Toad555

Hi I have a single pipe central heating system installed on my boat, the main circuit runs all the way around the boat in 22mm pipe. The system is heated by a 5kw Webasto unit. It actually works really well except for two issues. 1. It's quite cold in the middle of the boat where my office is so I'd like to add an extra radiator there. 2. The system is a nightmare to bleed because the pipe work goes up and down so much. Hence why I'd like to straighten out some of the pipework as part of this proposed work. My question is, should there be restrictions in the 22mm pipe between where radiators are currently installed. Most of the system is 22mm finrads which are obviously in the main circuit but there are currently two standard radiators, both have a reducer in the 22mm pipe between them. I assume this is simply to force water flow around the radiator but is it really necessary?

Ah sorry I forgot to mention, there cup ones. Quite a deep cup too at 12mm. I've been in touch with Perkins this morning and they confirmed 40mm is the correct size, I assume the interference clearance on the one the third party one I have tried is incorrect. Going to order directly from DiPerk now I think to ensure they're correct

Yeah I did do, it was clean and dry, I installed the new plug with Hylomar and it still leaks. I've been learning as much as I can but I'm still a little in the dark about why it leaks and why it was so easy to install. The next size up definitely won't fit and the nearest imperial size is smaller than 40mm so that won't do either. Maybe the 40mm plug I installed wasn't actually 40mm, going to do a little ringing around in the morning before ordering another new plug. Its not too bad to get to but I really don't want to make this a habit, the starter motor has to come off each time too so not ideal afternoon entertainment.

Ah, very valuable info, thanks for that. It's beginning to seem like the engine is a mismatch of metric and imperial anyway according to several PDF's. I think the answer has to be a 40mm plug, the one I bought had a shallower shoulder than the original so that has to contribute to a poor fit too. I'm going to get another 40mm plug from a different supplier with the correct shoulder height and give that a try. I sealed it with blue hylomar, does this sound appropriate to you? or should I use something else or nothing at all?

Morning I didn't get any replies to this post so I went ahead anyway and removed my failed core plug, I managed to measure it at 40mm and ordered a replacement. Unfortunately it didn't go so well. I fitted the new 40mm plug and it went in very easily which was a concern, sadly its still leaking so I'm guessing its not 40mm. Does anyone know if Perkins engines are imperial measurements meaning I should have ordered an imperial core plug. The nearest imperial measurement seems to be 1" 9/16ths, does this sound right???

Hi Does anyone know the size of the core plugs for a Perkins MC42. Its the one behind the starter motor which is leaking and needs replacement. I'd really like to get a replacement before I dismantle it to remove the failed one. Thanks Julian.

Hi Can anyone help confirm thread sizes for water temperature and oil pressure senders for a BMC 1.5 There is currently no instrumentation whatsoever, not even an oil pressure light. I'm hoping to fit a water temp gauge, oil pressure gauge and a oil pressure warning light, maybe a buzzer too. The boat is 200miles away in London so I'd like to try my best to take the correct fittings with me when I go to install. I'll be buying new electric gauges and senders to take so at least these will match but I'm not sure what I'll need when I get there. Current info seems to suggest the oil pressure fitting is 1/8 NPT, I assume I'll need a T piece to fit a switch and pressure sender? The water temp the gauge comes with a 1/8 NPT fitting, does anyone know what thread is in the head, do I need an adaptor?

Bearings and seals aren't expensive for this gearbox, the whole entire seal kit is only about £20 with P&P. Sadly I think other parts if required could run to a larger bill. Defo talk to Richard tho, he really helped me out with mine. Toad

I can't work out how or even if its possible to attach pictures.

It all depends where your oil is leaking from, mine was pretty much pouring out of the front of the gearbox where it joins onto the engine. The input shaft seal is a 30mm rubber oil seal that seals the front input shaft where the gearbox attaches to the engine. The chap from Primrose Engineering was really helpful with my oil leak and posted all these pics on his website http://www.primrose-engineering.co.uk/prm-delta/ I've also got a few pictures of my gearbox removal which I'll try to post later, they're on my phone at present. If you have to take the gearbox out I guess its well worth getting the whole seal kit from ASAP supplies only about £20 inc P&P and has every single seal and O ring. Only really worth it if you have to remove the gearbox, I guess if your noise turns out to be just prop fouling then no need to remove the gearbox, I had no choice as mine was spraying all the oil out in about 20mins. I think mine was easier to get off as the engine is mid mounted too so it was a nice job of kneeling down beside the engine to work rather than being cramped in a Trad stern or cruiser.

Thought I should come back and tie up this post. My gearbox leak is all sorted now, it definitely was the input shaft seal that had perished, under a fiver for a new one from Hayley Bearings in Stoke on Trent soon had it sorted. I did have to remove the gearbox to replace this seal as mentioned before but it wasn't too bad a job. Prob about 4hrs in total but I was learning all the time.

Any further progress on this one? I've recently recovered from a prob with my PRM Delta gearbox, thankfully no nasty noises but it kept spitting all the oil out into the engine tray. Turned out to be the input shaft seal which was under a fiver plus new oil. Reason I mentioned this is because I had to take the gearbox out to fit the new seal and it wasn't so bad, what I did discover is that its a fairly tough gearbox and also not too heavy to take out. You can easy do this on your own with only a handful of tools too.

Ah ha, thats useful info, helps calm my nerves about my oil level. I take it you topped up so the level was just on the top mark when the dipstick has been screwed in fully.

Yep I looked at a stainless tank option but the cheapest quote was £380 I think, even the plastic tank I bought in the end was a cash deal, it should have been £180.

Yep I fully agree, its a lot of money but not really comparable to household fittings. The £1000 I mentioned is actually over the top, its certainly less than that but I can't remember exactly what the deal was, if you look at the price of the LeeSan marine kits they're tons more than that. I paid less than that for all the bits but it was fairly complex to get the correct stuff, from memory is was something like this; Vetus ceramic electric macerator toilet £250 Tank £150 Brass fittings, pump out etc £100 Hoses, clips, plastic fittings, tools etc £100 Tank gauge £50 I don't think its possible to get the parts any cheaper than that. Its possible to install a dump through maybe for less but the layout of our boat dictates the spec we chose.