| ausmini https://www.ausmini.com/forums/ |
|
| Opinion on bearing condition https://www.ausmini.com/forums/viewtopic.php?f=2&t=99598 |
Page 2 of 3 |
| Author: | drmini in aust [ Wed Jan 15, 2020 4:04 am ] |
| Post subject: | Re: Opinion on bearing condition |
Use a micrometer to measure cranks, a caliper is too inaccurate. Original size was 1.6255" I believe. More than 0.001" taper or ovality I would regrind the crank. I recommend using a centre oil pickup, I have seen quite a few cranks worn oval on the crankpins at low mileage due to oil starvation on corners (suspect hooning through roundabouts). |
|
| Author: | Morbo28 [ Wed Jan 15, 2020 5:16 am ] |
| Post subject: | Re: Opinion on bearing condition |
drmini in aust wrote: Use a micrometer to measure cranks, a caliper is too inaccurate. I'll get the machine shop to measure, cheers. I would hope that after only 5k kays there would be no ovality/taper, but I'll see.Original size was 1.6255" I believe. More than 0.001" taper or ovality I would regrind the crank. I recommend using a centre oil pickup, I have seen quite a few cranks worn oval on the crankpins at low mileage due to oil starvation on corners (suspect hooning through roundabouts). Can you change oil pickups without removing any gearsets or shafts? Sent from my Pixel 2 XL using Tapatalk |
|
| Author: | drmini in aust [ Wed Jan 15, 2020 6:41 am ] |
| Post subject: | Re: Opinion on bearing condition |
Well you can check if it has one. Look under the cluster gear at front corner, if oil pipe goes into a square box strainer, it doesn't have one. Centre pickup now is shaped to suit a rodchange box, if fitting to a remote box it needs bending forward or the reverse idler arm will wear a hole in the mesh strainer. |
|
| Author: | Morbo28 [ Wed Jan 15, 2020 6:47 am ] |
| Post subject: | Re: Opinion on bearing condition |
I have a rod change and I don't have a centre oil pickup. I'll do that while the box is open, no worries. You've been a great help, I appreciate it. Sent from my Pixel 2 XL using Tapatalk |
|
| Author: | drmini in aust [ Wed Jan 15, 2020 8:05 am ] |
| Post subject: | Re: Opinion on bearing condition |
Layshaft and cluster gear need to come out. Take side cover off, remove mainshaft bearing retainer, but mainshaft and pinion don't disturb. |
|
| Author: | Morbo28 [ Wed Jan 15, 2020 8:02 pm ] |
| Post subject: | Re: Opinion on bearing condition |
drmini in aust wrote: Layshaft and cluster gear need to come out. Take side cover off, remove mainshaft bearing retainer, but mainshaft and pinion don't disturb. Ah, should have read the earlier post better lol. I'll decide whether I want to mess with the gearbox again. |
|
| Author: | hpal [ Mon Jan 20, 2020 6:28 pm ] |
| Post subject: | Re: Opinion on bearing condition |
out of interest, could a standard pickup pipe be modified to a centre oil pickup? |
|
| Author: | drmini in aust [ Mon Jan 20, 2020 9:36 pm ] |
| Post subject: | Re: Opinion on bearing condition |
hpal wrote: out of interest, could a standard pickup pipe be modified to a centre oil pickup? I am a fitter machinist. I did it once, cutting 2 pipes up and bending but it's not worth it. Too much mucking around to save $50 or so. And you then need to fit gauze for a strainer. Bends are tricky to miss things. |
|
| Author: | Morbo28 [ Fri Jan 24, 2020 6:57 am ] |
| Post subject: | Re: Opinion on bearing condition |
Machine shop have ground the primary gear surface to 998 specs. I got them to check taper and ovality, I just thought it would be a formality to confirm everything was in spec and that it'd be fine. When I rang now they said mains and rod journals are all getting reground as he wasn't happy with ovality. I was surprised that there would be those issues after only doing 5000kays, but I'm no expert. Doc I was surprised you even recommended checking them. But sure you enough there was an issue. I wonder if I should ask him about shot peening or nitriding etc etc. Any thoughts on all this? Edit: machine guy doesn't think it is necessary to nitride etc the crank. Also when asked about the low kays, he said some reasons could include that they were not machined well to begin with or there was an oil starvation issue at some point. Sent from my Pixel 2 XL using Tapatalk |
|
| Author: | drmini in aust [ Fri Jan 24, 2020 8:20 am ] |
| Post subject: | Re: Opinion on bearing condition |
Unless it's an EN40B Cooper S crank, nitriding won't do much. It only works on specific grades of steel. EN16 MK 2 S and later cranks were tufftrided instead. However the EPA has decreed that process illegal here now, as it used an arsenic salt bath. |
|
| Author: | FNQ [ Fri Jan 24, 2020 8:26 am ] |
| Post subject: | Re: Opinion on bearing condition |
Hi, when you put your new bearing shells in, give the oil flow a little help by filing off the lead side edge to about 45 degrees. Ask others who have more knowledge for specifics- i think you just use an ezilap /diamond file. ( ps sorry if I am not telling you anything new - i didn't go through your big build thread to check if you had previously done this) |
|
| Author: | Morbo28 [ Fri Feb 21, 2020 2:25 pm ] |
| Post subject: | Re: Opinion on bearing condition |
Hey everyone. Machine shop took mains and big ends to 0.020" I am looking for ACL Duraglide beairngs for these. https://classicmotoring.net.au/ have that them in the Big end 0.010" but not in 0.020" (non-S 1275). I have contacted them asking if they can source them. Any other leads as to who I could try to order these from? Thanks! |
|
| Author: | timmy201 [ Fri Feb 21, 2020 4:51 pm ] |
| Post subject: | Re: Opinion on bearing condition |
Karcraft have them listed, you’d have to check if they have them in stock |
|
| Author: | Morbo28 [ Fri Feb 21, 2020 5:51 pm ] |
| Post subject: | Re: Opinion on bearing condition |
Sweet as, thanks Timmy |
|
| Author: | lomin [ Fri Feb 21, 2020 9:30 pm ] |
| Post subject: | Re: Opinion on bearing condition |
Hi, I think Dr Mini has been on the money with all his comments, the Aluminium tin conrod bearings were struggling to hack the load this engine is under, and I am not really surprised by ovality. One thing I would add is those conrod bolts will not be Cooper S tensions, if you do that they will break. I have not seen the caps and bolts, but I guess they will be 5/16" dia ARP, and tension is more like 25 to 28ft/lb from memory. Check the ARP website for installation instructions, or the manufacturer of the conrods. If it was my own engine I would pull the dowels in the centre main and oil stone the block, as the cap is fretting a little, the only problem doing that is you can ruin dowels, and you have to clean the abrasive off the block. I can see the $$$ in that bottom end, you dont want more issues, I would also remove oil pump, check and clean it ... You have had a fair bit of shrapnel flying around . The engine builder looks to have done a good job cheers Lindsay Siebler |
|
| Page 2 of 3 | All times are UTC + 10 hours |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|