8 port plugs

[MrNoo]

What plugs are people using? I am on CR8E's and it's back from the rolling road running really nicely but it will fuel the plugs up if you just fire it up and move it around the yard etc. then it's a right pain to get started again and normally involves changing the plugs. Which is not a simple process with the very short inlet I made for it.
But if you get it full up to temp it seems fine re starting.I guess the moral of the storey is take it out for a good thrashing and no pootling about the yard,
Just interested to hear if some plugs are better than others for avoiding fuelling the plugs up.
It's on twin 40's, large valve head with one of the rally cams in it.

[timmy201]

I guess the options are:
Go to a hotter plugs like a 7 and check it after driving to make sure it’s not overheating
Only start it up if you’re going to drive it straight away

When I’m using my Dellorto side draft carb it’ll start up straight away with the choke from cold, but if you leave it idling with the choke on it’ll foul up a plug in under a minute. It’s best to get everything set, then start it up and drive as soon as possible

[Richspec]

I've recently changed to CR7's, having always used 8's. The engine in question has always had an issue with fouling plug 3 on startups and as ever once the NGK's get wet through they are bin fodder. Since having changed to the 7's I've only done one touring event but it ran (and started from cold) fine, and checking the plugs afterwards nothing untoward to be seen, I am going to continue to tweak timing and fueling as time goes on, the joy of injection!!
The other 8 ports will continue to run 8's as they never had a problem with starting.

[MrNoo]

Many thanks for your thoughts, interestingly I spoke with a motorcycle mechanic who said fuelling plugs up happens all the time. He always puts a dose of carb cleaner in with the petrol and he said one of his customers runs all his bikes on Avgas and suffers no problems at all, running both Classic and modern.
See how I get on.

[SPO41]

I would be tuning the engine properly before blaming the spark plugs.
Clearly the idle mixture is too rich and needs adjustment.
Find a reliable dyno operator with classic car/Mini knowlage and get them to sort it out for you.

[Richspec]

Find a reliable dyno operator with classic car/Mini knowlage and get them to sort it out for you.

(and who can do webers)

Sadly easier said than done nowadays.

[MrNoo]

I would be tuning the engine properly before blaming the spark plugs.
Clearly the idle mixture is too rich and needs adjustment.
Find a reliable dyno operator with classic car/Mini knowlage and get them to sort it out for you.

It has been to someone who knows his stuff, lots of Miglia, Mini Sevens etc
I’m pretty sure the very short inlets are not helping, trying to get it all to fit under the bonnet. Anyway I will see how I get on with it.

[MrNoo]

Find a reliable dyno operator with classic car/Mini knowlage and get them to sort it out for you.

(and who can do webers)

Sadly easier said than done nowadays.

Took it to Ralph at Pitstop who I used to race with, he’s run numerous Miglias and Se7ens for well over 30 years.
It came out at 137@7,500 on his rollers with an almost flat torque curve from around 3k to 7k. Again the short inlet not helping matters

[LMM76C]

Then as now?
Timo Makinen discussing 8 port plugs with Champion's John Glover at the start of the cancelled 1967 RAC Rally.

2008-08-19-0927-38_redigerad.jpg

[Fanfaniracing]

I have used both 7ish and 8ish NGK's on my 8port.
My inlet manifold is also very short and had the same issue of fueling the Sparkplugs. The CR7E i used worked a bit better concerning the fueling.

When i take it out i make sure i didn't forget something in the house and can drive it right away. This way i prevent the issue...

[BAD942B]

Why not use CR6Es unless competing & even then I don't think there would a problem, I used them on a 100bhp per ltr Aston engine & they were fine