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Jeff: There are differences between the sizes of the squirter holes. The Evo3 and 618 squirters have an outlet hole 1.0mm ID. The Wiseco, 907 and 217 have a squirter hole around 1.3mm. The difference can be seen in those close up shots I took of the squirter holes. Its kind of interesting... Just from comparing the squirters side by side it is obvious that the Evo3 and Wiseco are hand assembled and aimed. The bends in the each of the squirter arms are slightly different, as if each was bent by hand. The other squirters definitely have a mass produced appearance. As far as I can tell there are not any other significant differences, which might contribute to the large price difference. All of the squirters (including the 618 part) have a pressure valve that stops flow through the squirter at low oil pressures. I assume this is to prevent the squirters from draining all the oil pressure around idle. Just by using my finger I couldn't discern any real differences in the spring force of these valves. I assume they all start to open up right around the same pressure. One difference between the squirters is that the Evo3, Wiseco, and 217 parts seem to have a relief valve on the underside. You can see the small hole on bottom of these 3 squirters. I know its some kind of valve because you can see the spring inside. I'm guessing excess after a certain oil pressure the excess oil is escaped down through the relief valve to prevent damage to the squirter. The 907 and 618 parts do not have this relief valve. |
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Jeff: The 618 squirter appears to be the simplest solution to implement by far. The one obvious downside is that it will rob oil directly from the main bearings however (which leads to a direct rob of oil to the rod bearings). I am still not sure how significant this really is however. Ed note: Any oil squirter will rob pressurized engine oil from the other parts of the system. If the squirters are mounted to the main oil galley then oil supply to all others parts is reduced somewhat uniformly. As Jeff points out, mounting the squirters directly ON the main bearing caps, will cause the additional oil drain to occur only from the main bearings, and indirectly from the rod big ends, as these are supplied oil through holes in the crank arms which extend out from the main bearings. Installing the 618 part would basically just require a hole the proper size to be drilled up through the main bearing oil channel pointed towards the center of the bore and call it the day. No need to tap to the main oil galley, tap a threaded hole for a bolt, etc. For most motor configurations (where rod bearing lubrication is not so critical, as in high revving S14s) this solution is the best. I believe some of the Porsche oil squirters are mounted in a similar fashion to the 618 part. |
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Gustave: So, where does that leave us? Well, the ambitious S14 engine builder will find that there are a variety of options to choose from if wanting to incorporate under-piston oil squirters. And there are more choices than this; squirters from Audi, VW and Porsche can be had cheaply, and may also be made to work on an S14 block. But the implementations are not clear cut, and the consequences of oil supply to the main and rod bearings not always easy to estimate. The proven solution is of course and Evo III block with either Evo III squirters, or Motorsport squirters. |