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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Chevygold on August 31, 2025, 01:42:07 pm

Title: Vortec spark plugs
Post by: Chevygold on August 31, 2025, 01:42:07 pm

My '76 C10 came to me with a Vortec 383cu in crate engine which was a good incentive to purchase I thought, whilst idly browsing Summit racing site for Vortec information came across spark plugs and realised they were taper seat long reach and although I need to check tomorrow I'm pretty sure the plugs in the engine currently are short reach!
Anyway like I said I'll pull one in the morning if it ever stops raining and see whats in there.
Could explain why my truck is so thirsty!

Graham

Title: Re: Vortec spark plugs
Post by: Chevygold on September 01, 2025, 07:33:20 am

OK checked my plugs and they were short reach so just ordered a new set of long reach Bosch listed for 5.7 Corvette 89/90 LT5 which was all I could find so will have to do for now.
Busy running the plug thread cleaner down the plug holes now to get the carbon buid up cleaned out.

Graham

Title: Re: Vortec spark plugs
Post by: Chevygold on September 02, 2025, 11:13:54 am

Got 7 plug holes cleaned all the way down then rain stopped play, headers don't make for easy access to get anything into the threads on some cylinders!
Hopefully I'll get the new plugs tomorrow and can get them in then see how she runs with the right plugs, I imagine the recessed electrodes will have an affect on the dynamic ignition timing being buried 1/2" into the head?

Graham

Title: Re: Vortec spark plugs
Post by: Chevygold on September 04, 2025, 09:41:41 am

Completed cleaning the plug threads in the heads yesyerday, replacement plugs arrived but they weren't taper seats as shown in the description so have ordered different ones now which should be correct, Champion RS12YC, some of the plugs I found were $15 each with some even more so these will have to do for now, not a big fan of Champion but maybe they're better now?

Graham

Title: Re: Vortec spark plugs
Post by: Chevygold on September 06, 2025, 10:54:17 am

Fitted the new plugs yesterday and now running fine, first thing I noticed once warmed up was I had to screw in the idle screws  1/4 turn to get the idle mixture right again with the AFR, don't know if it's all in the mind but I think the exhaust note has changed as well.
I'm still trapped behind my MOHO so haven't been for a road test yet but will update once I've been out.

Graham

Title: Re: Vortec spark plugs
Post by: VileZambonie on October 18, 2025, 07:01:09 am

What is a moho?

Title: Re: Vortec spark plugs
Post by: bd on October 18, 2025, 12:36:17 pm

Mohorovičić discontinuity...   ;D

Title: Re: Vortec spark plugs
Post by: JohnnyPopper on October 22, 2025, 11:18:59 am

So you're saying it was running a richer AFR?

Title: Re: Vortec spark plugs
Post by: JohnnyPopper on October 22, 2025, 11:31:59 am

What part number/type of plugs did you pull out?