Cooler Plugs For Higher Compression Ratio?

[johnnyboy666 195 1 Cars]

I'm fitting a TU3s head on a saxo VTR block, and as such the compression ratio will be substantially higher.

 

Would it be advisable to run cooler plugs? It seems like it would be a good idea to me, but a lot of these conversions that I've heard/read/talked about seem to stick with standard ones.

 

To be honest, it's a bit of an afterthought, as the engine is just about to go back in the car, but I was just making a quick mental list of things to do before start-up, and the plugs sprang to mind

 

Thanks in advance

[calvinhorse 870]

I always used what ever is recommended for a Saxo vtr, fuel was important, I couldn't run it on anything but super unleaded (on standard xs dizzy coil, cam and pulley)

 

the last one of these engines I made I used a +0.2 repair gasket (multi layer steel) and drilled the jet out which made for a lot less pinky engine

 

My first engine was a standard gasket and I didn't drill the jet, it pinked a lot if you laboured it but went like stink!

[johnnyboy666 195 1 Cars]

Yeah I've got a repair gasket on 1.9mm mls, I make my own jets by turning down the head on weber dgav ones, so have plenty of sizes at my disposal, and will run it on super. And a backup plan if it pinks too much is to move to mappable ignition.

Would the vtr ones not be suited to a lower compression ratio?

[calvinhorse 870]

Just googled it and it shows 6s for a vtr which is what I probably used and 6/7 for an xs

 

Like I say mine worked very well with the vtr spec plugs and similar compression to what yours will be, just run it and see how it goes then have a look at the plugs.

 

I left my first jet standard and drilled the main jet, it overfueled judging by the plugs but I think this also helped with the detention..

[Sandy 191]

BCR8ES if you need to go cooler.

[johnnyboy666 195 1 Cars]

Cool I'll give it a bash and see what happens.

 

Cheers Sandy, they're a good £20 cheaper than the ones I'd found!