Score on block - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

waxer52 · 5th July 2008, 05:58 PM

Stripped my engine to find no.1 cyclinder scored.

Waht do you think?
Woud i get away with a hone and new rings or is it definately a rebore with forged pistons.
This is also my first rebuild, so any help is welcome.

Andy W · 5th July 2008, 09:41 PM

from a picture its hard to tell how bad it is, but it looks as if there are also marks on the right as well. have you checked the pistons for ringland damage ?

waxer52 · 5th July 2008, 10:01 PM

All rings are perfect.
It only barely catches your nail as you rub it across. It will not stop your nail passing over it.
Don't know if this gives you any more detail.

paul cawson · 5th July 2008, 10:14 PM

Those single line marks are common and not worth a rebore. As above check piston condition and measure the cylinders for wear

waxer52 · 5th July 2008, 10:37 PM

At last I am getting some inight into the situation.

GT-R Glenn · 5th July 2008, 10:57 PM

I have no idea how deep it is, you could most likely power hone it out.
But my question is,
If its in bits why not future proof the engine by drilling it out and putting .5mm over forged pistons in ?
Or, either way its going to the engine reconditioner , isnt it ?
You need to hot tank the block and fit new frost plugs, so the engine reconditioner should be able to tell you exaclty.
If its an r32 fit the oil pump drive collar too.
Always assume/new guides/valve springs/rod bolts/ when you open them up.

waxer52 · 5th July 2008, 11:12 PM

O.k its eaesy to future proof, but i was hopeing to rebuild as standard for now due to a shortage of funds.
If you think that it is screwed, please let me know.

GT-R Glenn · 6th July 2008, 12:05 AM

Why did you strip it ?

waxer52 · 6th July 2008, 01:45 AM

It started to heat so i did a compression test and the results showed low compresion. The headgasket went, but i caught it in time.

GT-R Glenn · 6th July 2008, 07:22 AM

Ok , re ring + rod bolts / check the oil pump for cracks starting on the corner of the inner drive flats....

1346bhp · 6th July 2008, 09:06 AM

Why is it common for oil pumps to crack.

paul cawson · 6th July 2008, 11:43 AM

Quote:

Originally Posted by 1346bhp

Why is it common for oil pumps to crack.

I would always remove the pump back plate and check its condition if the engine is out.
It is common for the bolts to work loose so a little locktite on those is a good insurance

SamuraiSam · 7th July 2008, 01:31 AM

Quote:

Originally Posted by 1346bhp

Why is it common for oil pumps to crack.

There are about ten thousand posts on oil pump failures and lots of FAQ pages on lots of Skyline websites. Lots of information out there.

5th July 2008, 05:58 PM	#1 (permalink)
waxer52 GTR Register Member Join Date: Jun 2006 Posts: 34	Score on block Stripped my engine to find no.1 cyclinder scored. Waht do you think? Woud i get away with a hone and new rings or is it definately a rebore with forged pistons. This is also my first rebuild, so any help is welcome.

5th July 2008, 09:41 PM	#2 (permalink)
Andy W GTROC Member Join Date: Dec 2005 Location: Eastbourne Posts: 1,149	from a picture its hard to tell how bad it is, but it looks as if there are also marks on the right as well. have you checked the pistons for ringland damage ? __________________ bovered me, do i look bovered, bovered , no AA join here

5th July 2008, 10:14 PM	#4 (permalink)
paul cawson New Users Join Date: Jul 2003 Location: Essex Posts: 1,960	Those single line marks are common and not worth a rebore. As above check piston condition and measure the cylinders for wear __________________ "I am clever because I know the cause of my ignorance..." ~ Bruce Lee

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5th July 2008, 10:01 PM	#3 (permalink)
waxer52 GTR Register Member Join Date: Jun 2006 Posts: 34	All rings are perfect. It only barely catches your nail as you rub it across. It will not stop your nail passing over it. Don't know if this gives you any more detail.

5th July 2008, 10:37 PM	#5 (permalink)
waxer52 GTR Register Member Join Date: Jun 2006 Posts: 34	At last I am getting some inight into the situation.

5th July 2008, 10:57 PM	#6 (permalink)
GT-R Glenn Banned Join Date: Nov 2002 Location: Waiuku NZ Posts: 928	I have no idea how deep it is, you could most likely power hone it out. But my question is, If its in bits why not future proof the engine by drilling it out and putting .5mm over forged pistons in ? Or, either way its going to the engine reconditioner , isnt it ? You need to hot tank the block and fit new frost plugs, so the engine reconditioner should be able to tell you exaclty. If its an r32 fit the oil pump drive collar too. Always assume/new guides/valve springs/rod bolts/ when you open them up.

5th July 2008, 11:12 PM	#7 (permalink)
waxer52 GTR Register Member Join Date: Jun 2006 Posts: 34	O.k its eaesy to future proof, but i was hopeing to rebuild as standard for now due to a shortage of funds. If you think that it is screwed, please let me know.

6th July 2008, 12:05 AM	#8 (permalink)
GT-R Glenn Banned Join Date: Nov 2002 Location: Waiuku NZ Posts: 928	Why did you strip it ?

6th July 2008, 01:45 AM	#9 (permalink)
waxer52 GTR Register Member Join Date: Jun 2006 Posts: 34	It started to heat so i did a compression test and the results showed low compresion. The headgasket went, but i caught it in time.

6th July 2008, 07:22 AM	#10 (permalink)
GT-R Glenn Banned Join Date: Nov 2002 Location: Waiuku NZ Posts: 928	Ok , re ring + rod bolts / check the oil pump for cracks starting on the corner of the inner drive flats....

6th July 2008, 09:06 AM	#11 (permalink)
1346bhp GTR Register Member Join Date: Feb 2008 Posts: 63	Why is it common for oil pumps to crack.