Rocker cover retaining bolts

[riceburner]

The ones that are trapped in the rocker cover - anyone know for sure what the specifications for the thread are??

M6 Fine?? M8 Coarse?? The specs don't seem to be included on the 'fiche...

[CycleRob]

M6 x 1.0

[riceburner]

M6 x 1.0

Perfect! - Many thanks Rob, I thought you'd know.

[riceburner]

Hmm - can't remember exactly why I posted this thread initially - but I suspect it was I thought I'd stripped the thead on one of the lugs in the head.

3 years later (and about 5 services after...), I can confirm it. The cam cover gasket is leaking visibly after a bit of a hammer up the M4 (long story).

So - who's had experience of re-drilling and re-tapping or using an insert of some sort on the cam-cover retaining bolt lug threads??
Anybody used Helicoils or Time-sert inserts?
Did you drill the alloy out "in situ", or remove the head and take it to a machine shop?

Have done a bit of searching because I'm sure it's come up before, but can't seem to find the threads.

[MIXR]

You can do this in-situ (obviously with the cover removed), but have to consider two very important points:

One is that you must be able to set the depth to match the seat of the cover bolt. Don't over-drill! Naturally, you need the correct size helicoil drill. I don't have my cross-reference book here, so can't check the size.

Two is to be able to get the drill bit to remain on centre. This will be difficult in-situ, but it's actually not as critical as you would think. The drill will clear and follow the damaged threads, and the tap will also follow the correct line if used correctly. It will need a starter tap, and bottoming tap.

Once that's done, the helicoil should screw straight in, assuming it is also the correct length. Use the appropriate helicoil sealer, or just locktite.

Before you do all this ..................... Have you tried very gently running a tap down the threads to clear the hole, and using a brand new bolt? This may (or may not) work to the required torque setting.

The other thing to try is liberally smearing the gasket (both sides) with 'Lubriplate 105'. This a marine grease that is often used as an assembly grease when reassembling engines and machinery. It helps seal the gaskets. Any excess won't hurt the engine.

Good luck.

[MIXR]

Deleted duplicate post?

[jm1515]

...
3 years later (and about 5 services after...), I can confirm it. The cam cover gasket is leaking visibly after a bit of a hammer up the M4 (long story).

So - who's had experience of re-drilling and re-tapping or using an insert of some sort on the cam-cover retaining bolt lug threads??
Anybody used Helicoils or Time-sert inserts?
Did you drill the alloy out "in situ", or remove the head and take it to a machine shop?

After stripping 2 of the threads, I've Time-Serted all eight of them. Easy as pie, just take your time and tap a plumb hole...
(My ex used to say that a lot....)

[riceburner]

...
3 years later (and about 5 services after...), I can confirm it. The cam cover gasket is leaking visibly after a bit of a hammer up the M4 (long story).

So - who's had experience of re-drilling and re-tapping or using an insert of some sort on the cam-cover retaining bolt lug threads??
Anybody used Helicoils or Time-sert inserts?
Did you drill the alloy out "in situ", or remove the head and take it to a machine shop?

After stripping 2 of the threads, I've Time-Serted all eight of them. Easy as pie, just take your time and tap a plumb hole...
(My ex used to say that a lot....)

Jim - did you do it all by hand? Or did you take the heads off and use a pillar-drill?

Did you use the bits provided by Time-sert, or other tools? Did you have to buy any other bits? eg a tap&die set maybe?

[riceburner]

...
3 years later (and about 5 services after...), I can confirm it. The cam cover gasket is leaking visibly after a bit of a hammer up the M4 (long story).

So - who's had experience of re-drilling and re-tapping or using an insert of some sort on the cam-cover retaining bolt lug threads??
Anybody used Helicoils or Time-sert inserts?
Did you drill the alloy out "in situ", or remove the head and take it to a machine shop?

After stripping 2 of the threads, I've Time-Serted all eight of them. Easy as pie, just take your time and tap a plumb hole...
(My ex used to say that a lot....)

How much did that cost you?? I just got quote £153.00 for a 5 piece kit!! that's EXPENSIVE!!!

(helicoil kit would be about £20!!)

[Airman]

...
3 years later (and about 5 services after...), I can confirm it. The cam cover gasket is leaking visibly after a bit of a hammer up the M4 (long story).

So - who's had experience of re-drilling and re-tapping or using an insert of some sort on the cam-cover retaining bolt lug threads??
Anybody used Helicoils or Time-sert inserts?
Did you drill the alloy out "in situ", or remove the head and take it to a machine shop?

After stripping 2 of the threads, I've Time-Serted all eight of them. Easy as pie, just take your time and tap a plumb hole...
(My ex used to say that a lot....)

How much did that cost you?? I just got quote £153.00 for a 5 piece kit!! that's EXPENSIVE!!!

(helicoil kit would be about £20!!)

http://www.amazon.com/TIME-SERT-Metric- ... B001JK802K

$60 at Amazon. Not too bad.

[riceburner]

Hmm.

Well - after looking at the head last night, I've decided to go for the Sealey Brand Helicoil kit. (it comes with the correct size drill bit, which a lot of Helicoil kits don't).

[jm1515]

Can't remember where, but I bought a kit as Airman linked above, plus some extra inserts. Was about $65 total.
I used a manual tap, not a drill, with just the covers removed. Worked carefully & took my time....
Works beautifully....
Had to do the same with an M8 bolt on the starter...
The kits are expensive, but come with everything you need except the handle (tap driver), and xtra inserts. They come w/ 5 inserts, and I needed 8.
Pricey, but you can never have enough tools.....

[gregor]

Well nuts and Time Serts ? Too many new types of fasteners. Any more lurking out there in the USA?