440-4 timing and temperature

[Clyde9]

From: Moesyn  (Original Message)
Sent: 3/7/2008 2:57 AM

Having read the relevant archived posts I am aware that the stock timing setting is 8 BTDC for my spankin' new 440-4...currently at 150 easy break-in miles. My engine builder set the timing to 12 (the current setting...via MSD distributor+ignition) while my rv mechanic recommends 10. Because the temp seems to be running a bit hotter than it was before the rebuild (as per the "dummy" water temp gauge), I am wondering if excessive advance could be the reason, and if I need to back the timing down to 8. I have not heard anything like a ping coming from the engine, and hope not to! Is there any good reason to not just use the stock setting of 8 BTDC?

Thanks,

Dave



From: denisondc
Sent: 3/7/2008 7:50 AM

The stock timing of 8° BTDC certainly wont hurt anything. Usually you can advance it a little - as long as there is no pinging, and it wont hurt anything. But I would call 10° BTDC a little, not sure I would want to use 12°.
If your engine runs hotter, I would wonder if the thermostat is the same unit or a new one, and if it is the correct type. You can see what the correct type looks like - by going to www.stewartcomponents.com and slide down the home page. You will see a side view of the 'skirted' thermostat, which you can order online from these folks. I got mine from www.summitracing.com, where the 180° unit is part # MRG4367. They have a 160° unit which is MRG4366 Stewart Components also carried the 195° unit - which will still work fine, just make your heater work a little better in cold weather. Also the water temp gauge will run a little bit to the right of where it ran with a 180° thermostat.
One of the reasons I haven't tried to super-insulate my engine cover is because I am willing to hear what the engine has to tell me. If its going to ping, I Want to hear that 'tinkling'.



From: AlbuqHenry
Sent: 3/7/2008 8:52 AM

Just a thought here, but isnt it normal for an engine to run a bit hotter right after a rebuild.  Everything is new and tight.  How much hotter?  A few degrees or putting your gauge into the not so good area?-Henry



From: Moesyn
Sent: 3/8/2008 6:19 AM

Thanks for the responses. I backed the timing down to 8, installed the mechanical water temp gauge and went for a long, long drive...over 100 miles round trip on the freeway over mixed terrain, varying speed between 50-55. Mind you, it is a cool night (55 deg), but the water temp pretty much stayed at 195, and went up to around 205 on a long grade, so I think I'm in good shape.Hopefully it will run even cooler after it breaks in more. I will check out the thermostat as well. Thanks again!

One small, yet expensive problem that I noticed after this drive was that my new  MSD spack plug wire boots are already fried: cracked and melted on the sides facing the manifolds... two of them severely. This set cost me $120! So much for "high-temp"! LOL.  I did a search on the subject of "MSD boot melted" and apparently this is not a rare occurrence, yet MSD seems to have a good rep. for customer service so I'll see what they can do on Monday.



From: 75Travco
Sent: 3/8/2008 6:54 AM

The 440 engine should have heat shields that protect the spark plugs and boots adjacent to the exhaust manifold outlets.  The two spark plugs (on each side) adjacent to the exhaust dump are very close to the manifold, and really need a steel barrier to block the radiant heat from that sometimes glowing manifold!  Should be no problem with the other two plugs, plenty of clearance there.  The shields fit under two of the cylinder head bolts and are repositionable if you change from a center dump to a rear outlet manifold like I did.

There's an ebay seller - I believe fruitridge something or other that offers a nice set of plug wires for around $25- search under dodge motorhome and it should be there.



From: AlbuqHenry
Sent: 3/8/2008 8:51 AM

I noticed the shields on mine yesterday since I changed my plugs. I noticed there is even a shield protecting the motor mount on the drivers side. ...Henry



From: Moesyn
Sent: 3/9/2008 9:53 PM

Many thanks for the info. My engine is currently missing the heat shields for the plugs/boots, and I'm not sure if that's because they weren't there before the rebuild, or if they were left off when the rebuild was done. I'll inquire tomorrow. Assuming they will not materialize at the engine shop, are the heat shields something I can order from a NAPA, or are they a motorhome specialty part I would need to find used?



From: denisondc
Sent: 3/13/2008 6:06 PM

On the 413 engines I believe the heat shield was just an extended part of the exhaust manifold gasket. It spanned the space between the ports on the head/manifold, shielding the plug wires from the radiant heat. Usually that part of the manifold 'gasket' would rust and fall off after a few years; it was certainly gone when I got mine. I haven't needed to replace them, but if I had a problem with melting plug wires, I would probably use some lightweight aluminum sheet: Propping or wiring it in place, rather than messing around with the nuts on the exhaust manifold studs. However your engine is newly rebuilt, and the nuts probably arent rusted onto the studs yet.
I did replace the heat shield that was between the drivers side of the engine and the items running along the top of the frame rail there; wiring harness, brake lines, speedo cable, etc. I hope yours has that heat shield in place. I can understand why they are often missing; its a difficult place to reach.



From: Moesyn
Sent: 3/15/2008 3:57 AM

Dave, as usual you are right on. According to the invoice the thermostat currently installed is a NAPA Superstat 532090 (192-195 deg), which is not skirted according to the below photo:

http://www.dmauto.com/web/dmauto/Catalog/NAPA_ECAT/mfg/THM/532090/

I have a Mr. Gasket 4367 on rush order so it will be very interesting to see the difference it makes. I'll report back mid-week with the results!