Perkins 4-108 Overhaul

[Goldjason]

I am just about run out of options in trying to do an overhaul of the Perkins 4-108 diesel. After removing all the head bolts the head will not part from the main block. It must be frozen to the block. Was able to turn the engine finally at the front end pulley after flooding the cylinders with penetrating oil. The service manual was no help. It simply says remove the head bolts and remove the head from engine block. Any suggestion will be greatly appreciated. Thanks

[Redcoat]

Here everyone thinks you can rebuild a Perkins for a dime. If you are serious take it to a reputable shop and spend the money to get it done right. Total rebuild every thing. And it will cost you about $7000.00 or call TA Diesel and buy one from them. NO RELATION. I have installed two of their motors and they both fired on the second turn and ran perfect. So if you don't have a big hammer or $7000.00 ????????? Best of Luck

[HappyMdRSailor]

Cylinder heads do not just fall off once you've removed the head bolts... Find a nice convenient protrusion to pry on... NOT the mating surface... Give that corner a little encouragement with a copper hammer...

PS: Most of the time when heads do not separate when motivated by tools... There is usually a missed fastener still bolting it down...

[model 10]

If you have the rockers off so the valves are closed, just crank the engine. It should pop right off.

[Cheechako]

Double check that all blots are removed.

[Goldjason]

Thanks for all the positive responses. All head bolts were definitely out. Yes I was thinking of cranking it to pop the head off. Yes all the rockers are off. Hope the compression is sufficient to pop the head off. Will probably do a Youtube video later for those attempting to do it themselves. Any new suggestions are still welcome !

[dwhite1172]

Dave, I hope that you were successful in removing the cylinder head on your Perkins 4.108 because I am in the middle of removing mine. I hope you can give me some advise.

How do you remove the coolant tank? The nuts on the holder for the rocker arms were very tight, I was afraid that I might break the studs. I have not removed the nuts that hold the head on the block, that's next.

I would appreciate any advise that you can give me. I thing I have cracked head, water in #2 cylinder.

Dave W

[Goldjason]

Thanks to all who gave suggestions. The head was off and cleaned. No major corrosion in the cylinders. We ordered the new set of gaskets and should have the engine for test run when everything is put back and hop to sail by spring.
One set of caution. There seem to be two different type of head gaskets. One of them is identical to the 107. The application seems to be different from the mfr. One type requires some kind of sealer before the head is put on. The other type requires the gasket to be put on dry. Could not figure out the reason.

[oldcal46skipper]

Patience.
We have disassembled 12 Perkins 4.108's so far this year and have 4 more in the shop. Sometimes it is easier if you remove the head studs, but you need a proper "stud remover". We use a Proto Stud Remover. Otherwise do as previous readers have suggested.
If you admit defeat, ship us your old 4.108 and we will rebuild, re-man or repair it and ship it back. Our price for a total re-manufacture of a 4.108 is $5,995 LONG BLOCK + shipping and possible other costs, like grinding a damaged crankshaft, replacing tappets and camshaft, maybe even rebuilding the injector pump, oil pump, etc.

Okay, we are somewhat biased, but we believe the Perkins 4.108 is one of the best diesel engines ever built. Otherwise why would
Ma Perkins have built over a half million of them? Our re-mans go over 10,000 hours with proper maintenance.

Hope this helps. We are booked up until March 2015.

Tom at BSH Marine, Bayou Chico, FL

[yachtiebob]

I have access to a brand new, never run, full marine 4108, ready to drop in for £8000 sterling if anyone is interested.
Bob


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[oldcal46skipper]

Originally Posted by yachtiebob

I have access to a brand new, never run, full marine 4108, ready to drop in for £8000 sterling if anyone is interested.
Bob


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Where is the engine? Is it crated for shipping?
Can you arrange shipping?

Tom, Pensacola, FL USA

[yachtiebob]

Hi Tom,
The engine is grated and we are in the UK, but unfortunately a deposit had been paid this evening. It is due to be collected in two weeks. If the deal fails I will post a message on the site.
Many thanks in your interest.
Bob


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