23 replies to this topic

[mike.]

Right i'm trying to fit a new rocker cover. I'v read through this thread: http://www.theminifo...showtopic=63209

I'm using a cork gasket. I tryed using grease at first but every time i tryed tightening the studs down the gasket just slipped inwards into the rockers. After about 5 attempts with this gasket and sealing method i gave up and bought a new gasket because the other one got recked because it was covered in grease. So now i'm using hylomar blue.

I put a layer of hylomar around the rocker cover and positioned the gasket on it. I flipped the cover over on a flat surface and left for 2 hours in a warm room. I came back to it and the hylmar had set slightly - Holding the gasket quite securly in place. So i cleaned the cylinder head mating surface with meths and scraped off any old sealent/C**p that was on it until it was clean metal. I then added another thin layer of hylomar to the mating surface of the cork gasket. i then let this settle for 10-15 minutes.

I then gently lowered the cover into place making sure i didn't disturb the gasket position. Once in position i checked the gasket - it was perfect and equal all the way round. So i put the studs on and tightened them down slowly and equaly - 5 turns each at a time, checking the gasket as i went along and made sure i didn't tighten them too tight. Once they were on i checked the gasket - it looked perfectly positioned all the way round. So i left that to settle for 5 minutes, made a final check of the gasket before starting the engine. It all went smoothly at first everything was running nice and smooth and quiet. So i let it get up to running temperature then gave it some revs (up to about 2500rpm) and checked everything - It was all fine! I thought at last its done!

So i leave the engine running for a while since its not been ran properly for a couple of weeks - Have one last look at the gasket and the bloody thing has slipped inwards again into the rockers! About 2 inches of the gasket have come out of place and are flapping about in the bloody rockers!

Now what the hell did i do wrong!!! Arggggggggghhhhhhh!!

Am i supposed to leave the hylomar to set before i run the engine?

I don't have a clue what else to try! What more can i do?

[mike.]

Should i just use hylomar without a gasket? Its the gasket thats causing the problems?

[GraemeC]

I would get some proper RTV sealant rather than hylomar - will hold it much better. Only really need to glue it to the cover and then I apply a smear of grease to the side that will sit against the head.

Are you sure you are not over or under tightening the bolts - both would cause the gasket to want to escape. It should just compress slightly.

Edited by GraemeC, 15 November 2007 - 02:13 PM.

[mike.]

hmmm well i couldn't really tell if the gasket had compressed but i had done them up fairly tight

[Ethel]

If you've got a good flat surface and a couple of sheets of fine production paper to stick to it you could try flatting the edge of the rocker cover to make sure it's true.

I think the gasket is too thick to leave out and expect to get a seal. I might be tempted to tack some alloy sheet to the inside of the cover to create a lip if all else fails

[mike.]

Right well i'v just nipped to the motorshop and got another gasket. The other one was all warped. I think i may have done the studs up a little too tight so i'm going to try and not over tighten them and maybe leave the hylomar an hour or so to settle.

I'm almost tempted to super glue the gasket to the cover with araldite and then smear vsome hylomar round the inside of the gasket to get seal - Anybody tryed this?

Ethel how would i got aout creating another lip.

[taffy1967]

I use some of that instant gasket stuff (it's red stuff in a red tube) to aid attaching the gasket to my cover.

I then use a (1/2"?) ring spanner to tighten my rocker cover bolts and I just nip them down evenly until I feel slight pressure. After the engine has been fully warmed up, I then check them again and tighten them slightly more if required.

Over tightening will cause problems and I remember someone from a local Mini Club used a socket set to fully tighten up his rocker cover bolts. He then asked why it was leaking oil even though it wouldn't go any tighter.

[Ethel]

I personally reckon you were overtightening it, the torque figure is only 3.5 ft/lb. I wouldn't use superglue anything tougher than the cork of the gasket is overkill and will take some effort to clear off.

I'd use some strips of alloy to weld, solder or Araldite (with screws or rivets at the ends) to the inside of the cover leaving an overhang of about half the thickness of the gasket - similar to that on the steel cover. Very much last resort tactics you shouldn't need though.

[mike.]

In that case i'v definatly over tightened them. I didn't tighten them so it put strain on my arms ut did do them up with a fairly long ratchet so yeah it looks like this may be the case.

I think i'll start over again and use the same process but just tighten them enough to seal it.

[taffy1967]

You just need to pinch it down Mike and take it a couple of turns at a time on each bolt until you start to feel slight resistance.

Then leave it, but check it again after it's been warmed up or after some use if you want.

[taffy1967]

Anyway I've been using the red stuff (Hylomar?) to hold my gasket against my rocker cover. I have to scrape it all off when I come to fit a new gasket, so would it be better if I used the blue Hylomar instead?

[Bass Man]

Ethel & Taffy are right here I think, it is like the tappet chest you hartly tighten at all, just enough so it starts to squeeze the gasket.

[mike.]

Right thanks guys i'm starting again now. Taffy i reckon hylomar blue is better for rocker covers. Its not setting so comes of pretty easy where as the red stuff is setting hylomar so will be a pain to get off

[taffy1967]

Cheers Mike, I'll have to get some of that blue Hylomar instead then.

[dklawson]

You've already read the other thread so I won't repeat my method here. However, as was mentioned above... use RTV, not Hylomar between the gasket and the cover. The RTV will fill any gaps from lack of flatness and will "glue" the gasket in place. In the other thread someone specifically mentioned trying Krazy-Glue with bad results. Don't waste your time. Lastly, very little torque is required to secure the valve cover in place. Over-tightening will cause the cover to bow and lift the gasket "up" off the head... or shoot it out the sides.