Jump to content

BMC 1.5 / Thornycroft 90 Dry Weight & Engine Mounts


beanpole

Featured Posts

What is the dry weight of the BMC 1.5 diesel, either with or without the transmission?  I cannot find this specification in any of the owner or service manuals.

 

The engine mounts need replacing so I need to figure out a size.

 

Also, if anyone has a recommendation for mounts I would love to hear it.

Link to comment
Share on other sites

The BMC Operators Manual for the 1500 & 1800 engines quotes the weight of the basic power unit of the 1500 engine as 186.4kg (410lb).

 

Calcutt boats would be able to advise on, (and presumably supply), suitable replacement mounts, although other sources are available, of course.

Assuming you don't have any kind of spider joints or "python drive" in the drive to the prop, alignment is very critical, and any misalignment can result in damage to the engine feet, or even how they bolt to the engine itself, (but please don't ask how I know this!).

Link to comment
Share on other sites

I am not up on the Thornycroft variant but the mounts on the official Tempest/Newage marinisation used very different mounts to those normally used today. the front mounts were the automotive ones and the rear ones (unless it was fitted with a B type gearbox when it had two more mounts) were weird and unobtainable Metalasic ones. They were available with different gearbox options so you would need to identify the box and then find its weight if its critical.

Link to comment
Share on other sites

Thank you gents.  What would the Hurth gearbox then weigh?  Approximately 46kg?

 

All I could find was a Dutch owner's manual that states "Gewicht motor en keerkoppeling:  +/- 300kg", which seems too high.  I just came across a poorly scanned copy of the Thornycroft 90/2 brochure which I believe states "Type 90/2 Engine with Hurth HBW 100 Gearbox: Weight 232 kg (511lbs)". 

 

My sailboat uses a hydraulic closed-loop (hydrostatic) drive, where the engine is mounted sideways aft of companionway and is connected to a manual variable hydraulic pump.  The hydraulic motor is down in the bilge.  So alignment of the engine matters only to the wet exhaust and to properly sharing the load amongst the mounts.

 

The photo is looking aft with the companionway stairs removed.  The centreline of the boat is roughly at the oil filter.  Thankfully no weird Metalasic mounts.

DeTroep_engine.JPG

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.