Outer Limits 4x4 Board

Posted: **Wed Jan 16, 2008 9:58 am**

The new capacity would be about 3.326L (original is 3.246L) so less than 0.1L increase

Posted: **Wed Jan 16, 2008 11:41 am**

SHES A BIG BORE

Posted: **Wed Jan 16, 2008 2:57 pm**

didnt think that sleeved motors could be bored out.

Please prove me wrong

Posted: **Wed Jan 16, 2008 4:53 pm**

pongo wrote:didnt think that sleeved motors could be bored out.

Please prove me wrong

Not trying to prove you wrong "pongo"
But motor bikes like my cr125 are sleeved and you can bore them out.

I don't see why you can't do it to a diesel, as long as you can get a piston and rings to match

Just a thought

Posted: **Wed Jan 16, 2008 5:10 pm**

i was talking to an engine reco place about getting my SD33 done, and he rekoned he could bore it out for me and make it a tad under 4l...

Posted: **Wed Jan 16, 2008 5:18 pm**

macca81 wrote:i was talking to an engine reco place about getting my SD33 done, and he rekoned he could bore it out for me and make it a tad under 4l...

now that would be nice!!!!!!!!!!

Posted: **Wed Jan 16, 2008 6:40 pm**

you can bore anything out if you know a good engineer.
i saw a photo of a 4-cylinder engine, bored out so that each cylinder was open to the next (imagine the abc logo kinda) and had a one-peice sleeve that seperated each cylinder.

in an sd33, i would imagine the sleeves are removed (too thin to hone), the actual block bore is increased, then new sleeves are made up to fit.

Posted: **Wed Jan 16, 2008 9:01 pm**

macca81 wrote:i was talking to an engine reco place about getting my SD33 done, and he rekoned he could bore it out for me and make it a tad under 4l...

wtf
That would have had to have been bored and stroked!!!

But yes the general rule is that a diesel can be bored out. We do this quiet a bit at work with small truck engine less than7L.

Simply put you can get oversize pistons and sleeves depending on the motor and generally usually to 40" (1mm) without touching the block.. Anything over just bore and deck the block to suit new sleeves.

I think to work an SD33 the head would be the major issue. They have never really stayed cool, and the head will always crack between the valves.

Posted: **Thu Jan 17, 2008 8:21 am**

Sterlo wrote:
macca81 wrote:i was talking to an engine reco place about getting my SD33 done, and he rekoned he could bore it out for me and make it a tad under 4l...
wtf
That would have had to have been bored and stroked!!!

But yes the general rule is that a diesel can be bored out. We do this quiet a bit at work with small truck engine less than7L.

Simply put you can get oversize pistons and sleeves depending on the motor and generally usually to 40" (1mm) without touching the block.. Anything over just bore and deck the block to suit new sleeves.

I think to work an SD33 the head would be the major issue. They have never really stayed cool, and the head will always crack between the valves.

What...??? a Nissian diesel cracking between the valves... NO!!

Posted: **Mon Jan 21, 2008 7:06 pm**

Formula:

Pie times diameter squared divided by four times stroke times number cylinders.

Pie being 3.141592654 from memory not something obese ppl eat for every meal

Posted: **Mon Jan 21, 2008 7:10 pm**

Brett S wrote:Formula:

Pi times diameter squared divided by four times stroke times number cylinders.

Pi being 3.141592654 from memory not something obese ppl eat for every meal

Posted: **Mon Jan 21, 2008 7:15 pm**

sd33t motors crack heads commonly, N/A not very often. They have a similar problem to 2H deisels, when they get to hot the castings crack usually caused from too high EGT's

Posted: **Mon Jan 21, 2008 8:21 pm**

but if they deck the block when the bore it out, because the new pistons have a lower compression height than the originals, so that the block can be decked so that you get the original compression ratio. so if theyve gone 40thou over, and decked the block, its still its original size.

if they have stroked it, then you will need to measure the new stroke to work out capacity.
but 700ml is alot to gain.

Posted: **Tue Jan 22, 2008 1:28 pm**

That is crazy mans talk ke70

The stroke hasn't changed at all it has only been bored out 1mm (40 thou for you old buggers) and can prob get 1.5mm o/s size pistons as is std oversizes from nissan for tb42 etc.
Even if the deck height is different which i gaurantee it isn't if nissan pistons all the deck height is going to affect is the compression ratio.
Capacity is purely the swept volume of which the year 5 formula i previously stated.

Posted: **Tue Jan 22, 2008 4:47 pm**

nastytroll wrote:sd33t motors crack heads commonly, N/A not very often. They have a similar problem to 2H deisels, when they get to hot the castings crack usually caused from too high EGT's

NOT often u say on the N/A's. Well maybe more people have better luck than me. when i needed another head for the old donk I thought ohh this will be easy just get 2nd hand head from N/A motor..

Not so I ended up with 4 wrecks & 3 old motors layin at the oldies place.. ALL the freakin heads were cracked!! SOme worse than others. Ended up getting a brand new genuine head for 1100$

But in saying all of this do the cracks between the valves actually leak??

Sterlo

Posted: **Thu Jan 24, 2008 8:31 am**

the cracks that happen between the vavles dont actually leak coz its in the solid part of the head and wouldn't or shouldnt hit any oil/water gallery.mine had cracked between the valves on my sd33t and i had never noticed until the head gasket rusted so i changed it one crask was looked that bad coz it had like a 1mm gap. nothing a quick weld didnt fix!
that was my expirience anyway!

Outer Limits 4x4 Board

sd33 bored out 1mm, what's its new capacity?