Bolt TQ ?'s

[GOBR]

So I got the 355 shortblock the other day. The guy didnt tq down one of the mains when he pulled it off so I could see what the bearings look like and the same with one of the rods. I checked the tq on one of the others and its not at 45 on the rods and not 65 on the mains. Should I call him and see what he tq'd them to and go to where he was OR should I crack em all loose and tq them to 45 and 65?

 

[crazy4offroad]

I wouldnt waste my time calling him, I would re-do all the torque specs of everything. It's the safe thing to do.

 

[GOBR]

I wouldnt waste my time calling him, I would re-do all the torque specs of everything. It's the safe thing to do.

Thats what I figured. It was ran in a truck for about 2 months but the owner decided to get a crate motor with more power. The guy who built it bought it back from him and now I have it. Bearings look almost brand new and there is still cross hatch pattern in the bores.

I was just thinking since its already been ran at whatever tq he set em to then maybe I need to redo where he had it? Maybe he tq'd tighter for different bearing tolerances? I dunno. The motor has been ran at whatever he tq'd it too tho. So still redo all the tqs?

 

[HotRodPC]

I wouldnt waste my time calling him, I would re-do all the torque specs of everything. It's the safe thing to do.

Yep, Take no chances.

 

[davbell22602]

Are we talking a 350 or did gm actually make a 355?

 

[crazy4offroad]

355 = 350 bored 0.030" over.

 

[davbell22602]

355 = 350 bored 0.030" over.

Ok thanks.

 

[GOBR]

So even tho it ran with these bearings that are in it now for 2 months, I should bust em loose and re tq?

 

[crazy4offroad]

I would. Can you be sure he didnt show someone else the engine and loosen some other main & rod caps? You may want to pick up some plasti-gauge and check all the oil tolerances anyway, get a look at all the bearings. It's what I would do, before throwing more money into it, then getting it into the truck where by that time it will be too late if something goes wrong, and you'd have to take it all the way back out agin.

 

[davbell22602]

So even tho it ran with these bearings that are in it now for 2 months, I should bust em loose and re tq?

How miles did the bearings run for? I probably would.

 

[HotRodPC]

huh, I posted, or so I thought I posted, 355 is 350 @ .030 over, and then I seen C4's post and realized my post didn't go thru??? WTF??? Guess I better get with a mod and find out what the fugg is going on here huh?

 

[HotRodPC]

Are we talking a 350 or did gm actually make a 355?

355 is a 350 @.030 over.

Ahh, here's my post in another window. Guess I never hit submit. Mystery Solved.

 

[HotRodPC]

How miles did the bearings run for? I probably would.

Why would it matter how many miles the bearing ran? Just curious?

 

[GOBR]

I cracked em all off and they all look like they should. I was thrown off by it being 4 bolt block. Center bolts are tq'd to 70 and outer to 65. Rod caps were tq'd to 50 but I re tq'd to 45.

I was just worried because Ive read where you can tq the mains tighter than specified to change tolerances but with the rod caps you have to find tighter bearings. Its a .010 crankshaft but everything looks good. I called him and he said to do the same.

Ill be adding new pics to my build thread over the next week. Ill be putting new valves in the heads and all that stuff and hopefully next sunday Ill be droppin it in!

 

[HotRodPC]