E30 Zone

evening folks looking for a bit of advise.

went to do a mates cambelt on his m20, when i went to remove the upper timing cover i noticed that on the bolts which holds both the upper cover & lifting eye had be helicoiled before & not very well as the coil was still on the bolt when i took it out.

thing is, what the best option to proceed with? retap it & use another helicoil?
or drill it out & retap it to M8 size?

got all the bits here to do either so just wondering which route folk think is best?

anyone?

Personally for me if there is enough meat around the hole I would go the drill and retap less chance of the threads pulling out again at a later date

Scotty200 wrote:Personally for me if there is enough meat around the hole I would go the drill and retap less chance of the threads pulling out again at a later date

thats what i was thinking, will have a god look today & see if there is enough there to drill it out & retap it.

As above, better a proper job then a bodge.

well it's all done now, used the correct tap & recut it to M8 size, also did the other side while i was there so they both match up.

steve_k wrote:well it's all done now, used the correct tap & recut it to M8 size, also did the other side while i was there so they both match up.

Just seen this Steve and thats exactly what I would have done and full marks for doing both sides as well mate !!!

Mart, toolmaker by trade.

I have the same issue, looking at the engine from the front its the left hand bolt that runs thru' the lifting eye and into the head? its a bolt with a long shank and end thread if I remember - so M8 is the next tap up? I need to do mine, is there any issue with swarf from drilling, internally I mean?

Paul

Dont know exactly but run the drill very slow and put grease on the bit to try and hold onto the cuttings making sure you clear the bit often.

Mart.

@mart, cheers dude, had a big tub of grease so dipped the bit & tap in it before going very slowly with the drill.

@paultv, thats the one i had to do, M8 is the next step up & a lot stronger when you consider that the engine hangs off there on a hoist.

Tallow for threading,