Any ideas about my new ticking / tapping noise at low revs, engine is warm when it starts...
Video link:
Many thanks 🙏
5th Aug 2020 6:04 pm
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1815
Hi,
Welcome...
You are asking a question about your engine in a topic from another..
Better and more polite is not to hijack such a topic, but to open your own..
So the help is measuring to you and not making the topic from another member cloudy..
An introduction first will help in getting more help.. Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
5th Aug 2020 6:19 pm
wallworkf1
Member Since: 01 Jul 2020
Location: South Staffs
Posts: 69
I thought I'd give a quick update.
Still searching for a short block, bare block, or decent priced jag engine. I've had a few leads - but nothing yet.
I've also been ringing round a few engineering places to see if the existing block could be repaired (line bored) - some say it depends on the extent of the damage and would probably need to see it - but as they are not local - and I don't have another car all the time it's not practical to take it anywhere just yet (I'm pretty sure the motorbike won't like carrying the block either!). And others say they can do it - but it's probably very uneconomical.
I think i'm going to get the crankshaft sorted anyway - just to keep my options open (light grind and polish on the mains). That's only £80 - and if I do find a decent block then i just need oversized main bearings. A block that's had a knocking big end but with OK mains would be ideal.
I've taken the crankshaft out now, and also taken some pictures of the bearings. You can clearly see the effect the spun bearing was having on the big end bearings around it.
Click image to enlarge
Click image to enlarge
2008 Disco 3 HSE TDV6 - Gone
2001 Disco 2 V8 - Gone
Other non-LR cars and motorbikes.
7th Aug 2020 8:32 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4628
Send DM a PM, he might have something lying around!yµ (idµ - eAµ) ψ=mψ
7th Aug 2020 8:46 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4628
By the way, how long was it knocking before it did that much damage?yµ (idµ - eAµ) ψ=mψ
7th Aug 2020 8:50 pm
wallworkf1
Member Since: 01 Jul 2020
Location: South Staffs
Posts: 69
Will do - i'm also just writing a wanted advert too!
Finding 'honest' blocks is the challenge - you see some on eBay - but when you ask questions or look closely you can see that they are either from snapped cranks, or have actually spun main bearings as well as big ends.2008 Disco 3 HSE TDV6 - Gone
2001 Disco 2 V8 - Gone
Other non-LR cars and motorbikes.
7th Aug 2020 8:50 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4628
Stay well away from anything on eblag! Something will turn up, hopefully soon yµ (idµ - eAµ) ψ=mψ
7th Aug 2020 8:55 pm
wallworkf1
Member Since: 01 Jul 2020
Location: South Staffs
Posts: 69
PROFSR G wrote:
By the way, how long was it knocking before it did that much damage?
Not very long at all, and it wasn't really what I would call knocking in the traditional sense (i.e. not piston slapping), it was more of a loud rumble to my ears. I probably did about 10 miles after i noticed it, but I noticed it at the end of a motorway journey (which was probably after another 10 miles) so lets say around 20 miles.2008 Disco 3 HSE TDV6 - Gone
2001 Disco 2 V8 - Gone
Other non-LR cars and motorbikes.
7th Aug 2020 8:55 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4628
That's actually quite long considering motorway speed and engine revs! I'm surprised the spun bearing didn't seize and take the crank and block with it. Lucky boy yµ (idµ - eAµ) ψ=mψ
7th Aug 2020 9:02 pm
wallworkf1
Member Since: 01 Jul 2020
Location: South Staffs
Posts: 69
Yea - it was spinning away quite happily unbeknown to me! It even sounded quieter at higher RPM everything actually seemed fine apart from the slight noise.
The bearing was actually quite well oiled...on the outside! which I guess is why it was still happily turning away!2008 Disco 3 HSE TDV6 - Gone
2001 Disco 2 V8 - Gone
Other non-LR cars and motorbikes.
7th Aug 2020 9:13 pm
jenseneverest
Member Since: 12 Jun 2017
Location: somewhere
Posts: 760
You have a good ear to mechanical noise mate, i bet most would not even have heard an issue and carried on until it went bang properly.
It is very hard to judge the damage to the spun main bearing housing on the block just by pictures, it would have to be measured to see if it is repairable. (nice to see your pics none the less!!)
My back ground is in engine machine work, many many years ago, in a country where we had to repair what we had, all spares that were imported there had a 100 % duty plus tax and vat added, so it was nearly always cheaper to repair things. TBH even if that block was in far worse condition the housing would have been fusion welded and repaired.....
Just to explain the line bore process....
The main bearing caps are machined on the bottom mating surface, normally to a maximum of about 6-7 thousands of an inch.
The caps are then fitted to the block and torqued correctly
By doing the above the housings will now be oval - like an egg shape
Then all the housings are line bored to the correct size, with the least amount of material taken off of the actual block possible, the idea is not the move the crankshaft to far into the block, normally there is a tolerance of 2 thousands of an inch.
This process is not perfect either, as the largest parts of the oval egg shaped damaged housing are not likely to be machined at all (because they should remain bigger than the required size) these will be at the blocks mating surface to the main cap, but the rule is at least 80% of the housing should be machined to the right size. (TBH if the machine shop managed to machine all of the housing then it is probably too big anyway)
Someone mentioned the possibility of fitting the tabbed bearings from the latter model engines - if that is actually do able, i would deffo want to do it if it were my motor.
If any of the con rods have gone blue in colour (due to heat) then you should have them standardised - basically the same process as above to each of the rods. (by doing that you also offset the line bored crankshaft housings back to std - the rods end up 1-2 thou shorter)
Grinding of the crankshaft should also be done with care, the radius point of the journals should not be machined much, if at all, most of the strength on the shaft is in that area.
Anyways what i am basically saying, is use a good machine shop that know what they are doing..... i have previously been very disappointed a shop in my area.....
Good luck
8th Aug 2020 10:05 am
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2459
If you cant use tab bearings i wonder if you could use loctite to bond the bearings in place?
8th Aug 2020 11:02 am
wallworkf1
Member Since: 01 Jul 2020
Location: South Staffs
Posts: 69
jenseneverest wrote:
Just to explain the line bore process....
The main bearing caps are machined on the bottom mating surface, normally to a maximum of about 6-7 thousands of an inch.
The caps are then fitted to the block and torqued correctly
By doing the above the housings will now be oval - like an egg shape
Then all the housings are line bored to the correct size, with the least amount of material taken off of the actual block possible, the idea is not the move the crankshaft to far into the block, normally there is a tolerance of 2 thousands of an inch.
This process is not perfect either, as the largest parts of the oval egg shaped damaged housing are not likely to be machined at all (because they should remain bigger than the required size) these will be at the blocks mating surface to the main cap, but the rule is at least 80% of the housing should be machined to the right size. (TBH if the machine shop managed to machine all of the housing then it is probably too big anyway)
Someone mentioned the possibility of fitting the tabbed bearings from the latter model engines - if that is actually do able, i would deffo want to do it if it were my motor.
Good luck
Thanks, that's a good explanation of what one of the engineering company's was trying to tell me, they mentioned they would probably offset the bore slightly (2 thousands of an inch).2008 Disco 3 HSE TDV6 - Gone
2001 Disco 2 V8 - Gone
Other non-LR cars and motorbikes.
8th Aug 2020 11:17 am
jenseneverest
Member Since: 12 Jun 2017
Location: somewhere
Posts: 760
doubt loctite would take the abuse TBH
I remember using 2mm brass pegs drilled right through the shell and into the main cap (not on a disco)
obviously a precision job as the peg would need to be interference fit to its hole and perfectly sized.
The issue is really why this happens in the first place. We have the effect here, rather than the route cause.
8th Aug 2020 11:22 am
wallworkf1
Member Since: 01 Jul 2020
Location: South Staffs
Posts: 69
aja4x4 wrote:
If you cant use tab bearings i wonder if you could use loctite to bond the bearings in place?
My dad often tells me about how he fixed a spun bearing on a motorcycle using Araldite (Epoxy resin) back in the day I'm not sure myself.. who knows!2008 Disco 3 HSE TDV6 - Gone
2001 Disco 2 V8 - Gone
Other non-LR cars and motorbikes.
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Will do - i'm also just writing a wanted advert too!
everything actually seemed fine apart from the slight noise.
