FSAE_Junkie

I’m assembling my engine the other night and after torqueing down the main caps, I noticed the engine was not as easy to turn over as I would have thought. I’ve read about 10 threads related to this topic everyone says it should turn over ‘by hand’, but there are varying degrees of ‘by hand’, so it’s hard to judge what is normal.

To give you an idea, I could turn it with my index finger on the side of a bob weight, but I struggled to turn it when using my pinky finger. Hanging some weight off the side, I’d estimate it at around 3-4 lb-ft of resistance. It’s nothing ridiculous at all, but it certainly doesn’t want to ‘coast’ as I saw one person put.

It’s been awhile since I disassembled the engine, but I thought I remember the crank spinning quite easily before. I was thinking/hoping it has to do with the fact that disassembly was on motor oil at 70*F whereas now it’s on assembly lube at 30*F.

Motor oil viscosity at 70*F would be about 0.08 Pa-s.
Assembly lube viscosity at 30*F appears to be around 14 Pa-s (similar to honey). This is about a 150x increase in viscosity and thus drag.

I would think this could be causing the difference, but I was hoping to hear from someone who has done this a few times to be sure. Will cold weather and assembly lube cause the crank to resist being spun? And yes, I checked the bearing clearances with a micrometer and dial bore gauge. I also ‘aligned’ the #3 bearing.

Appreciate any input.

S10xGN

iTrader: (11)

First, make sure all the caps are oriented correctly. On one thru four, the cap numbers face the rear, on cap five the number faces forward.

jwindbigler

iTrader: (20)

Did you accidentally over torque the crank bearing bolts

KCS

iTrader: (20)

In my experience, assembly lube definitely puts more drag on the crank than oil. With oil, good clearances, and a good straight crank, you can turn the crank by hand and it will spin 1 or two more times before stopping. With assembly lube, it might turn 1/4-1/2 revolution.

FSAE_Junkie

I've double checked and the caps are on correctly.

Taking the inner bolts to 80* and the outer bolts to 51* took about the limit of my strength on the breaker bar I had, so I think it's unlikely I went over the spec by and significant margin on any of the bolts.

This is what I was hoping to hear, though unfortunately your comment makes me think I could potentially have something wrong. There is no way that the crank would continue rotating even 5 degrees after I stop applying torque. I hate doing things twice, but there's enough doubt in my mind that I probably need to re attempt it with motor oil instead just to rule a possible issue out.

I did find two other people on other websites who had similar issues with the same green Sealed Power assembly lube I used. That it was so sticky, it pulled the bearings out with the crank when they went to pull the crank and re-try assembly with motor oil. But without having personally experienced this, I'm probably to the point of needing to waste a few hours re-doing it just to convince myself.

KCS

iTrader: (20)

Well with assembly lube, it's not an exact science how much the crank should rotate. I usually use the red Clevite assembly lube, but I've seen some stuff from Amsoil that was REALLY viscous. I'm a single guy so my right arm might be a little stronger too lol.

I really don't like to assemble with assembly lube for this reason though. If there is a problem, like some dirt or a nick in the bearing, it would cause a slight resistance that you couldn't really feel with assembly lube. I prefer to assembly with oil, preferably a "break in" oil. The only time I use assembly lube is if I knew the engine would be sitting for a long time before being used.

JS01

iTrader: (10)

This.

zulatr

iTrader: (10)

if you went wth main arp studs clamping pressure is higher and crank will be much tighter or distorted. crank may not even turn. stock tty and proper new bearing proper clearance should feel smooth. did you line hone with new bearings? Also double cheak no 5 bearing you can install bearing tabs backwards. excessive leverage to turn crank is red flag.....

A.R. Shale Targa

iTrader: (2)

Putting engines together here in WI where it's currently -5 to + 5 I can tell you that KCS is right on with the 1-2 turns (motor oil in warm summer) and that thick red Goo really creates drag and makes me think the same thing you are especially when it's this cold. I only use that stuff as KCS said when the engine won't be fired for quite a while. Trust your measuring instruments.

mebuildit

I'd take it apart, use some thin oil and reassemble. Use a dial torque wrench to see how much torque it takes to turn the crank. If it's free then you know that it's your assembly lube. If not then something is wrong.