Spark Plugs

[Clan]

Originally Posted by HDAV

I always thought NGK were top spec plugs in many applications the advise is to run NGK, high boost applications will need modified plugs depending on the levels of boost either different plugs or different gaps which may require upgraded coils. If the car has individual coil packs suggests new ones and get it on a dyno witch ecu monitoring as without it your probably ****ing in the wind trying to fix it

I never had any luck with NKG Plugs misfiring in the 1970's on a small high performance engine ... I used volvo 240 B21E plugs on it and still do today !

[Mkengineering]

Just to put this to rest.

Volvo Plugs are dog shiiite
NGK Iridiums 7s or 8s good plugs

Denso ik24 Plugs - AMAZING!

[Clan]

Originally Posted by Mkengineering

Just to put this to rest.

Volvo Plugs are dog shiiite
NGK Iridiums 7s or 8s good plugs

Denso ik24 Plugs - AMAZING!

In your opinion ... certainly not in my 45 years of experience with volvo plugs in all the models from 140 to the current day :-)

[Cookeh]

Originally Posted by Clan

In your opinion ... certainly not in my 45 years of experience with volvo plugs in all the models from 140 to the current day :-)

The important thing to consider here is that the V70 in the OP is tuned. No real details have been provided on what exactly has been done to the engine but the words "serious power" suggest significant modification.

It is entirely possible that these modifications may have changed the heat range, gap, or actual spark requirements of the engine - which is why it runs well on plugs that aren't direct replacements.

Also, sorry to pop the bubble, but Volvos plugs are made on the same manufacturing line, to the same spec and tolerances, as every other plug made by the OE (currently Bosch). Volvo plugs are not better than Bosch as they are the exact same thing. Bosch plugs are not necessarily better than any equivalent (heat range, electrode, thread length etc) plug from NGK or indeed any other major plug provider.

My car ran on NGK PFR6Bs for over 60k miles, before that it was on Champion RC8PYPs (OE). Its currently on Volvo plugs and runs no differently at all. In 15k when they're due again I'll either go back to the NGKs or I'll go for Bosch FR7DPs. All these plugs are equivalent. Unsurprisingly, the car runs the same on each.

With the Volvo plugs I just put in, they had been mishandled and two were snapped clean in half. It took Volvo 4 days to get two replacement plugs (they would not replace the full set). I had to spend 4 days driving on three Volvo plugs and two of the NGK PFR6Bs. Did it affect how the car ran? Of course not. The plugs are the same spec.

Over the 45 years or so of your experience the OE supplier for Volvo will have changed 4 or 5 times, and will also have been different between different engines. The P80's for example were supplied from factory with Bosch plugs for the N/A engines and Champions for the turbo engines.

[Clan]

Originally Posted by Cookeh

The important thing to consider here is that the V70 in the OP is tuned. No real details have been provided on what exactly has been done to the engine but the words "serious power" suggest significant modification.

It is entirely possible that these modifications may have changed the heat range, gap, or actual spark requirements of the engine - which is why it runs well on plugs that aren't direct replacements.

Also, sorry to pop the bubble, but Volvos plugs are made on the same manufacturing line, to the same spec and tolerances, as every other plug made by the OE (currently Bosch). Volvo plugs are not better than Bosch as they are the exact same thing. Bosch plugs are not necessarily better than any equivalent (heat range, electrode, thread length etc) plug from NGK or indeed any other major plug provider.

My car ran on NGK PFR6Bs for over 60k miles, before that it was on Champion RC8PYPs (OE). Its currently on Volvo plugs and runs no differently at all. In 15k when they're due again I'll either go back to the NGKs or I'll go for Bosch FR7DPs. All these plugs are equivalent. Unsurprisingly, the car runs the same on each.

With the Volvo plugs I just put in, they had been mishandled and two were snapped clean in half. It took Volvo 4 days to get two replacement plugs (they would not replace the full set). I had to spend 4 days driving on three Volvo plugs and two of the NGK PFR6Bs. Did it affect how the car ran? Of course not. The plugs are the same spec.

Over the 45 years or so of your experience the OE supplier for Volvo will have changed 4 or 5 times, and will also have been different between different engines. The P80's for example were supplied from factory with Bosch plugs for the N/A engines and Champions for the turbo engines.

well with a more powerful self tuned engine you have to go by the choice of whoever has done the job before of course . Although I used Volvo B21E plugs in a one litre 175 bhp turbo engine i built and set up .

[DaveNP]

Originally Posted by Cookeh

The important thing to consider here is that the V70 in the OP is tuned. ...

Was just about to point that out myself. My bog standard 2.5NA runs just fine on Volvo doggydoo and they can be cheaper than buying a 'brand' from the likes of ECP. But if the OP has changed the tuning, boost and other parameters of his engine it's a bit unfair to complain that original spec plugs don't do it anymore, there's a reason why there's so many types of plug available, and if you effectively want to redesign your engine you'd best either understand all about spark plugs or be prepared to experiment.

[classicswede]

Nick,

a big part of the problem is when you have more boost you tend to need to close the plug gap. With multi prong plugs you can not really adjust the gap (and they tend to perform poorly anyway) and a Single prong plug is better for high boost. It is the same with LPG and more so with high boost

[ASt85]

IMHO, if the engine spec is changed or running over pressure boosts on a remap then the plug needs to be married to the ambient running temp of the cylinder....had these problems years ago on a supercharged 997 Cooper S, hence the bonnet bulge and louvres (the "Aubergine Sleeper").

If memory serves I ended up using Champion N7YCC variants normally found in the Lotus Cortina - today's equivalent NGK would probably be BP7ES .....also used in lawn mowers.....go figure that one - but had to be changed @2500 mile intervals as the central electrode burned to almost flat rapidly...the days of condensers and rotor arms, five star petrol and a compression ratio of 13.5:1 with a high lift long dwell cam - deep joy, serious torque and a scintered almost concrete clutch!!!!

[Paul240480]

Just thought this maybe of interest. I’ve just finished replacing the plugs on my 99 T5.
I’ve fitted Bosch FR7DPP+ Platinum ones.

You can see the mix match I’ve removed, which I inherited with the car & it ran with those as sweet as a nut for the 2yrs I’ve had it .

[Mkengineering]

The bkr7eix are great plugs