New member hello & APD rebuild

[Goldnrust]

Thanks for that info Mike. I wasn't aware that you could trace the location from the Reg plate that way. I bought the car from South Wales, and it came with a keyring from a garage in Malvern, Worcestershire. The keyring had a 4 digit phone number, so must have been from the early 80s at the latest as I understand it. So it's been away from Buckinghamshire for a long time either way! I suspect my army green parts were purchased at a later date then. In many ways my car shows all the signs of being built up from spare parts, though the engine and chassis numbers are right for the age of the car and look original to me.

Thanks Howard. You'll notice a lot of the pictures are taken in the dark, even though it was the middle of summer. That's how I find the time, sneaking down to the shed late at night to tinker. After a day spent working on a computer I'd rather do that than settle down in front of a screen for my evenings.

Thanks John. I'm self taught when it comes to all the engineering stuff. Between Youtube and guides on forums I don't think theres much you can't have a go at yourself, if you're not afraid to get it wrong a few times in the process!

Yes I've timed my car to ~22 degrees advance, based on reading some other threads on here, at max revs and not worried what the idle advance reading is. I've played with it a little by ear once I got it on the road, giving it any more advance seems to result in a lot of rumbling from the bottom end of the engine and les advance is slower, so I think I've go the sweet spot for now.

That said, I've got more timing scatter than I'd like, I can see that a thinner gasket would take up slack between the cam gear and the dynamo, but do anyone know if there's a way to take up wear between the end of the dynamo and the distributor drive gear?

That's good to know there's no problem with using resistor plugs, that was going to be my next move. I like the iridium fine wire type plugs too, I'll see how flush I'm feeling when it comes to buying!

[Tony Griffiths]

Headlamps going out - John is almost certainly right about the interference. My LED Headlamps, with the engine off, have a steady light. With the engine ticking over, they flicker slightly, but then, as the dynamo starts charging, they come on with a steady beam. Might this be electrical interference from the dynamo or the ignition?

[Ivor Hawkins]

Thanks for going to such detail, this is a fascinating thread and you’ve made excellent progress!

[Colin Cooke]

I'm enjoying this thread, especially the problem solving.

Regarding the dampers: I use some plates from Suspension Supplies Limited. The best thing about them, is that their material has so little stiction, and adjusting them is very rewarding. I did find their recommended torque setting a bit high for my cars, but it is easy to adjust to precisely what you want.

And another one for the flickering leds at tickover. I use silicon HT leads. All my earths go individually to a busbar, then directly to the battery. 

All the best,
Colin

[Goldnrust]

Thanks guys ?

There's no flickering or anything with my LEDS, they work great.... right up till they don't! haha. I put a new ground all the way to battery direct, but to no avail. So will have to get some resistor plugs on order and see if that helps.

On the same test drive, I noticed that if I give the engine a bit of a rev when parked in neutral, the engine feel noticeably smoother with the clutch depressed? Are we thinking that means gearbox input bearing isn't great? Or more likely to be engine main bearings?

I didn't replace either the gearbox or engine bearings as they seemed 'ok' to go again. It's not urgent, at this point, but another thing to consider for the winter overhaul.

[David Stepney]

" On the same test drive, I noticed that if I give the engine a bit of a rev when parked in neutral, the engine feel noticeably smoother with the clutch depressed? Are we thinking that means gearbox input bearing isn't great? Or more likely to be engine main bearings? "

My RP does the same. I suspect that depressing the clutch puts an end load on crank and thus the rear main bearing, making it quieter.

[Goldnrust]

It;'s good to know I'm not the only one David!



I've been using the 7 all week for local errands and when it's not been raining. Had a lovely early run out for coffee the other morning. I'm getting more used to it and it's ways I'm thoroughly enjoying open top motoring, I have truly missed it these past couple of years.

I've been playing with the carb and ignition timing a bit more, not making a whole lot of progress though. I've got the Wideband o2 gauge and a rev counter now to help me tune it. It feels like the engine starts to come on song nicely around 2500rpm, but then feel strangled much past 3000 really. I could do with it running to 3500+ to get over the gap between 3rd and 4th better. I'm not complaining, this bit is good fun chasing down the performance!

As the engine feels like it's gasping a bit at higher revs I thought I'd try a run without the cover over the choke assembly, as it visibly seems like it might be a restriction.





I presume the cover is to stop debris from getting into the open carb so easily? I can confirm that removing it made no difference to fuelling or to sense of performance, so it must not be a restriction. Doesn't hurt to try! I see an SU carb in my future...

I played with the ignition timing a bit also. Advancing it further seemed to gain me performance at the expense of crank rumble. While checking the timing I was reminded just how much timing scatter I've got going on. Whilst theres a touch of play between the cam gear and the dynamo drive, but theres a huge amount between the dynamo and distributer. Way more than I'd realised when I put the car together. So I've got a new distributor drive gear coming in the post. Maybe with less scatter I can ride that line between under advanced and over advanced more easily and gain a bit of performance.

I also fitted a set of resistor plugs this week. The plugs I took out were more carboned than I expected given how few miles they've done, but it is a pretty tired old set of rings!



Shown there with 1 on the left and 4 on the right. The thing that stands out is that 2 is much lighter coloured than the others. With a single choke carb and siamese intake ports, I can't see it's a mixture issue? Might just give the engine a bit of a once over now it's had a bit of 'run in' time, check the valve clearances etc.

I can happily report that with resistor plugs fitted my LED headlights stay on. I was able to go for an 40 min run Friday night in the dark with no issues. Well... none apart from it coming on to rain!



So things are looking up for making the drive to Prescott next weekend, but chasing a vibrating/rumbling sound, different to the crank rumble, I have also discovered that I've got movement in the the output bearing of the gearbox, which is disappointing. I checked, but crucially didn't replace, the gearbox bearings and they seemed ok at the time. I presume a few miles of use has shown up some wear I didn't spot.

It wont be the end of the world to change it out, but there's no chance of doing it before the weekend. So will have to see how the car feels as the week progresses and whether I feel confident to take it that far or whether it's just not quite out of the 'teething problems' stage.

[David Stepney]

Standard engines do tend to run out of breath at about 3000 rpm, due mainly to the cam, as well as the porting. My own car will not quite reach 30 mph in third and the engine's getting quite busy at that. However, I have the first (crash) iteration of the four speed box which has a lower third gear ratio than the later 2 synchro boxes. That having been said, the gap between third and top is still pretty large on both boxes. Fortunately, a standard engine will pull happily from 20 mph in top, so I aim to get into top gear at or just above this speed.

[Goldnrust]

Thanks David. That's good to know. Mine is the later 2 synchro box, and it will run up to little over 30mph (my speedo bounces a fair amount!) in 3rd with relative comfort. After that I can feel the power roll off, but if I leave it in 3rd, the revs do still rise more slowly and it will struggle on to 35ish before actually topping out.

My cylinder block is ported and I've the 3/4" radius cam followers and '37 high comp head, but otherwise stock. I wonder if I've knocked a bit of the bottom end away with my mods, I think it would trundle on flat ground at 20mph in top, but would definitely be away from the power. When I shift into top it feels a bit flat till 35ish then picks up and pulls well from there.

I'll see what gains I can make with the ignition timing, but I think I'll be making an exhaust and intake manifold this winter and purchasing an SU to see if I can just get a touch more out of it.

[David Stepney]

The standard cam has virtually no valve overlap. Ideal for low speed torque. Modifying the cam will tend to shift the power band up to higher revs. It is no coincidence that the factory rated the standard engines' power output at 2400 rpm, which is about 35 mph in top gear (assuming standard 5.25:1 rear axle and 3.50 x 19 in tyres).

The racing boys can get the engines to rev to 7K plus! But, as I found out from the special that I had in the seventies, getting the car to do 70 mph in a straight line (well on a straight road at least)required sacrificing some tractability at lower speeds.