Crank hard to turn with just 3 pistons installed

[EagleTalonTim]

I am rebuilding my 6 bolt and have gone with standard bore Manley pistons, stock crank, clevite bearings (standard size) and standard size Manley H-beam rods. I have started to install the pistons one at a time after gapping the rings per cylinder and cannot turn the crank by hand at all with just 3 pistons installed. I could with 2 by grabbing onto the counter weights on the crank, but it was still tough. Is this normal? I can turn the crank with a ratchet without a tremendous amount of force but if I recall correctly, the last engine rebuild I did reusing all stock parts, it was much easier to turn. When I turn it with a ratchet, it feels like the pistons are having a tough time moving up and down the bore. I did hone it before installing the pistons and the PTW clearance is within spec for the Manley pistons. Please advise before I continue with the last piston.

 

[WES_393]

What did you use for assembly lube? Did you coat the cylinder walls with oil prior to install?

 

[EagleTalonTim]

I have always used STP oil treatment for my assembly lube. Never had a problem with it in the past. I did coat the cylinder walls with 10w40 using a rag and rubbing down each cylinder with an even coat. Also helps prevent rust when taking my time on this build

 

[bryanwheat]

It's pretty normal to not be able to turn the crank by hand.

 

[WES_393]

What do your oil clearances look like? The bearings might be undersized. Was it easy to turn before the pistons/rods were installed?

For what it's worth, on both of the 4g63's I've built myself I could rotate the engine by hand quite easily with a breaker bar.

 

[EagleTalonTim]

what do you mean by oil clearances? Sorry...it's late. brain is not working very well at the moment.

 

[bryanwheat]

Hmmm... What do your oil clearances look like? The bearings might be undersized.

If you use a thicker bearing with a stock diameter crank than it would be 100 percent locked up. You wouldn't even be able to turn it with a breaker bar. Normal oil clearance is around .0015-.0025 the next size bearing will be .010 which will have to actually be squished for the rod cap to tighten down all the way.

 

[dsmdeliveryboy]

What rings did you decide to go with?

 

[WES_393]

If you use a thicker bearing with a stock diameter crank than it would be 100 percent locked up. You wouldn't even be able to turn it with a breaker bar. Normal oil clearance is around .0015-.0025 the next size bearing will be .010 which will have to actually be squished for the rod cap to tighten down all the way.

Good point. Didn't think of that.

I'd still be concerned if it were hard to turn over by hand. Granted I haven't built nearly as many as most, but like I said I've never had to sweat to turn one over by hand.

 

[JusMX141]

Any chance you mixed up the rod caps during assembly? That could definitely pose a problem.

 

[EagleTalonTim]

Everything I got was ordered through STM. They gave me what they recommended for my build after I told them what I was wanting to do. From what I have bought, everything is for standard bore and standard crank for a 6 bolt engine. The Clevite bearings are for a stock 6 bolt crank which is what I am using. I told them I did not have to have the crank turned and they sent me what would work. I don't thing it is anything with the bearings since when installing the pistons, it is hard to push them up and down the cylinder wall without it connected to the crank. Has a scratching sound which sounds like the rings grabbing the cylinder wall. I can move them by hand up and down the cylinder, just has quite a bit more resistance than I remember.


EDIT : I have double, and triple checked the rod caps for correct installation direction on each rod and that the number on each rod matches the number on the cap which is how they were sent to me.

 

[dsmdeliveryboy]

Everything I got was ordered through STM. They gave me what they recommended for my build after I told them what I was wanting to do. From what I have bought, everything is for standard bore and standard crank for a 6 bolt engine. The Clevite bearings are for a stock 6 bolt crank which is what I am using. I told them I did not have to have the crank turned and they sent me what would work. I don't thing it is anything with the bearings since when installing the pistons, it is hard to push them up and down the cylinder wall without it connected to the crank. Has a scratching sound which sounds like the rings grabbing the cylinder wall. I can move them by hand up and down the cylinder, just has quite a bit more resistance than I remember.

This is why I asked which rings

 

[EagleTalonTim]

oh...must have missed that The rings are what came with the Manley Pistons. They are gapped at .21 and .25 as what i have found to be a good setting from about a month of research....

 

[dsmdeliveryboy]

That gap seems a little high, atleast to me. Everything I've read is a little bit smaller. I bet if changed the gap just a tad you'd be on the money.

 

[EagleTalonTim]

I can't make it smaller From what i have read and how much boost i am planning on running, plus being a DD, a larger gap than what was recommended on the sheet was recommended by many others....expecially because it is my DD.

 

[rlacasse1]

Did the crank turn freely by hand with no pistons in the block?

Were the pistons difficult to push down the cylinders before you put the rod caps on?

Or was it not hard to turn at all until you put the third rod cap on?

You should be able to easily crank it by hand even with all four in. So I wouls say your problem started at least at the second one where you mentioned you could turn it by using the counterweights, and it was difficult then.

 

[bryanwheat]

If you can grab it by the counter weights and turn it than it is fine. On no freshly assembled engine will you be able to grab the snout of the crank and turn it by hand.

 

[rlacasse1]

^^^^ Don't know if that was directed at me, but I will fix my second to last sentence. I meant turning it by hand with a ratchet. my bad.

 

[EagleTalonTim]

the crank spun freely with no pistons installed. It was smooth as butter when I put the first piston in, the piston was a little tough to move up and down the bore by hand, but I figured it was because the rings are new and needed to break in against the newly honed cylinder walls. The second one felt exactly the same as the first one, but made the crank a little more harder to turn. When I installed the third one, it felt the same pushing it down the bore and when I went to turn the crank, I could not get it to move without a ratchet on the end. I loosened the rod cap on the third rod and it still felt the same. I know it has to be something to do with the rings....that is where the "scratching" noise is coming from. It sounds just like my last engine build 6 years ago but I used stock pistons and OEM rings. I even used the same type of hone

 

[rlacasse1]

I would pull the pistons back out then and check out what is going on with the rings. Cause if you lubed everything the pistons should slide down the cylinders like butter, regardless of them freshly honed or new rings.

You should be able to turn it with a ratchet, but it should not take a whole lot of effort to do.

 

[bryanwheat]

I would pull the pistons back out then and check out what is going on with the rings. Cause if you lubed everything the pistons should slide down the cylinders like butter, regardless of them freshly honed or new rings.

You should be able to turn it with a ratchet, but it should not take a whole lot of effort to do.

Incorrect, there will be a decent amount of friction with freshly honed cylinders and new rings. The oil ring will scrape most of the oil from the cylinder and the top rings will not see that much oil when pushing the piston in.

 

[rlacasse1]

Incorrect, there will be a decent amount of friction with freshly honed cylinders and new rings. The oil ring will scrape most of the oil from the cylinder and the top rings will not see that much oil when pushing the piston in.

Incorrect my ass!!! There will not be a decent amount of friction. Sure there will be some. But not enough to damn near lock up the rotating assembly after three pistons are installed.

I have never had an engine that is anywhere close to what he is describing.

Oh OP, you said you were using 10-40 on the walls. What are you using on the bearings? Both Mains and Rods?

And Brian, I'm not trying to argue straight up with you, it's quite possible we have different opinions of what friction is.

 

[bryanwheat]

Compared to a piston sliding in a cylinder on a well broken in engine, a freshly honed and ringed engine will have more friction. There is no doubting this, it is what it is. He never once said that it is locking up the engine. He is just saying that he can't turn the crank with his hand. This is 100 percent normal.

 

[NHerron]

For reference, on my similar setup with pistons installed,

I could easily turn the crank with only a standard 1/2" ratchet
I could also push the counterweights with a little force and get things moving

 

[rlacasse1]

Compared to a piston sliding in a cylinder on a well broken in engine, a freshly honed and ringed engine will have more friction. There is no doubting this, it is what it is. He never once said that it is locking up the engine. He is just saying that he can't turn the crank with his hand. This is 100 percent normal.

I definitely agree with you on that. No doubt.

But it does sound like it's more than there should be. Like he says it doesn't require a "tremendous" amoung of force with a ratchet. That kind of makes me think something is wrong. Typically people say that when it's tough, but not over the top tough. If that makes sense.

But I personally have never had a motor, whether it was a 4, 6, or 8 cylinder, that I couldn't easily turn over with a 1/2 ratchet and one hand. Additionally, I've never had a piston require a whole lot of force to push down the cylinder.