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HybridZ

oil too hot??


280zex

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1976 280Z

F54 block, 10cc dished pistons

N42 head, ss valves, 280 deg duration .480 lift cam

T3/T04E 60 trim turbo blow thru Holley 4bbl carb @ 20psi boost

 

I noticed that my oil filter looks burnt, crispy paint, and 1 spot closest to the block is now bare/paint gone.

 

I do have a large size Hayden oil cooler, 10 x 15 inch, that cools the oil BEFORE the turbo.

 

I started loosing compression on the #3 cylinder, 115psi hot, 90psi cold, all other cylinders at/on 160psi hot/145 psi cold.

 

The head checks out ok, so does valve lash = .008 inch, cold, at the valve/lifter adjustment.

 

No metal particles seen in the oil, head gasket checks ok. Never seen more than 230F coolant/wetter water.

So far the cylinders look ok from the top side, piston tops look good, #3 piston top is oily, so is the spark plug, waiting to pull the block, I just need a hoist.

 

So what are the tell tale signs of excessive oil temp?? I don't have an oil temp guage yet. I have been reading that about 300F oil is where problems start. The fact that the oil filter looks to have been burnt tells me that my oil is getting too hot, what else do I need to look at?

 

This is a street driven/ weekend toy, not a race car, but I have gone max boost/rpm/5th gear many times. So I push the limits...

 

I can post pix later when I get home if thats needed...

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I would think the paint on the oil filter would be damaged by some liquid be dripped/poured on it. I've run oil temps over 300F for short periods and never had an oil filter look any different then brand new.

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dist timming 20 deg flat no advance no retard, cam timming 4 deg advanced I.E. hole #2 on the cam sprocket.

The filter definately got too hot as the end was crispy. There is nothing on the engine side side with the filter that would leak on it, or atleast I never seen anything leaking on the filter.

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I'm stil waiting on getting a hoist to pull the block. Sence I did the turbo upgrade I had strange happenings. The flywheel had radial cracks from the center going outward causing the bolts to come loose. That ate the entire clutch/flywheel/throw bearing and transmission input shaft/front main trans seal. I fixed all that and upgraded the clutch and flywheel to a 240sx 6 puck carbon composite disc and a pressure plate thats for 450ft lbs torq. This barely holds up to the power my Z is putting out. Now that I'm looking closer to the cylinder bores it seems that my crank thrust got knocked out of adjustment, as I can see some strange wear marks in the bores. I cant feel anything bad with my fingers but I will know soon enough when I get the pistons out and mic the bores and check the main bearings. I have never had such a hard time with ANY L28 like this! However this is the first time I have made so many modifications to an L28. I realy believe that I have something stuck in an oil passage or something wrong with the pickup in the oil pan, or mabe the oil pump went hinky?? So far I do not see anything that looks like upper engine oil loss, and the cam lobes look fine, so do the rockers and lash pads. After I get the block out and check the cylinders I'm going to find a shop that can hot tank the block. I want to make this block squeeky clean!! I hope I didnt have anything major happen on the bottom end. I have owned this block and custom crank/rods/pistons for 25 years now and I'm realy attached to it :wink:

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