MG MGB and MGB GT Tech Talk
If an MGB is burning oil, is that a head gasket issue? Or is that coolant?....
Anyway, does an engine need a complete overhaul if it is burning oil or is there a fix that goes directly to the heart of the problem?
Thanks,
Dave
If the engine is indeed burning oil rather than leaking it, you have a valve/guide issue and/or a ring issue. Unfortunatley there is no quick and easy fix. A compression test is a start, and a leakdown test will help you narrow down the source of the problem. Good thing is the heads are pretty simple to remove and a 'valve job' isnt really that expensive. If you have to pull the pistons our, things get expensive rather quickly with 'while your in there' items like reconditioning the rods and crank, maybe a overbore w/ new pistons and so on.
It's not the best thing for the environment, but unless the car is pumping a smoke cloud keep and eye on the oil level and enjoy. :)
Best of luck
1. Pull engine
2. Rebuild engine
3. Reinstall engine
..."burning" oil is different from 'leaking' oil..."burning" oil is usually synonymous with bad rings or serious valve problems (as opposed to brief oil blow-by caused by dry valve seals upon ititially starting engine after 4 or hours)..."burning" oil means you've lost compression & a combination of oil & gas are being ignited in cylinder (yes, oil can get there from on top of engine or from underneath).....'burning' oil usually means its time to REBUILD not REFRESH the engine....as my Grandaddy told me way back when I was knee high to a jack rabbit, "Boy, don't ever just rebuild the bottom of an engine. If you open her for anything other than minor stuff, rebuild everything."
....if you're indeed "burning" oil, don't waste time on compression checks, etc...pull it, rebuild it properly, & reinstall it! &, don't try to cut corners to save a few bucks ("in for a penny, oput for a pound!") If you're burning oil, figure boring block & oversize pistons, figure valve seats & probably several if not all new valves & springs, figure balancing, blueprinting, rings, bearings, gaskets, etc, etc, etc.......
What about just "refreshing" the bottom end of the B at 50k miles. Or does it always require a full rebuild?
Absolutely! Always refresh the bottom end at 50,000 &, to use the old term, "decoke" the head around 100,000 when you replace the timing chain tensioner....doing those jobs will ensure longer time between rebuilds!
why not just buy another good running engine and save a bundle of money
You could...& I have a great running 18V I'll sell you...however, you still don't know how good it really is...you buy them 'as is'....&, I'd refresh it before installing anyway....remember: In for a penny out for a pound!
That's usually a gamble. Unless it's installed in a car so you can drive it, you're just taking someone's word for it's condition, how long since the rebuild, what exactly was done, etc. If you gamble and lose, you're now the proud owner of TWO engines needing rebuilding!
Even if you can see it running, there are things that are hard (if not impossible) to detect from a brief running test. Things like a cracked head, worn bearings, cam or lifters can easily go undiagnosed until they get worse later.
If you build your own engine (Gary's problems notwithstanding), you know exactly what you've got. If you have someone like Tom B. build it, you'll spend more money - but you'll have an engine that's better than the one that came in it.
My long range plan (which I hopefully won't have to use for quite a while!!) is to buy another engine (good, non-running engines aren't that expensive), do a proper rebuild on that engine, then swap that engine into my car. Then, I'd have my current engine to rebuild for the next swap! This would let me take my time rebuilding the engines with a minimum of "down time" on the car.
what about the engine from proper mg? that seems like a good deal.
It's a gamble to rebuild too, if you have a 'tweaked' con rod and a crappy machine shop!! :o) I wouldn't stick in an engine I didn't know!! Like I have always said, do it once the right way instead of twice!!!
You need to diagnose why the engine is burning the oil before determining a course of action. Overhauling the engine should certainly take care of it but may not be necessary.
Richard
I think it's $2000. Fully overhauled to 1950cc. one year/12k mile warranty. Seems fair to me, but takes away the "fun" of doing it yourself.
On the other hand, I have sold 3 "used" engines since the first of the year, all showing new clutches and other signs that someone had been there recently, and not one complaint, while you paid big bux twice.
If the compression is there, it is worth the gamble.
