The International Cessna^® 170 Association

gahorn wrote: ............But... let me ask the question.... : What's the difference between letting the starter motor turn the engine until oil pressure is indicated.... versus simply starting the engine and letting oil pressure develop?
Answer: The second method is easier on the starter motor, and gets the upper cyls lubricated sooner.........

Another answer: With the spark plugs removed and the engine turning over with the starter motor, there is only pure rotation of the crankshaft without loading up the main and rod journal bearings. That should not harm any internal parts before the oil pressure picks up.

When oil pressure does pick up, the pressurized oil film prevents metal to metal contact between the journal bearings and the crankshaft and the engine is ready to be started. If oil pressure does not pick up quickly, no harm would be done.

If the engine is started dry and allowed to run, each power pulse will grind metal to metal contact between the crankshaft and the main and rod journal bearings, possibly wiping out the bearings if the oil pressure does not instantly pick up, which does happen.

I would not be nearly as worried about the lack of upper cylinder lubrication or being easy on the starter motor as I would be about metal to metal contact between the crankshaft and main and rod journal bearings before the oil pressure picks up.

gahorn wrote: A good method to get oil pressure to "exist" before first engine-start is to pressurize the oil galleries with a grease-gun filled with' engine oil fed into the galleries............

Agreed! The absolute best way to pre-oil is with external methods without rotating the engine.

Just to enlarge upon Bruce's comments.....
There are many many many times I receive phone calls from people who say they are "members" of the 170 club and want mx support. I ALWAYS help them.
But it usually turns out they are only PARTICIPANTS in these forums (which is free and open to the public)...and not actually MEMBERS of the Int'l Cessna 170 Assoc'n (which is the Host of these forums).

Only TIC170A Members have full access to our MX Library, where so much of the hard-to-find documentation of this airplane is kept. This is for several reasons, the major one being that the information has been collected, categorized, and archived due to the hard work of our Members and Volunteers...., and the addt'l reason being as an incentive for non-members to join our group and contribute to the expense, longevity, and efforts of the enterprise. Without Members who generously donate money and expertise and hard work these forums would not exist and TIC170A would no longer exist for the benefit of the larger Cessna 170 community.

So.... please consider joining the TIC170a. Your annual dues will go a long way to "preserving and promoting a truly classic airplane."

n2582d wrote:Here's a page from the C-177 Service Manual. It doesn't give different torque values for the O-320 vs. O-360 Cardinals. FWIW the numbers are also the same for the 1977 C-172.

C-177 Mounting.jpg

Yes, 450-500 in-lb. That's also the answer I got from Lord's tech support. I had mine under-torqued for a while and noticed a big reduction in vibration when I re-torqued them.

FAA publication AC 43.13-1b has a table showing torque values for all size bolts in shear and tension.

edbooth wrote:FAA publication AC 43.13-1b has a table showing torque values for all size bolts in shear and tension.

But sometimes manufacturers override the standard torque. For example, Cleveland wheel through-bolts are AN5. Standard torque in tension is 100-140 in-lb, but Parker calls out 150 in-lb in the wheel and brake service manual.

I just replaced my J3804-28 Lord Mounts that have been back ordered for three months. The usual suppliers could not get them and I finally got them through Aviall which is now a Boeing company that is not really user friendly. They are now about $325 each including tax. They seem to last about twenty years. Now a couple of thoughts about how to do this chore. Engine hoist at the lifting point and another strap around the prop so that you can control the tilt of the engine. Also it is helpful to first raise the tail to approximately level. Since the lower mount bolts cannot be removed without the engine away from the mounts here is a way to do this that is not to scary. With the weight of the engine on the hoist remove the lower nuts and pull the bolts out as far as you can, that will only be about 1.5 inches. You will probably have to remove the bracket that holds the throttle and mixture cables as that will interfere with tilting the engine. Next remove the top bolts as they can come out without interference. Lower the engine just enough to get the old uppers out and the new ones in. Replace the top bolts with some 1/4 inch hardware store bolts about 4 inches long. That will give you the flexibility to lift the engine enough to get the lower forward rubber mounts out so you can angle the lower bolts out. Put in the new lowers and lower the engine back down into position. Now the upper bolts can be put back in with a minimum of alignment problems. I hope this works for you. Good luck

Thanks for the write-up. I've got a few years before I have to do this job, but I remember what pain it was to install the mounts, even with the engine on the overhaul assembly stand.