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Nick Jones

Nick & Chris's Gt6 Mk 3

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3 hours ago, thebrookster said:

I presume the flaps are to ensure the air flow from the fan is better directed, Nick?

Yep, supposed to ensure that the fan pulls air through the radiator, rather than sideways through the other holes.

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So today I have been playing with the OD.

Detached the propshaft at the gearbox end and got Rogers gauge adapter fitted (thanks again Roger :smile:)
P1190703s.jpg

Works a treat - just had to open up the hole in the bottom of it a little as the spring follower got stuck in it the first time.

Initially the pressure was taking nearly 10 seconds to get to about 250 psi, at which point the OD would start to engage and the pressure would then rise rapidly.  End pressure was very dependent on rpm (propshaft) with it needing 50+ mph to get over 300 psi and just about reaching 400 psi at 80mph (noisy!).  The only book figure I can find for Vitesse/GT6 suggests 530psi!

I had a word with Overdrive Repair Services who gave me a long list of likely causes some harder to deal with than others.  The considered opinion was that pressure does not in itself particularly affect engagement speed unless it's very low, it's the speed that the pressure comes up that matters on the D-type.

He suggested manually pulling the engagement lever and seeing if moving it beyond the official setpoint helps speed or pressure.  I did and it did a bit so I over-adjusted the pull rod a little.  The other one he liked that is potentially fixable in the car is to drop the pump NRV plug, spring and ball out, make sure the ball is good and the seat is clean.  Then tap the ball firmly into the seat to help match the sealing surfaces before reassembling.  I haven't done this yet as though it is possible it'll mean dropping the exhaust for access and messing about with the mounting plate.

What I was able to do was to drop the relief valve out (somewhat messy), examine the shimming situation and add some more to see if that pushes the pressure up.  It had 0.035" in there and from Roger's earlier researches we know that 0.050" adds about 100psi.  I needed to add at least 130 psi......  that's not a shim..... that's a washer!  Just as well too as I didn't have any shims remotely the right size' but I had plenty of washers that could go between the bottom of the spring and the plug.  Some trial and error (and more oil spillage) followed.  Long story short, I ended up adding a whopping 0.090" and that got me to about 530 psi at 80mph and just under 400 psi at 50mph.  probably fair to say that either the pump NRV isn't seating well (potentially fixable in situ), the relief itself is worn (could be looking at the way increasing the shimming brought the low end up as well) or the pump itself is worn.  Might try driving it first though as it did actually work before and didn't need huge improvement to be acceptable.  Ran out of time and weather today.

I do have a couple of (very boring) videos which I can put on youtube if anyone is interested.  Mostly it shows how slow the pressure is to build..... possibly the volume of the test adapter slightly increases that....?

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Hello Nick

                   That is not right you should have the 530psi at 30mph or about 1500rpm on input shaft

Did you change the piston o/rings? 

I changed all o/rings as in the kit

Roger

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Yes, thought you might say that...... was my thought also and why I said I think there is something wrong with it.  After all my fiddling I was getting about 350 psi at 20mph and a fairly linear increase with speed until levelling out at 500 psi at 60-ish where the relief valve can be seen to take over.

I did change all the O-rings (I bought a kit from ORS at Stoneleigh).  The old ones were absolutely shot.  I also had the thing completely to bits as it was heavily contaminated with swarf from the gearbox.  It was then run on ATF (fairly briefly as my drill didn't like it!), and the ATF drained and filtered before being put back in for another run.  Got a  few "fines" the first time but very little the second so I was reasonably confident I got most of the rubbish out.

If it ever stops pissing down (!) I'll drive it and see if it's improved.  It worked before (perhaps surprisingly!), so if it now pops in a bit more promptly I'll probably just leave it. If not I'll drop the exhaust and have a fiddle with the pump NRV.  Anything else and the box has to come out again...... which I prefer to avoid!

If I do sort the "supply problem" I'll probably have to take most of the shims out again or risk 4 figure pressures!  Perhaps I should drag out my spare W58.......

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On another matter...... question for GT6 Mk3 owners

Where do the two breather pipes go through the boot floor.  That is:

There is one actual breather tube (5/16" nylon) that comes from the tank side of the filler neck that needs to go through to the outside world and also the smaller 1/4" nylon tube that goes from the water/fuel splashback drain hole under the filler flap.

US / Australian cars seem to have more breathers and gubbins so may differ.

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Ok.... well may not be how the factory did it, but it's how I've done it!

P1190705s.jpg

Red one is the tank vent (8mm) and yellow is the filler bowl drain (6mm)

P1190711s.jpg

And the other end.....

Also fitted a pair of Koni adjustables on the front (from Bastuck, who are still cheaper than any UK supplier even with shipping and badly wounded £) plus what appear to be TT 330 lb front springs.

They have displaced a pair of Spax adjustables which, though not new, appear to have done very little work - adjuster screws still perfectly free, most paint present, bushes good etc.  If anyone would like them, make me an offer.....

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So, last Sunday, Ian (AKA GT64fun) brought his gorgeous Mk2 to see me, to set a probably unattainable quality-of-finish benchmark... He also raised a point of curiosity, which is that whereas his (mK2) Delco distributor has vernier timing adjustment, my  Delco distributor (assumed original mk3 on the dubious basis that is came with the car) does not.  He has since also pointed out that Canleys drawings at least suggest that the Mk3 should also have vernier adjustment.  He's also found a Mk2 Spit distributor with Vernier adjustment whereas the two Spit ones we have here (presumed MkIV 1300) do not.

Not a big deal - I have a Vitesse Mk2 Lucas unit with Vernier that I can fit if I can be bothered, just curious to know what is "correct"

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Nick

Using Canley's website as the reference again, the Mk1&2 and the Mk3 Spitfire catalogues show the vernier vac unit, whereas the Mk4  does not have it (it looks like yours).

Your distributor body and shaft must be of GT6 heritage (as it got 6 lobes derr!), but it looks as though a Mk4 vac unit has been fitted, assuming that is even possible. Not sure how the Mk4 Spit and GT6 vac spec differ, but might be worth investigating.

Happy to post down the vac unit on my spare dis for you to try if you can be bothered.

Ian

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Boot-boards time - how hard can it be.....  Well, hard enough and very time consuming when you don't have any as patterns and have never even seen the proper things.  I did see some Mk2 ones (thanks Ian) but they are fairly different.

The car came with some 18mm thick ply "boards" that could politely be variously described as "rough and ready" and "fit where they touch".  They also had massive speaker holes.  I ignored them and bought a couple of sheets of 9mm ply.

After much measuring and alot more trial and error we arrived with at these ridiculously complicated things
P1190718s.jpg

This corner was especially obnoxious....
P1190716s.jpg

.......but came out ok in the end

P1190717s.jpg

One thing I had learnt from Ian's car is that there are meant to be shaped pegs in the section over the spare wheel that snap into spring clips in the forward support rail.  Didn't have any of these.  The spring clips were still there though - just needed the odd new rivet to stop them escaping.  I spent a bit of time on the internet finally finding what could be the correct things on the Bresco website listed for E-type Jag and priced accordingly.  At this point I remembered I have a lathe......

P1190714s.jpg
...and making a couple of these made a nice change from persecuting plywood.

Getting them in the right place took some careful measuring but turned out well
P1190719s.jpg

They still need paint, some sound insulation and possibly a bit of re-enforcement in the case of the larger one ........

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Hey Nick, I may be overthinking this- your fuel vapor vent ends just above the exhaust? Admittedly you'd have to have parked the car at a funny angle- but if you were to manage to roll it wouldn't you be directing fuel to a hot bit?

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I wouldn't rely on it, but from memory petrol on an exhaust manifold will boil off and not ignite, brake fluid on an exhaust manifold will cause a fire. This used to be a significant cause of car fires following crashes with early designs of plastic reservoir master cylinders- the crash would cause the reservoir to break off and deposit its contents on the manifold, the resulting fire could boil the carb float chambers, vapour would blow out of the air filter and things spiral out of control. The tail pipe is not going to be anything like as hot as the manifold, so nicks routing should be safe.  My memory of course is not safe!

 

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11 hours ago, mossmonaco said:

from memory petrol on an exhaust manifold will boil off and not ignite, brake fluid on an exhaust manifold will cause a fire

This is true.  Petrol just hisses nastily.  DoT 4 goes straight up.....whoosh! Scary!  Lucky it was only a small spill and went out of it's own accord :ohmy:

On ‎10‎/‎27‎/‎2019 at 7:52 AM, rustbuckit2011 said:

your fuel vapor vent ends just above the exhaust

The only orientation that puts the vent above (or sort of above, the camera lies) is with the car the right way up and as the vent pipe goes some way up the C pillar before it comes down there shouldn't be any liquid going that way...…  I'll probably just cut it shorter and point it straight down anyway - I just had that tail left and tucked it up, out of the way.  The filler pocket drain on the other hand does see regualt action as the filler neck seems to be specially designed to defeat the anti-spill feature in pump nozzles and barf fuel back at you :verymad:.  Bloody PI was the same, though I did develop a technique for dealing with that.

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Here it is at the Wheatsheaf Inn in Lower Woodford, 52 miles from home.  It made it back again as well - which was useful.

Topped up with oil before we left and it used very little.  Didn't blow anything out of the breather either (still open to atmosphere). Plugs look ok.  Electrodes and insulators clean and showing lean running if anything apart from #5 which has some well cooked deposits.

Still makes a very nasty noise at neutral throttle when hot which seemed to get worse and graduate to part throttle as well, but it then shut up for the last, slower part of the journey.  Might try my Lucas distributor instead (mainly because I have no better ideas!)

Overdrive has new trick now - sticks in after running at speed for 10+ miles but pops out normally if going slower or for shorter distances.  Once stuck in, it needs the application of some right foot in a lower gear to break it loose - it's mechanical not hydraulic.  Doesn't like the increase in operating pressure I'd say......  Comes in quicker than it did, but still rather slow.

Goes well and drives nicely.  Rather noisy as there is (of course!!) a propshaft vibration at speed, worst at 70mph (obviously!), and also some nasty exhaust resonance which seems to involve the boot floor, especially at 2000 rpm.  Pity as engine noise and wind noise seem minimal - by comparison anyway.  It gets to 70 very easily......

A pic as evidence.  Ben (great to finally meet you Ben, sorry to miss Vicky) and Mark get the heroes awards for turning up with the hoods down - it really wasn't that warm!

IMG_4159s.jpg

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Some impressive plywood origami Nick. A nice off cut of Axminster or Wilton would set it off nicely :blush:. Good to meet you too. Managed to get home without indicators (and only sidelights as the headlamps refused to work as well! My kneecap is not up to grovelling about under the dash so I'll send Vicky in to discover the loose connection(s):cool:.

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I’ve tidied up my Vitesse Lucas dizzy. It’s not as knackered as most and cleaned up ok. I have my doubts the springs are original though as both are the same. Will buy some new ones from DD and get a red rotor arm. I know the crappy black ones with rivets fail for fun.....

Meanwhile I’ve fitted it. This was harder than it should have been as the clamp it came with seems to be a Delco one and clamps the shaft rather than the larger flange intended for the clamp.

I didn’t have a Lucas one to hand so the Delco version lost a bit of weight. But now I can only get one bolt in as the second fouls on the tacho drive.  The other weirdness was that I had move the drive gear one tooth in order to get the tacho drive to sit where the cable could see it.... which is odd because the Delco was fine.

Anyway..... it still runs. Can’t repeat the noise in the garage, but though I have managed to in the past I don’t consider it definitive. Next drive will tell....

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So I drove it today, as the sun was out and the roads dry-ish.

Initially, no difference.  Bugger...... :mad: though not entirely unexpected.  Then I disconnected the vacuum advance.  Noise gone.  Hmm.... sure I tried that before with the Delco with little effect.

Anyway, I know that the vacuum advance on the Vitesse distributor is pretty aggressive and tips alot of advance in quickly as I've fought with them before in pre-EFI days to try and cure pinking when leaded petrol was phased out.  I also have a PI one kicking about, which only adds about half as much advance and needs more vacuum to do it.  So I swapped that in and went for another drive.  Noise is back, but less.  Backed the timing off a bit more on the vernier (now at 8º BTDC).  Still there.  Disconnect the vacuum advance - gone.  Also the engine seems sweeter and keener to rev.

So it is combustion knock.  Not sure quite why it is so pronounced on this engine.  I did check the timing marks when I built the engine and they are correct within a degree or so.

The Lucas dizzy is a bit suspect as both advance springs appear to be the same and both are quite light, so the mechanical advance may be coming in early.  I've had a word with the Distributor Doctor and ordered a pair of springs (which he confirms should be different) along with a red rotor arm.  This doesn't explain why the Delco gave the same issue - though I guess it could be similarly knackered.  It's also possible that the head has had a skim at some point (history unknown)  I did mean to measure it...... but never did.  Certainly the old girl likes to run-on after the ignition is switched off - just like the Vitesse did pre-efi.....  I haven't missed it.

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Either both dizzys are knackered or you have more CR than you think.

I have a H&H rebuilt Delco going spare if your interested, just looking at getting my money back on that one.

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Ok, thanks - I’ll see what effect the new springs have first.  The Lucas is in pretty fair shape mostly.  Missing the ability to drag out the laptop and just dial down the affected area.......

Also just noticed the wee monster has been piddling engine oil on the floor. It’s being quite subtle about it though - can’t see where it’s escaping from. Bah....

 

 

 

 

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Source of oil on the floor found I think....... bit scary, but caught in time.  Bolt holding the spin-on oil filter adapter to the block was loose.  Like 1.5 turns to tighten loose (UNC thread!) and the oil filter resting on the suspension turret under gravity.  Unclear why it hadn't just pumped all the oil out of the engine - but I'm grateful!

Water pump dripping a little too - but it was suspect before as I took it off the Vitesse when I fitted the new engine because there was rusting staining around the tell-tale hole.  I have another.

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So new springs arrived this morning. Entirely different from what was in there
New are vertical on the left

C7C8D225-10D8-4081-AB35-5C5ACB550851.jpeg

Not completely convinced as the stronger and longer spring doesn’t seem to get involved until near maximum advance, if at all.

Anyway had a 20 mile outing to one of the Bath &West car shows. Initially the problem seemed completely resolved and it was running really nicely. However, towards the end the noise was back, albeit only just. On the return journey however it seemed like most gains had been lost. I didn’t try disconnecting the vac advance, though I should have....  Bah!

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On 2/7/2020 at 9:06 PM, Nick Jones said:

Bolt holding the spin-on oil filter adapter to the block was loose.  Like 1.5 turns to tighten loose (UNC thread!) and the oil filter resting on the suspension turret under gravity.  Unclear why it hadn't just pumped all the oil out of the engine - but I'm grateful!

The filter adapter on mine (which also goes through the take-off for the cooler) now has a half nut on it to lock it up nicely... mine fell off at about 5K rpm (road speed about 50mph) and emptied the sump pretty much instantly. I think you had a lucky escape!

 

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1 hour ago, yorkshire_spam said:

I think you had a lucky escape!

No argument there!  My main curiosity is to whether it was loose because a certain red monkey forgot to do it up (with the current large filter on there it only just barely fits and some adjustment was needed when fitting the engine) or because it worked loose.  If the latter then it may do it again.  No lock-nut possible in this case.

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Did about 90 miles in it around Dorset on Friday, mainly to talk to a man about EV conversions.  I had the vac advance disconnected and it drove very nicely.  No nasty noises and revving smoothly, though I wasn't ragging it.  OD still slow and sticks in if you do more than about 10 miles at 65mph+.  You can apparently go as far as you like without sticking-in  if you stay under 60 and short bursts at 70 ish also don't cause it.

Found some really nice roads south of Shaftesbury heading for Blandford then on to Dorchester and home.  Weather was reasonable and roads dry apart from the last few miles home.  Enjoyed driving it.  However, "The Noise" was manifesting, albeit higher up the rev range and when under more load during the last part of the run.  More of a "going flat and harsh" feeling when previously it had been revving through that point quite happily.  Confused is I.... 

Used about 2mm of oil on the dipstick.  Nothing blown out of the open breather.

Washed it when I got home as it was very grubby.  Not used to having a car that actually looks better when washed!

Edit: Also meant to observe that although "The Noise" appears timing related, it never pinks/pings as such.

Second proper fill-up also meant a first mpg figure was possible.  30.2 mpg achieved - that's with a couple of running until warm sessions in the garage too so more to come.  Plus question mark on odo accuracy due to 3.63 diff.....  Maybe I should richen it up a touch.....

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For various reasons (I really dislike doing interior stuff is the main reason) I have been mostly ignoring this.  However, with the Vitesse back on the road and running well, plus Chris having more time, we been chipping away at the jobs list.

The rad cowl was fettled a bit to allow the bonnet to be finally adjusted and I'm pretty happy with the fit now.  I've even managed to get the LH headlight cowl to more or less fit, though I had to file to holes to get there.  Not sure why.  It fitted before paint.  Still need number plate mounts......

Inside I've been tidying up the boot boards and adding sound insulation.  I've also been finishing off the side trim panels Chris started last year, fitting new seatbelts (Securon 500/5) and fighting the carpet. 

P1200034s.jpg

I loathe doing carpet, but I'll put up with quite alot to avoid paying best part of £ 500 for moulded carpets that nearly fit (unlike the cheaper ones that don't even nearly fit).  Finally managed to get in the swing of it and some progress has been made.  Looks ok.....

P1200061s.jpg

Even put the refurbed drivers seat in.....

P1200065s.jpg

It's got more stuffing in it than the original but I still more or less fit.  Probably would fit with a haircut - got alot of fur at present.....

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