Re: BigKev's 1937 115-C Convertible Coupe
Posted by Karl On 2024/1/13 11:08:58
Hi Howard,
I think the weak point with this engine is that this engine needs care and attention. As a long stroker (?), who lubricates his cylinders by immersing the crank drive in the oil sump, he needs every drop of oil up to the maximum level. The assumption that 4 gal. There is enough oil to avoid having to constantly worry about the oil level... is wrong.
Does anyone remember the 50s and 60s when it was common for the gas station attendant to always ask if he should check the oil level? There was a reason for that at this time. Lubrication technology, the combustion of part of the oil and the incontinence of the engines, which was not uncommon at this time.
Comparing this engine to a 1950s-60s small block is... like comparing a farm horse to a racehorse. This Jaguar 6 cylinder is a reliable and technically advanced power unit for its time. It's not without reason that this engine won the 24 Hours of Le Mans 3 years in a row (1951-53). I personally know 3 Jaguar owners who didn't pay this engine the attention it needed. The consequence of oil levels being too low was piston seizing. And yes, ... that's certainly more expensive than converting a Chevy small-block. Especially since only a few workshops in the USA have dared to overhaul this engine. It's really not rocket science. However, intensive information about design features in the engine is required. For example, pins/bolts in the area of the chain control should not be lost and should not be forgotten to reinsert them during assembly. But there are very good books in English that describe all of these problems in great detail. The parts necessary to overhaul the engine have been available at all times and are in no way more expensive than comparable parts from GM. But the time required by an American workshop without experience with these engines was definitely significantly higher than that of branded workshops, which simply cannot be found on every corner in the USA. And a Porsche, Mercedes, BMW, or Jaguar owner/driver basically has plenty of money and is then presented with corresponding invoices/cost estimates. It is of course much easier and more profitable to install a small block.
A friend of mine brought such an XK 140 OTS conversion from California. And an “original” Jaguar engine. It then turned out to be a 3.8 liter MKII engine that could only be scrapped. I then restored this car to its original condition, thereby multiplying its value on the European market. Finally, maybe just this much... the SU carburetors should be in good mechanical condition. The vacuum pistons should be able to work cleanly and freely. The needles in these pistons should actually belong to this engine and this type of carburetor. There are a multitude of needles that at first glance all look alike but are not necessarily so. There are tables and lists. The same applies to the main jets. The float level should be set correctly. New needle valves are a must. If the float or nail is hanging, the pump may be pumping gasoline through the overflow pipes under the car. The carburettors must absolutely be synchronized. Everything should be as correct as possible because only then will the engine work cleanly and not emit any black clouds.
Karl
Attach file:
IMG_20240113_0001.jpg (1,412.09 KB)
I think the weak point with this engine is that this engine needs care and attention. As a long stroker (?), who lubricates his cylinders by immersing the crank drive in the oil sump, he needs every drop of oil up to the maximum level. The assumption that 4 gal. There is enough oil to avoid having to constantly worry about the oil level... is wrong.
Does anyone remember the 50s and 60s when it was common for the gas station attendant to always ask if he should check the oil level? There was a reason for that at this time. Lubrication technology, the combustion of part of the oil and the incontinence of the engines, which was not uncommon at this time.
Comparing this engine to a 1950s-60s small block is... like comparing a farm horse to a racehorse. This Jaguar 6 cylinder is a reliable and technically advanced power unit for its time. It's not without reason that this engine won the 24 Hours of Le Mans 3 years in a row (1951-53). I personally know 3 Jaguar owners who didn't pay this engine the attention it needed. The consequence of oil levels being too low was piston seizing. And yes, ... that's certainly more expensive than converting a Chevy small-block. Especially since only a few workshops in the USA have dared to overhaul this engine. It's really not rocket science. However, intensive information about design features in the engine is required. For example, pins/bolts in the area of the chain control should not be lost and should not be forgotten to reinsert them during assembly. But there are very good books in English that describe all of these problems in great detail. The parts necessary to overhaul the engine have been available at all times and are in no way more expensive than comparable parts from GM. But the time required by an American workshop without experience with these engines was definitely significantly higher than that of branded workshops, which simply cannot be found on every corner in the USA. And a Porsche, Mercedes, BMW, or Jaguar owner/driver basically has plenty of money and is then presented with corresponding invoices/cost estimates. It is of course much easier and more profitable to install a small block.
A friend of mine brought such an XK 140 OTS conversion from California. And an “original” Jaguar engine. It then turned out to be a 3.8 liter MKII engine that could only be scrapped. I then restored this car to its original condition, thereby multiplying its value on the European market. Finally, maybe just this much... the SU carburetors should be in good mechanical condition. The vacuum pistons should be able to work cleanly and freely. The needles in these pistons should actually belong to this engine and this type of carburetor. There are a multitude of needles that at first glance all look alike but are not necessarily so. There are tables and lists. The same applies to the main jets. The float level should be set correctly. New needle valves are a must. If the float or nail is hanging, the pump may be pumping gasoline through the overflow pipes under the car. The carburettors must absolutely be synchronized. Everything should be as correct as possible because only then will the engine work cleanly and not emit any black clouds.
Karl
Attach file:
IMG_20240113_0001.jpg (1,412.09 KB)
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