My 1st motor build kind of worried

[FastGS-T]

Alright. I have done head swaps, and pretty much everything else, but never a bottom end assembly. So I got with some machinist and a couple shop manuals and put together my own 6-bolt bottom end. When I first did it I could turn the crankshaft and the pistons and everything would rotate, now after a couple days (Waiting to put the head on still) It wont rotate, I didnt force it because im assuming the cylinder walls and pistons just need to be lubed again.

But my question: Will you guys check out my cardomain where I logged my whole procedure? I have no experienced 4g63 builders around so I had to do this myself and just need some feedback. Thanks

Click here


edit: Also after I put it together I took the crank back out, re lubed all of the bearings and then retorqued down all of the caps.

 

[jking29]

I don't see where you set the thrust bearings and checked endplay. This is a very important step in building any performance engine. If it is not set, the crank can ride on the radius of the bearing causing it to bind like you describe.

 

[FastGS-T]

I used plastigauge and checked my clearances. But the whole rotating assembly turned fine when I freshly built it, so I am pretty positive that it just needs to be lubed up again to rotate.

What do you mean set the thrust bearings

 

[h3o]

after you rotated the assembly a few times did you go and retorque everything? sounds like something is binding

 

[FastGS-T]

Well it bound up so i took each rod cap off and then torqued each one down and made sure the crank would turn as i added each one so they were all in the right place. Then i could rotate it for a while, then a few days later it wouldnt let me turn it. but I was turning by locking a crescent wrench on that key that lines up the crank sprocket, as i didnt have the bolt that accept the 1/2" drive ratchet so i probably wasnt turning hard enough

 

[jking29]

The thrust bearing is the main bearing that keeps the crank from walking back and forth. It is the one that is not just a round flat bearing, it wraps around the main saddle and cap. When you go to torque this bearing down, you need to tap the crank on each end with a dead blow hammer to center this bearing.

 

[FastGS-T]

I know what the thrust bearing is. So I just need to hit the crank from each side to set it right? thanks for that info.

 

[FastGS-T]

Do you think it may be because I dont have that center bolt that accepts a 1/2" drive ratchet? Would it make it easier to turn that way? Can I get it from the dealer?

 

[FastGS-T]

Ok I tried all the rod cap combos, none are working.. it seems that:

If I loosen the main caps it will turn, but if i leave the main caps torqued and just loosen the rod bolts it will turn, but it wont turn if they are all torqued

 

[madmike]

is the head on? do you have the timing belt on? and are the spark plugs in? just asking

 

[FastGS-T]

no its just a block, did you goto my cardomain ud seen that

 

[madmike]

man it looks like you did everything right, I put one piston in at a time like you did, then I rotate the crank 3-4 times to make sure its right and seats, then install the next. I wonder if your block is slightly warped if so you need to have the block lined bored, the machince shop removes the crank, installs the main journal caps, torque them then line bores the crank journals all together. sounds like this could be your issue! call your machine shop and check it out.

 

[FastGS-T]

I took it to the machineshop, they sent it off to get a line hone, and when they gave it back they said "your line checked out ok it doesnt need a hone".... crap i hope your not right

 

[madmike]

ah man just re-read your cardomain, looks like the machine shop already checked your line bore, hmmm did you check the back side of each bearing to read the size of the bearing? make sure you did not accidently get a standard size bearing in one of the undersized boxes? that happens every once in a while

 

[FastGS-T]

yeah i checked, since my crank is .010 under i made sure to get the 25 size bearings. (10 under)

 

[jking29]

A friend of mine had an engine do the same thing. He pulled it all back apart and sent everything out to be checked again. He found out that he had a rod with a very slight twist in it. He got a new rod and everything was fine. Have you looked at all of the bearings again for signs of contact?

 

[madmike]

man this is driving me crazy need to find out what is causing this! Let us know if you find anything, right now its the talk of my shop, we are all running through the "what ifs" Looks like your doing an excellent job, by the book with good skills, but Murphys law has stepped in (any thing that can go wrong will go wrong) good luck!

 

[FastGS-T]

Well right now I am in the middle of putting it together again. So far I have it narrowed down to probably being a rod cap mix up. So I am reinstalling the rods, one rod at a time to make sure it will turn with each cap on so that they are in the correct place

 

[turbo_lag92]

did you ever figure this out?

 

[JRSTANGE]

are you sure the bearing clearance are correct? I know you said you plastiq gauged them. What about the assembly lube? what type. I've seen it been done were something too thick was used and creating that extra hold when everything was torqed.

 

[bwhite]

Wow this post is 4 yrs old. Did you guys see that .

 

[KaLo_o]

hahahaha hope hes got the thing running by now

 

[ziggo0]

Regardless, I ran into this problem. Rings were sticking to the walls since it sat for to long and I didn't lube up the cylinder walls good enough. Could also be a rod journal out of round if that wasn't checked.