Sabre Perkins still overheating

[stuartwineberg]

Thanks

We have the ford sabre 150 x 2 ,. different engine, however same principals, v similar pumps

Are you running at equal boost pressures if not set engine speeds to get equal boost, & therefore equal power supply.

on these the thermostat opens one side, and at the same time blocks off another passage. this type cant be removed and the engine run safely at higher powers. If the perkins sabre is different , try running without t stat.
raw water pump is easyly done quite straight forward. at the same time replace the seal, on ours it is a carbon faced one side and ceramic the other. Definately replace the cam, back plate & impeller at the same time.


New impellers installed with worn plates take a long time to reach full efficiency, much longer than when all is replaced. not a problem at low engine power, but higher powers find the weaknesses. do the suction pipes have wire reinforcing to stop them collapsing with higher flows. are the pipes the correct size as indicated by sabres. Certain the sea cock is opening fully, not bunged with growths etc

Personally Iwould keep the power on a litttle longer, as t stst has to open fully, and it might not yet have done so. The fact it so quickly returns sounds like a blockage / back pressure issue. I take it the header tank doesnt bubble at higher power from lost combustion products. there is a tester avaailable to test for this.

If I had enough hose I would piut the water out put from one engine to the exhaust of the other, in both cases, and carefully start both at the same time to avoid engine flooding, then go for a spin. if no change ,revert & do the same for inlets. if no change revert, then swap sea water pumps engine to engine.

Good practical simple ideas there - I like the idea of swapping the hose feeds for the intakes - that should be easy - swapping the pumps comes next I think - but the reminder abotu the dinghy pump is appreciated - will do that as well.

 

[stuartwineberg]

Thanks Paul

As you have now given us some readings from your hand held thermometer from the area where the temp sender is that good, but you have only really looked at the hot area where the sender is.

The idea of checking temperatures in your case is to gather data from the sea trial, return and take stock of what data you have, then an answer to the problem can be found.

You really need to take more readings in other areas of the engines cooling system, and exhaust system in order to find whats working to its capacity and whats not working, thats where the answer to the problem will lie.

As you say you saw steam that could be from different reasons, 1 actuall heat created from lack of sea water in the exhaust elbow as thats the hottest area of the engine near the turbo. 2 the raw water actually really hot, up to somewhere near the same temp as the fresh water, if thats the case the heat exchanger is doing its job but the overheat is actually true temp in the system due to another component not doing its job. 3 a very high exhaust temp which is transfering back into the engine right through the system, if thats the case it needs sorting before you end up damaging the valves, turbo and piston tops.

Id have a sea trial with me or who ever that can go about diagnosing your problem with the data gathered.

As the sea temp is quite low the raw water side should work really well but there could be a massive imbalance between the two due to component failure somewhere on the engine, as ive said gathering the right data is the answer, as ive said in a previous volvo related post its a bit like pinning the tail on the donkey through a welding mask.

Ive just been talking to a Broom 41 owner with the 300 mti engines, hes just had a 24k rebuild by a well known Perkins agent, all because of a raw water problem not related to impeller failure, his exhaust manifold resembled a cullender from the heat.

Taking readings round the engine makes sense - just need a much less lumpy day to do it on. I'll pass on the really scary stuff later in your post for the moment - hope we don't go there. Simple solutions first and then when they don't work go deeper - but as always advice very much appreciated

 

[pampas]

to check that the instrument are not the cause, extend tne wiring for the sensor from port to starbd, ditto starbd and go for another run. Not un-common for the display to alter with age, might save a lot of grey hairs.

 

[stuartwineberg]

Readings are direct

to check that the instrument are not the cause, extend tne wiring for the sensor from port to starbd, ditto starbd and go for another run. Not un-common for the display to alter with age, might save a lot of grey hairs.

Thanks for that and because of that thought invested in the laser thermometer so the 10 degree difference between the blocks is a reading taken directly off the metal surface - same spot - front of head head just behind the header tank

 

[stuartwineberg]

Latest actions

Backflushed the inlet with the dinghy pump and checked all the hoses. To be honest can't see any change in flow when i open the stopcock. Couldn't take the boat out today but ran it at high revs on the dock (I know it isn't what you should do). No bubbles in the header tank so head gasket prob OK. Engines got up to normal working temp (about 84 on the gauges) but even after over 30 mins at 2200 revs the port engine didnt move upwards. I appreciate this wasn't under load but for interest here are temp readings round the engine
Port is the faulty one - port readings first in each case
Face of fresh water pump 76 78
Front of engine cylinder head 86 85
Exhaust elbow 19 19
Pipe between aircharge cooler and exchanger 77 82
Pipe from oil cooler to exchanger 22 19
Pipe from exchanger to exhaust 22 22
Thermostat housing 83 84

I realise this int going to help much until I do the same thing at speed out on the oggin - should I measure anywhere else?

Failing that I think I am looking at ?turbo issues? - I was interested by a previous post I hadn't noticed where someone with a similar engine was told by a Perkins engineer that this slow temp increase was normal - can this be the case?

 

[stuartwineberg]

PM Sent

had exactly this issue on my Sabre Perkins 225Ti's - it was always an irritation, but never came to anything. Shortly after buying boat the problem arose when I first cruised at speed in my semi d atlantic 38 . Fine all day at displacement speeds but once above 14 knots - up the temp went on starboard engine. Had engineer strip everything down and he found nothing at all to cause problems. he said it was normal and just to carry on and reduce revs if temp crept towards 100deg.
We cruise normally at displacement speeds so it was never a major issue until 5 years and many thousands of miles later we had the boat up for sale and the buyer was unhappy (understandably) At our expense, an engineer spent a week, stripping, sea trialling, part after part. Water pump housing backplate was found to be a little worn and replaced - made no difference. minor sludging around thermostat housing and themostat replaced - still no difference. Not an engineer myself , but the guy went through everything with a fine tooth comb and other than those very minor issues he found everything in tip top order and finally came to same conclusion as engineer #1. Perkins were consulted and they said the temp rise was within normal paramaters. Fair enough, but still didn't explain why the other engine allways ran cooler. Incidentally and paradoxically to me, the hotter engine in my case was the one runnning the calorifier!
The buyer was satisfied and bought the boat and is still happy with his purchase.
So OP, like you I was never happy with it, but learnt to live with it! If you don't get to the bottom of it try not to lose too much sleep.
I will watch the thread with interest to see if a solution arises.

PM sent

 

[scoty]

quick reply

Sorry I have only a few minutes to reply,,,,,,,in my experience, this type of overheating generally turned out to be silt build-up ,in the cooling water around the outside of the engine cylinders, thus stopping the transfer of heat to the cooling water etc,

will return another day to read your problem more carefully

 

[volvopaul]

Waste of time comparing notes while engine is not under load, im not surprised at the readings there hardly any different, yet you have said previous it runs too hot for your liking, go and do it on a calm day.

 

[david_bagshaw]

How can turbo issues cause overheating? (others add please)

they either spin or not, or leak oil, or whistle, or if damaged,blocked, engine under fueled, produce no boost.

I dont have any wastegate experiance on diesels, so may be issues there , other than over boost / no boost.

check gear box & shaft temps on your next run, as a great difference might indicate either a problem, or more power is going through that box. Would add oil temp in and out of box as well

 

[scoty]

back again

Having spent more time reading your problem,,,I would certainly put my money on, silt/crud what ever name your put on it,,,,depending on the waters you are in, ie. soft or hard,,,or with lots of suspended contamination, the muck/silt/crud, builds up slowly or quickly around the outside of each cylinder liner, the heat generated by the engine is then retained and not dispursed by cooling water (or at best more slowly than the engine generates more heat at higher rev·s (speeds)
Depending on how badly silted up,,dictates the method to use to cure the problem.

your choice, first is to find how bad is the muck build up,

 

[david_bagshaw]

Having spent more time reading your problem,,,I would certainly put my money on, silt/crud what ever name your put on it,,,,depending on the waters you are in, ie. soft or hard,,,or with lots of suspended contamination, the muck/silt/crud, builds up slowly or quickly around the outside of each cylinder liner, the heat generated by the engine is then retained and not dispursed by cooling water (or at best more slowly than the engine generates more heat at higher rev·s (speeds)
Depending on how badly silted up,,dictates the method to use to cure the problem.

your choice, first is to find how bad is the muck build up,

the OPs engines would not be direct cooled, so silt in cylinders would not be a problem.

 

[burgundyben]

the OPs engines would not be direct cooled, so silt in cylinders would not be a problem.

Not unheard of for remmnants of casting sand to be stuck in a block...

Could this be caused by fuel timing?

 

[david_bagshaw]

Not unheard of for remmnants of casting sand to be stuck in a block...

Could this be caused by fuel timing?

interesting,

Bentley enabled their engine, inhereted from RR to meet the emissions tests by casting a filler in the lower block to reduce the water volume. casting sand would lead to overheating cyl walls, not the water?

 

[Latestarter1]

interesting,

Bentley enabled their engine, inhereted from RR to meet the emissions tests by casting a filler in the lower block to reduce the water volume. casting sand would lead to overheating cyl walls, not the water?

The concept of only cooling the top half of the piston in an internal combustion engine was first recognised and patented by Phillip E Jones in the late 70's who was a leading designer for Perkins and latterly Cummins.

Logic is that you only cool the part of the piston which actually gets 'ot' and let the skirt look after itself. Leads to very temperature stable power cylinder, faster warmup and reduces heat rejection to coolant.

Going back to the original suggestion about core sand, issue is generally associated with new engines when residual core sand in the head casting restricts thermostat opening.

Volvopaul has reservations regarding the marginal nature of the Sabre cooling package on the higher rated 260/300 Phaser engines, however this motor is just a 225 and has done nothing in the way of engine hours.

Suggest nothing for it other than going through the cooling package all over again OR consider the possibility of a trapped air bubble causing a thermostat restriction, but not sure how sensitive Phaser engine is to coolant filling speed, and draw down.

Outside runner is coolant mix, in high ambient seawater tempertures 50/50 water coolant mix results in higher than normal engine operating temperture.

 

[tinkicker0]

Is one of your engines contra rotating or do they both spin the same way?

 

[Latestarter1]

Is one of your engines contra rotating or do they both spin the same way?

Hi Tinkicker,

This is a Phaser, Perkins gave up building contra engines at the end of Dot 3 I think.

 

[tinkicker0]

Ah I see. Only ever built one Phaser 4 cyl so don't know anything about them which is why I am keeping my nose out of this thread.

Did strike me about the water pump though

 

[stuartwineberg]

Thanks again

The concept of only cooling the top half of the piston in an internal combustion engine was first recognised and patented by Phillip E Jones in the late 70's who was a leading designer for Perkins and latterly Cummins.

Logic is that you only cool the part of the piston which actually gets 'ot' and let the skirt look after itself. Leads to very temperature stable power cylinder, faster warmup and reduces heat rejection to coolant.

Going back to the original suggestion about core sand, issue is generally associated with new engines when residual core sand in the head casting restricts thermostat opening.

Volvopaul has reservations regarding the marginal nature of the Sabre cooling package on the higher rated 260/300 Phaser engines, however this motor is just a 225 and has done nothing in the way of engine hours.

Suggest nothing for it other than going through the cooling package all over again OR consider the possibility of a trapped air bubble causing a thermostat restriction, but not sure how sensitive Phaser engine is to coolant filling speed, and draw down.

Outside runner is coolant mix, in high ambient seawater tempertures 50/50 water coolant mix results in higher than normal engine operating temperture.

My engine is the 265 so VP point may apply - however this is a problem that appeared after 4 years of no issues so doubt it is a design issue. Also understand the point about the coolant mix but we certainly dont have high seawater temps here!

Next step is the tour around the engine with the thermomemter whilst going at speed. That may give some answers

 

[Latestarter1]

Stuart,

Spent the weekend with owner of marine services company who had stong ties with Sabre in Poole.

As soon as I mentioned your problem his response was immediate. Ten degree rise in operating temperature, Problem well known to Sabre guys..........Strip the heat exchanger, and take tube stack out. You will find engine coolant side of heat exchanger coated in a gooey slime. Apparently slime results in long term reaction of coolant with chemical treatment used by the foundry who cast the heat exchanger body. Once the tube stack is 100% clean and cooling system completely flushed engine operating temperature return to normal and issue never returns.

Good luck

 

[burgundyben]

Stuart,
Spent the weekend with owner of marine services company who had stong ties with Sabre in Poole.

I wonder who that might be??

Fab weekend.