'61 MG Midget

[jaysenodell]

These aren't high compression engines. Verify what it should be with a service manual or ask on MGExp. Or ask Darryl.

Didn’t get oil flow at the top end while cranking. Only oil up top is what I squirted on when I started rolling it over. No pressure on gauge either.

Normal. Takes a minute for oil pressure to build up. Its a mechanical pump on (normally) #4 crank lobe. You won't see pressure until it's running and you won't see flow much before that either. It is OLD.

HVAC controls seem mostly missing. Blower and heater core under the hood…

HVAC controls? Keep dreaming. A switch for the fan is what you get in the cabin. If you are lucky a "defrost" knob. Heat should be from a vent in the footwell that opens to the engine compartment. Underhood there should be a stopcock to prevent flow into the heater core. That's it.

About as exciting as the Stovebolt in the Chevy: Seemed hopeful, and then not.

If you don't like this, move it along ASAP. This is 100% of how these thing run. what we think of as "bad" is normal. What you think is good is just her lulling you into a peaceful moment until she throws oil, metal and boiling fluid all over the road. These things are the high maintenance women of old cars.

I think I’ll try to get it oiling, and then see if it’ll run. Maybe bore scope it and see what I can see inside. Unless the oil pump failed it ought to be decent at 45,000 miles.

I'm at 45k. But that's 3 engines. The 1500's are shit, but these things are NOT high mileage cars. You may have better luck with yours (don't drive it like a sports car... that appears to kill 1500s).


I'd also recommend against electronic ignitions. I had nothing but problems until I went to points (it's actually in the service manual as a fix for timing (remove opus electronic and replace with points). Darryl swears by it so ask him what the best one for that engine would be. Remember that these old things don't rely on perfect electrical so don't freak out about the fuses in the engine bay. Once I beat the ignition problems all my electrical issues vanished.


If you like to tinker with things, these are great cars. PITA, but a lot of fun to tool around in with the Mrs in the passenger seat just looking at the sky (which is all you can do in these things so take a blanket for a grassy field if y'all like to have fun in the wild).


Also, once you get it running you MUST drive it at least once a week for at least 30min. If she sits more than that something will break. not sure how they are supposed to survive winter.

[mr.mindless]

hahaha great insights, thank you

I started measuring the compression from the back, and was expecting 140ish to be the number after seeing it on 2 in a row. That 190 was a surprise to me, and then the 110 was a big disappointment. Certainly not within the 10% that makes for a healthy engine regardless. Maybe some run time will even it out, maybe not.

I'll have to look into the oil pump, cam lobe driven sounds nigh impossible to prime.

I'll pop the dist cap, find the right wire order, see where static timing is sitting and go from there. No ignition module spotted so I expect to find points under the cap. voltage regulator is still Lucas (or at least still under a Lucas cover). this car seems very original.

I disconnected the fuel pump intake from the hard line before cranking, and put mighty vac on it. Got some very brown gasoline so will need to address the fuel tank in some manner too. Also need to pick the fuel cap lock: no key. Just about the only missing thing so far.

[mr.mindless]

Plugs in and wires on, no spark.
Cranking slows after half to one second. Something is getting warm and gaining resistance. Could be the battery, but I don’t think so since next crank is fast. Need to check drop across coil and starter wire. Could be tired starter too if that’s fine.

[jaysenodell]

My guess is that the 110 is the "correct" pressure and the others are high. I don't think my "high compression" motor gets much over 140. the 9s were much lower than the 15s.


On oil pump ... should be crank lobe. the pump should be in the pan attached to the bottom of the block. I think the triumphs used cyl4 lobe. I've stopped doing that type of work myself. I can look at my manual, but the engines are pretty different.

replace the fuel pump with a low-pressure electric. Those mechanicals are the devil. Also, the low-pressure pumps help reduce the vapor lock problem all these little cars have running over 80F ambient temp.

no spark ... coil, point/condenser first. those are the most likely and they just seem to crap their pants if they sit unused. Ask me how I know.

The starter thing is almost certainly the starter. Pretty standard symptoms. Always keep a spare on the shelf. They are the most common failure after the coil and dist ignition (point or electronics). Unless your me... then its the gd block/head.

[mr.mindless]

I have read many times of the electric pusher pump being much better for vapor lock. I think that was your applied solution too, wasn't it?

The starter itself was the warmest component. I don't know how the block is grounded to the body, so that's a possible issue as well. Seemed to die off quicker than a large motor should, but if it's all weak windings anything can happen.

I have many spare coils, didn't measure this one. I know I have a rotor in the spare parts, I'll laugh if that's just missing under the cap. I referenced a picture for plug wire position, didn't go through pulling cap and properly locating.

No work on this tonight, must be early to bed for 0530 departure. Only 3hr earlier than my typical...

[jaysenodell]

I have read many times of the electric pusher pump being much better for vapor lock. I think that was your applied solution too, wasn't it?

Yep. Work perfectly. At least it does as long as you can keep the engine together.


I'm not happy about that these days.

[mr.mindless]

Sarah is really pushing for a modern engine swap. Not that she’ll help… I feel a tiny bit bad about doing that to one so original, but with the general reliability issues i d do wonder why it’s so uncommon.

[jaysenodell]

because the cars tend to fold? these cars aren't really engineered for high performance. You'll need to reinforce the "frame" as well as modify a lot of the body.

[mr.mindless]

yeah I can see there's really very little to the structure.

in other news: I have a curse when it comes to leaving coils energized while trying to get things started 🙄

[jaysenodell]

throw in a "head light shut off" circuit. Use the alternator/generator output as the sensor leg (vs "run" off the key switch).


if the goal is a modern drive train you would probably be better shortening something from a not-as-small donor and then just putting the 61 body on it. that or a full e-drive conversion. No matter what you do, you're in for a full driveline rebuild as those axles and diff parts are unobtainium.


It will be a franken-midge no matter which way you go. Make it "franken" in a way you can live with supporting.

[mr.mindless]

Miata 1.6 + 5 speed procured
1990 with 122k

Recently had a turbo on it. Hoping that doesn’t screw me.

[M4wdFab]

o lord

[mr.mindless]

Don’t bother to trust at all. Just verify.

that is all

[mr.mindless]

missing harness plugs en route 🙄
not like I need coils or injectors or cps...

#2 compression is a bit low. 185-125(140wet)-165-177


I have a fair bit of splicing back together ahead of me. I should have held out for a complete donor. Nickel and diming on missing stuff adds up insanely fast.

[mr.mindless]

Twenty minutes at the carb side of the motor with sterner trigger, hand throttle, and starting fluid got this running.

Fires instantly and purrs like a kitten now.

Gross oil leak at block to filter adaptor though.

Will pull that apart later. Oil that was pouring out looks good quality. Need to find a couple seals for valve cover in the parts hoard, get it in the air and clean tanks and change other oil.

If oil smoke calms down with some run time might putt it around as is if the clutch is good. This week should tell