Thornycroft 38hb (T90)

[tidemaker3]

Am considering purchase of a Moody 33 MK1 1977. Boat looks clean and well appointed but I'm not familiar with the Thornycronft engine. I live in the U.S. and am concerned about getting replacement parts if necessary because of age and make of engine. Does anyone know about the engine? Any info would be appreciated. Thank you.

 

[Gordonmc]

Hi,
Although elderly and basic the T90 BMC 1500 is still rated as a robust workhorse. I believe they were standard for the Moody 33 as all of the boats I have seen have them, or were the original engine. Marinisation of the basic block was carried out by Thorneycroft. They were popular for narrow boats using keel coolers which has proved a blessing for owners of yachts as the engineering shops catering to the canal fraternity keep them going. Most yachts use Bowman heat exchangers, early ones with a fore-mounted header tank and exhaust cooler, later ones with a larger exhaust cooler with rubber end caps.
Spares are not a big problem. The consumables such a filtres are normally available from high street motor factors as the engines were used in some Leyland vans and taxis.
Most spares are available from ASAP Supplies, Thorneycroft or AMC Diesel Engineering.
Manuals are available on-line, see: http://www.onlinefreeebooks.net/aut...engine-service-manual-wiring-diagram-pdf.html
I have the original T90 in my Hillyard, married to a Borg Warner 1:1 Velvetdrive gearbox. It plugs away and the only major work I have done in ten years was to replace the cartridge type oil and fuel filtres with spin-on conversions.
The exhaust heat-exchanger is aluminium and suffers a bit from corrosion but they can be picked up at reasonable cost.
If you are concerned about the condition of the engine an oil analysis and compression check might be worthwhile, but that applies to diesels of any make.

 

[red beard]

I have a 76 moody 33 with the same engine and it breaks down every time I leave the pontoon, to be fair the block is ok but to date the failures are;
alternator, 3 times
fuel lift pump
water pump
exhaust in aft cabin corroded and blocked
gearbox
aquadrive
stop lever jamming on
air in fuel lines
leaks diesel & oil like a sieve

Thats just what I can remember

Great boat though, wish I could afford a new engine

 

[Pasarell]

T90

For balance, I have a '76 Moody 33 as well. Bought at the beginning of this year. Apart from oil leaking from the filter due to gasket not put on correctly when I first started the engine it has run faultlessly all season.
Fuel lift pump has been replaced at some stage but no other obvious major replacements.
I'm very pleased with the boat and all its gear. Lasted remarkably well I think.

 

[tidemaker3]

Thank you gentlemen. I will be taking a trip to view the vessel next week. I hope to find out the maintenance history of the engine. I suspect its condition is largely dependent on the care it was given by previous owners and of course by its general age.

 

[scottie]

Any engine over 35 years is subject to wear and tear but if looked after should be usable but replacement is a strong possibility so should be taken in your costing

The current owners should be able to advise on the procurement of engine & gearbox parts

From what I recall the moody 33 was direct drive and was restricted in propeller diameter so replacement may be more of a problem.

I would suggest contacting the moody owners association would be a logical option before going much further as they will be able to furnish more detailed information

 

[tidemaker3]

Thanks again for replies. I did try to post on MOA for potential buyers but was unable to. Even though it said it did not require registration it asked me to register which I did. Then it said I would hear back through email when my registration was activated. So far not reply. Its been 3 days. I will try again.

 

[maxi77]

We have the same engine in our Moody 36 and we have done some 300 hours this season with only an overheating problem caused by clogging in the FW side which has been cleared with a good dosing of radflush stuff. It starts on demand, doesnt smoke or use much oil, my only problem is it is a bit underpowered for the boat in a head sea.

 

[PetiteFleur]

Thanks again for replies. I did try to post on MOA for potential buyers but was unable to. Even though it said it did not require registration it asked me to register which I did. Then it said I would hear back through email when my registration was activated. So far not reply. Its been 3 days. I will try again.

That's unusual for the MOA - usually you get a very prompt reply and they are extremely helpful. I also have a M33 mk2 which had the original T90. The previous owner had not looked after it all - when I changed the oil it was like tar, one heater plug had been broken and never repaired, and it took up to a minute to start with clouds of smoke which followed me out of the marina. I did a compression test, two cylinders were well down. No 4 cylinder can suffer from water ingress if the water injection elbow fails and is not fixed promptly. Spares are available from Thornycroft and ASAP easily but some come from India and are of poor quality. If in good condition the engine should start easily but it's recommended that the key is held on the heat cycle for about 15 seconds before cranking. If maintained they are a good engine, but as said earlier they can only spin a small prop, from memory an 11" prop was fitted initially with a 1:1 gearbox. You will never use the full 38HP. I re-engined with a Beta 25HP and a 13" prop and a 2:1 g/box which is more than adequate. If the engine is suspect, get a compression test done and inspected by a good mechanic. Good Luck.