Taping Dipstick Hole

[MK1_Oz]

As part of the dry sump conversion I will need to block the old dipstick hole. My options are an interference fitting bung (aluminium?) or the tap a thread into the hole and use a bolt with suitable washer.

The engine is currently together but on a stand. If I remove the sump do you think I can safely tap the thread without the risk of metal swarf getting where it shouldnt????

[INBreplica]

Personally,I wouldn't risk it.I would go the aluminium bung and Loctite 604.
Why risk a big dollar engine lost to a bit of swarf that may be missed.

[MK1_Oz]

OK. Are such bungs available off the shelf or will I need to get one turned up?

[gen mk 1rs2000]

i wouldnt use an alloy bung , the expansion & contaction of the 2 diferent
materials cast vs ally , is very diferent , ive seen a few of these type bungs
fall out over time
as far as tapping a thread into the block in this spot
no problems , i just rotated the engine on the stand upside down
& drilled & tapped from underneath with the sump off & a magnet
over the hole , got zero swarth into the engine internal
i also did the breather hole the same way
my next job is to do the same for the new
gearbox oil drain plug
note,, just be VERRY VERRY CAREFULL
when tapping cast iron its probably the worst type
of material to tap a thread in to
there are a few tricks & traps

[MK1_Oz]

care to share those tips and traps? As I said in another post I am not at all experienced with tapping but one way or another I need this hole gone!

Any of the Adelaide boys good at this stuff?????????????

[gen mk 1rs2000]

the hardest bit is trying to get the tap to bite for about
1 or 2 turns to start with , after that its not too bad
but still gotta be carefull not to strip the thread
it realy is a matter of feel , keeping downward pressure
& keep it straight

i normaly try to taper the hole to start with
& use a "good quality" well tapered tap to start
a little bit of thin machine oil & keep cleaning out
the hole & tap every 1 or 2 turns

it sounds hard but once you get the feel of it
its fine

[Roger Miller]

http://toolmonger.com/2009/11/23/say-no ... d-threads/

[MK1_Oz]

If somebody had an offcut of aluminium I reacon they could make one for free!! Good idea though I expect...

I dont have a tapping set yet so have to buy one of those anyway......

To anybody that has done this mod before....what size hole did you drill/what bolt size did you go for??

[alex cowie]

from memory it is a 10mm hole, cup tipe plugs are available and if you look there is another hole the same towards the front of the engine on the same side. In the past I have tapped them, fitted aluminium bungs and fitted welsh plugs none of which have fallen out, now I just fit welsh plugs because it is simple.

[jpayne]

I found an appropriately sized bolt and nut, drilled through the end of the bolt for a lock wire and installed upside down (nut on outside) with fibre washers. Tightened and lockwired it shut. Hey presto, no need for machining, tapping or anything and no swarf. easy !(sure not pretty but its a pinto and Im damn cheap but effective)

JP

[gen mk 1rs2000]

bloody good idea JP
i like a bit of thinking outside the square
but if you still want to use the dipstick
a threaded hole is still the best option
how many pinto engines have we seen with oil leaking
around the dipstick tube that is MERELY a pressed fit ?
very poor design from the start eh ?

[MK1_Oz]

might look into the nut and bolt idea!!!!!