VH metallic tapping noise at TDC
-
- Posts: 69
- Joined: Wed Jul 04, 2018 1:04 pm
- Location: Colone, Germany
- Contact:
- Brian_Walker
- Holder of a Nylon Anorak
- Posts: 172
- Joined: Mon Mar 19, 2018 9:40 am
- Location: Sydney, Australia
- Contact:
Re: VH metallic tapping noise at TDC
Most common problems with monoblocs is idle passage, taking the jet out and blowing out with air doesn't work remember the idle screw effects the air flow for the mixture not fuel. pilot jet cleaning does not always solve the problem sometimes the passage is blocked which requires a fine piece of wire, I use a oxy jet cleaning tip. Thumping is often associated with too much fuel so problem could come back to the carby now you mention increasing advance effecting engine running.
1951-52 VCH under restoration
-
- Holder of a Platinum Anorak
- Posts: 5051
- Joined: Tue May 10, 2011 9:42 am
- Location: Victoria.. Australia.
- Contact:
Re: VH metallic tapping noise at TDC
Long shot but is the plug the right length or extended core? Nev
- paul.jameson
- Holder of a Golden Anorak
- Posts: 2950
- Joined: Wed Oct 12, 2011 3:04 pm
- Location: Herefordshire
- Contact:
Re: VH metallic tapping noise at TDC
When checking the exhaust valve clearance make sure that the valve lifter is not holding the rocker down. If it does, you can have quite a clearance between top of pushrod and the rocker which can be noisy.
Paul Jameson
35 LG (project), 37 RH500, 52 ex ISDT KHA, 54 KH(A), 75 Healey 1000/4.
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist (but not Machine Registrar), Gauges and Clocks Spares Organiser.
35 LG (project), 37 RH500, 52 ex ISDT KHA, 54 KH(A), 75 Healey 1000/4.
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist (but not Machine Registrar), Gauges and Clocks Spares Organiser.
Re: VH metallic tapping noise at TDC
Thanks for your answers Will, much appreciated. I spent all day yesterday, getting it ready to ride. It does start easily using the recommended method of releasing the de-compressor during the kick...this is a different method to what I've been using for years on big singles. A friend came round and though the rattling was not that bad but a trial run up and down my drive had me shaking my head as to me, there is quite a loud "clack" sound during hard acceleration. If it's not big end noise, it must be the piston slap I guess, so a bill of around 300 quid expected for a piston, rings and re-bore coming up then?
Re: VH metallic tapping noise at TDC
Thanks Nev and Paul, I will check out your suggestions. As far as I remember I think I removed the decompressor when the clearance was re-set. I re-ground the seal on it. The clearances of 6 and 8 thou seem unnecessarily large to me, I can only assume this is to absorb the push-rod expansion as the alloy head will expand too and INCREASE the gap... AMC big singles simply have the gap set as long as the push-rod cups can rotate when hot. Maybe the clearances created for the iron head engines were never adjusted smaller for the alloy head?
Re: VH metallic tapping noise at TDC
Hi Ralf...OoopS. Nearly missed your reply...It seems I am answering them all in a backward style ... I downloaded your excellent video. Thank you very much. I have to say your engine does sound a bit rattly too but maybe not as loud as my one. Maybe when I have my helmet on and take it for a ride I will not notice it so much. I will try to make a video of my one and try to enter it on this thread, we can both compare them together...Watch this space ....PS: What position of ignition advance does your engine run smoothest at and what was it set to on this video?...I find the fastest and smoothest is just over 1/2- 2/3 from maximum. Advancing the ignition more makes the engine run more harshly and slightly slower?
Last edited by Les H on Tue Jun 14, 2022 9:45 am, edited 2 times in total.
Re: VH metallic tapping noise at TDC
Also Brian thanks for your tips too. I will remove the carb today as I have an ultra-sonic bath cleaner to hand. I'll also check the jet sizes and settings...
-
- Holder of a Silver Anorak
- Posts: 968
- Joined: Thu Oct 08, 2015 12:56 am
- Contact:
Re: VH metallic tapping noise at TDC
I would expect your engine to have the cam with ramps which needs
a special technique to set the gaps.
There are both alloy and steel pushrods available and my understanding is
that the steel ones go with iron barrels and the alloy ones with alloy barrels.
I inadvertently fitted a steel pushrod into my all alloy trials bike many years ago
the row was deafening.
a special technique to set the gaps.
There are both alloy and steel pushrods available and my understanding is
that the steel ones go with iron barrels and the alloy ones with alloy barrels.
I inadvertently fitted a steel pushrod into my all alloy trials bike many years ago
the row was deafening.
-
- Holder of a Golden Anorak
- Posts: 1670
- Joined: Tue Aug 02, 2011 11:37 pm
- Location: South West (Bristol-ish)
- Contact:
Re: VH metallic tapping noise at TDC
Adjust inlet tappet with exhaust valve just opening and exhaust tappet with inlet valve just closing, according to the handbook.will_curry wrote: ↑Tue Jun 14, 2022 2:55 pm I would expect your engine to have the cam with ramps which needs
a special technique to set the gaps...
Mmmm - possibly written by someone who's only owned all-iron or all-alloy engines! Those of us mere mortals who have to use iron barrels with our alloy heads also need alloy push-rods...There are both alloy and steel pushrods available and my understanding is
that the steel ones go with iron barrels and the alloy ones with alloy barrels.
SG
Web admin (webmaster@arielownersmcc.com)
'55 Huntmaster, '56 VH, ' 51 VH, '62 Arrow, '80 R100RT, '00 Sprint ST (now with a new Arrow project, and just now those 4-stroke Ariel parts can't even make one running bike...)
'55 Huntmaster, '56 VH, ' 51 VH, '62 Arrow, '80 R100RT, '00 Sprint ST (now with a new Arrow project, and just now those 4-stroke Ariel parts can't even make one running bike...)
Who is online
Users browsing this forum: Ahrefs [Bot], Majestic-12 [Bot] and 24 guests