Rb25 crankshaft

[NEO25T]

Looking for an rb25 crank in good condition, if you have one thats useable and want to sell please ket me know, thank you ?

[GeeDog]

I've got one in SA that's in excellent condition. It has been crack tested & linished, and has the oil plugs replaced with grub screws. It also has an extended oil drive collar fitted. It is from a series 2 R33 GTST, so RB25DET. I don't know if the RB25 & RB25DET cranks are the same or not.

[NEO25T]

Do you know if it has been machined previously or will it still use standard bearing sizes?

Can you post up or send me some pics, showing keyway too please.

Thanks Russell

[GeeDog]

It has been machined, and I have an almost new set of big end & main bearings that can go with it. I'll need to take a closeup of the keyway, will try & do that tomorrow. The only reason we no longer need the crank is because we changed to an RB25/30.

[GeeDog]

A couple of close-up shots of the keyways:

[NEO25T]

Do you know what size the bearings are?

This seems to be exactly what i need however im just a little cautious about it being machined, so many mixed opinions so ill have to speak to the machine shop im using before i commit.

[GeeDog]

Long version of the story:

It's been to the crankshaft machinist twice. The first time it was crack tested, tested for straightness, had the oil pump collar fitted, the plugs were drilled & tapped for grubscrews, and it was linished. (I was thinking machined, but pretty sure I was wrong - more on this later). The cranksahft guy also supplied new bearings (ACL Race), I can't find the receipt for this job. This was in early 2016, and was as part of a full motor rebuild - block & head machined, forged pistons etc. The issue that prompted the rebuild was cracked ringlands.

We put the motor back together, and ran it for about 6 months. Then the turbo crapped itself, and the diagnosis was possible lack of lubrication. The turbo went back to be re-done, and at the same time we bought an extended baffled sump. While the sump was off we pulled the crank out, and because the thought was that oil supply was an issue, took it back to the machine shop to be checked. There was no crank damage, but a couple of the bearings showed some wear. At this stage the crank was checked & linished, and we bought another set of bearings. I do have this receipt - it was Sep 16, and the bearings we bought were 6B1216-STD & 7M1203-STD - so standard size. I can't remember the brand, but pretty sure we couldn't get ACL Race so these were an alternative. The receipt only has the part numbers as above.

We put the bottom end back together with the extended sump, fitted the new turbo, and took it to be dynoed. Results were not what they should be, so we changed a few things, checked valve timing etc, and took it back to the dyno. Still not what it should have been, so we pulled the head and found scratches in several bores - looked like bits of the turbine had gone throught it. At about the same time someone advertised a New Old Stock RB30 bottom end - had never been started, so we bought that and built an RB25/30.

The crankshaft & bearings have done 2 dyno sessions since the linish. Bearings are all still mated to the journals they were on, and I'd re-use them. If you are serious I'm sure the machinist would have a quick look and give you his opinion - he is an old school machine shop who only does crankshafts - business name is Crankshaft Grinding Specialist P/L.

Journal sizes are 48mm for rods, and 55mm for mains - all within around .03mm by my vernier. Pics of the hournals are at Journal pics

Edited January 25, 2018 by GeeDog

[NEO25T]

Ok thanks for that, ill talk to the guys and let you know.

How much do you want for it?

[GeeDog]

I'll sell it for $450 plus postage - and to put that into perspective it cost me $330 just to supply & fit the extended oil pump collar onto the RB30 crank.

 

[NEO25T]

On 27/01/2018 at 3:49 PM, GeeDog said:

I'll sell it for $450 plus postage - and to put that into perspective it cost me $330 just to supply & fit the extended oil pump collar onto the RB30 crank.

 

Hey mate thanks for taking the time to reply, i have found a couple of cranks local and will check those out first.

If they are no good ill get in touch.