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chevy 350 crank kit

brianj_92505 brianj_92505
New User | Posts: 15 | Joined: 12/09
Posted: 02/12/10
02:11 PM

While doing work on my transmission I noticed excessive end play on my crankshaft. Removing the oil pan revealed that the thrust bearing was completely worn and the thrust surface on the journal was damaged. So I pulled the engine and figured I'd replace the crank shaft and bearings (rod and mains). Now I'm wondering if this is possible to do without removing the pistons and all that goes along with that.  

waynep7122 waynep7122
Addict | Posts: 4551 | Joined: 08/09
Posted: 02/12/10
06:54 PM

yes.. but is not easy...  be sure you back off the rocker arms.. and line up the crank with the cam gear the same way it came out..

lots of short pieces of 3/8 ID vinyl hose over the rod bolts..   you also .. please... take a 2x4..  put some  big finishing nails in  it..   to hang the rod caps on as you take them off in order.. and to hang the rod nuts on..   they have to go back on in the exact order and direction..

do not stamp the rod caps...  use a paint marker..  stamping them usually ,,, not always causes distortion...   see if they are marked near the split.....  

see if you can find some stay lube brand... moly graphite engine assy lube.. in a black squeeze tube..   it does not drip out...

do post that you got this... and come back.. there are several links i will post to this thread later tonight...  thats important for you to read... on thrust bearing failures...

here is one of the articles...

you will have to copy and paste the link...  it is written by one of the best automotive writers around...  

brianj_92505 brianj_92505
New User | Posts: 15 | Joined: 12/09
Posted: 02/17/10
07:12 AM

Thanks for the reply, I would have been back sooner but been busy with my real job.
The main caps are marked with numbers and arrows and I marked the rod caps so I can reinstall them correctly. Too late for the nuts and bolts they were all thrown together into a tupperware. I never heard that they had to be replaced in they’re original location.
Why do you recommend backing off the rocker arms? Do the valves extend far enough to hit the pistons?
If one is getting a crank kit from a reputable source that includes crank, rod and main bearings do you think it would be safe to not bother with the plastigage testing because installing the crank once will be hard enough but installing without lube, testing, removing to add lube then reinstalling is too much.  

waynep7122 waynep7122
Addict | Posts: 4551 | Joined: 08/09
Posted: 02/17/10
09:33 AM

are you going to install it with the motor still in the car... ?????????? that is a really hard job...

the rod nuts and main bolts can go back anywhere...

i am glad that you could see the marks on the rod and main caps...

i have answered several posts around the web... that people mix them up...

i would think with 2 or 3 people ...   2, to hold and position the crank.. the third guy to put a pair of main caps on to hold the crank up... you might get it done..

its not totally impossible...

pulling the distributer...    using a priming tool to spin the oil pump after everything is together

and.. some of the valves will be open...  and you can drive the pistons up far enough to possibly hit them..  

brianj_92505 brianj_92505
New User | Posts: 15 | Joined: 12/09
Posted: 02/17/10
10:05 AM

No, the engine is upside down on a stand in my garage. Where did I lead you to think the engine was still installed?

I already had the idea of priming the oil pump and assuming I do that, is clean motor oil acceptable lubrication on the bearings during assembly or would one still apply assembly lube?

Also, I noticed that the rubber is coming out of the harmonic balancer. I wonder if that is related to the thrust bearing failure.  

waynep7122 waynep7122
Addict | Posts: 4551 | Joined: 08/09
Posted: 02/17/10
11:58 AM

when you mentioned how hard it would be to install the crank greased up with assy lube...

i just imagined you trying to stick it in from the bottom... i have seen it done...  on a 390 ford.. in a 65 galaxy ... not a fun project..

i usually spread the assy lube on the bearing shells before i drop the totally clean crank in..

then spread more on the bearing shells in the caps as i install them..

i usually crank a fresh motor over with the spark plugs out.. and the oil filter off till i get a squirt of oil out the filter adaptor..

then i put a filter on it  and crank till i get pressure on the gauge..

then i put the plugs in and start the motor...

you do i take it have an HEI distributer..

you do know the trick.. of setting the harmonic balancer to what ever the timing should be set at..   and turning the distributer till the reluctor tips and pick up coil tips line up exactly  lock the distributer there..  if you have done everything right.. it will start on the first try without having to turn the distributer like so many have to do..  

brianj_92505 brianj_92505
New User | Posts: 15 | Joined: 12/09
Posted: 02/18/10
05:44 AM

When I visualized this job in my head I imagined removing the rod caps, pushing the pistons to the top of the cylinder and then having plenty of room around the crank shaft. What I discovered is that there is very little room in between the throws of the crank and you cannot remove all the rods with the crank shaft in one position it must be rotated a certain amount and the disconnected rods get in the way of the rotating crank journals. Still I can see it is possible but it will take great care to avoid any contact that might damage the journal surfaces.

What I was stressing about is the oil clearance test that all the authorities seem to insist on. Place the crankshaft on the new bearings without any lubrication, positioning the rods as necessary to accomplish this. Then torque down the caps with the plastigage under them to measure the clearance. Then if it checks out I have to lift the crank back out, again dealing with the rods so that I can apply lube to the bearings and carefully put the crank back into position. Then repeat the whole plastigage routine with all the rod bearings. This is a lot of extra work that shouldn’t be mine. I’m getting the remanufactured crank and bearings as a set; I’d like to think the manufacturer has a degree of quality control so that I wouldn’t need to recheck their work. Know what I mean?  

waynep7122 waynep7122
Addict | Posts: 4551 | Joined: 08/09
Posted: 02/18/10
09:23 PM

just throw it in...

don't bother checking the clearances...  i don't ... i do have the crank supplier measure the crank before it leave the shop..

just to be sure.. takes them about a minute..

did you miss the part about rod boots or clear vinyl hose sections pushed onto the rod bolts to protect the journals..

if you want to install the crank dry.. so be it..  if you used liquid assy lube like most shops do.. it will just drip out anyway..

thats why i recommended the stay lube moly graphite assy lube..    it does not drip out..     white lithium grease will also work...

oh.. do me a favor...    throw a pair of super magnets in the corners of the oil pan..  catch any of the crank thrust material that was worn away..   you are going to install a new oil pump.. and an IS-55E oil pump drive with a steel collar.. instead of the plastic collar..  under 10 bucks..  autozone has oil pump screen installation tools in their loan a tool section.. use it with the pump against a block of wood...  not in a vice..  

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