Mazworx Main Bolts Issue - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

thurman548 · 12-10-2011, 12:04 PM

I am torqueing a set of Mazworx Main bolts to the torque spec which is 85 Ft lbs of torque (which the instructions say). I cannot turn the crank freely with by hand. I called Mazworx and they said that the changed the torque settings in the instructions down to 75 ft lbs of torque. 75 ft lbs are still a lot higher than the FSM. So I am wondering what everyone is torqueing the main bolts down to. Thanks!

Kingtal0n · 12-10-2011, 02:20 PM

did you torque the mains down and check with a dial bore gauge if the bearings are actually round? I believe you can torque incrementally until this occurs- there is your proper torque spec.

A machine shop should have done this, I would have thought, did you supply the bearings to any shop first? are the bearings installed facing the right way? Sometimes there a lip on the crankshaft main journals that needs to face the lip on the bearings. how did you determine the space between the bearing and the crankshaft, all the way around the journal?

thurman548 · 12-10-2011, 04:31 PM

The block is also from Mazworx and they told me what bearings to use. The bearing and the mains are on correctly. I did a search and there was a thread saying that the torque specs on the ARP bolts were to tight per an article from phase2motortrend, but I couldn't find it on their website.

Cunningham · 12-10-2011, 04:46 PM

It would be in your best interest to bring everything to a qualified machine shop to check all the sizes.

An extra 10ft lbs of torque shouldn't make the crank stop turning or be difficult to turn.

You need to determine what the hsg. bore of the main caps is, then torque up with the bearings installed(no crank) and find out what that size is and how round they are.

Then do the math to determine bearing clearance for your crankshaft.

idahotuner · 12-12-2011, 07:21 PM

i could turn mine with a wrench whenihad it all torqued, but not by hand

Def · 12-12-2011, 07:28 PM

You have to line hone your block when using main studs. The higher torque distorts the main caps.

idahotuner · 12-13-2011, 11:38 AM

hegot the block from mazworx they should have line bored it

12-10-2011, 12:04 PM	#1
thurman548 Leaky Injector Join Date: Jul 2005 Location: Charleston AFB, SC Posts: 116 Trader Rating: (3) Feedback Score: 3 reviews	Mazworx Main Bolts Issue I am torqueing a set of Mazworx Main bolts to the torque spec which is 85 Ft lbs of torque (which the instructions say). I cannot turn the crank freely with by hand. I called Mazworx and they said that the changed the torque settings in the instructions down to 75 ft lbs of torque. 75 ft lbs are still a lot higher than the FSM. So I am wondering what everyone is torqueing the main bolts down to. Thanks!

12-12-2011, 07:21 PM	#5
idahotuner Zilvia FREAK! Join Date: Jan 2008 Location: St. Maries, Idaho Age: 36 Posts: 1,276 Trader Rating: (17) Rides Gallery: idahotuner Feedback Score: 17 reviews	i could turn mine with a wrench whenihad it all torqued, but not by hand __________________ My Twin Scroll Gt30r Sr22det Build

12-12-2011, 07:28 PM	#6
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	You have to line hone your block when using main studs. The higher torque distorts the main caps. __________________ S13 Hatch - Goes around tracks quickly DEFSPORT

12-13-2011, 11:38 AM	#7
idahotuner Zilvia FREAK! Join Date: Jan 2008 Location: St. Maries, Idaho Age: 36 Posts: 1,276 Trader Rating: (17) Rides Gallery: idahotuner Feedback Score: 17 reviews	hegot the block from mazworx they should have line bored it __________________ My Twin Scroll Gt30r Sr22det Build

12-10-2011, 02:20 PM	#2
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 42 Posts: 4,829 Trader Rating: (17) Feedback Score: 17 reviews	did you torque the mains down and check with a dial bore gauge if the bearings are actually round? I believe you can torque incrementally until this occurs- there is your proper torque spec. A machine shop should have done this, I would have thought, did you supply the bearings to any shop first? are the bearings installed facing the right way? Sometimes there a lip on the crankshaft main journals that needs to face the lip on the bearings. how did you determine the space between the bearing and the crankshaft, all the way around the journal?

12-10-2011, 04:31 PM	#3
thurman548 Leaky Injector Join Date: Jul 2005 Location: Charleston AFB, SC Posts: 116 Trader Rating: (3) Feedback Score: 3 reviews	The block is also from Mazworx and they told me what bearings to use. The bearing and the mains are on correctly. I did a search and there was a thread saying that the torque specs on the ARP bolts were to tight per an article from phase2motortrend, but I couldn't find it on their website.

12-10-2011, 04:46 PM	#4
Cunningham Join Date: Feb 2011 Location: Crapswamp Posts: 15 Trader Rating: (3) Feedback Score: 3 reviews	It would be in your best interest to bring everything to a qualified machine shop to check all the sizes. An extra 10ft lbs of torque shouldn't make the crank stop turning or be difficult to turn. You need to determine what the hsg. bore of the main caps is, then torque up with the bearings installed(no crank) and find out what that size is and how round they are. Then do the math to determine bearing clearance for your crankshaft.