327 - Looking for Vacuum Leaks

Our fuelie has trouble starting and a vacuum leak is the likely cause.  I removed the cover of the fuel injection unit to take a look. 

This is the connection that draws air from the fuel bowl.  If you stand in front of the engine it would be located on the left side of the plenum.  Although the rubber hose and fittings are an 1/8" or so in diameter, there is only a tiny hole that draws air.  You can see the hole on the inside of the plenum just under the fitting.  No issues here.

This is the fitting for the PCV valve and it's located on the left side of the plenum near the rear.  We have a PCV installed but it might not be the correct one.  The 63 and 64 fuelies had unique PCV's so this might be part of the problem.  It's worth looking into.

This is the vacuum line that feeds the cold start enrichment valve and it's located on the front left corner of the plenum.  This one we want to draw air.

This is the throttle body valve and it's located on the right side of the plenum.  It's 99% closed during the cranking procedure.  I don't see any issues here.

This is a threaded outlet used for power brakes.  Since our Corvette doesn't have power brakes this outlet only gets a plug.  I don't see any issues here either.

I removed and cleaned the plenum lid gasket.  When I reinstall the gasket it looked like this.  The gasket has 4 corners so it wasn't just me stretching it.  There's just too much gasket on the far side.

I decided to replace the existing gasket with a home made gasket.  I cleaned the gasket channel then masked both sides with 1/4" masking tape. 

A tube of high temperature Permatex silicone gasket material was applied then smoothed over with a finger.

When the tape was removed it revealed a very nice form fit gasket.  Double click on the picture for a closer look.  This material takes 24 hours to fully cure so it will sit on the bench until tomorrow.

I am heading back to clean the wheel wells.  It's a crappy job and Ty's not here to do it.  Stay tuned, more to follow.

327 - The Engine Started - We are Safe at First Base!

Since the last posting Ty and I have re-looked at everything associated with the fuel.  We identified 3 items that we felt needed to be corrected.  The first item was the spill plunger.  As you recall we had to make a valve for the spill plunger that came with our 327.  That valve is shown in the spill plunger on the left.  Since then I was able to find an original NOS spill plunger, the one on the right.  Our valve does have a little more mass than the original so we decided to swap them out.  

The second item was the "filter support" as shown in the picture below.  This item was never installed in our unit.  The filter support keeps the spill plunger up tight inside the fuel bowl and it's a critical part.  Without it the spill plunger drops down and away from all the valving mechanism which means the fuel just recirculates. There are several different variations of this support and they range from rings to springs.  We decided to use the o-ring as shown.  It was a perfect fit.

 The third item we examined was the Cranking Signal Valve.  It's circled on the lower left of this picture.  This is a small check valve that has a long history of not working well and it's essential for starting the motor when cold.  If this valve fails closed the engine won't start.  Period.  I removed the valve and found the diaphragm couldn't hold a vacuum.

I tore it down and found the 5 components as shown.  I cleaned them up and reinstalled them using silicone along the edges.  It works better but needs to be replaced. 

Having tried to start the engine previously with little success I wasn't optimistic about it starting today.  In fact, I forgot to ask Gerri to film the event.  We cranked it over and it started.  Woo hoo!  We let it run for only 20 seconds or so, but it ran!  Gerri came running out with the camera and got the last few seconds and this short video captures our jubilation.  The motor needs to be tuned but that won't happen until after the radiator support is installed, the radiator is refurbished, correct hoses are purchased, etc. etc.



Our focus is now leaning more toward the body.  We modified the body dolly today to make access to the underside easier.  This winter we will remove the old undercoating, make fiberglass repairs and install bonding agent where needed.  We will work on the wheel wells first followed by the transmission tunnel, engine compartment, interior, then the exterior last.  That's plenty of work to get us through the winter.

Thanks for watching.