The problem:

Idle is fine... no skipping, no roughness, note is pretty good u cant tell anything is wrong.
Under load, makes s**t-all power, feels as if one cylinder is not firing (Stuttery)

Exhaust is very rich smelling.

Took a plug out of cyl#1 and socket slipped and spark plug snapped. Normally ya'd be like "Dumbass" but the wierd thing... A clean shear through insulator and core. The 2 faces of the core are smooth and flat, although pitted. It doesnt look like a shear or twist at all... almost as if the plug was shagged to begin with as the 2 faces of the core are pitted as though its been arcing across. This is on my 2 week old 347 engine. Also after 2 weeks the insulator of this plug is massively discoloured around the area where it sheared compared to the rest of the plugs on the donk. Around the rim of the core faces on one side is a small lip where there may have been electrical contact in the beginning.. I simulated the same snap using 2 spare old plugs of the same brand and I couldnt get the core to snap for the life of me... it just bent and the insulator cracked and fell away. Think I may have found the cause. Will replace tomrrow and see how it goes.

what yas think?

That will be your problem and I'd say it was probably accidently cracked when first installed and the resultant arcing has weakened the core to the point it easily snapped when your socket slipped.

Ask you old man

^^Indeed

well replaced the b0rked plug and it improved but it still doesnt make full power... Either way its done its run-in period now so its getting trucked up to BPT to be sorted.

Check the gaps mate. When I pulled mine out - the first time they've been out since they did my build - I discovered they hadn't been gapped. Some as far as 2.5mm

gaps were fine... Something else has shat itself and its up to them now to fix as It's past my ability to track down. Starting to understand how u felt with your top end rebuild scaffy...

Last edited by s-tranzor on Mon Apr 21, 2008 8:22 pm, edited 1 time in total.

Dude, I hope you don't end up feeling the way I am. And I hope you don't have to take it back after this time around. How long do you have to wait? If it's any considerable amount of time, it's s**t. You should take priority, as you shouldn't have any problems at all with a freshly built motor. Fair enough if it were someone like myself and had the top end done, then the bottom end shat itself... then expect to wait, but not in your case.

Well I did manage to sort it. It was crappy leads in the end along with that dodgy plug. Replaced the leads and the plug with a set of top gun leads and everything is back to the norm! Thanks for the help guys!