Which Spark Plug?

[Peter Mueller]

What are the opinions out there on which spark plug is the best for the V8? I am not necessarily looking for the cheapest!

Thanks

Peter

[Phil Nottingham]

See earlier Threads - I bekieve in either Bosch or NGK's definitley not Champions!!

[Phil Nottingham]

Ps Does this mean you have sorted your gearbox problem?

[dorsetflyer]

I've used NGK plugs now for over thirty years in all my cars. so far touch wood, with no failure either.
I'd certainly recommend them to anyone.

[Deleted]

I have used NGK in all my cars, the only car that didn't like them was a Alfa Bertone, that needed the original golden lodge plugs.

NGK...except no substitute

Ian

[lagain]

The best ones I have ever used are Unipart GSP 531
Readilly available from Roverpart who advertise in the mag.

[Peter Mueller]

Dear All

Thank you for your kind support. I think I have made my choice.

==> Phil, you seem to have an astonishing memory , remembering my gearbox problems. I have not solved them completely but am in the process of doing so. After a year of deliberation (mainly regarding the funding of the project but also the alternatives) the gearbox has now been removed from the car and will be overhauled by a local company. Thanks to Dave Cole, the driving force behind our small local group, I was persuaded to finally take the plunge. So the Bank Holiday Monday was spent on, in, and under the car using the engine+gearbox-out method. Worked a treat not the least thanks to 'a little help from some friends' - in this case Dave and his partner's dad John.

It will be interesting to see what really caused all the spewing and frothing and I promise to send an up-date here in the Forum as soon as I know (probably in three to four weeks time).

Peter

[Phil Nottingham]

I look forward to hearing what the problem was.

My memory only extends to to classic Rovers and fortunately my employment. Its sadly lacking in virtually everthing else!

[Smallfry]

Yep NGK every time for me too.

I have managed to get in touch with the second owner or my Rover P5B, who had it from just over a year old until he sold it some twelve years later. Interestingly, he told me that the only real problem he had with it, was that it would throw out the gearbox fluid by frothing. This would happen when the car was in traffic, or when towing a caravan.

To me, this points to transmission overheating, and as the BW 35 was not designed with an engine this size in mind, it is hardly suprising.

[Phil Nottingham]

All sorts of suggestions have been made but it could well be the fluid overheating - if there is no indication of slipping bands then it can only be the torque converterwhich has partially seized. This should always be replaced if a recon box is fitted anyway

[Peter Mueller]

It is interesting what Smallfry says about the frothing. Up to now the only other example I have been able to find was that of a mid-70s Mercedes 350 SE that did exactly that when towing.

Regardless of what the outcome of the gearbox surgery will be (it went this morning so let's all kneel down and pray for the poor little thing ;D) I have heard so many good things about adding a separate gearbox cooler that I will install one anyway. That should at least deal with any possible overheating, although I had never had any problems in traffic before, even on hot days, and I don't tow (which, of course, doesn't exclude overheating as a reason). So far the Kenlow kit seems to be the best alround option.

Peter

[Deleted]

NGK SPARK PLUGS FOR ME EVERY TIME.

WE USE THEM AT WORK AND SWEAR BY THEM, FIT THEM IN ALL THE ASTONS FROM STANDARD CARS TO FULL BLOWN RACERS WITH SUPERCHARGERS.

ADRIAN

[harvey]

As a thought on the throwing out of the trans fluid, there was a service modification to the early (solid) dipstick tube to overcome this, which involved moving the breather pipe up the tube.If you still have the solid tube, I would advise replacing it with the later flexible tube and dipstick.Frothing of the fluid can be caused by a fault to the fluid pick up pipe to the pump (or its seal) causing air to be drawn up with the fluid, rather than just pure fluid. If the box has gone in for an overhaul, all the gaskets and seals should be replaced as a matter of course, but its always nice to actually find the cause of the problem.
A seperate trans cooler avoids any chance of coolant getting in the gearbox, so is a good idea for that reason alone, but I would suggest a thermostatically operated one, as the standard one was put in the rad so the transmission got up to temperature quicker on short journeys by being heated by the coolant.

[Peter Mueller]

Harvey

Thanks for the additional thoughts. The possible cause of the gearbox problem that has so far got the most votes from specialists is that it is a matter of pressure building up inside the gearbox and that has apparently to do with the "Gov'nor" (why they use 70s coppers in gearboxes I will never know ). I really can't wait to hear the final verdict. The guys it goes to (A1 Gearboxes in St. Neots, near Cambridge) have been recommended to me by several people so I assume they know what they are doing and will replace all the seals and gaskets. Apart from that they also replace the torque converter as a matter of routine.

As to the thermostatically operated oil cooler, I absolutely agree. I think the Kenlow kit has a thermostat but will check.

Peter

[harvey]

Hi Peter, recommendation is the only way to go really, taking pot luck is just that. The recommendation should always be to fit a recon T/C when overhauling a box, but not everybody wants to spend the extra money. But if you don't i'm sure it will compromise your guarantee.
If there's a fault in the box an overhaul should find it, as everything should be checked and replaced as required, regardless of whether it's to do with the fault you took it in with.
P.S. if your other car is a Peterbilt, post a picture of it please!

[Peter Mueller]

Harvey

Thanks again for your comments. By the way, I have checked and the Kenlow kit for the BW35 does NOT have a thermostat. However, Think Auto (http://www.thinkauto.com/) supply a separate one that can go in-line.

As to the Peterbilt, I am afraid that is still wishful thinking on my part. But I freely admit to having an extremely weak spot for American trucks and Peterbilt in particular. Some time ago in Quebec I had the privilege of sitting in a 379X so I could pretend for 10 minutes to be a King of the Road. Yep, I know it's sad but I am working on it (getting the real thing, that is). There are quite a few nice examples in the country now, though, and the best place to see them is the Truckfest in May in Peterborough.

!!! But let's just briefly come back to those NGK spark plugs please. Does anyone have a part number per chance I had a look at the NGK website and what I could find was BP5HS. I have contacted NGK to check with them whether that would be the right choice but they have not come back to me so far.

Peter (unfortunately, without the -bilt )

[Phil Nottingham]

That is the correct plug - also I really do not think you will need and oil - cooler unless you propose towing a heavy trailer regularly or doing thousands of miles per annum. I have towed heavy weights without any problems so I should save your money for a decent radiator

[harvey]

Regardless of how good a radiator you have, while it has a transmission cooler in it there is a risk of getting coolant in the gearbox, (not a good idea) or filling the cooling system with ATF. I know they all came like that as standard but they did give problems on a regular basis (and still do) and as the 35 box is working pretty much on the limit with the V8 I personally would recommend a seperate cooler with a stat, but it is a matter of choice.From a reconditioners point of view,(although I no longer am one, I know some who are,and while there are coolers in radiators, there will always be a steady stream of problems to sort out.) and that goes for all cars with a smilar system, not just Rovers

[dorsetflyer]

I think there must be an error in the spark plug number.
My records show it should be 'BP6HS' not BP5HS.
These are the plugs I have fitted over the last three years.

For interest, the P5 3 litre uses 'BP6ES'.

[Phil Nottingham]

No error - that's the one I use when I can get them - the BP6HS is a colder plug for more highly tuned engine so would be more prone to fouling in a normal or worn engine but would work quite well as this was equivalent to Champ L87YC whereas the 5's are equivalent for the later specified L92YC

[Smallfry]

I would go for the BP5HS too, in addition, NGK plugs are generally a lot more tolerant in their heat range than Champion. You dont want to be paying more than a tenner for a set either !