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1983 280zx turbo engine

Dave WM

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thought I would start a fresh thread to document my journey on getting a turbo engine to run and perhaps install in my 1975. I say perhaps since at this point my main interest is to learn about turbos, and if I like what I learn I may install but will make sure its reversible since my car is an excellent example of a survivor. So now that all the qualifiers have been stated...

as titled its a 1983 i assume based on the P90a head with the hyd lifters. So far all I have done is mount the engine on a test run stand that and I have attached manifolds and EFI for NA testing. I will be swapping out the dizzy drive to use the standard dizzy since that is what i have used on the last NA engine that I had on the stand. The plan is to eventually run the stock turbo and turbo EFI, but for now I just want to get some NA base line runs.

The engine is extremely dirty with carbon both all over the valve train and in the pan. I cleaned out the pan and picked out the large carbon chunks from the top of the head under the cam.

I have started to clean the lifters, found an excellent video on youtube as guide. Its very satisfying so I will finish up that before test firing the engine.

I have a new oil filter and oil (15-40 rotella T4) for the initial test. I spun the engine on my test stand to confirm oil, At 1st there was no pressure so I pulled the pump and filled it, after that the oil pressure came up fine. I had one cam oil hole not producing any dribble so I poked it with a fine wire, and cleared. 

Based on the overall dirtiness I can see I will at the very least need to pull the cam, and flush with brake clean and prob use a gun bore brush to clean it, or else risk re fouling the oil feed holes in the cam.

The head had an excellent leak down test, the compression test on the stand was 2-6 all about 150 psi, 1 was 125. I am not sure if my starter was just getting weak at that point so I will test again after running. I have seen this before with engines that were left sitting for long times in storage, so not too worried about it at this time.

during the NA test run phase I plan to  check for exhaust gases in the coolant and coolant in the oil, standard stuff to see if the block/head are ok. 

If all those test check out the next step will be to remove the engine for a complete tear down and assessment of things like bore condition, bearing wear, rings etc...

Based on the condition of the oil I would expect to find some pretty dirty rings.

I have had the stock turbo rebuilt by a local shop. It looks GREAT will post up some pics later. The turbo was really trashed, and the oil supply as the culprit. The oil line is really filthy so before any turbo runs I will need to get the engine block hot tanked, the oil gallery plugs removed and clean out any junk in the galleries. The turbo is just too nice to even consider bolting on until I am sure it will have  a clean supply of oil. 

I have some early video on my channel of just mounting up the engine to the stand if you would like to see. they are on my youtube channel 

stay tuned as I progress. I will need some help on ideas about getting a clean oil supply line as the old one is I think beyond cleaning. Its on the back burner since so much else has to happen before the turbo as mentioned above but I would like to start planning. 










Edited by Dave WM
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progress so far..

removed the cam shaft, took it to a shop where they polished it. It had some pretty bad scoring on #10 and #9 cam base circle. for some reason the damage seemed limited to just the base and not the lobe itself. But since it had hyd pivots the base stays in contact so I did not want to run it and do more damage. the rockers themselves looked ok. The shop said it really should be re ground to clean it up, but agreed to try a polish. He said it came out better than he expected. I will take that as a partial win.

The cam bearing surfaces looked good both on the camshaft and the towers. there was some burnt oil on one side of the tower bearing I cleaned it up with some carb cleaner. Again the engine looks to have had too few oil changes, hence the cleaning of parts as I go.

the pivots are tedious but strangely satisfying. I to the tear down, drain the old oil, soak in gas, remove the internals, spray off with brake clean, allow to dry, then dunk in the gallon sized carb cleaner  (the one with the basket inside), let it soak for about 30 min, comes out pretty clean, use some Q tips and simple green on it. If its still dirty it gets dunked again. I am not sure if you can damage anything by leaving it too long, prob should do some research on that.

Anyway when clean I reassemble in a oil bath to keep air out, then clean out the head well of oil where they screw in, and tighten to about 62 ft lbs.

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re installed the cam shaft. I wrapped the lobes with some electrical tape making sure to cover the edges. I found it MUCH less stressful doing the install since I did not have to worry so much about the sharp edges of the lobe contacting the bearing surfaces. 

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ok got it started on the test stand today. Bad news I get a lot of oily brown foam coming out of the rad (I left the cap off so I could monitor the coolant level).  Pretty sure the oil level in the crankcase dropped as well. had some but not a lot of exhaust gas in the rad as well after testing with the blue turn yellow test kit (it was just a slight green actually). I retested the compression all were right at 150 psi, and did well on the leak down test (most were 90% one was about 85%).

temps went up not crazy high but def higher than should be, on the other test engine it was rock solid at middle of th e gauge this one was more like 2/3 towards high.

Oil pressure seemed lower on this engine as well. I was thinking it was just the higher temps thinning out the oil.

so based on the brown oily foam, apparent loss of oil in crankcase, and elevated temps I am HOPING its a blown head gasket. the Compression test don't really show that, but i would much rather have a head gasket problem over a block or head problem. I will get some video of it tomorrow to share, perhaps someone else will recognize if I show vid

I am pretty sure my next course of action will be to pull the head. 

Oh and I love the hyd rocker pivots. NO valve clatter at all. 

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