Any Nissan engine experts on here?

[m_c]

Anything is possible, just not always realistic.

Oil cooler is usually easy. Bypass it, and run the engine up for a while and see if you get oil out the coolant connections.
Head issues not so, as leaks may only happen under certain conditions, like heating up under high load.

My concern would be you mentioned the bores were scored. That sounds like it's been cooked at some point, so you could be looking at a cracked head or block.
Were the heads pressure tested when off?

 

[roofman]

Did you do any RB26 engines?

no bud...the VG motors

 

[sg66]

I've done vg and rb25, I've not met anyone running a skyline engine that didn't have a constant stream of issues.

 

[ukracer]

Anything is possible, just not always realistic.

Oil cooler is usually easy. Bypass it, and run the engine up for a while and see if you get oil out the coolant connections.
Head issues not so, as leaks may only happen under certain conditions, like heating up under high load.

My concern would be you mentioned the bores were scored. That sounds like it's been cooked at some point, so you could be looking at a cracked head or block.
Were the heads pressure tested when off?

No I don't think that it was ..

 

[ukracer]

I've done vg and rb25, I've not met anyone running a skyline engine that didn't have a constant stream of issues.

That's not a good sign.

 

[ukracer]

Anything is possible, just not always realistic.

Oil cooler is usually easy. Bypass it, and run the engine up for a while and see if you get oil out the coolant connections.
Head issues not so, as leaks may only happen under certain conditions, like heating up under high load.

My concern would be you mentioned the bores were scored. That sounds like it's been cooked at some point, so you could be looking at a cracked head or block.
Were the heads pressure tested when off?

Can you pressure test while in the car.

 

[sg66]

Not with the oil system. You tried testing the water for poc, it may not be showing up as a problem but if it's positive you can definitely start looking at the head.

If oil cooler is water/oil, bypass it first.

 

[ukracer]

Not with the oil system. You tried testing the water for poc, it may not be showing up as a problem but if it's positive you can definitely start looking at the head.

If oil cooler is water/oil, bypass it first.

What's POC?

Oil cooler is definately water/oil and it's original from when he got the car so I am hoping it's that.

Gonna run some Jizer through the water system when he fetches it on the trailer tommorow.

 

[m_c]

No I don't think that it was ..

Bore scoring has limited causes. Debris ingestion, corrosion (would typically also be accompanied with pitting), or lack of clearance (either due to wrong tolerances when built, or overheating). Lack of lubrication isn't likely to be a cause, as cylinder bores don't need that much lubrication, although having seen the state of the crank shells, I'd be interested to see the state of the original pistons. The condition of the piston ring groves/skirts would give a more definitive clue to the cause of scoring.

What's POC?

Oil cooler is definately water/oil and it's original from when he got the car so I am hoping it's that.

Gonna run some Jizer through the water system when he fetches it on the trailer tommorow.

Sniffer test.
You use a sniffer and a fluid, and sniff the gasses coming out the header tank/radiator. If any combustion gases are present, the fluid changes colour, however if it's just an oil leak, you won't have combustion gases, but it could still be a head problem. Just not one that involves a combustion leak.

 

[m_c]

Oh, and use liquid laundry detergent to clean the coolant system. It'll do a far better job than degreaser.

 

[ukracer]

Bore scoring has limited causes. Debris ingestion, corrosion (would typically also be accompanied with pitting), or lack of clearance (either due to wrong tolerances when built, or overheating). Lack of lubrication isn't likely to be a cause, as cylinder bores don't need that much lubrication, although having seen the state of the crank shells, I'd be interested to see the state of the original pistons. The condition of the piston ring groves/skirts would give a more definitive clue to the cause of scoring.

Sniffer test.
You use a sniffer and a fluid, and sniff the gasses coming out the header tank/radiator. If any combustion gases are present, the fluid changes colour, however if it's just an oil leak, you won't have combustion gases, but it could still be a head problem. Just not one that involves a combustion leak.

The piston rings had seized. Mains at the front had gone.
It's been stripped and fully rebuilt costing thousands since. But still has OEM oil block which was not renewed .
That was the part I was after an O ring for ....not sure where it leaks through or from but I can soon knock up a hydraulic rig to test that if need be.

 

[sg66]

Products of combustion, is the contamination a lot, could it just be festive from being stripped and not cleaned thoroughly?

It's not something I've ever had after doing a rebuild though.

 

[ukracer]

Products of combustion, is the contamination a lot, could it just be festive from being stripped and not cleaned thoroughly?

It's not something I've ever had after doing a rebuild though.

No they are struggling to get a stable map on it. Not knowing anything about mapping and getting third party info via my son who is very down over the whole thing is not good.....BUT despite trying to keep out of it I find it very depressing myself. I try not to but I am finding it hard.

This chasing horse power you don't need and can't use frustrates me.

It sounds like fresh oil is floating on the coolant and he has said there is definately no creaming which I associate with a dodgy head gasket.

The frustrating thing is he has been told about a head mod that prevents ingress of oil into the water that consists of drilling reaming and sleeving two parts of the head where hairline cracks can cause issues .
But I can't find it on Google or youtube.

 

[m_c]

The piston rings had seized. Mains at the front had gone.
It's been stripped and fully rebuilt costing thousands since. But still has OEM oil block which was not renewed .
That was the part I was after an O ring for ....not sure where it leaks through or from but I can soon knock up a hydraulic rig to test that if need be.

Seized rings are a sign of overheating.
It would have been good to see some photos of the pistons.

Knowing that, I suspect the issue is more likely a crack issue.
If you've got the ability to pressurise the cooler to a little bit above the normal oil pressure, and ideally at working temperature (although coolers are more likely to just leak regardless), it would give an answer to whether it's the problem or not.

 

[sg66]

I don't see why they would have trouble getting a good safe map on it unless it's got silly silly mods, just about every injector/turbo combination has been done to death, I think I still have a pair of standard 26turbos from a single conversion, I couldn't get shot of them at the time as nobody wanted standard.

Fast Road car is nice but once you start asking too much it becomes an expensive tail chasing exercise.