Project D - 1 DEC 2007

johansx · Post by **johansx** » Mon Oct 22, 2007 9:51 pm

Hmmm, mistaken those black marks on the sleeves for reflections from underneath.

Will it be possible to polish the marks (on the pistons & sleeves) or are they to deep already?

Vlade · Post by **Vlade** » Tue Oct 23, 2007 6:28 am

Yip will be able to hone them out... I hope... those dark areas are actually mirror like finishes very very smooth, but one don't want that

Ok hi-res pic of the piston

here you can see how the damage relates to the pic I posted of SK

shot of the rings, look very closely to the second ring, it is the correct way around, notice the little scraper groove on the bottom end of the ring

They are CP's

Rezlo · Post by **Rezlo** » Tue Oct 23, 2007 6:41 am

Notice how those pistons are worn very badly at the bottom of the skirt? what was the piston clearance/ what is it now? Ive seen JE's do that before when the guy went a touch generous on bore diameter, which also pivots the rings causing them to scrape rather than slide down the barrel wearing them out very fast on the load surfaces = glazing ectr.

Did you do a hard or soft break in? what was the top and 2nd ring gapped at? and did you check the coil rings for min clear?

Over fueling will do that, but usualy it takes quite some time, unless its over fueling like a mofo.

You obviously did put the mains on and torque them before bore/hone right?

You also dont want to let a motor with forged pistons like JE or CP sit and idle for long times, especialy if its cold/just started, this also causes wear like that.

Another thing, did you have anything sand or media blasted? what do your bearings look like? the one pic looks like media contamination on the skirt to.

Rezlo · Post by **Rezlo** » Tue Oct 23, 2007 6:47 am

p.s.

I have loads of packets of moly here, R10 + a speed services bag, or go bug some of the engine builders up there, most of them should have a few bags, I just use a bottle of it, easier, Rather use moly than engine oil, its more accurate.

Also that thing about pre-loading them X times ectr does not need to be used on the bolts available for CA/SR/RB ectr,

Also dont use so much copper spray on the head gasket, only re-use it once (if you have to) that shit gets stuck in everwhere, and does a brilliant job at blocking small oil passages.

Just from that one pic i would say bore size/clearance is incorrect, or motor is being left to idle when cold.

Vlade · Post by **Vlade** » Tue Oct 23, 2007 7:11 am

Rezlo wrote: Did you do a hard or soft break in? what was the top and 2nd ring gapped at? and did you check the coil rings for min clear?

- Semi hard break in, gave it lekka without boost for the first 1000KM, then after that with boost, Ring gaps was done by Duane he followed the little brochure that came with the pistons

Rezlo wrote:Over fueling will do that, but usualy it takes quite some time, unless its over fueling like a mofo.

- Happened after 2500KM A/F ratio was off the meter it was that rich

Rezlo wrote:You obviously did put the mains on and torque them before bore/hone right?

yip

Rezlo wrote:You also dont want to let a motor with forged pistons like JE or CP sit and idle for long times, especialy if its cold/just started, this also causes wear like that.

nope didn't do that at all, started it took it around the block and drove it home.

Rezlo wrote:Another thing, did you have anything sand or media blasted? what do your bearings look like? the one pic looks like media contamination on the skirt to.

Not this time round bearings looked cool

Rezlo wrote:I have loads of packets of moly here, R10 + a speed services bag, or go bug some of the engine builders up there, most of them should have a few bags, I just use a bottle of it, easier, Rather use moly than engine oil, its more accurate.

Cool thanks, I'll shout if I need some

Rezlo wrote:Also that thing about pre-loading them X times ectr does not need to be used on the bolts available for CA/SR/RB ectr,

was wondering about this, good to know that I don't need to preload.

Rezlo wrote:Also dont use so much copper spray on the head gasket, only re-use it once (if you have to) that shit gets stuck in everwhere, and does a brilliant job at blocking small oil passages.

Yeah that wasn't me, but i'll just give it a thin layer this time round, still on that ACL gasket of yours, that teflon layer has started to peel off in certain places, but overall the gasket is straight and still in tact, would have loved to change it but don't have $$$ for a new one

Thanks for advice.

Rezlo · Post by **Rezlo** » Tue Oct 23, 2007 7:18 am

Its not the outside you need to worry about on the gasket, its the compression ring that flattens out ;( and its viton BTW not teflon

When you say off the gauge rich, off the wideband or narrow?

Still to me looks like incorect bore size, fuel wash nails the rings and the middle of the skirt more, yours seems to be 2nd ring and lower skirt drag from the rod's latteral pull.

Also, for your next time round, you MUST boost it while breaking in or it wont push the rings out correctly. 20 mins of no boost, then start, just dont rev the hell out of it, the RPM is worse than boost.

That RX car I built that came second in the KOTM, that motor didnt even have 200km's on it the day it did the KOTM, its one of the longest lasting 220wkw+ SR20's in the country.

Vlade · Post by **Vlade** » Tue Oct 23, 2007 7:33 am

Rezlo wrote:Its not the outside you need to worry about on the gasket, its the compression ring that flattens out ;( and its viton BTW not teflon

- haha thought its that frying pan stuff, will attack the gasket with a micrometer and check

Rezlo wrote:When you say off the gauge rich, off the wideband or narrow?

- wide band I think, was just told it was off the guage

Rezlo wrote:Still to me looks like incorect bore size, fuel wash nails the rings and the middle of the skirt more, yours seems to be 2nd ring and lower skirt drag from the rod's latteral pull.

- might be i'm not really sure, again this wasn't done by me, I'll have the engineers tell me if the clearences and stuff is fine, sent it in yesterday...

BTW: what should the clearances be on these CP pistons? I don't have any of the documentation with me no more

Vlade · Post by **Vlade** » Wed Oct 24, 2007 9:33 pm

Eish... Sorry Freddy that ring set you gave me doesn't fit the CP pistons, it looks like the CP uses a 1.2, 1.2, 2.5 84mm rings, where stock Nissan ones is 1.5, 1.5, 2.8 84mm...

Sokar · Post by **Sokar** » Thu Oct 25, 2007 9:06 am

Vlade wrote:Eish... Sorry Freddy that ring set you gave me doesn't fit the CP pistons, it looks like the CP uses a 1.2, 1.2, 2.5 84mm rings, where stock Nissan ones is 1.5, 1.5, 2.8 84mm...

So....... Angle grind them!!!

veecee · Post by **veecee** » Thu Oct 25, 2007 9:35 am

Sokar wrote:
Vlade wrote:Eish... Sorry Freddy that ring set you gave me doesn't fit the CP pistons, it looks like the CP uses a 1.2, 1.2, 2.5 84mm rings, where stock Nissan ones is 1.5, 1.5, 2.8 84mm...

So....... Angle grind them!!!

Monkey!!! you wont get them nice and flat with an angle grinder. i reckon a benchtop grinder is better!!! just wear thick leather gloves hey!!!

Vlade · Post by **Vlade** » Thu Oct 25, 2007 9:57 am

used a wood "tafel skaaf" did the job

Draco · Post by **Draco** » Thu Oct 25, 2007 10:23 am

Vlade wrote:used a wood "tafel skaaf" did the job

Jusliket you ouens are like 007....always got a plan

veecee · Post by **veecee** » Thu Oct 25, 2007 10:57 am

ek het gedink dit was altyd die boere wat n' plan maak!!!

007 boer - verband, johan verband!!!!

Vlade · Post by **Vlade** » Thu Oct 25, 2007 1:56 pm

Does any one know what thickness the CP rings are?

Vlade · Post by **Vlade** » Thu Oct 25, 2007 2:50 pm

CP Piston Rings Sizes.... If you ever need to change them, don't bargain on getting shit locally... They don't really exist (funny enough some motorbikes use the following sizes)

Some useless info if you ever want it

CP Ring Set for CA18DET

3.268" (83mm) 3.307 (84mm)

1st: 1.0mm
2nd: 1.2mm
3rd: 2.8mm

Project is on hold for a little while, till some more import parts arrive, yip... Piston rings, no one have locally... Also my HG is Foooked... New one isn't really that expensive...

I can really recommend dealing with Import Parts, chap was really helpful.