FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: FC59BL on April 14, 2026, 07:42:40 PM

Title: 138 ex Speedway build
Post by: FC59BL on April 14, 2026, 07:42:40 PM
Hi Team,
Firstly, Thank you all, for all of information you share on this forum. It is an unbelievable resource. I now own 3 FC?s. My first, I purchased off this forum. (Old log in lost and gone)
I have just completed building a motor for my latest acquisition. The engine is believed to be an ex speedway build. It has Westlite high top, high comp pistons, custom ground cam (very lumpy), big valves, double valve springs, ported and polished ect. I have fitted a twin stromy manifold and extractors. I am still very much in the tuning stages but am having issues with spark plugs. It appears to be killing them quickly. I started with the standard BP4 ran ok for a little while, went to a BP6S ran beautifully for around a 15 minute drive then developed a miss. Plugs are brown (possibly a bit lean). Interested in thoughts and past experience. Running points at the moment, thinking of upgrading to Accuspark module.
Thanks in advance,
Brendan.
Title: Re: 138 ex Speedway build
Post by: FC59BL on April 14, 2026, 07:52:22 PM
(https://uploads.tapatalk-cdn.com/20260414/a03ac3ebfc316756f7bbc80a499f350d.jpg)


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Title: Re: 138 ex Speedway build
Post by: my8thholden on April 17, 2026, 07:33:31 AM
That tanish brown colour usually means fuel is a bit lean ...what carburation do you have ?  is the ignition condensor fuctioning correctly ,,
Title: Re: 138 ex Speedway build
Post by: FC59BL on April 18, 2026, 08:19:53 PM
My8thholden, thanks for your reply. I ended up sorting it today. I drilled the jets out in both carbs to the next number, new plugs and fitted an accu spark module to the disi. Timing at around 22 degrees, she?s running sweet as 👌 pulls like a train and purrs like an upset kitten 🤠


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Title: Re: 138 ex Speedway build
Post by: my8thholden on April 20, 2026, 06:43:44 AM
good outcome ..bit more fuel hey ? im glad the belief that plugs coloured like yours were is a sure sign of being too lean , lets know the colour of the plugs after some kilometers ..Vern ..