Just Finish Rebuilding My Rb25Det

[MJTru]

Hi mates

I just finished rebuilding my rb25det after blowing up the last one (det) 2 much boost on pump gas.

Well the first thing that happened was all the oil blowed into the catch tank, and then the lifters failed. After pulling the engine down and finding that the forge pistons were damaged. I didn't want to reuse anything, so i started fresh. I got 2 motors and gear boxes from e-bay. And rebuild them both, one being for another car and one for my R33 Skyline. Now The last motor worked well lifter wise, But after moding the crank and installing the crank collar i then installed 2x 1.5mm restrictors in the block (N1 oil pump) leaving the VTC restrictors alone. Next i installed an extra head oil return and fed it to the turbo oil return line. Most of this info i gathered from this site, so i must say, thank you all.

I should mention that the motor is fully built, exsept for the head. (OEM head with new valve seals)

The problem that i'm having is the f**cking lifters man. Even at low boost 11 psi at 7500 RPM's I'm having lifter problems. Now i know that most have converted to a solid lifter system, with supertech being the suppler of most of those parts needed. But i live in a country were if i want to do any machine work to the head i would have to ship the head to the states. I wouldn't mind shipping it to australia, but it cost abot 800 dollars just to ship it there and back, so guy's like Dan at Elite racing is out of the question. about the only thing i got from Australia is a 6Boost manifold and Haltech ECU.

Well last night i was driving the car hard, at about 15psi the highest i ever go with pump gas. At about 7000 RPM's the engine started to miss. At first i thought that it was just spark plugs, but after pulling up in the drive way i heard the lifters (maybe one) were making noise. I then cut the car off and checked everything. The oil was good, nothing in the catch tank, and all seemed good. Keeping in mind that a new born baby can be born dead, i changed all the plugs, oil's, filters etc. I didn't even start the car. i just went to sleep. The next morning i started the car, and it idled a little ruff, but then cleared up, I drove it to work, and all was fine. No noise from the lifters. The lifter had about 45000 km on them. After work i noised a little lifter noise, but after reaching home the noise was done. i then took it for a hard ride, and the thing is more quite that ever.

All being said and done, i now hate hydraulic lifters, because its in the back of my mind, and now i'm scared to run the car with race fuel at the 25psi.

What i'm after is the solid lifter system, and i have just some simple question about the cylinder head. Now i met a guy in Miami who said that he can do the head, but needs to now the gap space between the cam and the lifter cup.(buckets) for the intake and exhaust side.???

Next insted of buying the supertech kit, is there anything else i can do??

i've heard of people using GTR buckets??? Can this work.??

I want the most for my money, so if i can reuse the OEM valve, and just add spring the buckets, and then pay for the machining, that would be grate.

Well i hoped that i've explain myself well enough for you guy's to help with this problem.

Thanks in advance.

[tridentt150v]

what makes you so sure its lifters, or should i say a lifter?

[R31Nismoid]

Just what i was thinking. Seen many heads run 20-25psi without a problem, my own included in that.

If it is lifters, head reco (standard) would probably just be enough.

hate to say it, but i don't think boost killed your last motor, more likely the tune.

[wolverine]

New hydraulic lifters are cheap from the US if you are that worried. There was a thread floating around here somewhere with a link to a supplier.

If I start my R33 and shut it down without bringing it up to temperature (and let it cool completely) it will run quite rough for a few minutes. I have always assumed this is a lifter sticking. Once it warms up a little it is fine. I almost never start it and let it cool down completely so it is a non-issue day to day.

Once the engine comes out for a freshen up I will make a decision on whether it is worth doing anything with it.

[MJTru]

Well boost did kill the motor do to detonation. the fuel here is crap. its something like 93 octane. 25psi with that will kill it.

As for me thinking that its lifter, i build engines all the time, for years now and i know what lifters sound like.

I drove the car home a while ago, No sounds, but i noticed higher oil pressure. I'm lots as to that.

I do agree that a stock head can take 25psi. My last motor did that with no problems lifter wise. Because of the slowly dying bottom end, it all went to hell.

Well we must keep in mind that 25psi is close to the limits for hydraulic (oil) lifters, if not to close. so running it at that level hard is a bad idea. Ok I’m just assuming here, I'm an opened minded guy, by no means trying to brag. this would just be my thinking.???? I may be way off.

thanks for all your thoughts keep it comeing<BR style="mso-special-character: line-break"><BR style="mso-special-character: line-break">

[MJTru]

New hydraulic lifters are cheap from the US if you are that worried. There was a thread floating around here somewhere with a link to a supplier.

If I start my R33 and shut it down without bringing it up to temperature (and let it cool completely) it will run quite rough for a few minutes. I have always assumed this is a lifter sticking. Once it warms up a little it is fine. I almost never start it and let it cool down completely so it is a non-issue day to day.

Once the engine comes out for a freshen up I will make a decision on whether it is worth doing anything with it.

It would be nice to know of a suppler down here. I heard that the z32 300zx twin turbo has the same lifters. does anyone know if this is true.???

[wolverine]

I am pretty sure they are the same. If you search the forum that thread should eventually pop up.

In cylinder pressures during combustion should be anywhere around 1000psi (ish) detonation will double this suddenly. If the turbo is on the limit it will be pushing more heat in there which won't be helping.

Ultimately it really comes down to tuning to suit level of boost you are running relative to the quality of your fuels.

Did you mention what turbo you are using and was it making more power above 20, 21, 22, 24, 24, 25psi?

Here is the link to the thread on where to buy the lifters.

http://www.skylinesaustralia.com/forums/topic/361912-hydraulic-lifters-noisy/page__view__findpost__p__5776895

http://www.rockauto.com/catalog/x,carcode,1209844,parttype,5548

Edited June 1, 2011 by wolverine

[tridentt150v]

Poor fuel = knock and that can sound like lifter rattle [it can also sound much worse as we all know] just sayin'

If you always have poor fuel and it seems to be affecting your engine reliability esp. at higher boost levels -, and you can't get good fuel - why don't you try WMI as a solution?

[zebra]

lifter prob?

as the others said I doubt its lifters, unless your running huge cams and 10,000rpm they shouldnt be pumping up and hitting valves.

[DVS JEZ]

back the timing off 5 degrees and try it again to see if the noise is still there, then you can say its not det and its the lifters.

[GTScotT]

Next time the sound comes up, try free revving it with the bonnet up. If you can hear it while free revving, try unplug one coilpack or injector at a time, while leaving the other 6 plugged in.

If by shutting off a certain cylinder you can make the noise stop, your issue is far more serious than a noisy lifter. More like a stuffed big end bearing.

Bad big ends would either be a result of a dud tune (as stated before) or a bad build (considering its not an old motor, and was just rebuilt). As unfortunate as it is, I think this is the most likely scenario, and believe you will find it was most certainly your tune and not how much boost was run that killed the motor.

For reference, the tune could depict what sort of boost you could run.. It could be tuned so hard (and wrong for that matter) that it will ping with any more than 15 pounds of boost, OR you could tune it so soft that it will safely run 30 pounds of boost (turbo dependent).

Try to work out what your actual problem is before proceeding.

[The Mafia]

I pulled all of my lifters apart and cleaned them. NEver had a problem with them after that.

[MJTru]

I pulled all of my lifters apart and cleaned them. NEver had a problem with them after that.

I was thinking about doing that, but I’ve never rebuild lifters before. I just might give it a try, I can remember some one giving me a brake down on rebuilding the lifters, Right here on SAU. Now I know its the lifters and not the bottom end or big bearing. At 15psi I'm only getting about 19 knock levels. That’s good and the check engine light don't even flash (power fc). I know its not pinging or getting detonation. After seeing that the knock was low I then used A head set to listen for knock and its really good, going on boost i can hear a little ping for a slight sec. This is ok, as its no where near the last motors pinging levels. All the above mention ideas are good ones, and I can tell that you guy's really are into these cars according to your answers.

I like the fact the some one said to use WMI system. I already ordered one from E-bay, and I’ve been reading up on it. I was surprised to find out the window washer fluid is made from methanol. That’s cool. Now back to the topic at hand. Using the WMI system is ok and all, but lifters are a bigger problem.

Is the GTR's buckets the same? And do you guy's know if a machinist can make them work??? What’s the gap clearance between the cam and buckets for solid setup? ?????

If i was to go solid, I would need to know this. Also going solid, would put my mind at ease. From what the last motor was doing I know I can run a higher boost level with right tune and fuel. I had some idea that the last motor would have failed, Its just that I didn't understand detonation. So looking at the check engine light flashing, and the engine not braking right away. I thought that all will be ok. Later on I understand that detonation kills over time and that’s what happened. Well when i said that the motor blowed up. That was a over statement. I had a lifter failed do to cracked ring landings. This caused the blow by to push all the oil in the catch tank, leading to a oil deprived engine. This is when I noticed the lifter slapping. I swapped them out for a good set and it was the same. I then pulled the head, and that’s when i noticed the pistons were eaten out, and # 6 cylinder had a broken ring that slapped against the head. I then started over from scratch, I didn’t even reuse a single part.

Ok, still no noise after pushing it at 12 psi, I Drive the car almost everyday, the oil pressure goes up and down. Some day's it's low and some day's its high. I hooked up a good mechanical gauge off the oil filter housing, and when the factory one reads low I went under the hood and that one was reading 30-35psi at 800RPM's. When I rev it goes all the way to about 110 PSI It max's the gauge out at a 160Psi if I rev it hard.

So oil pressure is good, and the factory gauge is shit.

Do you guy's think that these lifters just needed a brake in period. ????

[17psi r33]

hay mate, i had this happen to me the other day, i had changed my timing belt on my rb25, after a few days had a noise come up that i was sure was the lifters as well, turned out to be the 4 bolts on the water pump pully were lose and thats where the tapping noise came from. was verry hard to single down to that. but i was my bad!!! still check that out while your under the bonnet.

[MJTru]

I pushed the car hard on sunday at the tracks, Still no noise.

Well i'll just have to hope for the best.

Thanks everyone

cheers.

[zebra]

I then used A head set to listen for knock and its really good, going on boost i can hear a little ping for a slight sec. This is ok, as its no where near the last motors pinging levels.

Is the GTR's buckets the same? And do you guy's know if a machinist can make them work???

Ok, still no noise after pushing it at 12 psi, I Drive the car almost everyday, the oil pressure goes up and down. Some day's it's low and some day's its high. I hooked up a good mechanical gauge off the oil filter housing, and when the factory one reads low I went under the hood and that one was reading 30-35psi at 800RPM's. When I rev it goes all the way to about 110 PSI It max's the gauge out at a 160Psi if I rev it hard.

So oil pressure is good, and the factory gauge is shit.

Any pinging is bad..even if its just a split second, the slight knock is hammering your rod bearings, then imagine in 50,000ks you have to rebuild again. I would find that load cell with the knock and knock a couple of degrees of timing out.

The GTR buckets dont fit and its not viable to stuff about with them to make them work, if you want solids use the Tomei kit with springs and cams to match.

160psi of oil pressure is WAY too high, Id bet there is something blocking an oil gallery which is also causing your lifter noise.