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Old Jun 7th, 2019, 20:37   #1
gothamus
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Last Online: Mar 23rd, 2022 02:07
Join Date: Aug 2016
Location: New York City
Default Post-Rebuild B20 - Coolant Leak

Last night was the first startup of my re-built B20f into B20b (dual SU HS6 carbs with Mech fuel pump and 123Ignition w/Petronix coil).
I've only run her in for 10 minutes. I shut her down for the temperature getting past High and it needed some idle correction I wasn't able to reach easily (I went to reduce the idle screw and then fast idle was screwed in too far on the rear carb).

The news here- no big leaks...outside. Bad stuff. I have coolant leaking into the oil. I used blue coolant intentionally to be able to see it well if there is a leak.

2 leaks- a small trickle of a few drops out the rear of where the head mates to block/head gasket. You can't wait for it but I can see some drops outside and I saw a tiny squirt while I was hunting things during cool down.

Big problem- there is coolant condensation inside the valve cover. See pictures attached. I don't see any noticeable sign that the sump is filled with all of the coolant, i.e. the oil isn't blue and the oil level is not showing above expected. But coolant is going in there at more than a drop or 2.

When I shut off there was some bubbling (maybe) weird sound and then I saw the coolant in the overflow drawn right out in full. I expect that to be from the engine coolant system filling out as thermostat opens and system opens and engine side draws in. Once that happened the odd sound was gone immediately. (I had filled engine with coolant with thermostat off first and then radiator and overflow).

The gasket was installed right side up. When I put the head on I was concerned that it might be mis-placed somehow. But with the head bolts and some other considerations at that time, I find it unlikely that it was mis-placed. But that is my first concern now.

My other concern is that I was sold a bad engine block or head. There was a bad end to my business dealings with this Swedish car enthusiast and I was taken for money and services not rendered. I am 90% sure the new rings and bearings were installed. I pulled the head off because sealant had been used on the head gasket (maybe there was a reason after all) and to see the condition and verify work. I had to clean the head. I didn't;t take it to a machinist but cleaned carbon deposits and swapped the rocker with the one from my old engine which I had already cleaned and refreshed.

I replaced the oil pump with that uprated IPD oil pump.
The B20 head gasket was a good one I bought from them a few years ago.
I have tightened down the head many times since assembly. Removing rocker, loosening a small bit before re-tightening. I used to different style torque wrenches so I would have some level of check against defective or mis-configured settings on one or the other. I followed procedure of tightening order.

One thing that may blow up some opinion/mistake or nothing- due to some issues with heater core and piping directions becoming a big side-tracking of the entire project- I got the idea from an old post of bypassing the heater matrix and thermostat for now and revisiting when I do the breaking-in flush. The coolant pipes in the rear are connected by a hose from the outlet pipe to the inlet pipe, in place of hoses going to matrix-thermostat. I am happy to explain more detail here if there are any questions. If I missed out on a major impact here, let me know. This project needed to get completed and I was/am into sudden death overtime.

Since coolant does not make a good lubricant, I guess the engine won't be running again this weekend. Tonight I'm going to have to find a spot to push my car to. I've been hogging this awesome parking spot with a Citibike stand behind me and fire hydrant 14 feet in front of me. Best spot on the block. After many months a certain person has brought down the law and I am on the run! Hopefully just across the street!

I will post some pictures of parts before assembly. Right-now I want to leave this lab I'm working at in NJ and get back to the safety of NYC.
Attached Images
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