghouse

Rainer, On my work sheet I have a question to answer since I easily get side tracked.(like now) Says did you test plenum on surface plate. Yes or no. So many of these midyear plenums are twisted all over the place. Solid axle plenums are usually pretty good. Don't forget to test the base plate also.
(Glad I don't live quite on the east coast but not two far from shore. Maybe 7 hrs.) After you take the cut don't forget to give the razor sharp edges a little TLC. Also you should take a look at the top of the plenum as they are typically twisted big time although a nice rubber gasket is very forgiving. Forget about using a NOS hard as steel original though. They are dangerous to use as you may crack the plenum lid. Put those one on ebay as the guys pay mega bucks for them as they know not what they do which is a polite way of saying DA. Glad you found the problem. John

[Alan Drake]

Re: Also Check

John if the legs were all over the place and bolted on that way WHAT do you think about the runners. Could there be those famous hair line cracks?
If those are there also - might it be best to fix those first.
Just a question (since I faced that problem this year)
Alan

[John D.]

Re: Also Check

Alan, Early 63 plenums are less prone to cracks that the later 63 to 65's. Long time ago I did a boring seminar on plenums. Tried to show the audience that the early plenums were much more flexible than the later style. Reason for this is that Winters foundry added more reforcing ribs to the legs thereby making them more rigid. Then when the old gaskets are used over and the plenum is overtorgued you know the results. Nothing ruins a nice resto more than a welded up plenum. Course today there are some pretty good craftsmen albeit not cheap. I prefer replacing the cracked plenums for the big buck show cars except in the case where the cars serial number is on it. Then you have to do whatever it takes to get a first class job. The alloy has a lot of impurities and is hard to repair. Porosity is a common problem-pin holes. The final step then for sure is resurfacing the bottom. Besides putting them on a surface plate you should place them on the installed base plate without gaskets to see if there is any movement or rocking. Never know when you have another problem in the works such a heads, etc. After the big show Alan I can see you are all fired up. That's how you achieve perfection. John

[Rainer S.]

Re: Also Check

I checked the plenum on a surface plate, thats how I detirmined, how bad the legs are twisted, or the seal surfaces are bent. I can see, since the gasgets are so hard, and the seal surface is so small, flatness of the seal surface is a must.
I checked the top cover surface, and that is bad too. It is "as cast" and twisted. That will be adressed, too.
John, I agree, that the top seal should be replaced with a rubber mat gasket.
I will check the base plate, also. Hope that one is flat...

Rainer

[Verle R.]

Re: Also Check

Rainer,

The base plate should be checked with it bolted on the engine.

Verle

[Rainer S.]

Re: Also Check

Thanks, Verle.
I will the base plate, mounted, it with a plate or straight edge, and later with the re-finished plenum...
We decided not to use Blanchard grinder, but a regular surface grinder instead. Blanchard is too risky..

Rainer

[Dan H.]

Re: Also Check

I found on my 64 that after installing the FI baseplate on the engine I could place the bare plemum on it and notice the slight wobble without any gaskets in place. I then began to tighten and loosen the base plate mounting bolts slightly and removed most of the wobble, enough so that the new gaskets did their job! I've put 8K on the motor, PV'D it at Las Vegas and she purrs! Might be worth a check.
Regards
Dan Holstein

[Rainer S.]

Re: Also Check

Dan,

I will proceed with milling the feet tomorrow (I hope). If I still have a small rocking, in case the mtg plate is not flat, I will try your suggestion.
The condition of theplenum right now, with .009" to .012" gap in some places, that's just too much to tweek-out..

Rainer