Piston cooling jets K series

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kasin
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Piston cooling jets K series

Hi

I am going to be rebuilding an engine in the coming months and I have decision to make. The engine needs rebuilding due to oil starvation during track driving. 

To rebuild the engine I have two potential blocks to use. One standard Rover block, where I need to do the cutting into the webbing to mount the starter or another block where the previous owner of the car has installed piston cooling jets(oil squinters). I will be mounting a PACE dry sump system to the engine. The engine will also have forged pistons and rods, as well as Mahle motorsport bearings. The head is ported with 285H cams. The induction will be throttle bodies with Emerald K6. 

Would the oil squirter have any negative impact? From what I could see they worked fine in the engine as long as I had a wet sump. 

Kristoffer

p.mole1
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Hi I am running the same spec engine as you with forged pistons. As far as I am aware oil jets are not required. I don't know anything about the oil capacity of the pump. I would contact Dave Andrews or Oilyhands on this forum and ask his advice

revilla
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I've rebuilt a couple of engines of a similar spec and neither had cooler jets. As to whether they will have a negative impact, I'm not sure, I guess as mentioned above it depends on the capacity of the pump to feed them. How are they fitted? To the block or oil rail? Are the block or rail modified or drilled to accept them? I'm thinking could you just remove them? Oil rails are interchangeable and easy to find. Modifying the standard block is not a hard job if you have a bell housing (or remove the one from your car) to use as a jig. Just fit it to the block, offer up the starter, see where it conflicts, mark it and take some metal out. Do it a bit at a time (you can't put any metal back easily!) until it all fits with a millimetre or so spare all around (slip a piece of card up between the starter and block to make sure there's a gap).

SV VVC 170 - 170.4 bhp @ 7100 rpm - 142.4 ft.lb. @ 4900 rpm

kasin
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The jets are installed by drilling in the block, not the oil rail. I would think it could be possible to block them off, but if so I could just use the other block. 

If there isnt any downsides to them I might leave them, some cooling to the pistons might be a good idea? 

 

Kristoffer Kåsin

Caterham Roadsport

Norway

revilla
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I have no experience of them but the questions in my mind would be 1) Where do they take their oil feed from? 2) How will they impact on oil pressure? 3) Do you need a higher capacity oil pump of some sort to compensate? If they somehow bleed oil off at lower pressure after the OPRG then it would be less of an issue, but I'm afraid I don't know whether they do and without having one in front of me I can't even think of that would be possible?

SV VVC 170 - 170.4 bhp @ 7100 rpm - 142.4 ft.lb. @ 4900 rpm

elie boone
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Aren't cooling jets for the pistons drilled in the big end of the con rod ?

garybee
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Many engines have a spray bar low down at the edge of the barrel.

revilla
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I'm guessing they must be something like this?

SV VVC 170 - 170.4 bhp @ 7100 rpm - 142.4 ft.lb. @ 4900 rpm

kasin
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In my case the squirters are made by drilling into the oil hole for the main bearing you see in the middle of the picture. I will take a picture this evening. 

 

Kristoffer Kåsin

Caterham Roadsport

Norway

garybee
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In which case they will be lowering the pressure and flow of fresh oil at the mains.  I wouldn't like that.

revilla
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Instinctively that would be my thought too. Unless somebody like Oily can come along and tell us it will be fine from experience, given that engines of that spec don't seem to need the oil jets I'd choose the standard block.

SV VVC 170 - 170.4 bhp @ 7100 rpm - 142.4 ft.lb. @ 4900 rpm