Fuel Tank Problem
by TrmpetDave

There is a problem with some Morgan gas tanks. The two baffles which run fore and aft dividing the tank roughly in thirds, come unsoldered from the inside of the tank and can fall to the bottom where they slide around and sometimes interfere with the correct functioning of the fuel gauge.

To repair this, you can drill 8 holes through the sides of the tank so that the baffles can be pop riveted into place securely and then the steel pop rivets are silver soldered over to plug the holes.

The original mounting, solid on good wood boards was an excellent solution.  The leaks are caused by either the boards coming adrift from the chassis, or the tank itself coming loose from the boards and moving around then stressing the soldered joints. The two wooden boards are fastened together by two metal straps that are screwed into the wood. Then the boards are fastened to the fuel tank by four bolts that pass through the mounting brackets that are soldered to the ends of the tank. Then this whole rigid assembly is attached to the frame by THREE screws ONLY. There is a good reason for that. THREE POINTS DETERMINE A PLANE. With the board platform attached in this manner, the boards and the tank form one unit that is insulated form any flexing of the frame, i.e..  the frame can move around but the tank will not be "bent" or twisted.

Removing a Morgan Fuel Tank

Removing a Morgan gas tank is easier than it looks, at least with the wood supported models and even user than that with a Mulfab steel bracket kt. (Morgan had a brief try at metal floor which rusted away and then switched back to the wooden planks by the Mulfab idea is rustproof and a bracket, not a floor.)

Detach the exterior fuel cap(s) by loosening the hose clamps accessible from the underside of the rear deck. Detach the fuel lines and sending unit. Then simply jack the car up and slide the supporting boards around after removing the appropriate securing bolts. You should be able to raise the tank enough to slide one board under the other and get the boards out. (You may have problems removing the bolts but at worst they are easily replaced.) With the boards out the tank will drop out out the bottom.

Refurbishing and Resealing a Morgan Fuel Tank
by Harald Sakshaug

There are two cardinal rules:

First: NEVER and I repeat NEVER use your lighter to check if there is gas in the tank!

Second: NEVER and I repeat NEVER use anything else which is warmer than your hand. (which excludes soldering irons, torches and axle grinders) on your tank either!

Now, remove the tank (click here) and buy a new one, or use another excellent stuff called TANK SEALER.  You will need to buy a kit with several bottles. First bottle is to degrease the tank. (It is some solvent of some kind mixed with water and old bolts and nuts where you shake the tank to get it clean)

The second bottle is to apply a rust proofing layer. (sulphoric acid I think).

Third bottle is a strong water mixing alcohol which evaporates quite fast to remove all the water from your tank.

Fourth bottle is a rubber mixture to pour in the tank while you rotate it, making a layer of (gasoline proof) rubber inside your tank.

It works like a dream and is not expensive. I use it on my motorbike tanks, to avoid welding to them (it destroys the chrome and IS dangerous!) if they are rusty. Repainting a car tank is probably not as cruical to get a nice result, but nevertheless.

I have used my tanks in 10 years without any problems after such a treatment.

Several brands available: Click


Various number of bottles and prices. I used a local variant bought here in Norway.

ENGINE COMPRESSION (revisited by special request 2020)
by Lorne Goldman

Your engine compression is a function of the compression ratio the engine was designed for. Earlier engines were more safely made with lower compression, easier on the engine as a whole and capable of useing a lower quality of petrol. Modern engines push the compression higher for more power. These ratios can be changed, (a bit)  by changing the design/shape of the piston, or skimming the heads or reducing head gasket thickness..all of which reduce the combustion chamber and force the same air/fuel into a smaller space producing a more potent combustion "pop".Significant compression change requires a change of the stroke which means a change of rods and crank. 

Lower compressions than the original are evidence of less tightly sealed combustion chambers. But that is not, in itself, necessarily cause for concern. 

A. An engine needs to "bed in" (to allow the parts to adapt to each other) to reach full engine potential. That is especially a problem with hyper-light Morgans.  For example, the Plus 8 was made for a 6000lb 4x4 truck. A 2000lb car cannot produce enough "load" to allow the rings to bed in. Sadly, many owners baby their cars in that most important period. I once had a conversation with Bill Beck on this subject. We had both found that Plus 8s, even with mileage in the 20k range, had STILL not bedded in and/or had glassified cylinder walls, prejudicing the power and torque! (The cure is to re-hone the cylinders and try again...all of which is extremely invasive.)

B. And there are compensations that lower compression creates...for example the car will be able to rev higher..offsettling power loss. Drag racers all run engines with low compression for that reason. 

The primary reason for compression testing is as a diagnostic tool. It is not dropping compression that is a cause for concern, it is HOW the compression is dropping.  If the compression is dropping comparatively evenly across all cylinders, there is generally no cause for concern. Low, but erratic values tend to indicate valve leakage. Dramatic differences, such as acceptable values in some cylinders and very low values in one or two cylinders are the sign of a localized failure, probably of the head gasket. It's time to get your compression gauge in hand. The following are the steps to take to get correct readings.

1. Make sure the battery is fully charged. A battery with a low charge will give low compression readings because of reduced cranking speeds.

2. Warm the engine to operating temperature to produce metal expansion and to reduce oil drag.  A cold engine will give low readings.

3. After the engine is warm, shut it off and loosen the spark plugs one turn. Restart the engine at a fast idle for about 5 seconds. This removes carbon debris from around the spark plug. This will keep small particles of carbon from being blown into the compression gauge.

4. Shut the engine off and remove all the spark plugs, noting which ones came from which cylinders.   

5. Block the throttle open or remove the air conduit to the plenum and block the butterfly open. 

6. Carefully insert the compression gauge in each cylinder and with the starter, turn the engine over through five compression strokes. 

7. Make a note of the maximum readings from each cylinder on a chart reflecting the relative placement of each cylinder. 

The variation should not be more than 10-15psi from lowest to highest. If that is your case, or better, your engine is aging very well.


8.  If you have low readings on some cylinders, retake them and if they are still it is still low, inject (or use a teaspoon) to put 30 weight oil into the combustion chamber and retest. called a "wet" test. 

9.  Check the spark plugs from the cylinders with abnormally low or high readings. Look for carbon buildup or oil deposits.

10. Replace the spark plugs and torque them to the recommended specs.

Once you've got the readings, it's time to evaluate them to determine just what the future of your engine is going to be.

If the gauge pumps up slowly, such as 30, 50, 70, 90, etc. to an almost normal reading, you probably have ring problems. A general rule is that a maximum reading should occur after two strokes. If oil is added to a low reading and the pressure improves, this will confirm worn rings. But a persistent low reading generally indicates valve problems.

Oil lost through worn valve guides will not be determined through compression testing. Low readings can also be caused by a warped head and often with the Plus 8 engine, two adjacent cylinders will have very low compression which can be the result of a blown head gasket. 

A. It is important to remember that the addition of oil to the combustion chamber will not improve the compression readings if your engine has burned, warped or stuck valves

B. Especially with Morgans, high compression readings are the result of carbon buildup..low usage and timid driving. Each summer, after a long storage, it takes agressive driving for 500 miles me to re-attain full power. 

Always check the specs in the the appropraite manual for your year and engine setup. But equal cylinder pressure is necessary to have a smooth running engine. It has been determined that an engine will run smoothly with only 70% of its original compression. Manufacturers specs usually list a bottom line (conservative) for acceptable pressures.

As a concrete example..let me use my own Plus 8...a 9.35 4.6L Land Rover block with Omega pistons..(making it effectively a 4.8L). It began life with an average compression of 170 psi which increased to 180 after the rings were bedded in properly. I advise Plus 8ers to ignore the LR instructions the MMC offers in their model Manuals. Bedding in instructions with an engine driving 6000lbs are NOT the same for the same engine pushing 2000lbs. The MMC was merely covering their derriers with their LR supplier by goiving the same instructions. However, as noted, the results can be sad and characterize the car for life. 

It has 95,000kms (59,000 miles) on it.Testing the car 17 years later shows only good, even extraordinary, news. The tested compression now ranges from 162-172 with an average of..or 5psi from a mid-point. There is a neglible change with a wet test. The engine is as near perfect that can be imagined. Between careful care, frequent oil changes, agressive usage with a BIG engine in a tiny car, the engine is virtually not aging at all.

AN Hose Diameters

Available Hose Sizes
-2   -3   -4   -5   -6   -8   -10   -12   -16   -20

Hose Size is the measurement of the Inner Diameter of the hose measured in units of 1/16th of an inch.

a -2 hose has an I.D. of 1/8" [306 only]
a -3 hose has an I.D. of 3/16"
a -4 hose has an I.D. of 1/4"
a -5 hose has an I.D. of 5/16"
a -6 hose has an I.D. of 3/8"
a -8 hose has an I.D. of 1/2"
a -10 hose has an I.D. of 5/8"
a -12 hose has an I.D. of 3/4"
a -16 hose has an I.D. of 1"
a -20 hose has an I.D. of 1 1/4"