Camshaft Bearing Cap torque L20b

[theeoracle]

I can't find what torque number are for these bolts. They weren't on The 620. It's an l20b. Someone help please.

[Doctor510]

18-20 ft#'s

[theeoracle]

Thanks doctor.

[datzenmike]

Very little or they strip the aluminum threads in the head. Those bolts only align the cam, the head bolt secures them.

 

Twenty ft. lbs. sounds like twice the amount. Better find out for sure.

[620Turbo4X4]

I torqued mine to 12 Ft/Lbs. I couldn't find specs either. Nissan Doesn't want these removed and don't provide torque specs...

 

The oil pump bolts are same m8 thread and similar length and call for 8-11Ft/Lbs. So I kind of based mine on that.

[scooter]

If your camshaft binds a little you can loosen them off and tap them around a little with a rubber mallet. And tighten one at a time then you know which one is causing the bind. Sounds strange but when you actually do it it makes alot of sense, works good on dattos and mercedes and anything with removable cam towers

[Sealik]

My Datsun Workshop Manual states................

Torque in 3 stages.......5-10-12 ft/lbs

[datzenmike]

Sounds better. If the head was cast iron maybe but almost 20 ft. lbs.? Seems a hit much

[theeoracle]

Well i tried 18ft. lbs and nothing stripped. So I guess that means i'm good.

[banzai510(hainz)]

10 to 13 pounds

[Doctor510]

FYI all of you, as an engine builder, the only 2 reasons that the cam tower bolts strip other than driving them with an impact wrench::

 

You had not installed the locating dowels properly or damaged them before the installation

 

Trying to install the towers with the cam already in them AND pulling them down with the rocker arms installed

[datzenmike]

.. and over torquing them. Why risk 18 pounds?

[paradime]

The reason the manual specifies 10-13 ftlb isn't to protect the aluminum threads, it's because thats what the bearings require for heat expansion. too much torque may not bind when cold, but that has nothing to do with running temp tolerances. 

[Sealik]

What bearingsÉ

Donèt forget.....half the side of the cam towers are torqued down to 60lbs with the head bolt

 

Hmmmmm....looks like my keyboard just partially calved

[paradime]

All the more critical, because the tower itself is the bearing.

[john510]

FYI all of you, as an engine builder, the only 2 reasons that the cam tower bolts strip other than driving them with an impact wrench::

 

You had not installed the locating dowels properly or damaged them before the installation

 

Trying to install the towers with the cam already in them AND pulling them down with the rocker arms installed

Make it 3 reasons,you would be putting a hardened steel bolt into a soft aluminum head.

[Sealik]

The reason the manual specifies 10-13 ftlb isn't to protect the aluminum threads, it's because thats what the bearings require for heat expansion. too much torque may not bind when cold, but that has nothing to do with running temp tolerances. 

 

Torquing the bolts (to any specs) has nothing to do with the clearances between the cam and tower.

Clearances are compromised when the towers are swapped out or.......not seated correctly