Search found 115 matches

by niftyrodman
Sun May 10, 2020 2:19 am
Forum: Mechanical
Topic: Oil pressure
Replies: 1
Views: 155

Oil pressure

How many seconds on a cold engine, with 20/50 oil in, should the average time be on a good 948 engine, (using an earlier split screen gauge) to begin to register pressure after the engine starts. Id be grateful to get a response.
by niftyrodman
Sun May 10, 2020 2:09 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

With all due respect to all the tech advice I will test my elec vernier with the mic and visa a versa. The reason I bought the mic is because of its design with a finer point of reference, but my theory is that if the cold start rattle disappears when the cylinder No3 is disabled it has to be the be...
by niftyrodman
Sat May 09, 2020 9:53 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

Thanks Kennet. Ive just ordered a 25-50mill inside and outside Micrometers Ive got a good vernier but I want to be exactly sure. I know the journal that is in question, its too light(the rattle) to be the centre main, so I will take off the sump and pull all the rods off and measure the lot.Incident...
by niftyrodman
Wed May 06, 2020 10:03 am
Forum: Mechanical
Topic: A Motor breathing/ leaking as a result
Replies: 13
Views: 614

Re: A Motor breathing/ leaking as a result

I see. I see, the PCV. One could describe it as a one way valve, that restricts the vacuum. only allowing enough for a positive flow from the engine innards. I shall get one and drill right in the centre of the inlet manifold, then decide where best to draw from. You are right about the price Phil, ...
by niftyrodman
Tue May 05, 2020 8:59 am
Forum: Mechanical
Topic: A Motor breathing/ leaking as a result
Replies: 13
Views: 614

Re: A Motor breathing/ leaking as a result

Thanks Phil for your informative post. Y'now the breather pipe down the side of the motor that is designed to create a vacuum as you travel, and create that negative pressure you mention, primitive as it is, one has to accept as restorers, and that is what it is. I noticed on this forum a pic of a b...
by niftyrodman
Mon May 04, 2020 10:49 am
Forum: Mechanical
Topic: A Motor breathing/ leaking as a result
Replies: 13
Views: 614

Re: A Motor breathing/ leaking as a result

Thanks for your reply, we think alike. The area I was wanting to improve was the seal bearing area at the crank end. I would have liked it to have been a better surface for the seal lip. I am really interested in your "suck' from the bell housing, drawing the oil back. Can you explain how that works...
by niftyrodman
Mon May 04, 2020 7:31 am
Forum: Mechanical
Topic: A Motor breathing/ leaking as a result
Replies: 13
Views: 614

A Motor breathing/ leaking as a result

I being one of the rear main seal addition mob, ,fitted long ago now wonder how by fitting that seal interferes with the action of the scroll. As well, I wondered if adding a breather to the fuel pump blank plate, would alleviate crank case pressure, better than the existing side plate breather, if ...
by niftyrodman
Tue Apr 21, 2020 11:22 pm
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

I have thought the same thing about the rod, Oliver, and that it may be the problem. Fortunately I have another engine which is not bottom end dismantled, so if the problem I have persists, there is a crank and rods to work with. Inspiration killer for sure, sweet little engine.
by niftyrodman
Mon Apr 20, 2020 11:17 pm
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

Thanks Dr Phil. Of course the vernier is electronic, as it has a battery, why do people split hairs? If I know the diameter of the crank when it was new, and I measure it according to that and deduct whatever has come off it from being ground I will be somewhere pretty close. The vernier I have, is ...
by niftyrodman
Mon Apr 20, 2020 2:28 pm
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

Thanks Kennatt and Oliver. First, Oliver I read you,and do understand your point and of course, nothing is off the table. Impossible to measure mains, without the crank out so that would be a last resort. And Kennatt, I understand your confusion. The man in the shop that did the work assures me that...
by niftyrodman
Mon Apr 20, 2020 12:43 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

Thanks Oliver. The main journals were ground as well. The whole thing is, if you have a knock, and you can stop it by disconnecting a plug lead, on start up,then one can assume that normal combustion pressure etc is going to increase the load on the conrod crank bearing, and if the noise stopped whe...
by niftyrodman
Sat Apr 18, 2020 8:43 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

Thanks Kennet. The thing is the noise disappeared when I disconnected the plug lead on No3 before starting the engine cold. Completely. So oiling up the pot, would change a piston noise, which I did and the knock persisted. Im amazed, because its only a couple of thou over what it should be.At the m...
by niftyrodman
Sat Apr 18, 2020 1:37 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

Goes to show reconditioners can be wrong. Its all about oil pressure, and its interesting. Knocking on No3 with lead back on plug. Sump off again, measure properly, ( thanks Phil) and hopefully I have an all round room for a .002 under shells. I don't mind buying a set, as they will be used eventual...
by niftyrodman
Fri Apr 17, 2020 8:10 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle/knock

Starting the engine with No.3 Lead off the plug, it was quiet. So Ive squirted 8 oil can squirts of 20/50 oil into that cylinder and I will leave it and start it tomorrow morning, and see what happens. If it knocks, I have an over clearance number 3. big end bearing. And in theory it should be a lit...
by niftyrodman
Thu Apr 16, 2020 7:29 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

I quizzed the reconditioner mainly about getting an odd set of bearings .002, or .003 under whatever size is in the engine, and thats possible. He said it doesn't sound like a bearing if there is no noise hot, and I cant argue with his hypothesis, so as I progress eventually to single out the cylind...
by niftyrodman
Thu Apr 16, 2020 2:06 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

Thanks Phil.It sounds about right for a big end. It is a knock/rattle I think the main knock would be deeper. I tried start with No4 lead off, and the noise was still there but much muted. Tomorrow No3 . Its a restorers inspiration killer, these things.When I assembled the engine I should have check...
by niftyrodman
Wed Apr 15, 2020 11:02 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

I know nowt about the bottom end of these engines. I would be checking the centre main bearing. It is likely out of spec. I had this on a 5 bearing crank which rattled until the oil pressure built up at a cold start. Only lasted a couple of seconds but indicated big trouble ahead (especially the wa...
by niftyrodman
Wed Apr 15, 2020 10:39 am
Forum: Bodywork
Topic: Reassembling the inner door from scratch series 2
Replies: 4
Views: 368

Re: Reassembling the inner door from scratch series 2

Thanks Mark. Ive written to a well known Minor restoration business Charles Ware, and asked can they sell me the step by step I need. If not, its trial and error. Its a pain but thats all I can do.
by niftyrodman
Wed Apr 15, 2020 9:43 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Re: Cold start rattle

Yes, I think sometimes hope distorts diagnosis. I will start engine cold with a random plug lead off, every morning until I locate the bearing in question, I will then measure that crank journal and the rod end, as you suggest, and buy a set of .002 bearing shells and fit a pair to that particular r...
by niftyrodman
Wed Apr 15, 2020 2:34 am
Forum: Mechanical
Topic: Cold start rattle
Replies: 39
Views: 1721

Cold start rattle

Motor is fairly newly reco, (948 A motor) and Ive plastiguaged the big ends twice, and if anything one may have 3-4 thou instead of 2 Motor runs quiet as a mouse otherwise. A technical point that maybe someone can enlighten me, is how much big end clearance, would allow that to happen as a guesstima...