Smokey Ford Sabre 250 - Page 4

doggypaddle · 08 October 2012, 20:46

I will keep my fingers crossed for you, not to find any more nasty surprises left behind by the monkey that put it together

Rokraider · 08 October 2012, 20:54

Thanks. Engine block etc now dumped at the machine shop. It will be a couple of weeks before I will get it all back. Will spend the next few evenings stripping out the remaining heat exchangers and Tig welding the turbo intercooler up.

Should get the Jet mainshaft back tomorrow, so can put the jet back together as well.

mister p · 08 October 2012, 21:02

Does the lobster pot thread contain more words than the smokey sabre?

Rokraider · 08 October 2012, 21:04

Aiming to overtake the "Lobster Pot" shortly. Thank you for contributing to the word count.

doggypaddle · 09 October 2012, 16:02

Well I haven't really got anything to say right now, but I thought i would post something just to add to the word count

Did have a thought about the thermostat though and assume you will be fitting a new one anyway, but when the one on our cargo got taken out it was surprising how smokey it got very quickly on light load, soon as the temp dropped to 60C it started to smoke on tickover.

Rokraider · 09 October 2012, 18:03

Yes, will be fitting a thermostat. pretty sure that was contributing to the problem, as it never really got warm.
This was doing exactly as you decribed, when left idling it would start to smoke and would continue to do so until it had a good thrash.
Apparently these engine are prone to getting too hot when pushed, so a common bodge is to remove the thermostat to keep it running cooler.

doggypaddle · 09 October 2012, 19:05

i seem to recall some engines of that era Perkins 6-354T possibly had 2 stats in parallel. I suppose you could do something like that to get more flow, or fit a bigger stat in the hose.

Rokraider · 15 October 2012, 18:01

Feeling happier today, started putting some stuff back together! Built up the jet drives mainshaft with all new bearings and seals. There was quite a bit of damage on the shaft where the water seal is supposed to sit and seal, so I had the shaft turned down at that point and had a sleeve machined up and shrunk fitted and then turned down to the correct tolerance. Everything is nice and tight and should seal properly now. I have also had a new sleeve made for the cutlass bearing to to sit on, as the old sleeve was quite chewed up and worn. Once I have tidied up the tail housing, it can go back together. That will be the job done in the jet department.

I am impressed with the Hamilton design, very simple and easy to maintain and very strong.
Having rebuilt the Castoldi for the last project, I definitely prefer the Hamilton design.

Popped in and had a look at the cylinder head last week, It is looking very nice, should be collecting it this week.

Rokraider · 25 October 2012, 16:27

So, the bad news continues.. The machine shop have measured the bores and number 5 has a +.005" outward wear area on the Starboard side of the liner about halfway up its bore! Why it should be like this is anybodies guess? There are signs that the bores have had water ingress as well. Apparently they only offered a +015 oversize piston, which are no longer available. At best it means new liners and pistons, at worst it means another block.
The upside is that No 5's problems will have contributed to the smoke problems. so I am gradually getting more answers together.
The head has been skimmed on its faces and the valve seats have been recut. Problem is there is a tiny contact area probably about 2mm wide on the outer edge of the inlet valves and the exhaust valves, although better, the inserts faces are still not very nice and No 1 still has a chunk out of it. In fairness I don't think we will be able to do much with that seat. Probably looking a new inserts now.

Am starting to get the hump with this...

doggypaddle · 27 October 2012, 13:42

sounds like you need a set of valves and liners.
If the pistons are within tolerance you may get away with liners and rings?
probably save a fair bit of money.
have you tried the likes of Sparex and Vapormatic for these parts?
they may be the same as some of the tractor/industrial engines?
the .005 in the middle of the bore would explain some of the problems too.
its an expensive business building an engine

Rokraider · 27 October 2012, 16:20

I am going to get No 5 liner pushed out to see if the block is deformed or cracked, as can't figure out why just one point on the bore has ovalled outwards by 5 thou? If the block looks ok, then will replace all the liners and measure up the pistons to see if they will go again. (not holding my breath). The pistons are not the same as tractor / truck. The bowl has to be machined to alter the compression ratio. The rings need to be chrome type to cope with the turbo.
The valves themselves may go again, it is the seats in the head that are not good.

Rokraider · 29 October 2012, 18:06

Block is scrap.... Cracked behind the point where the liner is deformed. Possibly caused when liner was installed?

captnjack · 29 October 2012, 18:18

Ugh

all this diagnostic effort and now what?

Rokraider · 29 October 2012, 18:54

Another block has been sourced, will have it crack tested, light skim on the head face to ensure it is flat. line bore the main bearings and then fit new liners. As I am into it this far now, going to raise the compression ratio a bit, should help with smoke when cold. Have found some brand new, but old stock pistons that I will have the bores machined to.
Turns out the crank needs a grind, so will have that done as well. just the rods to check and hopefully it will start to go back together.

A1an · 29 October 2012, 19:56

Blimey!

If you didn't have bad luck then you would have no luck at all!

captnjack · 29 October 2012, 20:12

Is the Saber worth all this effort? Its not all that modern of a design (although my knowledge of it is 2nd hand)

Rokraider · 29 October 2012, 21:33

This Rib was apparently a development boat built by Halmatic to evaluate using a Jet on a Pacific. It is interesting and quite different to the later production models. I wanted to restore it to its former glory with a couple of modern tweaks to make it more user friendly. I have a 3.0 BMW Tdi in bits that I could have assembled and marinised that would happily make 275 BHP all day long at probably half the weight, but I like the idea of a big old chugger working properly, so I continue on this quest. Apart from the financial horror it has become, I am actually really enjoying the project. It would be nice to get a couple of breaks though.

doggypaddle · 30 October 2012, 15:05

Quote:

Originally Posted by Rokraider

Another block has been sourced, will have it crack tested, light skim on the head face to ensure it is flat. line bore the main bearings and then fit new liners. As I am into it this far now, going to raise the compression ratio a bit, should help with smoke when cold. Have found some brand new, but old stock pistons that I will have the bores machined to.
Turns out the crank needs a grind, so will have that done as well. just the rods to check and hopefully it will start to go back together.

How are you going to raise the compression ratio?
The pistons should be virtually flush with the top of the block, The head is Flat so skimming that makes no difference, Gasket thickness makes a small change to the bump clearence, the only real significant change can be a piston change which i would be weary of, the CR needs to be fairly Low as its turbocharged.
If the CR is 16:1 static its nearer 30:1 at 1 bar boost. the head gasket could be a weak point.

Rokraider · 30 October 2012, 18:51

The new pistons will need to have the bowls machined to reduce the compression ratio to make them suitable for a turbo. They will be machined less than the old ones with a target CR of around 14.7:1 instead of the original 13.7:1. this should help burn the diesel at idle and should still be safe at the top end.

doggypaddle · 30 October 2012, 20:08

I take it the the pistons aren't coated then which is good
I thought the CR of these engines was around 17-1. I am surprised the thing will even start from cold without Ether at the figures you quoted

I have seen production petrol engines running CRs higher than that (mazda 14-1 in the new engines same as the diesel derivative)
Skip it and wing a 24 valve Cummins 6BT in there