Torque specs for intake/exhaust manifold

[Roald]

Hi

Does somebody here have the torque spec's for the intake and exhaust manifold bolts?

It would also be nice if someone can recommend me a good workshop manual for a late wm300?

Thanks,

Roald

[John Waak]

The manual gives a torque value of 20 ft/lbs. I assume this is for a 251 ci engine, as you state a manual preference for a late model WM300.

Depending on your year truck, I would suggest looking for a factory service manual on eBay.


Quoting from the 1960 Truck Service Manual, the procedure for assembling and installing the manifolds is below.

1. Install new gasket between exhaust and intake manifold (be sure heat control is free and operates smoothly).
2. Insert the four bolts through the exhaust manifold, gasket and into the intake manifold. Draw bolts down snug but DO NOT TIGHTEN!
3.N/A
4.Install the manifold to cylinder block gaskets over studs, and install assembled manifolds.
5. Holding manifold assembly evenly against gaskets and cylinder block, install long center bolts and draw down snugly. (if these bolts show signs of coolant leakage, coat threads with a suitable sealer before installation).
6. Install balance of washers and nuts.
7. To avoid heat cracking of manifold, be sure to install the four conical brass washers and nuts on the extreme ends of exhaust manifold. This is important! Due to expansion and contraction of the exhaust manifold, the conical nuts and washers allow movement of the exhaust manifold without loosening.
8. Tighten manifold bolts and nuts, (starting from the center and working out to the ends) to 20 foot-pounds.
9. Tighten the bolts holding exhaust manifold to intake manifold to 25 foot-pounds. (This was done to allow mating flanges of both manifolds to rest evenly against cylinder block and gaskets to avoid distortion and leaks.

[Roald]

Thank you very much, that was just the information I needed!

Point 7 is the reason why I'm changing the exhaust manifold :-)

[Bob2]

WM300 Heat control in exhaust manifold

Can any one help me in locating a heat control valve for my 1966 WM300 251 ci engine. Any help would be appreciated.

Thanks,
Bob