Bills 33 Gtst Streeter/track Car

[admS15]

Sorry for delay guys, been busy. May be a quiet day at work tomorrow. I'll see if I can get those pistons under the big lit magnifying glass our sparky has on his work bench.

Head was dropped off yesterday, shop says I should have it back by the end of next week. Nissan stuffed me around with replacement piston circlips. Ordered 12 (was showing heaps of stock) but somehow they only had 10. Should get last 2 by next week. I hope anyway.

I mentioned to engine builder that I had 11 pistons and asked if I should aim to run the 6 that came out of the motor that's being rebuilt. Before I could finish my sentence he said he would pick out the best 6 from the pile. So that's what I've been doing.

Out of the 11,  2 where ruled out because of the maybe or maybe not cracks. 1 other was ruled out due to a tight 2nd ring groove (I may or may not have dropped this, lol). Out of the 8 useables, they where weighed and then the 6 closest weights where picked.

 

Nissan did a damn good job casting RB pistons. They're within 0.7 of a gram. Could have been 0.5 but I didn't like the look out of 1 of the other 8. There was 1 outlier that was over 1.2g heavier The 6 selected range from 404.08g to 404.78.

 

[No Crust Racing]

It's all coming together


 

[admS15]

The piston pins are within 0.24g across the 6.

With some rearranging of the pin locations the total piston/pin weight comes down to  0.46g

Once the rod weights are factored in the variance comes down to 0.2g. if I shave a tiny bit of 2 pistons I can get it down to 0.07g.

I know this will make stuff all difference but I'm here and will take bugger all time to do.

Question time. Should I even bother with rearranging the pin locations or leave them in their original homes? If I don't the variance will be 0.43 with rod weights accounted for. Or do I go all out, shave a few pistons and end up less than 0.05g variance and call it balanced and BILLprinted.

Anyway here are my workings.

 

 

Thoughts gents.

[No Crust Racing]

Given the are already so closely matched, do not touch them is my advise or you risk adding stress risers unnecessarily. 

That's incredibly close. 

 

[Duncan]

original locations, because then you don't need to worry about any sizing differences

[No Crust Racing]

Oh you should also leave gudgeon pins with their pistons as a rule of thumb, 

Don't move those around. 

[admS15]

On 15/11/2023 at 12:15 PM, No Crust Racing said:

Given the are already so closely matched, do not touch them is my advise or you risk adding stress risers unnecessarily. 

That's incredibly close. 

 

Oops, my bad. Lol. I decided to leave the pins in original spots but went ahead and shaved around 0.15g from the 2 heaviest pistons. Going to take 0.10 off one more and call it done. BILLprinted baby.

 

This is the area I shaved material off from 

On 15/11/2023 at 3:45 PM, Duncan said:

original locations, because then you don't need to worry about any sizing differences

As above decided to leave them in original locations.

[No Crust Racing]

As long as it's smooth and transitions from one plane to the next uniformally it'll be fine, I was removing 5g on some pistons and they've seen 800ks and 7k rpm already.

 

Doesn't mean they won't explode but who knows when

[admS15]

Just checked the ring gaps. Thanks Mr Nissan for being spot on and not needing adjustment. OEM is life.

Around mid spec for all. Starting to assemble the pistons now. Got 2 done so far, will continue at next opportunity.

[admS15]

On 15/11/2023 at 4:24 PM, No Crust Racing said:

As long as it's smooth and transitions from one plane to the next uniformally it'll be fine, I was removing 5g on some pistons and they've seen 800ks and 7k rpm already.

 

Doesn't mean they won't explode but who knows when

Geez man, where do you find 5 grams to remove. I only took .2 of a gram and was scared I was taking too much off.

Pic of my work

Shaved

Will clean it up and a bit with some fine paper tomorrow.

Unshaved

Rings are all installed now, will re weigh all pistons tomorrow with rings fitted up. I doubt there's much difference in the ring weights but you never know.

[r32-25t]

The oil splashing on them will probably create a bigger weight discrepancy then you’re trying to shave off 

[No Crust Racing]

You work all 4 sides of the pin boss taking them from square edge to tapered round edge all the way to near the crown. 

Risky business lol 

[admS15]

On 15/11/2023 at 8:52 PM, r32-25t said:

The oil splashing on them will probably create a bigger weight discrepancy then you’re trying to shave off 

Most probably true but what's done is done

On 15/11/2023 at 9:03 PM, No Crust Racing said:

You work all 4 sides of the pin boss taking them from square edge to tapered round edge all the way to near the crown. 

Risky business lol 

Yolo lol

[Dose Pipe Sutututu]

Send its mum, go hard! 

Billprinted haha

[admS15]

On 16/11/2023 at 7:14 AM, Dose Pipe Sutututu said:

Send its mum, go hard! 

Billprinted haha

She will be sent and rattled hard🤣

[admS15]

Final numbers are in after ring fitment and arrangement. Variance is down to 0.12g worked out well, may be able to improve a tiny bit more with the arrangement of circlips once they all arrive. 

Billprinting almost complete

 

I've ended up with 3 pistons from each motor. The 3 that came out of this one will go back to their original locations,  the others will be measured up and a spot selected for them.

Opened up the box of goodies from EFI solutions yesterday. Must say they're a well organised mob and everything they said was in stock actually was.

 

[Dose Pipe Sutututu]

EFI Solutions is a well oiled eComm powerhouse! 

They probably have a proper ERP running, thus have real-time stock display on their eCommerce site. Not many car related businesses can do this, not even Sparesbox (Shitbox really).

[admS15]

You mean dropshipbox

[Dose Pipe Sutututu]

15 minutes ago, admS15 said:

You mean dropshipbox

Yep!

Waited a few months for my turbo, they then couldn't get the turbo, then offered a larger GTX3582R Gen 2, which I then agreed to, but what I received was what I initially ordered lol. 

Wrote a bad review on Google, Facebook, etc. they then apologised and offered a free turbine housing 🤣

So yeah that's the story of how I got my Garrett turbo cheap.

[admS15]

Started on assembly on the weekend. I checked the mains clearance with plastigauge.  Was surprised to see bigger clearances with the ACL race bearings.  Was concerned the readings weren't right, so I disassembled and reassembled numerous times, measured with micrometre and bore gauge. The mic readings where close to the plastigauge but slightly tighter. I did the readings 3 times and although they where a tiny bit different each time, they where close enough for me to be confident what I'm seeing is correct.

Clearances on the mains are between 2 - 2.5 thou or .050-.063mm I was initially concerned as that's outside of Nissan's ideal range so I stopped assembling and considered running a -.010" bearing on 1 side in a mixed pair arrangement, sounds dodgy but apparently it's a done thing. You obviously need 2 sets of bearings. I have since been told that my numbers are fine, between 2-2.5 thou is good and I don't need to change anything. The avge across the 7 is around 2.3thou.

The rod bearing clearances where checked with the mic and they're a bit tighter at 1.45-1.77thou or .036-.045mm. Again I'm told that that's good and even a little looser would've been better. Will see what engine shop has to say about these clearances when I pick the head up.

Atm, the crank is in and torqued down, will start putting the rest together when I get time.

 

So the plastigauge turned out pretty close, if only I trusted it initially, could've saved hours of measuring, cleaning and unnecessary stress. Better to be sure than find out the hard way I suppose.