BMW D7 engine wanted/or similar/or advice

[Scorpiokent]

Hi i have a BMW D7 engine that has seized and am looking for a replacement D7 or if anyone has replaced one of these what engine di you replace it with and was it much of a problem to do so, what will i need or can i just unbolt the D7 and drop a different engine in? look forward to your replies, thanks Alan

 

[Latestarter1]

BMW D-7 was a marinised Hatz as I remember, last ones were sold around 1980 so you have had a good bottle of blood out of the motor.

Beta 10 would probably do the job as a replacement.

 

[toad]

I think these engines were used in a lot of small plant,cement mixers and the like. Dunmow engines may know what will be a straight swop.www.uni-power.co.uk

 

[Topcat47]

You'll need a new prop too, if not a new prop shaft. If you want raw water cooling, the Yanmar 1GM10 would seem to be the simplest replacement. If you want FW cooling, the Beta is the best bet IMO and it is a twin so it will be smoother running.

 

[Avocet]

There's a BMW D7 (and 12) user group on Yahoo

http://groups.yahoo.com/group/bmwmarineengines/

Worth joining and sending a message. There is more D7 activity on there than any other sort.

 

[RichLangtry]

Alan,

The following is a biased opinion. Based on our experience (and that's more than ten years' worth), the BMW D7, probably manufactured around 1985, is better than anything on the market today.

If you were here in North America, rebuilding your BMW D7 is not a problem.

There in the UK, we have yet to re-establish a network of quality machine shops. You might try David Watt at Kilmarnock Engines Services in Scotland. They run an excellent shop.

Economically, it is best to rebuild or repower with an identical unit. Changing brands can require moving or rebuilding the stringers, replacing the prop shaft, cutlass bearing and propeller. Next comes the plumbing and the electrical.

You might contact Steinar Danielsen in Norway. I believe he has a D7 in stock. Condition unknown.

There in the UK, there is also George Huxtable and his website covering the D7.

Alan, let's see what comments come back now!

Best regards from Canada,

Rich Langtry
V12 Engineering
www.bmwmarine.com

 

[davey]

Re the seizure, I know of THREE types of seizure on small marine engines. (1) Is the ubiquitous damp in the cylinder and rusted piston rings. (2) Which is particularly relevant to the BMW D7 is big end seizure (the seized Hatz that I examined was actually in a marine generator which had been grossly neglected as the lubricating oil was so loaded with iron that the oil was magnetic!) (3) A very unusual type of seizure can occur on the Yanmar 1GM10. This seizure allows the engine to turn almost two turns and is caused by a seized tappet. The problem can be caused by water leakage from the head gasket which runs into the aft tappet tunnel. Note that the BMW D7 which is really a Hatz HE673 has no oil pump and no oil filter as lubrication is done with a dipper. There is however a magnetic drain plug which needs cleaning at every oil change. Frequent oil changes are of course needed. A year or two ago I was surprised to discover that Bryco at Daimler Road could allegedly still obtain brand new crankshafts. The price was about £400 however. Considering how much a brand new marine engine costs, plus all the hassle and expense of the refit, it is usually more economic to keep the old engine running. A large number of the 6HP air-cooled Hatz diesels were employed on those vibrating pedestrian controlled paving rollers made by Stothert & Pitt (?) and Bomag (?) so there may still be many thousands of them still in use. Good luck!

 

[sailorman]

I would guess the OP has fixed the problem by now