Loose trumpets in air intake plenum

[JohannC]

I'm a bit new to all this, but something tells me this is not right

https://www.dropbox.com/s/ntwdu2yshrlp4a2/File%204-04-2016%2C%2012%2044%2059%20PM.jpeg'dl=0
https://www.dropbox.com/s/8fk0nuwj2uc6vzj/File%204-04-2016%2C%2012%2051%2014%20PM.jpeg'dl=0


Are they all supposed to be the same height? One is totally loose. Do I just hammer them back down?

Also, what's the go with the gasket for the air intake chamber, it looks like old sticky varnish. Is silicone gasket ok for reassembly?

Thanks for advice.
J.

[JohannC]

Sorry, not sure how the pics ended upside down, they were right way up on the computer!

[aussearcher]

Johann,
The trumpets themselves are all the same length, the base is machined so that four sit at a higher level than the other four. They should not be loose. I've just shortened mine by ~20mm each to provide better airflow, given the difficulty I had in getting mine out (needed to heat in a high oven) I'd say an earlier owner has been messing around. I'd use the appropriate Loctite to cement them in.

In terms of gasket when refitting, I use Hylomar.

[JohannC]

That's interesting. They're all fairly loose, can pull them out by hand. The wonky one had been like that for a while as it had worn a smooth spot on the underside of the cover where it had been rubbing.
Any recommendations on the loctite? High strength?

When you say hylomar, is that the brand?

I'm actually just trying to get the air intake out of the way to inspect the passenger side rockers as I suspect an oil pressure issue there. One job turns into another! Glad I found it tho.

[TheTree]

I fitted a set of carbon fibre trumpets to mine and they were glued in with epoxy.

I agree it can be hard to get the old ones out !

In theory shorter trumpets = more power and less torque.

As per Ron's recommendation, I use permatex anerobic flange sealant on my plenum

Steve

[p38arover]

Sorry, not sure how the pics ended upside down, they were right way up on the computer!

Taken with an iPhone?


When you say hylomar, is that the brand?

Yes.

[JohannC]

Taken with an iPhone?

Yes they were.

I went and got some high strength Loctite and smeared each loose trumpet and pressed them back into place. They felt nice and solid after 20 mins. Going to give it another day before I start the car again, don't want to ingest any loctite into the cylinders, and give it some time to fully cure.

Disappointingly the whole reason for removing it all turned out to be a dud. I was sure the source of my low oil pressure problems were in the rockers of that bank. I ran the engine with the rocker cover off and it all looked normal, no signs of excessive oiling.

In case anyone wants to give a second opinion here are 2 youtubes with the engine running:

One
Two

At this point I'm going to have to start to check stuff that has already been checked/replaced to find the low pressure issue. Sigh.

Cheers,
J.

[TheTree]

I have a dim memory of something to do with the oil pump cover. Others will know more