J60 spark plugs

[Grasshopper]

Anybody know what the plug gaps should be on a CVRT J60 engine? :?

[fv1609]

If you are using RSN13P, I don't think you can adjust the side electrode. I tried that once & it pinged off!

[sirhc]

Don't use RSN13P! They were having problems with them causing burnt pistons in service, they also foul up quickly. The issue plug was changed to the RSN12Y Land Rover plug. I have the gaps at home in the J60 EMER, I can check it later.

 

Chris

[fv1609]

Don't use RSN13P! They were having problems with them causing burnt pistons in service, Chris

 

 

Like the B60, the J60 could use Sparking Plug No.1 Mk 1 and Mk 1/1, which could be mixed. However there were reports of extensive engine damage occurring with the Plug No.1 Mk 1/1 i.e. the Champion RSN 13P. It is not clear what the actual problem was but given the difficulty of regapping them, it may have been the earth electrode weld failing. There was also an issue of piston crown burn, which may have been plug related. All these plugs were to be withdrawn and as an emergency replacement RSN 12Y plugs were fitted. The RSN 12Y was the plug fitted to FFR Land Rovers and were at least in plentiful supply.

 

Champion RSN 12Y

 

Although intended as a stop-gap some enthusiasts use RSN 12Y plugs in their ‘B’ Series engines on the basis that they foul up less readily than RSN 13P and although not cheap they are more readily available than RSN 13P. Note that the problems of engine damage from the RSN 13P were an issue for the J60 it did not apply to ‘B’ Series engines. Some users of B60 and J60 engines have dispensed with the screened wiring altogether and used commercial 14mm ¾ in reach plugs. They are readily available, cheaper and less prone to foul up. There can be improved reliability once the screened cables have been removed, the capacitance effect of the cable has gone, which will give should be a bigger spark.

 

It was found that a newer version of RSN 13P, FV817225, which I take to be Sparking Plug No.1 Mk 2, was quite safe to use with the J60 engine. The newer plug is identified by diamond pattern knurling on the upper part of the body, whereas the older plug had longitudinal serrations. The earlier plug was marked “Made in England” and had a Government Property pheon (arrow).

 

At the top is the late pattern RSN 13P, beneath is the troublesome early version

Edited September 15, 2009 by Marmite!!

[Grasshopper]

Don't use RSN13P! They were having problems with them causing burnt pistons in service, they also foul up quickly. The issue plug was changed to the RSN12Y Land Rover plug. I have the gaps at home in the J60 EMER, I can check it later.

 

 

We have RSN12Y plugs fitted to our engine, but the gaps are all different.

[sirhc]

0.45mm (0.018 inches)

 

If it runs like crap when you get it going, change the plugs for new ones. I've had a couple of engines which ran really rough, and struggled to spark, using old plugs which looked perfectly fine. Fitting new plugs cured the problem, my Spartan will now idle at 500rpm and starts on the button.

 

Chris

[Grasshopper]

Thanks Chris. I guessed nearlly right when i set them at 14 thou.

[Richard Notton]

Like the B60, the J60 could use Sparking Plug No.1 Mk 1 and Mk 1/1, which could be mixed. However there were reports of extensive engine damage occurring with the Plug No.1 Mk 1/1 i.e. the Champion RSN 13P.

Clive is quite right. I was involved with a CVR(T) that ran badly, well, you could calibrate the rev counter by the misfires starting at 2650rpm, so much so we were convinced that it wasn't an ignition problem.

 

The plugs were the correct later type of RSN13P with knurled tops. Over 6 months everything was either substituted or changed, fuel supplied from a gravity source, and the ignition module returned to Luminition for factory test. It would still misfire dreadfully at 2650 even in neutral.

 

Finally we changed the plugs for a boxed set of unused RSN13P which cured it for 100yrs of driving and then the whole scenario returned.

 

At this point the platinums came out for good and RSN12Ys substituted and its been perfect ever since.

 

The CVR(T)/(W) EMERs give the gaps at 25thou for 13Ps because of the extra spark voltage of the Luminition electronics, the 12Ys could likely stand a lot more, indeed the Jolley Eng kit, which is almost identical, suggests 40thou on "normal" plugs.

 

I can add that historically myself, other non-mil vehicle friends and some interesting posts on other vehicle lists suggest that platinum plugs fall a long way short of the accepted hype and except in engines specifically designed for them then trouble will occur. Poor or non-starting has been personally witnessed in car, motor cycle and B Range engines, the latter in B81 guise being so prone to idle air bleed icing that it will foul a 13P to non-firing very easily; mine has been on 12Ys for years with excellent results.

 

You can readily convert the CVR(T)/(W) to normal leads; the screw-in plastic cable sealing bushes readily available in anappropriate sizes can be fitted into the flanges of some old ignition harnesses by drilling out the cable feed-outs and so giving a still sealed distributor but with normal leads. Ordinary caps and plugs can then be used at a huge saving. The Jaguar engine would have used a N9Y or equivalent in domestic service.

[Grasshopper]

Thanks for sharing that Richard. We have alo experianced CVRT engine troubles which have entailed changing just about every component on the engine, and also gravity feeding fuel. The first problem was that our Spartan would just die when hot. It aways ran ok when we took the engine covers off to investigate the fault, and after many unit changes, it turned out to be the distributor.

The next problem we had was an engine that would only run on full choke. We changed the carb at least twice, including one from another engine that was a known runner, and still had the same problem. After much head scratching, a fourth carb seemed to cure it. To this day we still don't know why a known good carb would not run with that engine. :dunno:

 

Looking forward to your show. :-) (I think we met you at Firepower? We were sitting on chairs in front of the Ward LaFrance).

 

[Richard Notton]

Thanks for sharing that Richard. We have alo experianced CVRT engine troubles which have entailed changing just about every component on the engine, and also gravity feeding fuel. The first problem was that our Spartan would just die when hot. It aways ran ok when we took the engine covers off to investigate the fault, and after many unit changes, it turned out to be the distributor.

You're most welcome; the distr problem could have been a tracking cap or the Luminition module failing. I've had an identical scenario in the Stalwart which proved to be cap and rotor arm.

The next problem we had was an engine that would only run on full choke. We changed the carb at least twice, including one from another engine that was a known runner, and still had the same problem. After much head scratching, a fourth carb seemed to cure it. To this day we still don't know why a known good carb would not run with that engine. :dunno:

Goodness knows. Bear in mind the 48NNIP Solex has slightly different jets in the CVRT & W application, the mains are 165 whereas the more common Stalwart configured ones are 170 main jets. We have never been down this alley, the five spares I have all performed the same.

 

The 170 mains are actually better for our American cousins in CVR's since the alcohol laced Yank petrol needs a tad richer mixture is the engine isn't to hang back a bit and become fluffy at the torque peak.

Looking forward to your show. :-) (I think we met you at Firepower? We were sitting on chairs in front of the Ward LaFrance).

Probably not Firepower, however, I look forward to meeting you and any other HMVF members at the show. Hopefully, if the clerk of the weather doesn't make up for this long period of decidedly summery weather with another wet month end, and my plans of some job delegation comes to fruition, then for once we may be able to socialise a bit.

 

Looking forward to it.

 

 

[AlienFTM]

FWIW. CVR(T)s are renowned Ignition Monsters. We had four huge batteries, two for turret services (mainly radio) and two for engine services (starting). Because Recce is all about relaying information, in the field (forest might be a better word) radios were never off and the drain on the batteries took its toll.

 

Sultan ACVs carried a 500W generator to keep the radio batteries charged up but even so, it was SOP to run the engines at a fast idle (1000 revs) during the radio dead stag 0200-0400 so that there'd be power in the batteries at first light for stand-to. As a result, even Control Signallers had to be qualified drivers (not an issue because we couldn't take the B1 Control Signaller Course unless we were already B2 Crewmen, which required both B3 Driver and B3 Gunner - each of which required the Basic Operator's Course which you may be surprised to hear wasn't a B4 trade because B4 was as low as it gets: completely untrained you were paid B4 rate of pay. So you had to be an operator to be a crewman and you needed to a crewman to be a Class 1 operator. Roger so far over?)

 

The dead stag was a dreadful two hours of your life. We couldn't move during the day because of the perceived Soviet air monopoly over the battlefield. By the early 80s Soviet night vision equipment was getting so good that waiting until dark wasn't such a big advantage, but we had to take what we could. So we never moved before dark o'clock. We could pack everything up and then decam at last light (but again, when Soviet NVE improved we couldn't decam until five minutes before we moved). They had to replace all our cam nets with new, IRR nets to try and defeat Soviet NVE. Then we'd move, the only time we ever moved if possible, but it was dark so the lighting would be taking its toll on the batteries. When we got into a new location, driver and gunner or driver and commander would cam up while the third crewman encoded and sent the troop / section / vehicle Location State (LocStat) back up the chain of command. We'd have to Last Parade the vehicle, clean weapons, etc and then eat. In an ACV you'd have the added joy of erecting the penthouse, table, chairs, mapboard, etc. If you got first stag, you then did two hours on stag (radio for commanders and operators; prowler guard for drivers). Then you got some sleep, if you were lucky, through until First Light and Stand-To. Likewise on last stag you could get your head down through until maybe 0400, two hours on stag, then you could prepare breakfast for your crew and get on with the day. But the dead stag meant, if you were lucky, you got two times something less than two hours' sleep with a stag in the middle.

 

It was no good trying to get ahead on your sleep prior to an exercise, either, because they always started with an Active Edge, whereby the Commanding Officer crashed the Regiment out at some time before 0200 on a Monday morning (BAOR spent decades on permanent four hours, notice to move - less the nearer you were to the Inner German Border. The Recce Regiment at Wolfenbuettel near Braunschweig had a predicted wartime life span in the event of hostilies of 20 minutes from 3 Shock Army crossing the IGB. They were there purely as a tripwire.

 

So even if we loaded onto trains, we'd be out of camp and either at the railhead or into the country depending where the exercise took place, clear of the morning rush hour by 0600 so that German civvies wouldn't plough their Mercs into the backs of armoured vehicles and discover too late their cars weren't the hardest vehicles on the road.

 

So, it's 3 o'clock in the morning and you're on radio stag with matchsticks keeping the eyelids apart. If you're really lucky you'll have an officer with you to take executive decisions, and his snoring may or may not help keep you awake. Likewise there may be a second operator on the BID radio (it's okay: it was SECRET in my day but if you Google for BID radio you'll find that the information is already in the public domain. I once didn't mention BID in an e-mail to a radio collector: he had a BID 150 based on a C42 in his collection), but the BID was entirely physically separate from the rest of the vehicle harness. Being scrambled, you could talk in clear, but if it was in the harness, there might be pass-through of signal from BID onto the insecure net. Also, the BID scrambler beeped 72 times per minute in the operator's earpiece to remind him he was secure. The beeps were nicely in time with the heartbeat and guaranteed to put him asleep. The scrambler also took so much out of the C42 system that it became too noisy to use the squelch circuit and the white noise also helped you sleep. The BID operator's snoring might also or not help keep you awake.

 

There was the CO's copy of Armour, Volume 2, The Armoured Reconaissance Regiment to read but it was very dry. The operator who had gone off stag at midnight will have changed at least one set of code boards prior to changing the frequencies, but it was busy busy busy, so it made good practice upon taking over on stag to verify that all the code boards had been correctly filled in. The only thing worse than sending a message that wouldn't decode because there was a code transcription error by the operator before you was sending a message that wouldn't decode because he hadn't changed the codes at all and you'd sent it on yesterday's codes. And you could read the radio log for each net to see what had happened since you'd last been on stag. (Even when not on ops, I always read the log book from last time I had been on that particular duty to keep on top of the gossip: Guard Commander's Occurrences Book, Squadron Orderly Sergeant's Occurrences Book, etc.) But again, SOS Occurrences Book aside which wasn't a formal document, it was very dry reading. At least the radio logs allowed you to see where other units and sub-units had moved to, so you could check the map board was up to date.

 

But by mid-stag, you'd be going up the wall in your efforts to stay sane, interested and awake. I could tell you some stories about Tired, but this post has gone on enough. So the opportunity to climb through from the commander's seat to the driver's seat, start the engine and set the hand-throttle to 1000 revs was a Godsend. It also helped warm up the vehicle: even in mid-summer, by the wee small hours it was COLD.

 

Another useful trick for breaking up the monotony of the stag:

 

"Hello all stations this is Zero. I shall be off this means for two minutes. Two assume command. Out."

 

Everybody knew what this meant: the Battlegroup Command Net operator was off into the woods for a wazz. Note he didn't ask for an acknowledgement of the signal from the senior squadron (B Squadron, callsign 2: "A" being Divisonal Close Recce Squadron - in our regiment - didn't come with a Field HQ and didn't appear on our battlegroup's OrBat). He didn't want to disturb the beauty sleep of his fellow operator in B Squadron's FHQ by demanding a response, everybody knew where he'd gone and nothing was going to happen in the next two minutes. It was procedure, done by the book. Nothing else. You were expected to be on-air 24/7, but two minutes wouldn't be enough time to switch off the radios, fit the earthing spike to the vehicle and refuel it from Jerry cans, so it was tolerated. At least nobody would call you in those two minutes. If you didn't pass on control and the Colonel was out at an Orders Group or the RSM was out on a recce, you can guarantee the second you leave the vehicle, he'll be on the air to tell you his "ETA at your location 0307 hours" and, getting no reply, accuse you of sleeping on stag. Of course, if the prowler guard is sufficiently radio savvy, you could swap roles for the two minutes, but then you have compromised the security of your location. Hard call.

 

So to sum up ("Hurrah!!! Ed). CVR(T)s spent an unhealthy amount of time running at (a fast) tickover with no load on the engine. As a result, we went through plugs and points at an inordinate rate (as no doubt our local ex-REEMs will happily remind us). That's all I wanted to say really. Got there in the end.