MG MGB and MGB GT Tech Talk
I found out that the engine of my 73 mgb (recently bought) suffers from a very tiny (I would say microscopic) cooling leak near one of the sparkles. It leaks only when the engine is running, but the loss of cooling fluid is negligible. What shall I do to prevent further damages? Thanks for your help.
Jose Sequeira
sparkplug, replace the head gasket and hope the head isn't cracked
Small crack in the head or a bad headgasket, based on my limited experience.
Try re-torqueing the head first, then resort to the the sealers, and then to head gasket replacement. Also be sure that the car is tuned properly. Engine pinging can actually promote head gasket leaks.
Limited Yeah! That experiance was almost unlimited while it was going on.
I had a B with a weeping crack in the head between #2 and #3. There was no water in the oil and it just wept until the engine warmed up, then stopped. I say check the head torque but otherwise leave it alone... it was probably "molested" at some point by a dpo.
:-/
I still get that occasional weeping around #2 and #3. That's where a dpo had stitched a small crack in the head. My 71 bgt will drive about anywhere when I get the exhaust manifold leaks fixed. Where does one get those Felpro gaskets anyway? Still limited,yet unlimited here in the middle of the Hillbilly Nation. Thanks for the Weimerism JDW!!
Most auto parts stores have Fel-Pro. When you find one that doesn't just go to another one.
Thanks John. I reinstated the liability insurance on the 79 roadster today. It's a $500 fine to get caught in Kentucky, without insurance. Haven't driven the 79 much since last October. We had a crappy winter. I'm looking forward to improving, fixing, and driving both my B's in the next couple of months. Thanks for all the wisdom.
I had the same problem on my rebuilt engine, and posted it here on this BBS, and was reminded of something that I saw whilst surfing all things MG but chose to ignore. Hey, if I didn't do everything twice, what would I do with my spare time?
Anyway, I redid the head as per below (from University Motors, I think), and have run it for 15 minutes or so, so far so good!
MGB WEEPING CYLINDER HEAD: The rule is, all rebuilt B series engines weep between the block and head, between the 2nd and 3rd spark plug. Some actually piss. To remedy this problem: That center exposed head stud, RH side, between #2 and #3 is the guide stud -- the hole in the head is 3/8 whereas the other holes are 7/16. Clean out the stud hole in the head with a 3/8 drill. Polish that stud, at least. Ensure a chamfer at the threaded hole in the block. Chase the threads on the stud, nut, and block (3/8-18 and 3/8-24). Ensure the head is planed to 0.001." Ensure that the top of the block is cleaned to a SMOOTH finish. Fit the studs back into the block with only about 5 lb-ft torque. Place a THIN film of clear silicone, RTV, sealant on the RH side of the head gasket. Into that EXTREMELY THIN film, place two strands of stranded, flexible wire about six inches long, twisted together, along the outboard side of the gasket, between its edge and the water jacket holes so that the thickness of the head gasket is effectively increased by several thousandths. Goodbye leaks.
Sorry, Al, but what is it a dpo? And do you think that this weeping will not turn into something more drastic?
Thanks to everybody, in particular to Eric´s detailed explanation. For the time being I will leave it as it is and concentrate on other things more urgent to be done in my B (namely, suspension and rear brakes). Afterwards I will try Eric´s formula. If there are no other suggestions, that´s all concerning this problem.
See discussion on subject of "White smoke! Help!" May be helpful.
later, tom
