Hey guys this question is for those of you who have striped a vtec motor down and put it back together, where did you postion the oil squirters. They have a little capability to swivel more towards the middle of the piston or back towards the cylinder wall. Where did you position them before tightening them down? It’s funny, my acura shop manual says be careful installing them, but that’s about it. Doesn’t say make sure they are dead center or away from the cylinder wall or anything like that. It’s scary to see how close the crank comes to those squirters. I didn’t notice that when i was taking it apart, but now that i’ve spent so much money on the project I notice every little thing. Okay, well hopefully can give me some insight.
there should be a guide pin on the squirters that keep them centered. when the squirters are removed the pin either stays on the squirter or on the block. you have to make sure that they are properly torqued down so oil will squirt through the squirter and not seep out of the bolt.
Yes there are guide pins, but even with those in place, you can move the squirter side to side quite a bit (it pivets around those pins) because there is a little play between the squirters and the squirter bolt. So I was wondering if there is any benifit/necessity to possitioning them.
Oh yeah, was anyone else surprised when they saw how close the crank comes to those squirters?
Those jets need to positioned toward the outside of the piston because they lubricate the wrist pins. If you look at the underside of the GSR/ITR pistons you’ll see small holes for the oil to enter. Here’s a great picture to show what I’m talking about:
The wrist pin’s oiling holes are only present on certain engines. All the R-spec. pistons have those holes. Non of the B16A or B17A pistons have them and only some of the B18C1 engines have them. Those holes are unnecessary. The after market pistons don’t have them since they are in an structural area. The pistons get lubricated by splash lubrication. Whatever oil gets splashed up by the crank and rods lubricates them. The oil jets are there to help cool the pistons by squirting oil to the bottom of the pistons. The pistons are the only item in the combustion chamber that can’t get cooled easily. The cylinder walls and the head have a coolant jacket. The intake valves have fuel to cool them and the exhaust valves have a high temp steel composition. But the piston doesn’t get cooled of very easily.
Honda and some imports were some of the first engines to employ a similar technology to their rods. The all engines aside from DOHC VTEC engines had an oil hole drilled into the bottom of the rod facing the intake side and with the proper rod jornal oil lubrication hole position, the oil would shoot out to the bottom of the piston. Since it only allowed oil to reach the piston only at a certain crank angle and the amount of oil delivered to the piston drastically reduced at high RPM, the DOHC VTEC engines employed oil squirters. The squirters have some way of controlling oil delivery in the bolt . There is a check valve that only allows the oil to flow when there is enough oil pressure so as to allow for sufficient lubrication. The crank throws of the counter weight are pretty close to these squirters. So if you plan to utilize a stroker kit like one like a crower kit ,which uses a prelude B18 95 mm crank, you will need to plug these holes up. This is one of the reasons that I don’t like the stroker kits.Stroker kits also ruin the rod ratio so the high reving useability is reduced. These aren’t the only engines the have such technology. The MK4 Supra’s 2JZ-GTE, G2 MR2 and the celica alltrac turbo’s 3S-GTE also employ piston oil squirters. I believe the NA 300ZX (last gen) also had them. These squirters help prolong the life of the engine. By cooling the pistons the rings live longer. The oil doesn’t cook on the ring lands and the oil control ring doesn’t collapse. All this also has other factors as far as tuning, how its driven and maintanance.
Those squirters only fit one way. If they don’t line up properly then something isn’t right. There is a divet in the block and a protrusion in the squirter that line up together so if they are installed improperly there may be some damage to the squirter,bolt and/or the block. if you have some play with them installed properly then this is probably normal and not at all critial as far as positioning, as long as it points to the bottom of the piston.
Very good info carchitect, yeah I think the play I see is normal and not a manifistation of a defective bolt/squirter. I’m going to just center them someplace in the middle and tighten them down. I have full floating rods/pistons and they do not even have metal where the -R pistons do (where those holes are) so aiming the jets at those is not applicable to my situation, but is a good suggestion for those running honda pistons.
I once tore down a 1994 Mazda MX6 4 cylinder engine and it had those same oil jets, but they were pressed into the block. A pain to get out and a pain to put back in. But they did the job and those engines run for 250k+ with normal maintenance.
