gundee

I have this neat tool I would love to test number 4 with. Spark KV, Burn KV, Burn time in ms.

Seeing as how this is an earlier California Datsun head, its time to pull it. Check the valve guides and any evidence of oil coming from the head gasket.

Plug wires are likely fine. Under load is when they can break down. His issue is at idle. Under load he says the plug cleans itself up. Hopefully the issue is in the head and not the bottom end. Would be nice if it were just an oil seal.

Any guesses on sale price? https://www.barrett-jackson.com/Events/Event/Details/1970-DATSUN-240Z-271091

I'm curious. What paint colors did BRE use for the red car?

View Advert Ceramic Micro polished L6 stock spring kit. Includes both inner and outers plus retainers. Datsun 240, 260, 280Z. Finish off that nice head rebuild. – Reduced surface stress – Reduced friction, vibration and noise – Longer component life – Reduction in lubrication temperature – Increased heat transfer – Mirror like finish Advertiser gundee Date 11/12/2023 Price $139 Category Parts for Sale  

I think you have been running that thing way too rich. Lean that thing out more.

Just start with 2 turns down and slowly adjust where it runs real good. I cannot imagine why you would want more then 2-1/2 turns. When you like how it runs, stop. Don't worry about what a plug looks like. Just enjoy it. You want your car to run good in traffic like you want. If it does that, your good.

That carb setting seems too rich from all the manuals. Will it run better on 2-1/2 turns? Its going to be how it runs best now. The plug look would not bother me.

Also have Mikuni set up. Had to trim the manifold some to clear the thermostat housing. Pretty common on these. I am not a fan of your choice of head studs. Some of those are too short for my liking. Same with the Mikuni studs. Just too short IMO.

There really is just 2. The first 2 are the same. Second one supersedes the first one.

Lean that back carb out a bit more. Probably carbon. Should clean themselves up. Bump that timing up to 17 degrees. Makes a difference how it runs.

We are starting to get there as far as plugs starting to look the same. Manual says 2-1/2 turns with 17 degrees advance. Lean them out just a little more and see how the car runs.

Do Not use anti seize on plugs. If you do get the copper impregnated type. You must have a good ground path on the threads for plugs.