RB25DET tapping after hard autocross run
 

Im hoping to get some good advise. I've scoured the forums looking for the best solution to my possible oil starvation problem on my S14 RB25DET. It is fully built and the shop claims to have done all the necessary things to improve oil flow for racing in the head including restrictors and the whole deal. However, yesterday at the autocross it would tap for ten minutes or so after a couple of 55sec runs. I seem to be able to get on it as much as I want in a straight line with no problems so Im wandering if it could be the lack of decent oil baffles in the RB25DET when Im throwing it around. I am shifting just shy of 8k so I may need to verify the hydraulic lifter arent the culprit do to my RPM. Thanks in advance for your help!!!

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How do you know its oil starvation? Do you see your oil pressure gauge dance/jumping around while on the throttle? If you're worried about oil starvation, time to go dry sump setup.

Are you using the stock oil pump? Ive heard restrictors are only needed when using an after market high flow oil pump on the s1/s2 rb's and rb's with solid lifter heads. I've been reving mine to 8k for almost a year on a new stock oil pump and stock head with no restrictors fine. Only had a hydro lifter bleed off 1 time after 3 back to back runs but went away after idling for a little bit.

Shit, I'm running N1 oil pump with no restrictor...no issues here. I have yet to see my oil pressure gauge jump around like the sump is empty.

What oil are ya using for one?!

Thank you all for your responses. The first thing I need to do is add an oil pressure gauge. It has a brand new N1 oil pump but I went out this weekend before installing the gauge since she has been running so great. I assume it is oil starvation due to what sounds like all the lifters are tapping after some hard runs, Im pulling over a G in back to back turns and slaloms with a couple decent straights for no more than a minute at a shot. The lifters slowly quiet as the engine idles after the runs and you can here them individually slowly quiet down as they catch up. I know the gauge will tell a lot in those moments it just doesnt seem like I will be able to safely recreate that on the street and was hoping someone has had this same situation so I didnt have to run my motor in the same way to recreate if I dont have to. The shop that built the motor said there are no restrictors in the head and says he runs the same setup on mine as all the other RB's they build.

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Mobil1 Synthetic 10w-30

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that oil is way too think. 40weight man.

are you running an oil cooler?

I plan to install an oil cooler along with the pressure sensor and remote filter.

Im confused about your comment about the oil weight. 30 weight isnt as think as 40 weight? Did you mean not thick enough?

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10-40 for a dd, 10-50 for racing...

I only race it. Does 50 weight make that much of a difference? Does it not slosh away from the pick up as easy or does it have something to do with the head draining properly?

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Honestly, if you have oil coolers and your oil temp doesnt get close to 100*, you dont need 50 weight oil. Most I've seen my oil temp get up to is about 90 with an oil cooler and I'm running 10-30w right now since its winter. Thicker oil takes too damn long to warm up and circulate in the morning.