Engine sticking after rebuild...

[Axis 7m]

This is the first time ive rebuilt the 7mgte myself. After i finished the bottom end (few new bearings) and torqued everything down, I went to turn the engine over and it spun perfectly. I used Engine Assembly Lube on the front of all the bearings. After I put my head back on which was a couple days later i went to spin the engine over and it was really hard to do but it broke free and spun freely. now that the engine is back in the car it is still sticking pretty bad. I am looking for suggestions on what it could be. Appreciate it in advance. O yea i havent started the engine yet still waiting for battery to charge..... But still any ideas would help before i screw sumting else up.

 

[CyFi6]

dont start the engine! If something is sticking you must have tight clearances somewhere or lack of lubrication somewhere, did you double check all your measurement such as oil clearances, piston clearance, ring end gap etc? Try removing the timing belt and turning the crank, that way you can isolate the problem better. Again, dont start the engine.

 

[Axis 7m]

dont start the engine! If something is sticking you must have tight clearances somewhere or lack of lubrication somewhere, did you double check all your measurement such as oil clearances, piston clearance, ring end gap etc? Try removing the timing belt and turning the crank, that way you can isolate the problem better. Again, dont start the engine.

Ok. Well i did not double check my clearences. I'm 90 percent positive that it is sumwhere in the crankshaft....it may be the fact that i didnt lube the crankshaft rod journals enough. damit i hope i dont have to pull the engine again.

 

[Poodles]

Are the spark plugs in? If so, it's just compression...

 

[Zumtizzle]

^and if they aren't.

 

[randandrawson@v]

make sure the cam caps are in order, and pointing the right way.
pull the timing belt loose from the top sprockets and move the cams with a adjustable wrench (flats on camshaft just for this)
Try the crank now.
not sure if the GTE is an interference motor or not, careful not to bend valves.
If it was good until you put the head on, it almost has to be something up top binding.
Its also important to not over torque the cam caps, as they distort like hell.
I dont know any of this from personal experience.....

 

[IJ.]

Non interference....

If you're NOT sure on something please don't post in the tech section.

 

[Axis 7m]

Are the spark plugs in? If so, it's just compression...

Well it was sticking a little bit before i had the spark plugs in. I'm really thinking it is lack of lubrication. i wasn't too sure if i would use too much engine assembly lube on the crankshaft. I didn't want to get any on the back of the bearings n what not.

 

[Nick M]

What was the turning torque?

 

[92TealSupra]

Well if something is sticking, it's never good to " Force Something " like your motor. Looks like you will be pulling your motor back out. now it looks liek you're going to have to start all over again. You may find one problem, but what makes you so sure there is not another problem. This time I would double check everything you're doing- becuase you didn't check everything, you may now have problems, or caused more.

 

[Axis 7m]

What was the turning torque?

Not sure what you mean by turning torque. After i break it loose it turns perfectly fine which is why i think it is a lubrication problem. I had the bottom end sitting on the engine stand for about 2 weeks before i got my head on and dropped the engine in the car so im thinking the assembly lube maybe leaked out or became non existent through that time.

 

[Neil W]

Hi Folks. I'm new here, but I have built a lot of motors, Honda B series and Nissan 240Zs seem to be the most applicable to the 7M-GTE (I bought my Supra a few weeks ago).

From my experience, the following applies:

1. It's not a lube problem. Even with no lube, the crank will spin easily with no compression (plugs removed).

2. Remove the timing chain and spin the cams, and the crank all individually. You should be able to narrow the problem to a single component (possibly both cams).

3. I suspect your problem is a warped cylinder head, causing your cam bore axis to be a curve. This is mainly caused by having the head planed to flatten it. If you need an explaination, ask. Did you have your head planed?

Also, the previous posts regarding the amount of "stick" you've got are important. There may not be a problem. Have you built motor's before? There is a lot of resistance in the valve train from the springs, and it is sometimes confused with an issue.

Good luck, keep us in the loop.

Neil

 

[Axis 7m]

Ok guys i pulled the engine back out today, pulled the oil pan off and checked the main caps. it looks like I over torqued all of them so I had sumone else re torque them and I relubed all of the bearings now the engine spins normally. Thx for all the info.

 

[suprabad]

Ok guys i pulled the engine back out today, pulled the oil pan off and checked the main caps. it looks like I over torqued all of them so I had sumone else re torque them and I relubed all of the bearings now the engine spins normally. Thx for all the info.

Did you look at the journals and main bearings before you buttoned it all up?

The reason I ask is because you may have damaged them by turning the motor with the caps over-torqued.
It's better to find out now than after you start the motor.

Word to the wise.:icon_bigg

 

[Axis 7m]

Did you look at the journals and main bearings before you buttoned it all up?

The reason I ask is because you may have damaged them by turning the motor with the caps over-torqued.
It's better to find out now than after you start the motor.

Word to the wise.:icon_bigg

Yea i looked at all of the bearings and journals. There was only one bearing that was a little shiny from the over torque but it was nothing serious and all of the journals were fine.

 

[TooGoode]

Yea i looked at all of the bearings and journals. There was only one bearing that was a little shiny from the over torque but it was nothing serious and all of the journals were fine.

are you fucking crazy??:aigo: replace all your bearing....dont care what they look like, you'lll have rod knock so fast it'll be stupid...."shiny"=metal that has been taken of=bigger clearances than allowed=rock knock!!! dont put the motor back together yet!! go and spend a few more dollars and get some bearings!!!

 

[Poodles]

they might be fine, but he REALLY needs to plastiguage the clearances...

 

[rumptis]

Ok guys i pulled the engine back out today, pulled the oil pan off and checked the main caps. it looks like I over torqued all of them so I had sumone else re torque them and I relubed all of the bearings now the engine spins normally. Thx for all the info.

Not possible if things are right. Over torquing is bad but there is no way you could over tighten things enough to cause this problems if everything else is right.

Did you have the crank ground or anything? Or did you use the stock crank and just get over sized bearings?

Something is not right here, stop before you make things worse then they already are.

 

[Neil W]

X2

Not possible if things are right. Over torquing is bad but there is no way you could over tighten things enough to cause this problems if everything else is right.

Did you have the crank ground or anything? Or did you use the stock crank and just get over sized bearings?

Something is not right here, stop before you make things worse then they already are.

 

[92TealSupra]

I hope that shiny* bearing you put back in will not go bad..... I would've suggested replacing everything after that happned.