Rockers: 46 years and 90,000+ Miles

[bunnspecial]

I thought I'd throw a quick picture of this up. I removed the valve cover last night to adjust the valve clearance.

I have no service history on this engine, and have only owned it since October. Judging from the overall condition of the car, I think it was likely given a "light restore" in the 90s(probably a respray and some interior work) but nothing to make me think the engine has ever been out of the car. The odometer is showing 85,000 miles, but it hasn't worked since before I bought the car and the title I received showed 83,000 miles when the previous owner bought the car 5 years ago.

In any case, I suspect this likely isn't too bad.

This is a BMC 1.8L "B" series engine in a North American MGB.

 

[OneEyeJack]

Brings back memories. I worked as a mechanic at a BMC dealership in the 70's while attending college.

The MGB was a good car for mechanics. It made them a steady income. The car was fun to drive and easy to fix, not like the later ones.

Unfortunately there was the Marina, same engine with one SU vs two. That car was a plague. Over a few weeks I rebuilt several engines in brand new never driven cars that had bad crankshafts. We could never get the alignment correct because there was not adjustment besides toe-in. When a hydraulic ram and a torch we finally figured it out. It was a terrible car to drive. It rattled, shook and vibrated, all at once and with the reduced power B engine it was gutless.

Just make sure you get familiar with those SU's and figure out which oil works best for the dampers. Don't let anyone tell you they're difficult. With some trial and error you'll get it.

 

[bunnspecial]

Originally Posted By: OneEyeJack

Just make sure you get familiar with those SU's and figure out which oil works best for the dampers. Don't let anyone tell you they're difficult. With some trial and error you'll get it.


Fortunately, there are a lot of good videos that deal with things like tuning SUs. I splurged a bit and bought a Unisyn to synchronize the airflow at idle, but aside from that I have had no issues getting them tuned. I've used the standard "lift the piston and see what happens to the RPMs" test. I tuned them back in December, and checked again this morning after adjusting the valves. They're still dead on(RPMs rise slightly and settle when lifting the piston).

I tried the full range of oil from ATF to 90 wt hypoid gear oil, and finally settled on 20W-50. It works well, and it's nice to be able to carry one bottle of oil for several applications-that's what I run in the engine, the dash pots, and in a pinch could top up the transmission with it.

The little 4-banger in this light weight car has a nice amount of pep in it.

Even though these cars do have sort of a poor reputation for reliability, the nice thing is that they are mechanically very simple and I can(and have) fixed it on the roadside before. My modern car rarely breaks down, but it seems that when something goes in it, it REALLY goes.

 

[Wampahoofus]

Looks pretty nice; better than the rockers in my A series at 50,000 miles (not helped by the massive overfuelling from the previous owner...)

Gotta love the old Austin motors. They'll run on hope and pocket change.

 

[Silk]

We often used to pull the rocker cover on B engines and they were full of icecream. They had a poor breathing system, first a road tube from the tappet cover, then a tube from rocker cover to intake horn. I coverted my MkI 1800 to the later PCV system, tossed the diaphram PCV valve and fitted a normal one, of Nissan I think....then no more icecream.