TRnorm
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Posts posted by TRnorm
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Thanks Guys - really good stuff.
The car is a 4, not 4A, and the GB & OD came from a 2.5 saloon (and seem to be OK as far as i am able to judge give the masking effect of the vibration). I should emphasise that it is far more than just vibration - its that in spades plus a real loud accompanying din.
The wheels and tyres were new and balanced etc say 12 months ago and have since just supported the car plus done a total of about 400 miles.
Front dampers are new and all the suspension was rebuilt with polybush and Revington's camber kit etc. Perhaps i should say that I stupidly did not renew the prop, just freed up up - we all learn, eventually!
The more I think about it the more I tend to suspect, like I think Peejay does, the play in the sliding splines. And being realistic- am I going to be happy doing various things like reversing the shaft, renewing the UJs, balancing the prop etc - with all the effort involved, if in the end i know i still have the play. .
Having said that, It would still be interesting to hear how others view the 1 mm play.
Thanks as always
Norman
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Hi everyone and a happy Bank Holiday WE.
Those that are not occupied with the festivities - can you help on this one?
Took my car on its first longish trip (250 miles - much on motorways) on Wednesday. Had previously only done about 170 miles locally, so not at any speed.
Problem is at speeds above 40-45 mph a severe vibration and noise sets in.
- It is felt particularly through the gear knob (in and out of gear).
- Seems to be related to road speed
- Knock it out of gear at say 55, and there is not much difference - except of course, as the car quickly slows to the 40-45 mph region most of the noise and vibrations goes.
- Seems the same with OD in or out.
All I've been able to do so far is check the UJ bolts which all seem nice and tight. However, the prop seems to be the wrong way round (ie the sliding part is to the rear, whereas the Part Manual shows it to the GB end). But I cannot imagine that would have any effect(?)
There is no noticeable play in the OD output and Diff input shafts.
But there is some play in the sliding part of the prop. Difficult to say exactly how much but side pressure to the prop at this point results in a total sideways movement of perhaps 1 mm (at the point of pressure).
I've had a good ol' search on this forum for similar complaints and found much helpful advice - except for any clear view on the spline wear aspect. It doesn't seem much to me, but perhaps its critical - so any learned comments most welcome!
Thanks for reading yet another of my trials and tribulations!
Norman
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Just want to say Thanks for all the advice and experience - although having taken my car for its maiden longish trip of 250 miles yesterday I find i have a more pressing problem! I wont go off topic here, but suffice to say it has really bad vibration at more than 40mph that needs sorting mega urgent.
Window gaps will have to wait awhile, but info gratefully logged into the few remaining grey cells.
Norman
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As always, much food for thought, and good to know Its not just me!
My plan for the WE then is to take the measurements as suggested. Then see what adjustment to the frame might accomplish - now I know there should be some adjustment.
The glass shows quite a bit of wear and tear, and although not proof positive, suggests it's original.
So, many thanks guys.
Norman
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Thanks Roger
Norman
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I didn't pay too much attention when I fitted the windscreen. But now I see that I have a small clearance (at the top) between leading edge of window and the windscreen frame. And I have a much larger gap lower down.
I appreciate that it may be the tilt of the window, but at the B post area, the edge of the window seems nice and parallel with the vertical line of the hood. So, is there adjustment to the windscreen frame such that its tilt can be "adjusted"? I could of course slacken the frame and find out but would like to save myself wasted effort if I find no adjustment is possible.
Thanks for any suggestions.
Norman
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Why can't I see the photos of the rack that were presumably posted?
Someone please enlighten
Thanks
Norman
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Thanks Monty and Mark,
After managing to get it running only with >12 flats I too have now got it back to the 12F, but still have the very high idle. I don't think its an air leak as seems the most popular diagnosis, but this weekend I fit my Distributor Doctor dizzy and will see Whats What after that. Now it is running I'm happy with a slower incremental approach.
Norman
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I agonised for ages as to what to use on my chassis, scouring this and many other forums.
Although I don't as yet have any long term experience to support using Epoxy Mastic 121 from Rustbusters (http://www.rust.co.uk/epoxy-mastic-rust-proofing-paint/c28117/) in the end I decided on this material because I liked the finish I had seen a shows but more importantly I tracked down what I am 99% sure is the source of this rust preventative system.
I'm confident that its made by a very high end Norwegian specialist who seems to be de rigueur when you want to protect your oil rig or similar - and that was good enough for me. It isn't cheap, and I might have been quite happy with another epoxy like Bondaprimer, but so far I'm pleased I went this route and compared to the total i have spent, it's peanuts!
Norman
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Just to say Thanks to everyone - I have been reading all the recent help and suggestions, and taken them on board. But other than that I'm in a state of limbo as my Dizzy is away with Martin Jay as I wanted it to be beyond suspicion for when my rolling road session takes place.
Not to my total surprise, I was told with the authority of someone Who Knows, that what I had was the lowest grade of Chinese rubbish yet seen! I did have my suspicions as the timing mark was fluctuating considerably even after i got some form of reasonable tick-over, albeit at high revs. So fingers crossed, this may well make a significant difference once the totally new dizzy is installed and statically set-up.
I'll update on this and the rolling road tune up, as and when.
Norman
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Alan,
I'll be looking at mintylamb (mintylamb!) and the finer points of needle profiles. But certainly encouraging to know a similar set up is working well for you.
Actually, now I've finally got the engine running (as opposed to stuttering and not running) I'm finding it is responding to the finer tweeking. But it does seem to me that the area of coincidence of the variables that has to be achieved for basic running is a lot smaller than is generally assumed.
Bit of a learning curve - as they say.
Norman
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Impressive stuff Peter!
Norman
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Hi Alan,
My needles are spring loaded, biased towards the engine. But you're correct in that they are not originals. The car is Ex US and came with Strombergs. The carbs I have fitted were waxstat type - I think from a triumph 2500. They went to Burlin with the request to make them non-waxstat and to be jetted for a fast road tune TR4, and there were no ali tags - so that's their history. But I didn't understand the chronology of the needle evolution - so thanks for explaining that for me.
And Peter, that seems a fascinating project you are undertaking - I do hope you will be sharing it with us all. Even the less auto-technical of us understand how fuel injection and electronics has advanced the performance (in the widest sense) of our cars, but if we achieve a little of this whilst retaining our beloved SUs that's a really satisfying achievement. (Just found the AEM info on http://www.efi-parts.co.uk/index.php?productID=204&sent=yes - looks interesting and a fair price! )
And I wait wait patiently for your explanation as to how you are going to "....control the lean mixture continually at cruise..."! Some form of PID loop acting on the jet nut perhaps?
Great stuff
Norman
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Peter, you mention a wideband AFR meter so i guess you have, or do, use one. Can i ask if you have used one where the lambda probe goes up the exhaust pipe and if so, is it any good.Appreciate that a boss in the downpipe is the right way, but with other problems at the moment I want to know if one up the exhaust is worth the (small) effort or not.
PS. I do have the 4.5oz red springs which i measured at 2.6" compression to be within a few grams.
Finally taken the needles out and these I find are BAM (not the SMs that I thought they were).
Booked in for a rolling road carb set-up for early April, but meanwhile have to get enough miles on the clock to get the engine run-in.
Norman
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Thanks Peter - My caps do have the hole, but I'll certainly have a look at the straightness of the damper rods.
I'm beginning to feel I risk becoming a bit of an expert on HS6 carbs through acquired knowledge!
Which reminds me of that salutary definition of an expert...An expert is someone who knows more and more, about less and less, until he know everything about nothing.
Norman
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Thanks Peter for the link to Lynx rolling road people, but what's more...
Looks like I'll be able to get there under my own steam!!
Frankly I didn't think that going richer as per Mark's experience was the way to go - all the evidence of sooty and wet plugs and plenty of petrol sloshing around suggested otherwise.
Nevertheless, I reset everything to the "standardised" starting point (12F,1.5T and fast idle screw just touching cam when the choke is just about to lift the jet).
Except I then made the jet richer by 2 more flats.
Oh Joy!
OK, the choke-out speed was still around 1600-1800 rpm, and it still rose to around 2200-2500 when the Choke was In. But...But...but.. the engine didn't die. This was real progress.
Emboldened by this; successive reduction in the idle screw from 1.5T to 1T, 3/4T,1/2T and 1/4T reduced the speed to 2000, 1800, 1700, and 1600 respectively.
Separating the throttle shaft for the final adjustment to the two slow speed idle screws got me a final 1500rpm - with equal Hiss.
Lifting the pistons by the requisite 1mm seemed to indicate that the mixture was correct - so no change to the jets position seemed necessary..
So in the end I have an engine that will get me to the SU specialist for a pukka set-up on a rolling road with gas analysers et al.
Obviously 1500 rpm is still a little high for a choke-In idle and it runs a little lumpy - a strobe light on the crank shows a regular fluctuation between about 6 to 0 degrees BTDC. Maybe I let the specialist work this out - but if anyone has an idea about this then Id love to know.
Thanks for everyone's contributions, all of which I took into account and which helped with the thought process..... but in the end the one I thought most unlikely proved to have been the most effective in my case - must be a lesson there!
Just seen your post Alan, so thanks for that. I was thinking about getting the Colour Tune but like you I think, found the Hiss method easy and I think effective. And I certainly don't want to be running lean. Also interesting that there's another vote for the rolling road.
Great stuff!
Norman
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Pete - the needles look located OK but I have not had them out - so that's another thing to add to, checking the float level.
And Mark - that's really interesting about 12F being too lean - cant wait to try it richer but double! How many gallons to the mile are you getting!
PS
Tried the carb cleaner routine earlier and nothing - so inclined to rule out an air leak.
Thanks also to Mike MD for the text - looking out for your email with details of your carb-man, near Cambridge
Thanks everyone
Norman
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Thanks Justin - I have not checked the floats although it was in my mind that that should probably be the next move - now you've convinced me!
Although they looked good, I'll now give more than the cursory look at the throttle disk sealing.
Thanks
Norman
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More interesting stuff - many thanks
Chris - I'm now wondering why I thought SM was the needle. I need to review were that came from. Might be that because of the cam.
The engine is number CT20 thousand and something. It has BP270 cam (Piper I think) and the later exhaust header (cast iron 2 into 1 type). I forget exactly what the exhaust is but it was basically a Moss straight through(?) I've measured the head and reckon the CR might have been upped by no more than 0.5.
The needle/jet centralisation seems fine. With the jets fully in (lean), both pistons fall freely at the same rate and hit with that nice "clonk".
(Think I've just remembered why SM. When I sent the carbs away to Burlin 20 yrs+ ago for a full refurb (but only fitted last year) I asked for them to be jetted for a Fast Road set-up. They never confirmed the detail but because of the problems I'm now having I checked the jet dia (0.1") and the needle at 3 stations and concluded that it was a SM needle.)
Mark - interesting about what you experienced; similar symptoms yet as I indicated to Chris, I'm certain there is no binding twix needle and jet?!
I was puzzled about "checking the jets are fully up". Are you saying that your car runs with the jets fully up (lean)? Whilst I did raise them to bridge level to check the centralisation, I then lowered by 12 flats (2T) for the initial setting that I understand is the starting point that should allow the engine to run.
One other thing I have noticed that doesn't feel right is that with the dampers screwed in it takes quite an effort to manually push the piston up - real effort that I find difficult to think could be overcome by the suction in the upper chamber. Yes - its has Penrite SU carb oil in the pots and of course with the damper withdrawn, or with the oil removed , the piston rises with light finger pressure. (So no binding there i think.)
Recollections anyone on the force needed to lift the pistons?
Meanwhile - off to Halfords for some Wynn carb cleaner for a leak-test later today.
Thanks again
Norman
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If this turns out to be something as simple as an air leak I'll be well and truly jiggered - but delighted!
Alan, the funny thing is that when the choke cam is set-up to give the appropriate tweek to the throttle, that's when i get the high speed tick-over (choke out). And it's only when i readjust so that the cam does not contribute to the throttle opening that the high tick-over reduces to a reasonably sensible 1500 RPM. As I initially said, it doesn't really add up.
I have this kind of worrying feeling that in the end it will be a combinations of factors. Certainly the permutations of adjustments that you can make are legion which makes homing in on the culprit(s) less than easy.
As usual, airing a problem on the Forum inevitably gets the little grey cells darting off into completely different directions! What would most of us do without it?
Norman
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Thanks guys - optimism is being restored!
Certainly if I could get it going I would be heading Womble way - and when I do get it going, that is what I'll be doing.
If nothing else, I've realised that for me, the final carb set-up is something for the specialist.
I like the rolling road idea but its basically a new engine, so something for when its run-in.
So, off for some carb cleaner.
Thanks Tom and Tony.
Norman
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I'm trying to get to the point where I can sustain a running engine long enough to get hot enough to go through the Carb Balancing and the Mixture fine tuning.
I just cannot get it running other than on the Choke (at about 1500 RPM), but then any attempt to push the choke in results in an initial rise in RPM followed by a progressive loss of revs and final stall.
My HS6 carbs have the 0.1" jet and SM needle and Red spring. I closely followed the generally recommended set-up with the jets 2 Turns (12 Flats) down from the bridge level and with 1.5 Turns on the idle screw. The distributor is statically timed at I judge to be between 6 and 4 deg BTDC.
I also followed the instructions regarding setting the fast idle cam screw (and so far this has been the only adjustment that has had any marked effect on the running - more of that later)
According to everything I have read, this set-up ought to get it going sufficient to fine tune everything - the problem is in my case it won’t!
Initially I found that the engine fired instantly on full choke - but to a very high RPM in the order of 3000 RPM! I then did several systematic (and recorded) changes to try to get the choke-out speed down and allow the choke to be pushed in without the rise in revs followed by the decrease to stall.
To cut a very long story short (or just shorter) weakening the mixture (from the starting point of 12 flats) by up to 4 flats and/or similarly winding the idle screw from 1.5 to 1 Turns had virtually no effect.
The only thing that got the revs down (to about 1500) was by taking 1T out of the cam screw. In effect this meant that even with the choke fully “out” and cam at its maximum, the screw was barely touching the cam and consequently having little or no effect on the throttle position. This frankly seems all wrong to me, but it’s what I’ve found so far!
PS
I should mention that the plugs are incredibly sooty.
I can’t really say I expect someone will have an easy explanation and cure for what I have described, but can I just ask…….
Does it make any sense that pushing in the choke will result in a strong rise in revs (which then dies)? I suspect that if I could just get an explanation for that, then I might just start to make some progress fathoming out the rest.
Or more pragmatically, can anyone recommend an SU specialist mechanic in my area, Harpenden/St Albans?
Thanks in anticipation
Norman
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And developing John's idea one more step.............
...........I found
3/8" BSPT M-M
http://www.ebay.co.uk/itm/120726691312
and 3/8" FM hose taper elbow
From same ebay vendor and has the benefit of a proper hose tail.
Norman
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Perfect
The photos make it very clear and as I'm also no plumber either I'll print them off and down to the merchants. Although I do rather like the tap idea - Hmm?
Thanks again everyone.
Norman
TR4 severe vibration
in TR4/4A Forum
Posted
And thanks Tony - just seen your advice (no sooner does one push Post button than another helpful reply lands!)
You have reminded me that I did not (re)fit the tie bar that was certainly there on the original non OD GB extension. I can't remember why i didn't but it might have been because I wasn't sure how (or if) it was fitted to the OD and perhaps i thought the overall bulk of the OD itself negated the need for further support - but maybe it does(?)
I do hope it is not the clutch and flywheel scenario!
When bolting it all together I couldn't force myself to trust using just (stretched) bolts for the flywheel so went for the security, as I saw it, of using the turned-up tab washers. So I'm confident its shouldn't be a loose flywheel,
Trying to rock the diff input and OD output bearings by hand and with the prop attached doesn't seem to show up any play, but again, another reason i guess to get the prop out and replaced, and at the same time check the bearings.
Norman