Bills 33 Gtst Streeter/track Car

[admS15]

On 08/11/2023 at 3:06 PM, Komdotkom said:

Make a basic slide hammer out of a bit of all thread the plugs are not that tight (which always surprises me).

 

 

What size all thread are we talking here. It be pretty thin wouldn't it?

[admS15]

Anyway, valves have arrived from both partsouq and amayama. Also got a nifty adjustable tapered ring compressor cheap off eBay, looks like it's been used once 

 

 

 

Still waiting on the rods, meant to be here in the next hour according to auspost. Considering the torrential rain that just started, I reckon the posty will probably hold it for tomorrow or drop back at the post office.

[No Crust Racing]

Be careful with that type of ring compressor they are known to snap rings.

 

Single size tapered ring compressor from someone like is a better option but obviously only suits one bore size.

 

Go slow, lots of lube, just generally good advice..

 

 

 

 

[admS15]

Dang, it's company 23 brand. Meant for subarus. Seems like the tools made for them are about as good as the cars, sti's excluded. I bought that one as I though being tapered I wouldn't have to knock the piston down. It's only adjustable from like 78 -86.8mm. if the ring ends aren't in the 10mm of open gap I can't see how it's going to be an issue. Anyway, I'll be careful and treat it like a virgin. Plenty of lube, proceed with caution.

 

Rods have been delivered, I'm not home ATM to check them out. Will do later.

[No Crust Racing]

I might have missed it but what was the answer the valve size question? 

[admS15]

Valve guides you mean. Well I don't have a definitive answer but now that I have the valves in my possession, going to visit the local supplier that has listings for rb25 guides and work out if any are suitable. If not, I'm stuck. May have to ring Nissan and see if they have stock and how far I have to bend over..

[admS15]

Just spent some time this morning weighing up the rods on some super accurate scales at work. Pretty damn good. They're advertised as being within a gram of each other. They where much better than that at around 0.3 of a gram. Not bedh. They're close to 80 grams lighter each than stock too.

Preliminary measurements of the bores of the big and little ends are spot on using the internal mic. I'm getting really good with using those now, can get accurate measurements quicker. I'm hoping to use the bore dial on them a bit later to confirm my measurements and roundness a bit better.

 

[No Crust Racing]

That's awesome! 

My piston/rod assemblies were up to 8g out of balance, machine shop said 3g is nice for a street engine on stock components so I balanced them down to 1g because I'm an idiot who thought spending literally 10hrs on that was a good idea...

[admS15]

I haven't weighed the piston assemblies yet, watch this space. 

What are people's thoughts on how to select which weights go where? Pair 2 that are closest in weight and run them as matched pairs?  I was thinking of doing that and putting the 2 heaviest in the middle. Don't know how I came up with that.

Probably wouldn't matter 1 bit but I'm here and would only take a minute to arrange. 

[No Crust Racing]

See what the total weight is for a given piston/rod assembly, including rings/pins/bearing shells, rod bolts. 

If you can just move parts around to get them all within 1g for a total assembly or so you are golden.

If not, move them around such that the weight differences are minimal vs everything else, I.E don't put all your lightest things together on one piston/rod assembly as now you need to bring everything down. 

"Best" way is watch matching each component and adjusting as necessary, I only went as far as doing rods/pistons individually as the variance between ring sets/rod bolts/and shells was miniscule on a 3 decimal scale. Also using a rod weighing assembly so big and small end can be reviewed separately as there's more to it than just total weight. 

New forged rods will be basically spot on for this purpose, it'll only be the pistons that might need attention. Cast pistons usually vary a little, just depends on the batch, if you have to remove material you do it VERY gradually around the pin boss (where the gudgeon goes through) on the inside, do not touch the crown/skirts etc - lots of videos online. 

I'm waiting to see if a few 7k rpm trips blows a piston up from stress risers... 

 

[GTSBoy]

2 hours ago, admS15 said:

Just spent some time this morning weighing up the rods on some super accurate scales at work. Pretty damn good. They're advertised as being within a gram of each other. They where much better than that at around 0.3 of a gram. Not bedh. They're close to 80 grams lighter each than stock too.

Preliminary measurements of the bores of the big and little ends are spot on using the internal mic. I'm getting really good with using those now, can get accurate measurements quicker. I'm hoping to use the bore dial on them a bit later to confirm my measurements and roundness a bit better.

 

Hmm. This is making me want to unnecessarily rebuild my engine.

[Komdotkom]

20 hours ago, admS15 said:

What size all thread are we talking here. It be pretty thin wouldn't it?

M4 or M6  something like that. I can't recall the size for RB's but I mostly use 1/8 NPT

[GTSBoy]

Just now, Komdotkom said:

M4 or M6  something like that. I can't recall the size for RB's but I mostly use 1/8 NPT

They make grub screws with pipe thread?

[admS15]

Hey @PranK is something funny going on in the forum. New posts don't seem to be showing for me. I only see posts from like a week ago. Is it just me?

 

[GTSBoy]

20 minutes ago, admS15 said:

Hey @PranK is something funny going on in the forum. New posts don't seem to be showing for me. I only see posts from like a week ago. Is it just me?

 

Nah, it's borked. Depends on what you mean by "new posts don't show". I see new posts, but the latest posts page isn't working, and other issues. There's 2 reports of this in the feedback forum.

[Komdotkom]

2 hours ago, GTSBoy said:

They make grub screws with pipe thread?

https://speedflow.com.au/npt-in-hex-plugs-from/

[GTSBoy]

Fair enough. Plugs, not grub screws, given that the two are quite different things, even if they're being used for the same thing.

I guess it's reasonable to presume that "grub screwed" is the wrong term anyway, given the usage case here.

[Komdotkom]

[GTSBoy]

Nah, you see, because people say "grub screwed the crank" I always just presumed that they were actually just using grub screws. I should just know better than to take people's wordbabble at face value.

[admS15]

Re valve guides. I have a freaking headache. Been down the rabbit hole trying to work out what's what. Nissan wants 65 each for intake (in stock) 85 for exh (import from jap)

I read an old SAU thread where CA18 guides where used for intake on an rb25 and had to be trimmed down 2mm as slightly too long.

I found this in the fsm

If I'm reading that correctly, the only difference between the in and exh valves for the purpose of the guides is 2mm in shaft length and a minute diameter difference of shaft which will be accounted for with reaming.

So I'm thinking the CA guides should work. The exhaust should fit straight in and the inlet trimmed 2mm.

I've come across nason guides part numbers

PVG9019 10.03mm OD 5.994 ID 40.005 length listed as CA18 and RB25DE/DET 

Also PVG9018 same ID and OD but 42.926 length. Listed only for CA18.

I believe PVG9019 should work or do I buy 2 of each? I know the best bet would be to get the old ones removed and measured but I'd rather give the shop all the bits and pieces so they don't have to stop half way and wait for parts. I've got an even bigger headache now. Going to get some Panadol.