Spark plugs

Hi all ... I was wondering if anyone has any advice on the correct spark plug type (heat rating etc.) for my set up. I run on 98 octane pump gas with 9.5:1 compression. The plugs I am using at present are Bosch FR8D+ and they always seem very pale and white even every time I remove them, The car seems to run OK though. When I bought the Edelbrock Performer RPM heads, they came with no mention of which plug types to use.
 
  • Sponsors (?)


They are pretty much always going to be pale or white with the MSD box. ust as long as there is no sign of blistering from detonation. 98 octane with only 9.5 ? you can probably run and plug you want. :rlaugh: Bt if she runs fine, no worries.
 
98 Octane RON, MON or RON+MON/2?

I thought Spain used a different rating for Octane. Seems when we go over to the MXdesNations, or ISDofN, we always have issues with the octane rating, as it is a different standard than ours and is subsequently a lower octane.

Whatever the case, Spain always kicks our butt in the Trials des Nations. Man can those guys ride!!!!!
 
Hi
I just always have put 98 octane gas in the car .. I have a 328i BMW which doesn't seem to have the same performance with 95 octane as 98 so that is what I put in both cars.
I don't know if the octane ratings are comparable with the US but here we can get 95 and 98 in unleaded and 97 in what I believe is lead substitute gas. The prices are very close anyway and most cars here are diesel.
Surely it won't harm the engine using 98 ?? wiill it :(
The plugs I am using are 14mm thread, 3/4in reach .. but it was just the heat range I was wanting to get right. Also the compression ratio has been worked out by myself and it was really confusing with calculating gasket thicknesses etc. It may be higher (or lower) than that anyway. If anyone is good at working out these things ... the heads are performer RPMs with 60cc on a stock 289 block bored 30 over with Keith Black silv-o-lite flat top pistons and Fel Pro permatorque head gaskets.
The gas does smell good as I have discovered this morning as it has been dripping out all night onto the garage floor :rlaugh: the short rubber pipe next to the tank guage has a split in it. Nearly knocke me out when I opened the door.
 
In california we have
87,89,91 octane fuel at the pump
If you look hard you can find a specialty station that has higher octane.
But sometimes its not worth it to drive 30 miles to find the higher octane fuel.
By the time you get back home , you've used 1/4 tank.
With 9.8:1 & alum heads I use 91 octane, its up near $3.00 a gal again, ouch!
 
Spanish Dave said:
Hi
I just always have put 98 octane gas in the car .. I have a 328i BMW which doesn't seem to have the same performance with 95 octane as 98 so that is what I put in both cars.
I don't know if the octane ratings are comparable with the US but here we can get 95 and 98 in unleaded and 97 in what I believe is lead substitute gas. .

Dear SD:

The US uses the PON (pump octane number) measurement while the EU uses the RON (research octane number) measurement. 98 RON is equal to about 93 PON.
In other words, what you are putting in your car is not the same as the 98 octane available in the US. You are pumping the equivalent of US 93 octane.

Hope this clarifies things even if just a bit.

Best regards from just east of Amsterdamistan

jS