inlet manifold removed - what to do???

[petercam]

Just removed the inlet manifold as there was a oil leak from the valley gasket. Couple of problems the PH collective might be able to help with.
Firstly I have had 2 of the 12 retaining nuts of the inlet manifold shear (the 2 nearest the water pump end). Would I get running problems if I put it back together with just the 10 nuts? (so I can take it somewhere to get rectified). I do not have the equipment to do this myself.
Also should there be a gasket at the plenum chamber top cover? (There is some gunk round the edge of it, looks like someone pasted it on).
Is there any other stuff I should consider getting done while the inlet manifold is off? I am replacing the inaccessible water hoses to and from it.
As always, your comments are appreciated ......

[jmorgan]

"Is there any other stuff I should consider getting done while the inlet manifold is off?"
Plenum insulator? I had one fitted, nice cool plenum chamber.

>> Edited by jmorgan on Sunday 13th June 18:39

[Boosted Ls1]

You sheared two bolts? You will be able to drive the car if you put some sealant around the inlet ports whilst taking it to have the bolts extracted. As for the plenum, there aren't any gaskets as such, just use some silicone and wipe off the excess.

[petercam]

Thanks for the replies guys. Whats a plenum insulator by the way? Also, what type of sealant should I use on the plenum cover (shower room stuff???)?

[father ted]

petercam said:

Thanks for the replies guys. Whats a plenum insulator by the way? Also, what type of sealant should I use on the plenum cover (shower room stuff???)?

look for something that has a higher temperature rating to be safe......we use oodles of it on aircraft
(streaky - not to glue the wings on before you say it)

[greenv8s]

petercam said:

Thanks for the replies guys. Whats a plenum insulator by the way? Also, what type of sealant should I use on the plenum cover (shower room stuff???)?

There are various ways to do it, but the easiest way is to add an insulating spacer between the manifold and the trumpet base. Phenolic sheet is the best stuff to use for the spacer. (I used to have a stock of the stuff but somebody has 'borrowed' it. It isn't too expensive to buy though.)

[jmorgan]

petercam said:

Thanks for the replies guys. Whats a plenum insulator by the way?

One of these. Need to check price with DJE but £60 part only when I had mine done during a service.

[HeyAndy]

Where is the valley gasket and how does one know if there is a leak as I have a collection of oil sitting on top of the bell housing. Could it be the oil breather in need of a clean?

[HeyAndy]

Where is the valley gasket and how does one know if there is a leak as I have a collection of oil sitting on top of the bell housing. Could it be the oil breather in need of a clean?

[HeyAndy]

Where is the valley gasket and how does one know if there is a leak as I have a collection of oil sitting on top of the bell housing. Could it be the oil breather in need of a clean?

[petercam]

HeyAndy said:

Where is the valley gasket and how does one know if there is a leak as I have a collection of oil sitting on top of the bell housing. Could it be the oil breather in need of a clean?

The gaskets (2 of them) are at the front and back of the valley between the heads and underneath the inlet manifold. The oil breather is a known cause of pressure buildup, and the valley gasket is a weakspot for oil to escape.

Another question for the collective .... should I replace the thin metal cover over the valley or would a cleanup of the old part suffice?

[rus wood]

The thin cover over the valley is also the inlet gasket. I think you should replace this every time you disturb it. You might get away with a sealant but is it worth the risk?

[2 sheds]

They also only cost a few quid

[Boosted Ls1]

2 sheds said:

They also only cost a few quid

and come in two types, tin or composite. Whichever type you choose, make sure you get the correct rubber end seals to match. Oh, put a bit of silicone at the ends of the rubber gaskets where they meat the heads

[streaky]

father ted said:

petercam said: Thanks for the replies guys. Whats a plenum insulator by the way? Also, what type of sealant should I use on the plenum cover (shower room stuff???)? look for something that has a higher temperature rating to be safe......we use oodles of it on aircraft (streaky - not to glue the wings on before you say it)

Why would I say that? Mind you, I flew on G-BAOE, the Concorde that lost the tip of its tail-fin over Australia ... because the glue failed! Any anyway, I refer you to this statement:

A380 will use MaSSPS derived lightweight sealants wherever possible throughout the wing set, leading to estimated weight saving of up to 80Kg. [I do appreciate that this is a sealant and not an adhesive .]

But, don't the secondary structure and flight surfaces in the wing contain CFRP? And are you not using "Glare" for the upper fuselage?

- Streaky

PS - during WW2, my father flew Mosquitoes on PR missions - as he used to say, "All wood and dope ... and that was just the observer/navigator!" - S