Packard Forum Index » Pre-War (1899-1942)

Hi guys

Im getting ready to do the intake and exhaust manifold gasket set on my 6cyc .. is there any thing i should know ?? Tips or Tricks to make it better or last longer ?..

Where can i find the torque specs

or have i missed them in the shop book some how

Thanks all

Hi Ramcuda,
Welcome to Packard Info. I just completed this on my car a few months ago. The biggest single issue with R&Ring the Exhaust & Intake manifolds is taking care not to break anything! The castings are very old, have been through countless heat cycles and are very brittle. The second most important issue is, of course, to get a good seal. The two manifolds are bolted together and there is a bit of play in their alignment as the intake to exhaust nuts are tightened down. Using a straight edge across the face of both E&I head-to-manifold ports allows for proper positioning prior to attachment to the head. I too looked for torque specs on the stud nuts but couldn't come up with anything concrete. Maybe others will weigh in here with some numbers for you. What I found was they needed re-tightening several times after initial installation as, with the heat they are exposed to, and with some natural gasket compression, I found they went from quite snug to needing 1/2 to 3/4 of a turn in the first few miles. On my car, the nuts were brass and I believe this is correct/original and a very uniform tightening sequence, going just a bit at a time on each nut until they are all tight, is the best way to avoid breakage. Remember: old brittle castings, extreme care required! The six exhaust manifold is a difficult to find part, and is not cheap!! Good luck, Chris P.S. Ramcuda, it is also a great time to check out your heat riser valve, make sure it is nice and free and the spring is there, installed correctly and is functioning. (see pic)

Attach file:

---

  (297.64 KB)

Good Morning...Someone posted a torque chart a while back. It basically showed the size of the bolt and gave the torque for that size bolt. Hopefully, if the right person sees this thread...they can post it again. It also seems to me that there is such a chart in the old Motors Manuals...Ernie in Arizona

Ernie, I've posted a chart like that several times and would be glad to do so again. However, considerable caution should be exercised when using it, there can be a very wide disparity between what a fastener is designed for and the claiming force that the car manufacturer desires between two surfaces. It is far better to find a similar application (manifolds, heads, bearing caps, etc.) and fastener sizing from a later but similar model engine where the car manufacturers specifications are available. In this case I'd be guided by the torque specs for the postwar 6-cylinder Packard motor.

On manifolds, it's important to keep in mind that the exhaust manifold gets much hotter than the engine block and hence expands further so the gaskets and fasteners must allow for some very small "slip" between them.

Welcome! We are nearly neighbors as I live in next door San Jose in spite what the side bar to the left shows. Terrebonne, OR is where my shop, cars and parts are.

As for torquing a manifold, I don't recall ever doing so and not sure how I would have ever gotten a socket onto some of the nuts anyway as they are difficult to reach even with a wrench. I've always tightened and retightened as much as I could using a relatively long box wrench and never a leak.

Agreed, Don - a couple of those nuts are challenging to get at and even get a box-end on! 'Grunt-and-a-half' torque specs probably apply here. I found mine stopped needing additional tightening after about three chases. Chris.

HI Don i would like to meet Packard owners around me and talk shop and what not ... Please send me a massage ..

Thank you to everyone that chimed in on this ... I had a feeling that this would be a lot like the slant 6 in the dart ... do to the way the intake and manifold relate .. same as the slant the parts have to have some side as they heat and cool at different rates and the flapper is best to be in working order..

I did find it odd that there was not any Spec in the shop book not even a disassembly info.

Thanks
David

The Packard Service Manuals were written specifically with Packard service personnel in mind who had gone through training. Third-party manuals, such as Motors or Chiltons were written for general or backyard mechanics so have more of the small details like that.