Page: |
Home > Help Needed / General Tech Chat > Headgasket failure and deposits on valves and plugs | |||||||
113 Posts Member #: 11786 Advanced Member |
1st Oct, 2020 at 06:33:04am
Hallo guys,
|
||||||
849 Posts Member #: 951 Post Whore Bromsgrove |
1st Oct, 2020 at 07:57:05am
Sounds like a problem with blowby, hence rings not head gasket. the deposits in the chambers probably caused by oil also. 'Where does the engine go?' |
||||||
113 Posts Member #: 11786 Advanced Member |
1st Oct, 2020 at 08:04:12am
thanks steve for your quick reply.
|
||||||
238 Posts Member #: 11017 Senior Member Shropshire |
2nd Oct, 2020 at 11:06:36am
Did you tuner use any knock sensing whilst tuning? You say leakdown test, did you include a compression test?
|
||||||
2618 Posts Member #: 1246 Post Whore Lowestoft, Suffolk. |
2nd Oct, 2020 at 06:53:35pm
I’d be inclined to pull the pistons for piece of mind to check the ring pack and ring lands.
|
||||||
2478 Posts Member #: 1954 Post Whore Luton Bedfordshire |
3rd Oct, 2020 at 06:31:46pm
Yep looks like piston material. Everything you have detailed points to piston and rings the deposit on the exhaust valve confirms it. I had the exact same issue so am confident that's where your issue is. Own the day
|
||||||
238 Posts Member #: 11017 Senior Member Shropshire |
4th Oct, 2020 at 02:38:54pm
Yep, without seeing the piston crowns, I suspect there's been detonation. |
||||||
12307 Posts Member #: 565 Carlos Fandango Burnham-on-Crouch, Essex |
4th Oct, 2020 at 04:49:11pm
Ive know leakdown tests to not pick up ring land issues, I think if the rings are good at the pressures your doing a leakdown they can seal ok, but once the piston is moving, or at combustiion presures then the piston wont support the ring and it will leak causiing blowby.
On 28th Aug, 2011 Kean said:
At the risk of being sigged... Joe, do you have a photo of your tool? http://www.turbominis.co.uk/forums/index.p...9064&lastpost=1 https://joe1977.imgbb.com/ |
||||||
113 Posts Member #: 11786 Advanced Member |
5th Oct, 2020 at 06:15:54am
The rolling road setup was done with a det-sensor.
|
||||||
238 Posts Member #: 11017 Senior Member Shropshire |
5th Oct, 2020 at 04:53:13pm
What was your compression like on the test? What breathers have you got? |
||||||
5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
5th Oct, 2020 at 05:55:14pm
The imprint of the gasket fire rings on your first photo look OK.
Schrödinger's cat - so which one am I ??? |
||||||
2618 Posts Member #: 1246 Post Whore Lowestoft, Suffolk. |
5th Oct, 2020 at 07:31:01pm
Many years ago I had a few issues that at the time remained unresolved and I was going through pistons at an alarming rate (Some of the more vintage members may recall).
|
||||||
113 Posts Member #: 11786 Advanced Member |
7th Oct, 2020 at 08:09:57am
what i was thinking about are these dark areas i marked in the picture:
Edited by JackZwiebel on 7th Oct, 2020. |
||||||
238 Posts Member #: 11017 Senior Member Shropshire |
7th Oct, 2020 at 11:54:21am
Do you remember what you tightened the head nuts to? |
||||||
113 Posts Member #: 11786 Advanced Member |
7th Oct, 2020 at 12:26:43pm
I didnt tight it myself, my engine builder put on the head when rebuilding the whole engine - but i was there when he put the head on and it was 61Nm (45ftlb) (I have the ARP Bolts)
|
||||||
5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
7th Oct, 2020 at 03:03:46pm
It would be nice to see a picture of the other side of the head gasket but from the one you have shown (top side on the head face ?) there is no sign of it being "blown".
Edited by Rod S on 8th Oct, 2020. Schrödinger's cat - so which one am I ??? |
||||||
113 Posts Member #: 11786 Advanced Member |
8th Oct, 2020 at 10:12:34am
ok - one last thing. what do you think how dangerous it would be to put the head back on with a new gasket and see if it still has this high pressure? Is it risky do get a bigger damage if the ringlands are broken? |
||||||
5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
8th Oct, 2020 at 04:24:24pm
Why waste money on a new gasket ?
Schrödinger's cat - so which one am I ??? |
||||||
113 Posts Member #: 11786 Advanced Member |
8th Oct, 2020 at 06:50:57pm
oh, i didnt take a picture of the other side since it looks exactly the same - i know it doesnt look blown.
|
||||||
2618 Posts Member #: 1246 Post Whore Lowestoft, Suffolk. |
8th Oct, 2020 at 07:36:58pm
I had similar markings on my last catastrophic failure, detonation followed by a blown head gasket lead to high EGT’s and the resultant heat/lean mixture melted the piston and it looked as if it had expanded and picked up on the bore.
|
||||||
113 Posts Member #: 11786 Advanced Member |
8th Oct, 2020 at 07:56:08pm
since i am thinking of going back to n/a now i measured the cc in the head and the pistons. I have 27cc in the head, 12 in the pistons and the headgasket, resulting in a compression ratio of about 1:8.8.
Edited by JackZwiebel on 8th Oct, 2020. |
||||||
12307 Posts Member #: 565 Carlos Fandango Burnham-on-Crouch, Essex |
8th Oct, 2020 at 09:34:15pm
a few scratches...
On 28th Aug, 2011 Kean said:
At the risk of being sigged... Joe, do you have a photo of your tool? http://www.turbominis.co.uk/forums/index.p...9064&lastpost=1 https://joe1977.imgbb.com/ |
||||||
238 Posts Member #: 11017 Senior Member Shropshire |
8th Oct, 2020 at 09:37:16pm
On 8th Oct, 2020 JackZwiebel said:
- i am just trying to wrap my head around what caused all this Possibilities: -Using inferior or low octane fuel -Inlet temps too high/poor map set up -Overboost -High engine temp -Not running the engine in correctly, leading to oil mist lowering octane/carbon deposits creating hot spots or increasing CR. Edited by Steve220 on 9th Oct, 2020. |
||||||
113 Posts Member #: 11786 Advanced Member |
9th Oct, 2020 at 05:54:00am
at the rebuild there were one or two scratches that you couldnt feel with the finger nail - so most of them are new.
|
||||||
238 Posts Member #: 11017 Senior Member Shropshire |
9th Oct, 2020 at 10:52:23am
Will be interested to see what your ringlands actually look like once you've pulled them out. |
||||||
Home > Help Needed / General Tech Chat > Headgasket failure and deposits on valves and plugs | |||||||
|
Page: |