Perkins 4108 silent blocks

Roberto

Roberto

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Hello,
my Perkins 4108 (perhaps all) has the four silent blocks mounted on four metal pieces which are in turn bolted to the engine.
Do you reckon it would be possible to change the silent blocks (and maybe the four attachments) one by one, just supporting/lifting a little the engine, without removing the whole engine?
Has anyone done it? If so, which precautions?
thanks r
 

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Yes, but if they are 'tired' the position of the engine might not be correct to the shaft. So, a check on the shaft flange clearance with the bolts loosened would be good idea.
We did the chocking/ changing bit, but also the shaft alignment.

Out of interest, also had a problem with a 4108, where the engine was shifting forward under drive due to the forward mounts being attached to the front steel plate behind the accessories gearing, which flexed. It was enough to make the shaft seal leak quite a bit. Two braces back to the block sorted it.
 
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Yes, Ive done that on the two back ones that went soft on me, just block the engine to stop it moving
You have, of course, to remove the brackets from the engine,
otherwise you cant get the threaded shaft on the foot through the hole in the bracket.
The brackets are very strongly built and shouldn't need replacing,
If there rusty, the wire brush treatment and a few coats of paint will last another 20 years.
 
Thank you all!
Next winter my marina will be dredged so all boats will have a couple of months free storage space on land, I am planning to replace seacocks etc, do some rudder work, the engine silent blocks might go at the same time. :)
 
scottie said:
It’s worth checking if your engine is a factory produced marine spec or not as this may affect what mounts and even bell housing you have
Click to expand...

I don't think Perkins Engine Company Limited ever made a 4 107 or 4 108 marine diesel engine.
 
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A Perkins mechanic told me that the Perkins factory never made a diesel version of the 4 107 or 4 108. He said there were about six "jobbers" who would buy the industrial motors and marinise them. If you look at the photos he must be right :D


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coopec said:
I don't think Perkins Engine Company Limited ever made a 4 107 or 4 108 marine diesel engine.
Click to expand...
That may be true in the past. The current Perkins marine engines are done in house by Perkins Sabre. Part of the Perkins group. Ours is the M92B. An 86hp 4.4litre lump. Naturally aspirated stump puller. Low reving and fuel efficient ?
 
geem said:
That may be true in the past. The current Perkins marine engines are done in house by Perkins Sabre. Part of the Perkins group. Ours is the M92B. An 86hp 4.4litre lump. Naturally aspirated stump puller. Low reving and fuel efficient ?
Click to expand...

The mechanic didn't say anything about other Perkins motors (just the 4 107 and 4 108)

Of course these days Perkins Engine Company is now part of Caterpillar Inc.
 
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Roberto said:
Hello,
my Perkins 4108 (perhaps all) has the four silent blocks mounted on four metal pieces which are in turn bolted to the engine.
Do you reckon it would be possible to change the silent blocks (and maybe the four attachments) one by one, just supporting/lifting a little the engine, without removing the whole engine?
Has anyone done it? If so, which precautions?
thanks r
Click to expand...
I replaced all four, two at front single lift,but individual lift on rear. Easy access on my (then) boat,but maybe not so on some. I took many measurements for reference points of the engine to ensure relocation/alignment was as good as possible.
Be aware that the "shore hardness" is important if buying cheap replacements.
 
coopec said:
I don't think Perkins Engine Company Limited ever made a 4 107 or 4 108 marine diesel engine.
Click to expand...
There (the engines) a little before my time but Perkins the Company published manuals and parts books with the 'M' suffix which I believe indicated the marine variant of the base model. This would suggest that they did in fact manufacture a 'marine' variant.
Many people (3rd parties) 'marinized' the engines principally by modifying the cooling system etc but a pucka Perkins unit would have had many other considerations both internally and externally such as double valve springs etc that were seldom fitted to 3rd party conversions.
 
ean_p said:
There (the engines) a little before my time but Perkins the Company published manuals and parts books with the 'M' suffix which I believe indicated the marine variant of the base model. This would suggest that they did in fact manufacture a 'marine' variant.
Click to expand...
That is the one I have, 4.108M with Bowman exchanger (and Hurth reduction gear); indeed all blue booklets, documentation etc are printed "Perkins".
Another common marinized version was made by Westerbeke, US market essentially.
 
Roberto said:
That is the one I have, 4.108M with Bowman exchanger (and Hurth reduction gear); indeed all blue booklets, documentation etc are printed "Perkins".
Another common marinized version was made by Westerbeke, US market essentially.
Click to expand...

I have a blue book for my Perkins 4 108 but there is no mention of heat exchangers, water cooled manifolds etc .
Apart from Westerbeke was there a Noordeman Perkins too?

Maybe this is the manual you are referring to? I've had a quick look at it but all I can see is "raw water cooling"

User manual Perkins 4.108 (72 pages)
 
coopec said:
I have a blue book for my Perkins 4 108 but there is no mention of heat exchangers, water cooled manifolds etc .
Apart from Westerbeke was there a Noordeman Perkins too?

Maybe this is the manual you are referring to? I've had a quick look at it but all I can see is "raw water cooling"

User manual Perkins 4.108 (72 pages)
Click to expand...
You need to look again as raw water cooling isn't considered as an option. On page 54 ( page 56 of the pdf) the options are 'Indirect' & 'Keel''. The schematic there shows it all ! ?
 
ean_p said:
You need to look again as raw water cooling isn't considered as an option. On page 54 ( page 56 of the pdf) the options are 'Indirect' & 'Keel''. The schematic there shows it all ! ?
Click to expand...

I'll take your word for it!:D ( Can't spare the time to examine it). I'm working like a one armed wall-paper hanger here at the moment.:rolleyes:
 
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