Motor Very Hard to Turn Over????

[306deranged]

Once again i have ran into another problem and need some advice.. I have a 88 ranger im building a 1994 302 HO for it. This is my first build and im learning alot at 20 yrs old ive been asking for alot of help. One of my budys helped me put the motor together hes got several mustangs and knows alot about 5.0's. I had the motor bored .030 over and new cambearings relaced. Also new rod and mains obviouslly. All clevite bearings, 0.30 over hyper speed pro pistons installed. The problem is the motor is hard as hell to turn over by hand. I have to put a bar on the end of my torque wrench to get it to spin, although its seems like its gotten ALOT easier in the past couple days. Could this just be the motor trying to break in the new bore???? Any help would be appreciated and no the spark plugs are not in so no compression.

 

[Teddyzee]

I'd pull the main caps off, one at a time, and see if it gets easier. Could be a bent crank.

Could probably be many other things...

 

[v-8power]

Or a rod cap on backwards. I did that once.

 

[306deranged]

alright i might try taking the oil pan back off tonight and checking them out...when i was putting the motor back togetther as soon as i notcied it getting hard i pulled the main caps off and put more oil on them but it didnt make a difference so ill check the rod caps...ive heard that sometimes this is just normal?? any experience , like maybe it just has to break itself back in or something like the little coating on the bearings has to get worn good??

 

[85_Ranger4x4]

Did you check the clearances with Plastigauge as you was reassembling the crank/rod bearings?

We had a guy that just stuck his brand new tractor engine together without checking... and on that particular engine you were supposed to shim the caps to get the proper clearance. He was all bent out of shape his engine wouldn't turn over and thought we got him the wrong parts.

 

[COPPERHEAD85]

Check your bearing clearence,the last 351 I put together would turn with a 1/2" ratchet no problem.

 

[trail B2]

That's not right turns too hard i'll bet it's one of the above suggestions.

 

[fordmike1]

If the machine shop put the pistons on the rods I would check to see if they crossed any of the rods. In other words the pistons should have a mark on them that shows which way they go into the block and the mark should point to the front of the block. Now with that said if they hung two pistons on the rods backwards and you installed each rod and piston into the cylinder that matched the number on the rod you would have this problem and the reason why is the rod bearing is off set in the rod to clear the radii on the journal of the crank. the bearing should be off set toward the center of the journal when the rod and piston is installed. The other posible thing could be the wrong sized bearings. Well I hope that this helps you out and keep us updated.....Mike.

 

[306deranged]

yea on my pistons they have like a little triangle on the top of them and we put those pointing towards the front of the motor...so it should def not be that tight? i checked the bore tonight and it was 4.025 approx...could that be the problem. But i tryed to turn it with just the breaker bar on their and i cannot turn the motor without a leverage bar on the end of it, and im scared i will break the crank bolt off eventually....its getting easier to turn but im scared to try to turn it by the flywheel and starter. When i put the main and rod bearings on i didnt measure them just slid them on. My rods were not machined any, just new pistons pressed on. I honestly dont know where to start or what to measure, kinda stuck right now and it sucks

 

[alwaysFlOoReD]

I'd say go to the beginning. Take it apart and put it back together. A pain but...
Check everything as you take it apart and then again as you put it back together.
Good luck,

Richard

 

[306deranged]

BUT does it matter that the rods are not where they used to be. Yes they still match such as cap 1 rod 1....cap2 rod 2....and so on but rod 1 is not in cylinder 1 anymore and so on if u know what i mean....the guy helping me build the motor said it didnt matter anymore as long as the rod and cap number matched

 

[Teddyzee]

BUT does it matter that the rods are not where they used to be. Yes they still match such as cap 1 rod 1....cap2 rod 2....and so on but rod 1 is not in cylinder 1 anymore and so on if u know what i mean....the guy helping me build the motor said it didnt matter anymore as long as the rod and cap number matched

If it bothers you, it's easy to correct.

If you don't investigate now, how long do you think the engine will last?

Take your time, you'll find something.

 

[alwaysFlOoReD]

If the machine shop put the pistons on the rods I would check to see if they crossed any of the rods. In other words the pistons should have a mark on them that shows which way they go into the block and the mark should point to the front of the block. Now with that said if they hung two pistons on the rods backwards and you installed each rod and piston into the cylinder that matched the number on the rod you would have this problem and the reason why is the rod bearing is off set in the rod to clear the radii on the journal of the crank. the bearing should be off set toward the center of the journal when the rod and piston is installed. The other posible thing could be the wrong sized bearings. Well I hope that this helps you out and keep us updated.....Mike.

Take a look at above,does it make a difference if you swapped rods from one bank[side of the motor] to another?

 

[fordmike1]

Take a look at above,does it make a difference if you swapped rods from one bank[side of the motor] to another?

No it does not make a diffrence if rod #1 is in hole #7 as long as the rod is turned the right way. Like I said before you need to make sure that the bearing in the rod is toward the center of the journal and away from the Radii or the edge of the journal. I am willing to bet that this is the whole problem with his engine as I have seen it done before. I will look and see if I can find any pics on the web and post them so he can see what I am talking about.

 

[alwaysFlOoReD]

No it does not make a diffrence if rod #1 is in hole #7 as long as the rod is turned the right way. Like I said before you need to make sure that the bearing in the rod is toward the center of the journal and away from the Radii or the edge of the journal. I am willing to bet that this is the whole problem with his engine as I have seen it done before. I will look and see if I can find any pics on the web and post them so he can see what I am talking about.

Thanks for the response.
So he has the rods on the wrong side of each other? It's been a long time since I've been in side a motor. Even though he has the piston facing the right direction, can the rod slide along the wrist pin enough to place the crank end of the rod on the wrong side of the journal?
In any case I think he has to do a teardown and inspection.
I find myself in the same situations sometimes when I go too quick or have 'just enough' knowledge to be dangerous. That's why I like TRS, for the knowledge that I don't have yet.

Richard