I almost lost us an American Classic Yesterday.

[OUTFXD]

12 hours ago, Adam H P15 D30 said:

Judging by the way your floor looks cooked above the muffler, you may have found your problem.

I noticed that too and I agree.  realy realy realy want to paint that but it would never dry.  Have to wait till spring.

[Dan Hiebert]

Your exhaust setup looks kinda like mine.  I installed new exhaust from the manifold back when we restored the car 30 years ago (don't remember the vendor, it was either Kanter or Andy Bernbaum), either way, it placed the muffler under the rear seat, to the rear of the heat shield.  I think I'm catching a glimpse of the rear of your car's heat shield ahead of the muffler.  That means the heat your muffler was generating was going directly to the floor, that combined with the rear seat detritus of your daily use of the car heated something up to its combustion temperature.  I haven't had any issues with that setup, but I don't have anything in, on, or around the rear seat other than the seat itself.   But, I'm now going to keep a better eye on whether or not the rear floor is getting hot, just never thought it could be an issue before.

[OUTFXD]

13 hours ago, Dan Hiebert said:

That means the heat your muffler was generating was going directly to the floor, that combined with the rear seat detritus of your daily use of the car heated something up to its combustion temperature.

 

Correct, but (I dont think)  its not the entire story.  The floor has been heating up since I got the car,  At first I thought it was the rear diff.  once I got her up on a lift after a 10 or so mile jaunt and the diff was cool to the touch.  

 

The underhood temperature also is well above normal, mainly in the area of the exhaust manifold.

 

For whatever reason the exhaust system is heating up more than is proper.   That combined with the misplaced muffler and junk floating around the floor pan measured up to near disaster.

 

I suspect some clever rodant  made themselves a stash in the muffler,  or something like.  I plan on cutting the muffler apart to see what is what.  But currently the temp is hovering near freezing and my limbs dont circulate the heating fluid as well as they used to(need to see if I can dig up the warrenty papers).

[OUTFXD]

Took her for a jaunt tonight.  20 mintues or so at 50 mph and a few miles at 60.  I checked after and the floor was luke warm to the touch.  At this point I think it is safe to say  the floor heat issues was a pep boys exhaust with the muffler plugged and over heating away from the safety of the heat shield.

[Adam H P15 D30]

Just curious, what's your timing set at?  Late timing makes a lot of exhaust heat.

[OUTFXD]

I will have to check again.  I got it as close to spec as I could but the distributor wouldnt turn enough to get it spot on.

[PT81PlymouthPickup]

Jay Leno knows a thing about fire.  ?   Anybody know about these Element extinguishers?  Sure looks like a good alternative to those bulky ones.

[Marcel Backs]

Reminds me of a story my brother told me. While getting ready for dinner at the fire station one night, a car which was on fire in the back seat area drives into the station with open flame and lots of smoke. Their first drive in fire! They put it out and found that a hole in the floor above the catalytic converter caused the carpet to ignite. The car had some damage but the driver was taken by ambulance for smoke inhalation. That guy must have really liked that car. Personally, I would have bailed given the proximity of the fire to the petrol tank. I am glad you saved your ride and you are OK. M

Edited December 14, 2022 by Marcel Backs

[Adam H P15 D30]

15 hours ago, OUTFXD said:

I will have to check again.  I got it as close to spec as I could but the distributor wouldnt turn enough to get it spot on.

Factory spec is relative to the fuels used during that time, I would set it at least 4 degrees advanced.  Today's fuels are less volatile and burn slower.

[OUTFXD]

3 hours ago, Adam H P15 D30 said:

I would set it at least 4 degrees advanced.

Do you mean you would set it AT 4 degrees advanced,  or factory spec + 4 degrees advanced?

[SteveR]

20 minutes ago, OUTFXD said:

Do you mean you would set it AT 4 degrees advanced,  or factory spec + 4 degrees advanced?

I wondered that myself. 4 degrees or 8 degrees advanced

[Los_Control]

19 hours ago, PT81PlymouthPickup said:

Jay Leno knows a thing about fire.  ?   Anybody know about these Element extinguishers?  Sure looks like a good alternative to those bulky ones.

I'm not big on "new hype" .... What caught my attention was it is not affected by heat, humidity or time.

A standard fire extinguisher can be carried around for years & hopefully never used.  But they do need to be checked & re-filled from time to time.

 

I like the idea of my truck having a traditional fire extinguisher on display & ready to use .... I also like the element extinguisher as a backup.

It did not seem to last long, if caught early enough it could be all you need  ..... If your out of date conventional fire extinguisher fails, is better then nothing.

[Adam H P15 D30]

21 hours ago, OUTFXD said:

Do you mean you would set it AT 4 degrees advanced,  or factory spec + 4 degrees advanced?

I meant a good starting point would be at 4 degrees advanced.  There are several methods to optimize initial through total timing but using specs from almost a century ago is leaving a lot on the table.

Example 1:

P15 Tune Up	1946	1947	1948	Notes:
Plug Type*	AC 44, Autolite A7, Champion J8	AC 44, Autolite A7, Champion J8	AC 44, Autolite A7, Champion J8	Auto-Lite A7-AN7, Resistor AR-8. AC 45 or 45R is one step hotter than AC44
Plug Gap	0.028	0.028	0.028	Set Resistor Plugs At 0.035 Gap
Ignition Timing	TDC	TDC	TDC

 

Even worse is example 2:

D24 Tune Up	1946	1947	1948	Notes:
Plug Type	AC 44, Autolite A7, Champion J8	AC 44, Autolite A7, Champion J8	AC 44, Autolite A7, Champion J8	Auto-Lite A7-AN7, Resistor AR-8. AC 45 or 45R is one step hotter than AC44
Plug Gap	0.025	0.025	0.025	Set Resistor Plugs At 0.035 Gap
Ignition Timing	2 Deg. After TDC	2 Deg. After TDC	2 Deg. After TDC

 

With our extreme undersquare engines, a lot of ignition advance is not needed due to the small bore, long TDC dwell time but our fuels burn much slower than a century ago so some advance is optimal.

I think I ended up at 8 degrees initial and 28-30 degrees total mechanical advance using a slant 6 distributor.  Your results will vary...

[DJ194950]

Advanced in auto terms means Before Top Dead Center (BTDC).  motor rotation.

Old cars running old low octane gas were often run at Top Dead Center (TDC)  (piston at top of rotation or even after  reaching top  ATDC)) to prevent knocking.  No knocks and a LOW power out put  from the fuel.

AS fuel quality improved and additives added allowed for the ignition to fire the fuel before the piston reached top dead center of rotation (bdtc) without knocks the fuel actually burned more completely and yielded more power  and most often increased fuel mileage

 

It has been Many years since any car  needed the ATDC or even TDC spark timing was used.

 

Even the old cars with the ATDC or TDC  recommended back in the day now love the BTDC timing as  the modern fuels make it run way better.  Advance he timing more btdc until when motor is up to temp and doing  a heavy pull it knocks slightly and retard the timing until the knock completely disappears.

 

Hope I finally wrote this such that it makes sense. ?

 

DJ