R33 GTR AFR levels at cold start, cruising and WOT....please help

[judasentinel]

I totally forgot about the crankcase breather connecting back to the intake. Yes, it is. One side is going back into the intake side of the head thru a PCV valve, but that will work ONLY if the car is running and there is vacuum built into the intake, right? The other side is connected to the catch can, which is recirculated back to the intake tubing on the rear turbo. And that is where I felt the air coming out of - the rear turbo. So this is probably rings then...? I might have been wrong then....its not the head.

I will ask him to do the leakdown again with the breather hoses disconnected. Let's see how it goes.

[judasentinel]

Engine is done. All air coming out of the breathers. I think that's what was causing my idle and oil in turbo issues all along and I was blind to it. I guess I am in the market for a used bottom end. The head is fine, so only shortblock. Sigh....sigh....

[future_R34]

😢another sad day. Hopefully #5 isn't damaged and you could just replace the rings on all the Pistons, instead of getting a whole bottom end.


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[judasentinel]

The mechanic says that it might cost more to do the bottom end than to just buy a used one with good compression.

Not sure about it yet. I have to save up money now to get a shortblock and then get this done. This hurts bad.

[GTRADDICT]

Sorry to hear that buddy. Atleast you learned stuff from it...

[judasentinel]

I did. But at what cost!!!

Besides, the ONLY way to know the extent of the damage is with a bore scope or by taking the head off. Bore scope is not available and taking the head off is pointless unless I have a replacement block. It is still driving fine, so I will drive her home, wait until I have access to a decent block and then swap it out. No point paying him to take the engine out now, leave the car there until I get an engine and then do it.

[steveo1502]

Ahhhh that sucks , used rb's aren't cheap... then it's still 20 yrs old , I'd do a rebuild , oem parts , rings bearings gaskets

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[judasentinel]

So much for the LS2 swap and getting a nice R33 GTR....hah!!

I dont know what will be cheaper - a used RB26 bottom-end with acceptable compression or buying internals and swapping them out in my R33 RB26. Any ideas? What all can I reuse from my engine, assuming the damage is limited to cylinder 5 alone?

[future_R34]

So much for the LS2 swap and getting a nice R33 GTR....hah!!

I dont know what will be cheaper - a used RB26 bottom-end with acceptable compression or buying internals and swapping them out in my R33 RB26. Any ideas? What all can I reuse from my engine, assuming the damage is limited to cylinder 5 alone?

If the cylinder walls are not damaged, just a quick hon and new rings on the current Pistons new head gasket...... Then head back on and set timing. That's what I would do!


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[judasentinel]

Thank you for the suggestion.

The only way to truly find out if there is any damage to cylinder(s) is by taking the engine out. And at that stage, I will have to decide whether to just do what you are suggesting or use a different block.

Here is my question: If I can source out an R32 block, can I just put my R33 crankshaft into it without any work required, or will I need to rebalance the crank and do any adjustments into the other block's internals? That is also an option that I am contemplating. The other thing I can do is to just use an R32 block and slam the R33 head on it, drive it until it croaks, while I rebuild my R33 bottom-end with new internals over time. The mystery would be to be sure that the R32 bottom-end I get is not damaged in any way.

So as I see it, I have the following options:

1. Buy a used R32 engine and just do a straight swap
2. Buy a used bottom-end R32, put the head from my car on it, and drive it for as long as it lasts, while I rebuild the R33 block form my car
3. Buy a used R32 bopttom-end and put my R33 crank in it, and use that
4. Just rehone my R33 bottom-end if needed, buy new rings, and put it back in

And for the decision to be made, I will need to have the engine out in all cases, and the mechanic will have to inspect the bottom-end to see if there is any damage. He doesn't have the time for it right now. So I am flying blind and need to decide whether I should buy a used bottom-end and fix it (if needed) over the next few months, after which I can swap it into the car with the existing head, or just drive her back to the mechanic, have him pull the engine out, tow the car back to my place, bring the engine back and put it out in the cold on an engine stand, and then when I have the time and weather permits, tear it apart and inspect it. I am leaning towards the first option, as it gives me the added flexibility to have a spare block for the future, and doesnt break my bank immediately.

[future_R34]

R33 GTR AFR levels at cold start, cruising and WOT....please help

Winter is just on our door step. Fix your engine over the winter or just replace it. I personally Wouldn't bother making a frankin-skyline motor($$$) and also build another ($$$$). Just fix yours and save yourself extra money, one rb26 is enough to worry about, never mind making two engines! Lol
My 2 cents😏


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[judasentinel]

A little update:

Finally got a mechanic to actually take a look at it - cylinder 5 is now down to 20 psi....and some others (2 & 3) are also showing signs of wear (compression getting close to under 110). The guy wouldnt tear apart the engine and insists it is the bottom-end. I am seeing blowby through the crank case, and when I let go of the throttle after revving, I see smoke coming out of the rear turbo as well - the PCV is recirculated to the rear turbo.

He has assured me that there is no catastrophic damage to engine - not yet!! So I am in the market for another engine. The cost to rebuild it, I was told, could be over $5K, what with taking it out, tearing it apart and then getting the work done and purchase of parts. Since I am trying to economize, perhaps a used engine block with internals would work better as an option for me?

Opinions? Ideas? If someone has a used RB26 block with internals and no issues with the compression or cylinders, I might be interested. Thanks for all the inputs and support.

[tommytomatoes]

If this car isnt your daily driver [hope not]: I would save up money and redo the bottom end yourself. Whether building or reusing the rods while getting 86.5mm piston set and boring the block with a hone. With the compression being lower in many cylinders, I would bet a few of the cylinders are tapering near the top.

While youre there, do small things like replacing all gaskets with an oem gasket and seal kit, water pump, oil pump [inspect for wear along inner gear, if good reseal and put loctite on backing plate bolts, or new pump] oil restrictor [tomei], t-belt and pullies etc

The main problem is the cost on labour since you havent done anything like this before.... have any prof mechanic friends to help you out?

[judasentinel]

I don't have any mechanic friends. And since I live in a small-ish town in an apartment, it is quite challenging. I am weighing the option to either buy a fully assembled bottom end, slam my head on it, getting a disassembled engine (with all internals), or just tearing my own engine apart and replacing the rings. The last one seems to be pricier somehow, primarily due to the labor costs different shops have quoted to me. So I am at a loss as to what to do. Seems the fully disassembled engine option is better as I will have a spare engine that I can continue to build over the next few months at my own pace.

I wish there was a way to temporarily restore compression and fix any sitcking/stuck valves to bring the compression up if possible while I do all this.