Twin Cam - Cam Cover

[englishmaninwales]

I’d get the holes welded in the local fabrication shop and spend my time reducing my stock of 500 bottles....
Malcolm

[mbell]

I think this had been suggested before but I'd probably buy some of those Ali welding/soldering sticks and attempt to fill the holes and re-drill my self.

https://www.harborfreight.com/8-piece-l ... 44810.html

Not sure if that is an option that falls within the mysterious restrictions for fixing this thou.

[2cams70]

Well each to their own..... Pleased to know I didn't cause offence though!

[Andy8421]

I think this had been suggested before but I'd probably buy some of those Ali welding/soldering sticks and attempt to fill the holes and re-drill my self.

https://www.harborfreight.com/8-piece-l ... 44810.html

Not sure if that is an option that falls within the mysterious restrictions for fixing this thou.

I have TIG welded a few ali castings, and its a pain in the neck. Unlike ali stock, the castings always seem to be full of rubbish which floats to the top of the weld making a decent job very tricky. Sand castings are worse than die castings, but I still try to avoid it whenever possible.

The sticks you link to look interesting, they appear to be more like soldering / brazing - I am not sure they fuse with the ali in the same way as welding, however for 'bunging up' the holes in the cam cover before re drilling it should be fine. A word of caution, ali is a great conductor of heat, and if you are using a blowtorch it will be quite a mission to get the ali hot enough to melt the rods - and you do have the risk of distorting the cover.

If you are prepared to risk knackering the cover, then there's not much to be lost. Were it me, I would find a local shop with a TIG welder, or drill out and use a epoxy or similar resin to fix a bushing.

[J J DIKKE]

Hello Andy8421
Thank you for your posting and the information contained within.

You used the word distortion, this is my major concern with this particular cam cover among other concerns. If I have this cam cover welded and it became distorted then my next job would be to have this skimmed flat. The bottom flange on this cam cover that fits to the cylinder head is extremely thin, therefore this may lead me to assume that this has been skimmed flat in the past.

Depending on how bad the potential distortion was following heat and therefore the quantity of material that would then need to be removed may possibly be problematic.

It is my opinion that these new high performance 2 pack epoxies are so good that when assembled with clean surfaces in this situation they would not move nor would they leak oil. I need now to search out a supplier of suitable bushes of whatever material and ensure I get this thing done, and I am really looking forward to this small engineering task.

Thank you once again for your help.

[h20hamelan]

And presumably, if going the epoxy route. Dry fitting the cover, then adding a tack of epoxy to the sleeves (rainbow?) as precise fit is going to be the issue I think?

I would be happy with the grommets option to keep it simple.

[J J DIKKE]

Hello H20hamelan
Thank you for your reply. Could I please check what you mean by this. Do you mean, drill the holes to a finished size, place the cam cover on the head and place a small area of epoxy to hold the bush in the exact place on the stud?

If that is the meaning of your post then I think that is superb. They will then be centred on the stud and in exactly the correct place in the cover. Would I presume then that I could mark them in someway, remove them one at a time in order to fill the gap between the OD of the flanged bush and the drill hole in the cover.

Thank you once again.

[h20hamelan]

Roughly, this is what to infer.
Of course I do or did not know what your plan was. Rather, what I would choose to do.

Have some fun eh!

[h20hamelan]

Another option would be to use a release material under the cover/above the head (packing tape would do fine). With the syringes from epoxy, fill the gap between the bush and the cover. Have some of that wine for me. Next day it should be good.
This is similar to the tack option, more strength and less possibility’s of error.

[mbell]

The sticks you link to look interesting, they appear to be more like soldering / brazing - I am not sure they fuse with the ali in the same way as welding, however for 'bunging up' the holes in the cam cover before re drilling it should be fine. A word of caution, ali is a great conductor of heat, and if you are using a blowtorch it will be quite a mission to get the ali hot enough to melt the rods - and you do have the risk of distorting the cover.

I think you raise some valid concerns, in theory the heat level to required should be ok but the covers are large and probably not made of the best metal so there is some risk.

There good comparison video (project farm) that will give idea of strength and temps required for the ALi stick methods:
https://www.youtube.com/watch?v=fKIKsDfRAcs

[2cams70]

To help with the concerns here are some pictures of the repair done to my cam cover. Someone had drilled a big hole in the front for a breather and I wanted it back to original. The cost to have it done professionally and to grit blast the front of the cover afterward so the texture of the metal after repair blended with the original texture was $A150 - and I had a glass or two of red whilst it was being done! No problems with distortion and the metal here is thinner than it is at the top of the cover. Similarly I had a repair done to the oil filler opening which previously had quite a large groove in it on the sealing surface which would have caused an oil leak. Again no distortion and hardly visible. I'd suggest as a minimum taking your cover to a professional welder and to seek their advice before proceeding with glue and bushes. You are going to have to make the existing holes even bigger to fit the bushes and the repair will be obvious and will look dodgy brothers and not original.

[J J DIKKE]

Hello
I am now in the process of having custom made viton or nitrile rubber flanged bushes. I intend to try this as an initial experiment and see where we go from there.

I have also this week purchased an additional cam cover, not sure quite why as I now own 12 !! Oh dear.

Rather exciting is it not !

[2cams70]

Best of luck - don’t forget to post some before and after pictures!

[The Veg]

Yes, definitely keep us informed on it!