Headers melted wiring!

[Detect15]

Sent: 12/17/2003 3:59 PM

Hi all!  I need a novice out there for some advice.  We recently took out our Dodge Winnebago 1978  440 cu in 4 bbl V8, for our last camping trip.  The camp site is only a 2 and 1/2 hoour drive.  Everything went well on the way down, however, on the return trip we had trouble.  One of the heat-shields on the drivers side of the engine came loose.  This caused the ignition wireing harness that runs along the side of the engine to catch fire.  After putting the insulation that was on fire out, I was getting meltdown in other places on the harness, due to the grounding out and heating up of the harness.  I disconected the engine battery and was able to put out the small insulation fires.  While on the side of the highway, I managed to tape up the bare harness enough in order to get it running and get it home.
On the way home, I left the engine cover off to check for any problems while driving.  I noticed that the hedder pipes were glowing significantly orange, for some reason the engine is throwing off a lot of heat.  I was thinking that the engine was possibly running lean, but the engine has always started right up and ran smooth.
I am in the process of re-wiring the entire harness and other wires that "cooked" in the process.  I was wondering if there is some typy of heat resistant material I can wrap the wires in, since I can't find a place to re-route them any further away from the hedders.  Also, I was wondering if I can wrap the hedders in order to cut down on the heat they are throwing off.  I had previously insulated the engine cover to cut down the heat and noise in the coach, so I don't think that would be an issue.

Any suggestions would be helpful to prevent this from happening again, and are also appreciated while I'm still in the repair stage.

Thanks!
Earl   




From: denison
Sent: 12/17/2003 9:05 PM

I dont know if it is normal for headers to glow.... But: I would check your vacuum lines, any steady vacuum leak will make it run lean. Check that the carburetor base gasket hasnt shrunk in, creating a vacuum leak. Make sure the secondary butterfly valve in the carb. is really closing all the way; that could make it run lean at a cruise. If your distributor has a mechanical centrifugal advance, check that it isn't sticking in an advanced position, that the inner dist. shaft is lubricated - there would be a felt wick under the rotor for this. In fact, check your ignition timing, and the operation of the centrifugal advance. Is it the distributor that came with the vehicle?
In my 72 with the 413, I made up wire bails to support the wires that run down the drivers side of the engine, and got the whole bundle to perch up about even with the coach floor, well above the exhaust manifolds. I have had to fix the results of the wires that were melted when I got it years ago. I also made up new heat shields, since the handbrake cable and brakes lines need protection from that manifold heat too.
My belief is that unless the headers are thicker than most, wrapping them might void any warranty - which is just a way of saying they might crack or sag sooner if wrapped.
Check the condition of your spark plugs. I like mine to be a light beige - not too light, but not medium brown. If they are too near to white, it may be running lean or overadvanced.
Anything you wrap the wires with that keeps them from being in sight of the radiant heat will help. And teflon insulated wiring is the best to use - but bothersome to strip that insulation. denison




From: denison
Sent: 12/17/2003 9:07 PM

And is it possible the carburetor is jetted too lean, and that is the reason it doesn't have its original exhaust manifolds? denison



From: Liv42dayOK
Sent: 1/5/2004 11:22 PM

Headers vary greatly.  The best ones are ceramic coated... for a reason.  HEAT.  Header tubing is much, much thinner than the original manifolds and the thickness of header tubing varies as well. 

Typically, at high RPM or under heavy load (like the weight of an RV) headers will get extremely hot.  So hot, they WILL glow.  Glow red like iron in a kiln.  A heat shield will help but, is it worth the pain and worrying  if the heat is going to damage other vital components?

This has been a debate I've been following closely for a while.  My conclusion is:  for the price, the benefit is minimal unless you get the correct Low End designed headers.  For 440-3's, they're almost non-existant and what is available is outrageous in price. 

I will echo the wise words of Winnie-Wizard Dave Denison.  STICK WITH THE OEM EXHAUST MANIFOLDS.  They're much safer, cheaper and they do the job.  If it's more power you want, upgrade the carb, intake manifold, ignition, and install dual exhaust with H pipe and Dynomax series 50 mufflers. My 10 cents worth (inflation has caused an increase in the rate of cheap advice) - Sob


 

From: mightybooboo
Sent: 1/5/2004 11:40 PM

I think member Matt Mylesh uses headers on his 350 chevy and is very happy with them,if Im not brain dead here and have it confused with someone else.I got  some spark plug end sleeves from Napa at a cost of 17.99 for 2,and they are GREAT,no more boot burning,they are about 6 inches or so long,right Lefty?
BooBoo



From: Liv42dayOK
Sent: 1/6/2004 2:03 AM

You can get header heat wrap at most auto parts shops.  NOTE:  if you installed the headers, heat tape may void the warranty.

Check at Summitt Racing's on-line catalog for the tape and spark plug boot insulators (the link is in the Resources option of the home page side-bar).  They are usually cheaper than parts stores and shipping is free.

I figure I will save over $300 on the performance parts I have and want for the WinneBeast through Summitt. - Sob



From: UluzYarx
Sent: 1/6/2004 3:32 PM

Hi Sir

I advize you to ask yourself: - Did I get this problem when I used cast manifolds?  Where are my old cast manifolds?  How long will it take to swop back?  How much are my used headers worth?  How much is peace of mind worth?
Is the pain worth the gain?

If you are sure that the gain is worth the pain: -  In England we run out wires in Cooltek thermal sleeving -  Asbestos-free heat protection for pipes and cables.

20 mm x 1 metre
£9.95

30 mm x 1 metre
£11.95

50 mm x 1 metre
£12.95

A metre is a heathen device invented by a Frenchman called Napoleon.  It is one thousandth of one thousandth of the distance between Paris and some other God foresaken French city (I must point out that I don't actually know if French cities are God foresaken, but the first time I went to France I frequently saw Frenchmen standing at the side of the road blatantly urinating and drew the conclusion that all French cities are Godforsaken).  For the record, a metre is 3ft, 3ins, and 3/8in long.
If you are still reading and cannot find a supplier in your country try: -http://www.merlinmotorsport.co.uk/.

We also run electric fans to suck hot air from the engine compartment - typically we trepan a say 12" hole in the bonnet (hood) and fit an electric radiator fan there (not much use if you have a cab-over).
We reckon that a cool carb is a happy carb.

All the best - Dave
PS My other bit of advice is: - never take my advice, always work it out for yourself.


Reply
 
From: denison
Sent: 1/6/2004 5:09 PM

I personally think headers are okay if that is what is on the motor, but I think the original manifolds were fine too. Is it possible that the reason it has headers now is because it warped its cast iron exhaust manifold from running too lean - or kept burning out the manifold gaskets? Lacking a pyrometer to check the temp of the exhaust gas, I would look for any vacuum leaks due to old leaky rubber hoses, or a shriveled carburetor base gasket, or a warped carburetor base. If the carburetor is non-original, it might have the wrong jets in it too, or the secondary throat butterfly might not be staying fully shut at light throttle openings. There should be a spring holding it shut, and linkage too - but the linkage can wear and the spring can weaken. If the timing is -late- it might make the exhaust system run hotter, and would also lack power and have poor miles-per-gallon. This would also happen if the centrifugal advance was sticking and not advancing - you would have to run the throttle much further open to keep going at highway speeds in that case. One way to check the operation of the vacuum and centrifugal advances; Set the timing mark at top-dead-center, and paint mating marks on the bottom of the crankshaft pulley and the front of the oil pan, so you can lie underneath with a timing light, and watch the timing advance and retard, as someone taps the gas pedal. I think these engines should run very pleasantly, once you have solved what might be several layers of interconnected problems -- some of which are the sort that only happen every 25 or 30 years. denison 




From: mightybooboo
Sent: 1/6/2004 6:01 PM

Hmm..I took Earls post to mean he had manifolds as headers on a 440 MH are a rare puppy.If its manifolds,my passenger side closest to cab does run a dull cherry red.I think its normal as I do pass smog check.FWIW.

"It is one thousandth of one thousandth of the distance between Paris and some other God foresaken French city (I must point out that I don't actually know if French cities are God foresaken, but the first time I went to France I frequently saw Frenchmen standing at the side of the road blatantly urinating and drew the conclusion that all French cities are Godforsaken). "
ROFLMAO!!! Hope its taken in the lighthearted manner as presented,cracked up warped little ole me!
BooBoo 

Dave D...Hannah needs help on an engine swap.



From: Discoverer
Sent: 1/6/2004 7:57 PM

THIS is a problem with the 440....the routing of the plug wires IS a nightmare! The 413 was a much better design.

As for your situation.....I would go with that header-wrap. And I would also suggest the Jacobs ignition wires BUT they are very HI $$ !! 



From: Discoverer
Sent: 1/7/2004 4:53 PM

440 MH headers are rare ??!! .......... because they haven't been made in any kind of production-run-basis as of late? I have got a set of 440 headers are in NICE shape....and TWO sets for the 413. One set is brand new- the other is used but in decent shape. "Coating" the headers would make them "new" . Anyone interested?...drop me an email. Thx, Eric 



From: mightybooboo
Sent: 1/7/2004 7:19 PM

"440 MH headers are rare ??!! "

Well lets put it this way,the only ones I could find for MH were thorleys and they were pricey.Is there another source?Not that Im looking,after putting on the copper seal manifold gaskets my leaking/burning gasket problem is solved.
BooBoo