Engine re-build - Detroit - Desicion made - Start 03 Nov 2011

well done Alf,
can perfectly imagine what a big relief for the good result
after so much hard work, ;)

and you prooved that with some patience, carefull and hard work,
YOU can manage a serious and thorrow rebuild on DD's
congratulations !
 
Our engines are straight six's... so no V configuration ... correct label is 6/71 TIA.

Deliberately did not go for a boat with the "B" configuration as they have a bypass and rated at 2600 RPM and up to 485 hp... for the reasons you state in respect to reliability.

Take your point about the weight to HP ratio, but as I did not have any intention of pushing the 30 knot barrier and was going for an older boat with high displacement with abilit to keep reasonable speeds in rough sea, and with low maintenance cost, the DD's became a preferred option in the ranges we were looking...

If I were to change engines in our current boat, I'd be tempted by Cummins CTA's at 450 hp..., but would be woried about the boat's dynamics and how it would affect it's behavior at sea as I would loose about 1000 Kg...

Apologies Alf,

Now you know why I stay away from DD as well as Green engines. Only inline DD I have ever come across was a 4-53 in a Dutch barge I repowered. 4-53 was a sweet little motor.

Interesting you refer to 6CTA, rarely crops up, plenty in commercial use and replaced CAT 3208 in Flemings, a real no nonsense workhorse.

Good luck
 
Need to clean up, and work a bit on replacing carpets etc. (getting old anyway).

However, I thought I should post something about the cost of the re-build. Bearing in mind it was made more expensive than absolutely required as I did choose to replace full liner and piston. (Intent is to replace piston crown and rings on old piston and keep this & liner as cheap and readily available spare parts).

Anyway:

1x Cylinder repair kit (Piston, rings, liner, clamshell bearings, cylinder head guide stud and full set of seals for an engine re-build) £480
Replaced bolts, nuts etc. £10
2x Replaced coolant pipes (pictured and one more 1" x 2 foot) £60
New Oil £60
Coolant £50
New Torque wrench £35

Total cost £695 inclusive of VAT

I could have saved about £250, by going for piston crown & rings only, but now I have available spares in case something happens again...

Edit: cylinder head guide stud added to the re-build kit (was included in the cost)
 
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Need to clean up, and work a bit on replacing carpets etc. (getting old anyway).

However, I thought I should post something about the cost of the re-build. Bearing in mind it was made more expensive than absolutely required as I did choose to replace full liner and piston. (Intent is to replace piston crown and rings on old piston and keep this & liner as cheap and readily available spare parts).

Anyway:

1x Cylinder repair kit (Piston, rings, liner, clamshell bearings, and full set of seals for an engine re-build) £480
Replaced bolts, nuts etc. £10
2x Replaced coolant pipes (pictured and one more 1" x 2 foot) £60
New Oil £60
Coolant £50
New Torque wrench £35

Total cost £695 inclusive of VAT

I could have saved about £250, by going for piston crown & rings only, but now I have available spares in case something happens again...

Wow! Next time I need two engines rebuilt I know who to go to :D This isn't much more than just one piston replacement for my engines :confused:
 
As a fellow consultant I feel it fair to ask if you're willing to pay my current day rate on top of the parts ? :D

:D Unfortunately, I am still PAYE so I couldn't afford that as the Government almost take as much money from my earnings as I take home :( In only another year or so I expect to go back to contracting and switching to keeping most of my income and of course no longer having to work ridiculous hours just to keep my job.
 
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Then remove the idle screw cover from governor (as discribed in PM ....oil in here so be prepared and not surprised when leaking).

DSC_0172.jpg


And undo the locking nut (11mm) whilst holding the bolt steady with an allen key (cannot recall the size) ...

Back off idle screw a couple of mm...

....

Then loosen the “buffer screw” ... the one with a locking bolt next to the oil supply line on this picture, and back off a couple of mm.. (you won’t have to open the cover)

DSC_0147.jpg


Disconnect the cables (including stop solenoid) and lock the levers to “no fuel” ... throttle should do this by default, but “no fuel” on stop leaver may have to be taped up or tied back with a cable...

The “Stop” lever is the one to the far right in this picture... and needs to be lifted up...

DSC_0172.jpg
 
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The valve clearances is set by rotating the engine (with said power bar and socket) until injector rocker (middle one) is fully depressed, and the two outer ones (valves) are in the top position...

The insert a feeler gauge (0.016") into gap indicated in the first ot these pictures....

The feeler shold get in, but with resistance..... if it is loose, or too tight, you need to adjust the clearance.... by loosening the lock nut at the top of the valve rocker lifting mechanism (top arrow in second picture) and adjust the square on the lifter (lower arrow in second picture) with a 7mm spanner...

Adjustmets are exected to take place on cold engine.... and assuming you have a 4 exhaust valve engine... but looking at your model number, I am 99% certain that you have...

Let me know if you need anythign else.... :)
 
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Superb thread and job well done. I didn't interrupt while you were doing the work but enjoyed reading the various posts. Good pictures too.

Given me the encouragement to change the head gasket on our old Coventry CDB (1951). It's going to be a nightmare to do but hopefully not as uncomfortable as your job! Hope you have a good season. :D:D
 
Superb thread and job well done. I didn't interrupt while you were doing the work but enjoyed reading the various posts. Good pictures too.

Given me the encouragement to change the head gasket on our old Coventry CDB (1951). It's going to be a nightmare to do but hopefully not as uncomfortable as your job! Hope you have a good season. :D:D

Thanks .... much apprecated !!!

Was the original intention to share ....but if it has encouraged people to learn more about their own boats and engines, that is great !!

I do these things myself as in this way I get to know the engines better and if anything happens when at sea, I can troubleshoot with more confidence and take more informed corrective actions in the interest of safety and comfort for all onboard.. (not that I plan to replace pistons at sea of course ... :) )

.... and please post pictures of your work during or after the job is complete...
 
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