Perkins Perama M20 Replacement

[russcannell]

Hi All,
I have a perkins perama M20 which is the KB 100 series. (103-06) It has lost compresssion following an overheat last season. I have been offered a new 400 series 403-07 to replace it. My question is will the marinising parts on the old engine...manifold, SW pump and sump fit the 400 series? Perkins do not marinise engines so i am at a loss as to who to ask. I realise the engine is slightly larger in capacity but unfortunately i have no other alternative as the 103-06 is no longer manufactured.
Cheers
Russ

[beneteau-500]

Why dont you just rebuild the existing engine parts are still available fit new liners and pistons and rings plus a few other bobs and bits

[russcannell]

Originally Posted by beneteau-500

Why dont you just rebuild the existing engine parts are still available fit new liners and pistons and rings plus a few other bobs and bits

Reason is I really wanted a new engine in there. Not just for residual value but also for peace of mind. The marinising gear is in really good shape so I thought it would be easier to swap it over to a new engine. I have had a price to rebuild the existing engine for £1950. However the 400 series new old stock is only £1450. So no brainer really. The question is will the marinising parts from the 100 series fit!

Cheers

Russ

[beneteau-500]

if memory serves me correctly No they wont check with perkins sabre marine they have the specs and answers on there site ?

[Boracay]

I had a look on the Perkins website and the 400 series engine does not appear to have a marinised version.

Your choices look to be to rebuild your existing engine or to fit one of the several new small marine diesels that are available.

My experience in trying to fix old, worn out engines has been that it is an exercise in futility and a waste of time and money.

[russcannell]

The 400 series also comes as a marine genset. Also the external dimensions appear to be as per the 100 series. The company that is selling the 400 seems to think the marinising gear will swap over with no problems. However I wanted to check before I lash out £1450! decisins decisions.

Cheers
Russ

[s/vAngel]

The overheat, if it was caught in decent time and didn't seize the pistons, may've contributed to blown head gasket = loss compression and loss o' power. New head gaskets are available for these if U decide to rebuild. I had the same exact thing happen to my M20- the thermostat failed and she overheated. Was caught right away, but still caused some warpage and blew the gasket. Had to do a top end overhaul and found that it wasn't that bad. Now she runs like a top.
It's worth taking the head off at least, clean out the carbon and peeking inside: valves burnt? Springs okay? any cracks in head or block? Pistons tight? cylinders clean or scored? Those tiny "swirl" type combustion chambers clogged? If she still looks good, it's worth a rebuild. save $$$!

[s/vAngel]

YouTube - Liveaboard Boater Repairs Her Perkins M20 Diesel

oops, hopefully this jibberish above leads to a video on Perkins perama M20 head gasket repair...

[russcannell]

Originally Posted by s/vAngel

The overheat, if it was caught in decent time and didn't seize the pistons, may've contributed to blown head gasket = loss compression and loss o' power. New head gaskets are available for these if U decide to rebuild. I had the same exact thing happen to my M20- the thermostat failed and she overheated. Was caught right away, but still caused some warpage and blew the gasket. Had to do a top end overhaul and found that it wasn't that bad. Now she runs like a top.
It's worth taking the head off at least, clean out the carbon and peeking inside: valves burnt? Springs okay? any cracks in head or block? Pistons tight? cylinders clean or scored? Those tiny "swirl" type combustion chambers clogged? If she still looks good, it's worth a rebuild. save $$$!

Hi there...Having spoken to a tech guy at Perkins regarding using a 400 series as a replacement engine. He pointed out that the M20 is in fact a 103-06 built specifically for boats. Whilst the marinising parts will fit a 400 series and also a 103-07 industrial engine. The increase in cubic capacity would mean the engine will run hot under load. So it looks like I will have to strip the engine after all. I suspect the overheat caused the rings to bind to the piston. If so it will mean an engine out and rebore with new pistons. Going to the boat next weekend to start stripping the engine. Unfortunately I don't have a crane to haul the engine out. So just going to set a tackle on the boom and haul it up and swing it over to the pontoon. Just hope I can still remember how to put it all back together. Always had bits left over when I did this as a yoof...!!!

[Laidback]

Originally Posted by russcannell

Just hope I can still remember how to put it all back together. Always had bits left over when I did this as a yoof...!!!

Digital Camera

[russcannell]

Ok well pulled the engine out of the boat. Stripped it down and have found that the cylinders are brown from the top of the block to halfway down the cylinders. There is no appreciable scoring. The exhaust elbow was badly clogged as are all the exhaust ports. The inlet manifold is also lined with carbon / oil. It looks like the engine has been blowing past the rings for sometime. Soo what next? My thoughts are to have the block honed and fit new pistons & rings? What other work would you all recommend whilst the engine is out?

Cheers

Russ

[s/vAngel]

Wow - the question is= is what looks like piston blow-by from the seriously clogged exuast ports and elbow (that'll cause much power loss and symptoms looking like blow-by) those ehaust gasses have to go somewhere! Clean those exhaust passeges really well and check the piston rings to see if they're still seating okay... if the cyl bore is not scored that is GOOD news.
keep me posted. sounds like I had same problem (overheat, then head gasket blew which sent oil into cyl and clogged everything, forcing exhaust gasses to go where they shouldn't.) Hope all goes well
Rebecca