Intake Manifold

Thank you Brooks! Won’t get back to it until week after next. Headed to Sun nFun Monday for the week. Mike (Frank’s brother and partner in the plane)

I won't be able to get to the hangar today (change of plans at work) but I did dig up some information that might be useful.

Here's a photo from the engine overhaul manual about the "Seal-o-Lock" aka "Lock-o-Seal" aka "O-rings" for the intake spider mounts. Univair has them listed here  with a photo. You'll need 4 of these, and the overhaul manual repeatedly states that the castle nuts should be finger tight only - and even states "Do not use wrench on castle nut. (See Figure 38.)"

 

You can download the overhaul manual here . The above information is from page 103.

I remember putting mine together, and I can imagine that if enough time passed and the rubber part of the Lock-o-Seals perished away, the intake spider would feel pretty loose. I'd be interested to hear what you find when you take yours apart... was it just loose, were the studs backed out, or was the rubber worn away?

 

Thank you! One learns something every day! Photos of the lock o seal would be appreciated! Perhaps mine is normal!

John beat me to it!

Frank, let me know if you want some photos - I happen to be de-cowled right now so I can get some good shots of what the hardware should look like.

The intake spyder uses "lock-o-seal" washers (see parts diagram) and is to be tightened "finger tight" (see Continental maintenance/overhaul manual). That allows the carb to slightly float with engine vibration and not have the sloshing mess up the float level. I found that the shop on one of my annuals had really cranked down the mounting nuts, preventing that play and had it corrected with new lock-o-seal washer and proper tightening.

It was where the spider mounts to the case. Two bolts with cotter pins. No opportunity for an intake leak at the mounting point so valves are fine. Carb is tight. I posted this so others would make a point to check theirs. I am an A&P and wanted to alert others to the same possibility on their planes.