kasin Posted August 13, 2020 Share Posted August 13, 2020 HiI 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 Link to comment Share on other sites More sharing options...
p.mole1 Posted August 13, 2020 Share Posted August 13, 2020 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 Link to comment Share on other sites More sharing options...
revilla Posted August 13, 2020 Share Posted August 13, 2020 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). Link to comment Share on other sites More sharing options...
kasin Posted August 13, 2020 Author Share Posted August 13, 2020 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? Link to comment Share on other sites More sharing options...
revilla Posted August 13, 2020 Share Posted August 13, 2020 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? Link to comment Share on other sites More sharing options...
elie boone Posted August 14, 2020 Share Posted August 14, 2020 Aren't cooling jets for the pistons drilled in the big end of the con rod ? Link to comment Share on other sites More sharing options...
garybee Posted August 14, 2020 Share Posted August 14, 2020 Many engines have a spray bar low down at the edge of the barrel. Link to comment Share on other sites More sharing options...
revilla Posted August 14, 2020 Share Posted August 14, 2020 I'm guessing they must be something like this? Link to comment Share on other sites More sharing options...
kasin Posted August 14, 2020 Author Share Posted August 14, 2020 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. Link to comment Share on other sites More sharing options...
garybee Posted August 14, 2020 Share Posted August 14, 2020 In which case they will be lowering the pressure and flow of fresh oil at the mains. I wouldn't like that. Link to comment Share on other sites More sharing options...
revilla Posted August 14, 2020 Share Posted August 14, 2020 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. Link to comment Share on other sites More sharing options...
simon_h Posted August 14, 2020 Share Posted August 14, 2020 Unless they have proper jets like the ones in the picture that shut off at lower pressures I wouldn’t want to use it. Does the turbo k block have them? Maybe that’s what it was originally. A home brew bodge doesn’t sound good at all though Link to comment Share on other sites More sharing options...
kasin Posted August 14, 2020 Author Share Posted August 14, 2020 This is not any original part, I would think this is home made. Link to comment Share on other sites More sharing options...
oilyhands Posted August 14, 2020 Share Posted August 14, 2020 I think that would be overkill on a naturally aspirated engine, on turbo or supercharged engines dissipation of piston crown heat is more difficult and a cooling jet of oil on the underside of the piston can be beneficial, I've never seen that implemented on an NA engine. Normally an engine with cooling jets and/or turbo oil feed will be specified with an oil pump that has 30-40% more capacity to ensure that other vital feds are not starved of flow or pressure. If it were me I would be removing any jets/feeds and blanking them off.Oily Link to comment Share on other sites More sharing options...
oilyhands Posted August 14, 2020 Share Posted August 14, 2020 Excessive oil delivery to the bore/piston underside can overwhelm the oil control rings with resulting increase in oil consumption. The drilled feeds present in some rod big end eyes are usually for oil delivery to the bore rather than the piston underside.oily Link to comment Share on other sites More sharing options...
21jigsaw Posted August 14, 2020 Share Posted August 14, 2020 Why did it fail was it due to Oil aeration - pistons hit valves?rod bearing pick up?main bearing pickup?were you running with just a wet sump? Apollo? dry sump, oil level? oil temperature? Hydraulic / solid tappets. As mentioned previously was it a standard pump or modified to account for the extra capacity. Link to comment Share on other sites More sharing options...
kasin Posted August 14, 2020 Author Share Posted August 14, 2020 When the engine failed it was due to rod bearing failure. I do belive due to lack of oil, due to running sticky tyres on a track with a long fast right hand turn. Rod bearing number 1 was in pieces, I found a lot of it in the oil pickup - and the rod bearing on number 2 was also damaged. The rest of the bearings where fine. Normal wet sump was used, no apollo tank. Oil level slightly above max on the dipstick with a hot running engine. Oil temp not too high, didnt run long stints. The cam is a 285H, so hydraulic tappets.I do belive the oil pump to be from the turbo engine. As I promised earlier there are some pictures of the oil squirters attached. Link to comment Share on other sites More sharing options...
garybee Posted August 14, 2020 Share Posted August 14, 2020 Well, that mod will have reduced the pressure at the big ends so certainly won't have helped (pressure being the result of restriction to flow and you would have had less restriction with the extra squirters). Impossible to say what would have happened without them of course.I make sure my camera keeps the OPG in shot when I do track days so that I can have a quick check afterwards as I know that I'm unlikely to notice at the time. Did you see any reduced pressure displayed? Link to comment Share on other sites More sharing options...
kasin Posted August 14, 2020 Author Share Posted August 14, 2020 My passager noticed that the pressure dropped during the long right hander, and then we heard the start of the knocking. Link to comment Share on other sites More sharing options...
21jigsaw Posted August 14, 2020 Share Posted August 14, 2020 The turbo oil pump is the same as std k but a thicker rota to increase capacity. The wet sump scavenging is border line especially without an Apollo or dry sump.The extra capacity of the turbo oil pump was possibly to much. Link to comment Share on other sites More sharing options...
oilyhands Posted August 14, 2020 Share Posted August 14, 2020 As from 2001 all oil pumps have the thicker 11.5mm rotor. Failures on 1 and 2 are classic oil surge failures, air reaches those two bearings before the rear two and they fail rapidly. An Apollo will mitigate against that sort of failure, even if pressure drops in the Apollo tank due to surge and consequent pump effiency dropping when pumping air, oil will still reach the bearings albeit at reduced pressure or at worst by force of gravity.Oily Link to comment Share on other sites More sharing options...
kasin Posted August 14, 2020 Author Share Posted August 14, 2020 For the next engine I have purchased a PACE dry sump system. Link to comment Share on other sites More sharing options...
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