Engine Hard to Spin after New Piston Rings and Rod Bearings

[scottr126]

Im currently doing a 6 bolt swap into my 97 GST and the 6 Bolt from My old car was giving low compression readings due to bad piston rings so while I had it out I installed new Piston rings and New clevite Rod Bearings, I did everything to spec and tightened down the rod nuts to 35 ft. lbs. I dont have the engine installed yet but I noticed even without the head on (no compression) the engine is kind of hard to spin, its smooth and all and i dumped a bunch of oil on it but it just seems kind of difficult to move like the only way to get it to spin is put a 1/2in rachet on the crank and crank on it but once u get it goin it goes decently easy, is this normal after new rod bearing, piston rings?

 

[steve]

Did you check your bearing clearances with plastigage?
What did you set your ring end gaps too?

Steve

 

[scottr126]

hMMMM Plastigage, heard about it but didnt know if it was needed, please explain the use of plastigage and how u adjust accordingly.
Also with the piston rings I just installed them, the motor is stock bore so i figured nothing else was needed but i did set the gaps in there correct places if thats what you mean. Let me knowm, thanks.

 

[steve]

I'm just a newbie at engine assembly, so perhaps a few of the more experenced builders will chime in on what else to watch for.

A google search will net you lots of information on how to use plastigauge to check the main and rod bearing clearances. A quick look in the overhaul or service manual wiil give you the correct clearance specs (IIRC 0.0008 to 0.0020) You also need to check the crankshaft endplay to make sure the thrust bearing is correct.

Ring end gap is the distance between the ends of the piston ring when the ring is it the cylinder bore and square to it. Each of the three rings has a spec for the end gap.

What kind of assembly lube did you use.

 

[AWDlaserRS]

I just did an engine rebuild and that is normal, Its kinda hard even on an old engine. Dont worry about it. Its because of all the new surfaces. As long as you torqued everything right you'll be fine. Its exciting starting an engine for the first time Check my gallery for pics of my new engine!

 

[scottr126]

I just did an engine rebuild and that is normal, Its kinda hard even on an old engine. Dont worry about it. Its because of all the new surfaces. As long as you torqued everything right you'll be fine. Its exciting starting an engine for the first time Check my gallery for pics of my new engine!

Yah thats what i figured, because all the bearings and rings arent all worn in the engine is going to be a lil harder to spin, but yes I did torque everything down to spec, I checked like 5 times!! Im going to be firing it up in about 4 days, Ill let ya all know how it goes, thanks.

Scott

 

[bigbroompilot]

If the rings arent end gapped correctly they can tear the crap outta things.....also if your nor sure of the clearances plastigage them....if things are wrong it WILL tear up your new engine. plastigage is cheap, all it takes is a little extra time, and then you wont be nervous....if the rings are binding it can be cured with nothing but a file. I strongly suggets you take the time to check....

 

[steve]

I'm glad someone else thinks so too.
I notice that AWDlaserRS seems to have cracked a ring. I wonder if it's the same engine.

 

[AWDlaserRS]

The reason I have a cracked ring is because I wasn't careful enough putting the # 2 cylinder into its bore. Not because I didn't check ring endgaps, which by the way I did.

 

[steve]

Sorry man, for your hardship and implying that you didn't check clearances.
That's the impression I got from your post. My mistake.

 

[ArticNemesis]

So you didn't check bearing clearances at all.? Kinda risky if you ask me. I was scared the first time I started my motor... Confident that I did everything correctly, but scared nonetheless (money wise...)

 

[AWDlaserRS]

So you didn't check bearing clearances at all.? Kinda risky if you ask me. I was scared the first time I started my motor... Confident that I did everything correctly, but scared nonetheless (money wise...)

Same here, I had my fingers crossed when I turned the key and all the horror stories I have read on here about spinning rod bearings after rebuilds came back to me. Luckily it fired right up and has gone 68 miles since then. By the way the cracked ring Is fixed now.

 

[scottr126]

Yup Im praying myself, I think Im going to try and fire mine up tommoro. I just put in new Clevite rod bearings and a New set of Stock Bore Size piston rings. So I dunno I figured that the piston rings shouldnt have to be checked and since the bearings were stock sized they wouldnt have to be checked so I just threw them in and tightened em down to spec. Everything is smooth and all its just a lil hard to move but im guessing thats just because the bearings and piston rings dont have 100k miles on them. Ill get back to you all on how it goes. But I do have ONE question, how would I go about using Plastigage and how would I adjust if its too tight?

 

[scottr126]

Well guys after about a total of 20 minutes cranking the motor, swearing, bleeding, crying and sweating it finally started up... But ya it runs pretty smooth, had a few oil leaks but its all good now. But I still have this weird problem whenever I start it up at first you hear the engine crank then right when it fires up it makes this horrible grinding sound for like a split second but then proceeds to run perfectly and rev perfectly. I dunno what the hell it is it makes me nervous as hell but the motor runs Perfectly. Any ideas?

 

[dbdragster14-]

Did u check the starter. it may not be disengaging right away

 

[scottr126]

30 Miles an everything is Great! But Yah Im guessing the starter is messed up. Im gonna try and find a new one.

 

[AWDlaserRS]

30 Miles an everything is Great! But Yah Im guessing the starter is messed up. Im gonna try and find a new one.

Yeah sounds like the starter is not disengaging right away. You will probably find a lot of small problems for awhile. I was having issues with my oil cooler loop leaking and recently my damn water pump siezed up, scared the hell out of me because the engine wouldn't turn over afterwards and I thought something gave out inside but it turned out it was just the waterpump.

 

[scottr126]

Damm waterpump, that sucks. But ya other than the starter I have been having some oil leaks. I hate oil leaks, I always get the tricky ones that I cant find. :thumbdown