Need help on rebuild

[eDeclpse92]

i am rebuilding a turbo motor and i ran into a problem. while checking to see if the motor will turn over by hand, i noticed that it got really easy in some spots and harder in other spots. the easiest was when the piston where at tdc and bdc, and it got stiff as it starts going down. I was wondering if this is normal or if it should be the same resistence all the way around? The top end is on and the timing belt is in time correctly.
Any help would be much appreciated.
Thank you.

 

[rlacasse1]

Yes it will get stiffer because as one piston hits its compression stroke it will build pressure and will be hard to turn. If you sit there and just turn it over for five minutes by had you will feel it getting sitffer then easy like its pulsing. that is completely normal

 

[eDeclpse92]

i dont have the spark plugs in becasue i didnt want it to build compression. i just wanted to see if everything was put together right.

 

[rlacasse1]

Ok. It may also get stiffer when the valve springs start to compress. If your valve cover is off or take it off then see if they are being compressed when it gets harder to turn

 

[eDeclpse92]

i took it off becasue one of my friends said this might be the case. it does get harder when the valves start to fully compress and is the hardest when they were fully compressed. but i thought that the motor should turn over easier than that. i could turn the motor with a 1/2 rathcet and breaker bar but i twas pretty hard to do so. and on top of that, i am in an awkward position. i am just wondering if it is going to be ok to crank the motor over for the first time and it wont spin anything or mess anything up?

 

[rlacasse1]

That sounds like there is something wrong. They shouldn't be that hard. Is the engine in the car right now?

Are you positive your timing is correct?

I use a 1/2 ratchet to turn them over. And it works fine. Some engines you have to put in alot of muscle though.

 

[eDeclpse92]

i am positive the timing is correct and the engine is in the car. i was going to take the head off and turn the motor to see if it is in the bottom end or the top end that is causing the trouble. i live in belleville and i see that you live on scott, i was wondering if you could come and take a look sometime?

 

[rlacasse1]

I just pm'ed you

 

[aaannntt1965]

Did you take the timing belt off and remove your cams to see what happens?(if it turns freely?)
The new rings are not seated in correct? Did you put a balance shaft stubby in?(check to make sure it is in correctly)
Is the oil pump primed?
Did you use assembly lube to build your engine?
Ant

 

[eDeclpse92]

no i did not take it off yet, i am about to take the head off and see if the problem is in the bottom end or not.
the rings are seated correctly
i have the stock balance shaft in
i have not primed the oil pump yet. this is a fresh rebuild. motor has not been turned on
yes i used assembly lube on everything.
any suggeestions.

 

[aaannntt1965]

Prime the oil pump before you start the engine. i think you may be a little tight on the thrust bearing i am not sure only guessing. the engine will need to run before your rings seat. the tension of the rings or as we say ring drag may a contributor to that problem.
pull the timing and balance belts off and see if that makes ant difference.
did you get it bored and honed? with or with out a torque plate?

 

[1pt5barboost]

Just finishing up my own long-block, and the engine is also "stiff" when turning over. This isn't really a problem, it just the mechanical leverage you have over the pistons at TDC and BDC. When you are half way through a stroke (i.e. when all four pistons are actually in the middle of the stroke) you will naturally have a lot of resistance. Especially on a new build.

 

[quiksilver20004]

It would also be a lot more stiff if the head didnt have stock cams and valve springs. larger cams have a bigger lobe and are paired with stiffer springs.

 

[GooeyGus]

From my personal experience, I would say you're fine.

If it were any sort of resistance that would cause a problem, you wouldn't be able to turn past it.

Since you CAN turn past it, and it just gets a bit more difficult to turn, I would say prime her up and turn the key.


Again, this is just based on what I've experienced when rebuilding motors.

 

[eDeclpse92]

ok. thanks alot guys for all your input. i just havent talked to anybody that has built these turbo motors before and this is my first one so im a bit paranoid on it and i dont want something bad to happen when i turn the motor over for the first time. i appreciate all the help.
thanks
ed

 

[Clutch GSX]

You're fine. Mines the same way, although mines a stroker. If it were anything that would cause serious problems it would be really hard to turn. If your timing belt is on then it should be pretty hard to turn anyways because you have to compress the valve springs. It always turns easier when the pistons are dwelling at the top and bottom because they aren't moving that much and therefore there is less friction. Fire it up and have some fun!