Slant Six Forum
https://slantsix.org/forum/

Rehabbing a motor that lost oil pressure
https://slantsix.org/forum/viewtopic.php?t=57602		 Page 1 of 2
Author:  Reed [ Wed Apr 29, 2015 12:40 pm ]
Post subject:  Rehabbing a motor that lost oil pressure
I am rehabilitating a motor that was rebuilt by Jasper but that lost oil pressure and wiped out numerous connecting rod bearings.

I will be replacing the crank and all the bearings to deal with the damage.

Aside from tracking down the cause of the oil pressure failure (I think it is because a five hole oil pump was used) what else should I be looking at? I know the timing chain is badly stretched. Should I assume the cam bearings need to be replaced?

Any other suggestions?
Author:  BUCKET 636 [ Wed Apr 29, 2015 1:47 pm ]
Post subject: 
What do you mean by a 5 hole oil pump ?
I am about to put a motor back together and would like to know if i should be looking at this ?
Author:  Reed [ Wed Apr 29, 2015 2:09 pm ]
Post subject: 
The difference between the six hole and five hole oil pumps as well as the problem with five hole pumps and the solution is discussed in this thread HERE.

As always, a big thanks to Doctor Dodge and the other slant gurus who post excellent information and threads to help out the rest of us.
Author:  BUCKET 636 [ Thu Apr 30, 2015 12:24 am ]
Post subject: 
Thanks for that Reed , but all the oil pumps I have look nothing like that .
Maybe because the Australian slants run a remote oil filter because of the steering box being on the right hand side .
Author:  SlantSteve [ Thu Apr 30, 2015 3:20 am ]
Post subject: 
The Aussie slant sixes have a specific oil pump,the USA models are different and are not designed to accommodate the remote oil filter...all this was due to the RHD setup....the Aussie pumps are just fine,standard rebuilding,check clearances and your done....as a bonus we don't have all the hassles of gear failures etc that the USA pumps have.
Author:  mopardean [ Thu Apr 30, 2015 6:52 am ]
Post subject: 
Wow

I learn something everyday by reading this forum

thanks Reed and Doc for the great info and good luck Reed fixing your motor
Author:  slantzilla [ Thu Apr 30, 2015 9:42 am ]
Post subject: 
I would have the cam bearings replaced for sure. I would also be suspicious of the rod big ends, and check the cylinder bores for taper.
Author:  Reed [ Thu Apr 30, 2015 9:48 am ]
Post subject: 
Hmmm. This free motor may not be such a great deal after all. :? I'm trying to avoid the expense and down time of a full rebuild. I already have a new crank and rod and main bearings coming, but I will pull the pistons and the cam and check the bores and cam bearings. If this Jasper motor is too worn, I might just use the crank and bearings and repair a different running motor. Thanks.
Author:  nm9stheham [ Thu Apr 30, 2015 2:28 pm ]
Post subject: 
Check the rod big ends AND the main bearing bores AND the bearing shells for ANY sign of the bearings having turned, even a little. If any sign of such, the rod big ends needs to be resized, and/or the main bearing bores re-line bored.
Author:  Reed [ Thu Apr 30, 2015 2:42 pm ]
Post subject: 
I already know the #3 con rod bearing seized, spun, and completely disintegrated. It was a silty grey mess in the oil pan. The other con rod bearings are worn, but not too far gone. I haven't pulled the main bearing caps yet.

I need to put together a reliable motor for a daily driver, and I need to do it before the end of May. I am worried about putting this engine into service without a full teardown and inspection of all alignments and bearing surfaces.
Author:  SlantSteve [ Thu Apr 30, 2015 9:47 pm ]
Post subject: 
The engine will need to come apart...that rod that spun a bearing will need resizing at best,perhaps replacing. To do either you will need to press the piston pin off the rod to remove the piston...and hopefully not damage the piston. That thing has had metal go through it...it's also possible there will be bits of steel and other minute pieces of shrapnel embedded in the piston skirts...it's gotta come apart and likely turn into something larger than you may be hoping for...but hey,that's old cars in general. I really can't see it lasting if you just fit another crank into it and use the rods the way they are,you need to look at everything,let's face it,it had a bearing failure,what standard was it rebuilt to in the first place or what sort of life has it had since rebuild? :roll:
Author:  Reed [ Thu Apr 30, 2015 11:41 pm ]
Post subject: 
Ah, phooey. OK, time to rethink this.

I am actually trying to get this motor together for someone else whose 225 has a knocking rod. It is looking like I may just put the new crank and bearings into the knocking motor and let this one sit until I can rebuild it. Argh.
Author:  slantzilla [ Fri May 01, 2015 6:37 am ]
Post subject: 
If that motor has a knocking rod chances are it needs a rod resized at least and probably has trash all through it too. :shock:
Author:  Reed [ Fri May 01, 2015 7:56 am ]
Post subject: 
Poo. I was really hoping to just replace the crank and bearings a motor that had ben rebuilt but lost oil pressure and then drop that motor into the car.

If the cause of the oil pressure failure in a motor is loss of suction at the oil pump due to gasket failure on a five hole pump, is it possible that bearing material did not get into the rest of the motor? I really need to tear it all down, I guess.
Author:  slantzilla [ Fri May 01, 2015 9:28 am ]
Post subject: 
I put a crank and bearings in a small block Chevy once that rattled the #1 rod bearing. When we put it back together it was apparent that the rod was out of round. We rolled the dice and buttoned it up. It ran for a very long time in a Chevelle with a stick and 4.10 gears.

Roll the dice, it will either run or puke. :lol:
Page 1 of 2 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/