Leak Down Test (Don't Laugh!!)

Status
Not open for further replies.
baz said:
The very best piston ring compressors I have ever used are 3" house drain pipe pipe plastic clamps from a DIY shop with a bit of 6mm studding and some wing nuts.
You can do them up as tight as you like ,tap the barrel down with a rubber mallet no problems at all.
I have used steel motorcycle type ones + car type ones but they don't come close to the gutter clamps for ease of use or for ease of removal, cheers
Click to expand...

Wouldn't this end up with tiny plastic shavings/particles in the ring grooves? I would be concerned that the rings would scrape plastic from the pipe as the "compressor" slides down. But maybe that doesn't happen. I'm just asking, not criticizing. It certainly sounds like an easy way to do it.
 
comnoz said:
Yes, and that would be the way I would assemble them.
I sell lots of rings to replace rings damaged by ring compressors. I just use my fingers. Jim
Click to expand...

Glad to hear this.
Always thought it was a bit Neanderthal of me to squeeze the rings in with fingers but it always worked easily. The ring compressor was just awkward as hell every time I tried it.
Tried again recently to use the ring compressor and quickly went back to fingers, job done in a few seconds.
Seems likely that we were given fingers just to squeeze rings and pistons into cylinders.

Glen
 
MexicoMike said:
Wouldn't this end up with tiny plastic shavings/particles in the ring grooves? I would be concerned that the rings would scrape plastic from the pipe as the "compressor" slides down. But maybe that doesn't happen. I'm just asking, not criticizing. It certainly sounds like an easy way to do it.
Click to expand...
nope no shavings come off ,and for me i find it the easiest method. i have in the past fitted the pistons to the barrel then the gudeon pins and circlips but i find this a bit awkward but maybe with assistance or maybe some means of lowering the barrel this would be better?
 
While I have the barrels away with Jim C. is there anything worth checking/doing while I have the barrels off?

I've checked:

1. Oil drail hole through crankcase to timing chest
2. Oil filter in sump. I have Jim C's crankcase breather, no 'bits' in the filter
3. Checked conrods for any nicks/bumps etc. All good & shiny
4. Visually inspected the cam, everything looks fine, no strange wear, cam lobes seem fine.
5. Pushrods seem fine, is it worth polishing them or just leave well alone?

Things to still do:

1. Check oil system, filter in oil tank, general check of hoses

Anything else worth doing?
 
have a good look in the oil tank. when you drain the tank it will not totally empty so check whats left in the bottom for shiny bits floating in the oil. remove and flush tank...
 
850commando said:
have a good look in the oil tank. when you drain the tank it will not totally empty so check whats left in the bottom for shiny bits floating in the oil. remove and flush tank...
Click to expand...

Good suggestion, I might as well give the whole oil system a good cleaning.
 
Anything else worth doing?

1. put rubber cushion under oil tank w/o the bottom securing bolt transmitting metal fracturing vibes into tank, after JBWelding the area more robust to shock load tolerance.
2. BoreTech treat bores after final hone sizing
3. Cryogenic temper rod caps and fasteners, cam, crank bearings, valves, crankshaft, trany shafts/cogs, chain, drilled out sprockets and lifters.
4. Titanium Dioxide dry friction coat surfaces.
5. Piston and chamber ceramic coatings.
6. clean up head and cylinder over casting air flow blockers.
7. Drill hole in front head fin air pocket blocking flow through hot spot
8. get silly con rocker gaskets
9. Do BSA AMAL carb fuel flow restriction slot mod
10. Diddle push rod lengths to center rockers on valve stems w/o a head gasket or cylinder base plate to up CR reponse a distinct bit and lessen leak proneness
11. grind very ends off rocker arms to solve push rod remove/install puzzle completely.
12. drill out lighten lifters slide plates 1/2" hole and tiny drain holes on cam lobes.
 
hobot said:
Anything else worth doing?

1. put rubber cushion under oil tank w/o the bottom securing bolt transmitting metal fracturing vibes into tank, after JBWelding the area more robust to shock load tolerance.
2. BoreTech treat bores after final hone sizing
3. Cryogenic temper rod caps and fasteners, cam, crank bearings, valves, crankshaft, trany shafts/cogs, chain, drilled out sprockets and lifters.
4. Titanium Dioxide dry friction coat surfaces.
5. Piston and chamber ceramic coatings.
6. clean up head and cylinder over casting air flow blockers.
7. Drill hole in front head fin air pocket blocking flow through hot spot
8. get silly con rocker gaskets
9. Do BSA AMAL carb fuel flow restriction slot mod
10. Diddle push rod lengths to center rockers on valve stems w/o a head gasket or cylinder base plate to up CR reponse a distinct bit and lessen leak proneness
11. grind very ends off rocker arms to solve push rod remove/install puzzle completely.
12. drill out lighten lifters slide plates 1/2" hole and tiny drain holes on cam lobes.
Click to expand...

:):):):):):):):):):)

Well, I did ask!!o_O

What a list, apart from not knowing what some of these processes are!, I won't be getting in that deep:rolleyes: BUT if you would like to visit Ireland in the next few weeks and get all this done that would be great but bring your own tools as some on this forum think my hammer & adjustable wrench are not of sufficient quality to work on Nortons:(

One question, No. 9 Do BSA AMAL carb fuel flow restriction slot mod, what is this mod?
 
click said:
:):):):):):):):):):)

Well, I did ask!!o_O

What a list, apart from not knowing what some of these processes are!, I won't be getting in that deep:rolleyes: BUT if you would like to visit Ireland in the next few weeks and get all this done that would be great but bring your own tools as some on this forum think my hammer & adjustable wrench are not of sufficient quality to work on Nortons:(

One question, No. 9 Do BSA AMAL carb fuel flow restriction slot mod, what is this mod?
Click to expand...

Hi click, it’s this mod to the float bowls on Amals...

https://www.accessnorton.com/NortonCommando/fuel-flow-through-32mm-amal-bowl.14579/

One preparation suggestion - you may want to stock up on whiskey
 
Last edited:
cliffa said:
Hi click, it’s this mod to the float bowls on Amals...

https://www.google.ch/search?q=bsa+..._AUIESgB&biw=768&bih=922#imgrc=jlMwU_85YGcgXM:

One preparation suggestion - you may want to stock up on whiskey
Click to expand...

Thanks for the link to the mod, never knew about this, don't think I need to be worried about such a mod 'plodding' around on my Norton!!

I thought I had enough in stock, but if you insist :rolleyes:

Leak Down Test (Don't Laugh!!)
 
Well, it's in one of my smaller garages so I had to keep the size modest

(you do realise I'm Irish & have my tongue firmly in my cheek ;) )
 
click said:
Well, it's in one of my smaller garages so I had to keep the size modest

(you do realise I'm Irish & have my tongue firmly in my cheek ;) )
Click to expand...


I'm half Irish meself, so recognize (and appreciate) Blarney when I read it.;)

Regarding the Amal mod (which Deets55 has just posted a nice piccy of) I was thinking of doing it myself, as when I was setting the float heights last year I noticed that the petrol shoots out the top of the brass seat and soaks the gasket. It must lead to seepage and possibly accounts for the staining you see on the Amals. Unfortunately I didn't have anything handy at the time to cut the slots, so put them back as they were. Might have another go this year.
 
Cliffs,

Sorta like a Dremel, but I use Dremel accessories. I used doubled up discs that I ran up against a piece of steel to get the approximate diameter. Then carefully cut into the bowl. I’m honestly not sure if that mod really matters with twin carbs, I was hunting another problem and just tried it to see what would happen. As discussed here before different size needle valves are an option if you think you need more flow. Just read up on installed depth of valve if using Stay-ups.
Pete
 
Status
Not open for further replies.

Similar threads

ILLF8ED
  • Locked
750 combat leak down test
Replies
3
Views
700
comnoz
comnoz
acadian
  • Locked
help narrowing down slight oil leak into left cylinder
Replies
8
Views
1,035
ashman
ashman
jseng1
  • Locked
Leak down test for lightweight pistons in Cmdo motor
Replies
10
Views
992
Hobot
Hobot
Back
Top