Rb26 Compression Test Results

[shaunus]

Looking into buying an R34 GTR, had a seller take the car of interest to a reputable workshop of my choice this morning for an inspection.

Compression test results are as follows:

C1 - 145

C2 - 147

C3 - 152

C4 - 148

C5 - 148

C6 - 130

Leak down test results:

C1 - 6.5%

C2 - 6%

C3 - 5%

C4 - 7%

C5 - 9%

C6 - 15%

Now, the motor has been rebuilt and has forgies etc that were done mid 2013 (seller has provided receipts). It has apparently only done ~ 6000kms since rebuild... But obviously I have my concerns.

After speaking with the owner of the shop who did the inspection he ensures me it is a solid example and will give me no grief for daily use. (No track work as it doesn't interest me + I live in the sticks).

Told me it pulls very hard and after performing a leak down test he has narrowed the cause of lower compression in cylinder # 6 down to the rings.

I am sure some of you folks have been through a similar situation in the past so I guess my questions are:

- Should I walk away?

- Should I run away?

- Is the deviation between the first five cylinders to the sixth of serious concern?

Any info/advice/experience will be greatly appreciated and help me make the right decision as these cars are not cheap!

Cheers

Edited February 12, 2015 by shaunus

[fatz]

walk away

[GTSBoy]

Walk away or budget to pull it apart, hone it and re-ring it. It wasn't run in properly.

[Humbla]

naa fatz think in I'd run away. :-) :-)

[colourclassic]

Another victim of the RB26 forward facing plenum? Ram air straight into #5 and #6?

[fatz]

running may result in a pulled hammy

so walk away get a beer and find a engine thats not f**ked

[Count Grantleyish]

If you have concerns, walk away.

Running away might result in pulling a hamstring as fatz said.

[shaunus]

I had turfed the idea of buying that particular GTR the minute Fats said "walk away"hahaha.

Was all I needed to hear, thanks everyone.

Such hard cars to find over here in WA for not crack prices.

[GTSBoy]

I had turfed the idea of buying that particular GTR the minute Fats said "walk away"hahaha.

You have to keep in mind that Fatz will probably lowball the guy, snatch the car out from under you and turn it into a track whore or wreck it for profit. Ulterior motives are ulterior!

[Kinkstaah]

That said, even that is a massive headache, so walk away

[djr81]

Walk away or budget to pull it apart, hone it and re-ring it. It wasn't run in properly.

This is in all probability what has happened. Yes it should get redone - but budget that and if the numbers stack up and the car is still good why not?

Link to car?

[shaunus]

http://www.carsales.com.au/private/details/Nissan-Skyline-1999/SSE-AD-3066429/?Cr=4

To be honest mate, spending 50k on a car you'd want it to be near on perfect mechanically. I don't have the time nor patience to be bothered pulling the motor.

[oldmatey]

Offer the seller a lower price factoring in the rebuild cost?

[AngryRB]

a set of mild cams would drop the comp 30psi on a comp test, if that were the case those numbers would start to become decent..

In most other similar posts everyone is fine with a 10percent variance so why the walk away in this case?

Edited February 19, 2015 by AngryRB

[GTSBoy]

a set of mild cams would drop the comp 30psi on a comp test, if that were the case those numbers would start to become decent..

In most other similar posts everyone is fine with a 10percent variance so why the walk away in this case?

A set of mild cams should affect all cylinders unless it's a scatter cam for a Mini. Besides, the leakdown results scale perfectly with compression results, indicating that it's all in the rings.

10% variance between cylinders is deemed acceptable for an original engine that's done a lot of miles. Not one that was supposedly recently put together carefully and only done 6000 kays since.