Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 X-Wedge engine life

My car has now done 42,000 miles on its original engine. All it has had is regular maintenance, oil changes, filters etc along with some 569 cams and roller rockers at about 20,000 miles. The general wisdom is that these motorcycle engines will not last as long as a modern "car engine" and will need a rebuild at fairly modest mileages.

I know there are a few owners on here that have done some big mileages and I was wondering if their engines are still going strong or are they heading towards a rebuild or at least some parts changing? I have had a look inside the cylinders in my engine with an endoprobe and they look like new still, no scuffing or discolouration. Do we have any idea of what is a reasonable expected life for an X-Wedge in a M3W? It's hard to tell how things are wearing without a strip down and hopefully there won't be a reason to do that any time soon.

I think that look at 50,000 miles for a modest rebuild. A major overhaul would be in keeping with oil being burnt off or excess smoke coming out the pipes. I had the crank and pistons replaced at 22,000 miles and now have 55,000 miles total. This was just for the splines on the crank being twisted. I think it was just easier for S&S to replace the whole assembly rather than piecemeal. No smoke or excessive consumption of oil so far. If this beast was on a bike, I would probably look for a rebuild sooner as the number two cylinder "behind" number one will get hotter and take more of a beating just like a Harley would. Since both cylinders receive equal airflow that is not a problem. Adding an oil cooler would definitely add life to this motor.

Thanks for your view Michael but I hope your 50,000 miles is a bit pessimistic, I am not that far off! There are no obvious signs of impending doom with my engine yet 🤞, oil consumption is the same as it has always been at about 1/2 litre every 3,000 miles between changes, oil pressure still 60 psi when running warm, 25 psi at idle, no "new" noises.

I know we don't get the very hot temperatures here in the UK that some areas do but excessive oil temperature has never been a big issue for me, without an oil cooler. I have an SPA oil pressure and temperature gauge that seems fairly accurate. With ambient temperatures over 30c the oil temperature doesn't go much over 110c, even when sat in traffic on idle with the Urban Cooling Kit blowing. The main problem has been getting the oil temp up to reasonable levels when the air temp is lower. I think the Urban Cooling kit will add life to the engine, as high temperatures on air cooled engines are a killer but not sure about the need for an oil cooler unless you live in a very hot climate.

We don't get extreme temps in Vermont, either. Few Stop signs and fewer traffic signals. Just about every biker who has admired the beast shares that an oil cooler should be a 'must have' as it works ALL the time and drops the oil temps down significantly. It's also an oil cooled engine. It's also a fairly straight forward install compared to the Urban Cooling Kit on the older cars.

An oil cooler is not needed unless high oil temps are an issue, and would be detrimental to engine life if the oil is not allowed to come up to full temperature (210-250F) on a regular basis.
The large remote oil reservoir is already too much of an oil cooler for shorter trips. Unless you live in a desert climate and take very long drives, you should not need an oil cooler. But if you must fit one, do so with one that has a thermostat to bypass the cooler until the oil comes up to temp.

"Every biker" is not a good source of petroleum engineering information. Seek out information from an actual petroleum engineer or read things written by them.

All of the people involved with bikes who gave advice pointed out that all of the V-twins had, at a bare minimum, passive oil coolers with a thermostat at minimum. There must be a reason for this. The oil tank we have is in an enclosed space and on long runs in moderate weather gets very hot under the hood.

I would suggest the reason would be the lack of airflow across the rear cylinder, which causes that cylinder to run hotter, which is not an issue with the M3W. What's important here is getting the oil hot enough to lubricate as intended and to burn off water which is introduced into the oil via blow by. As noted in this thread and others on the forum who have monitor actual oil temp, the X-wedge does not seem to run abnormally high oil temps. Highest (short term) max numbers I've read are 110-120C or 230-250F which is generally considered normal/safe for synthetic oils.

I have just under 20,000 miles. A couple of years back on the DGR I had the oil get up in the 240-50 range. Since then my engine puts about 1.5 quarts into the sump after a few days sitting and it seems to get dirtier quicker. I also notice I need to top off the oil occasionally. I now drian the sump before start up and put that oil back in the tank, otherwise I fogged the whole neighbourhood

Sorry to digress, my 2013 car Chassis 003 had an oil tank of around 2 litres (?) capacity, I swopped it for a later tank with a 5 litres (?) capacity, gotta help?

The specific output (bhp/litre) and hence stress is pretty low for these engines (even with fancy cams) compared with modern motorcycle engines (often well over 100bhp/litre) or modern car engines.

With decent oil/regular drains plus well-controlled ignition/fuelling and no EGR, there should be limited potential for coking or other deposits.

My expection is that the limitations will be based on choice of materials in the valve train/piston rings/cylinder liners and there seems little evidence (so far) for problems in these areas