Author Topic: exhaust manifolds  (Read 3441 times)

Offline bluetoque

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exhaust manifolds
« on: December 20, 2008, 09:19:08 am »
I just installed a 300 six wi c6 auto in my narrow ga bug...both overhauled.The exhaust manifold gets red hot to the tail pipe extension on easy going.The muffler is a straight pipe going out the side ,same as original..heat risor is all in tact.Not sure of correct timing but runs nice at 8 d btdc. This engine is out of a 87 van..carberated but has electronic egnition.I have never seen manifolds that red hot...any suggestions??

Offline Cranman

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Re: exhaust manifolds
« Reply #1 on: December 20, 2008, 09:27:33 am »
Too far retarded, you'll have to advance your timing a bit.

Offline grfishmaker

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Re: exhaust manifolds
« Reply #2 on: December 20, 2008, 11:03:35 am »
I have a Ford 300 6 in my 53 wide and I noticed last winter that the mainifold gets red hot (even at 30 below). I will also make good use of your timing check advice. Thanks Cranman.

Offline bluetoque

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Re: red hot exhaust manifolds
« Reply #3 on: December 22, 2008, 06:45:10 pm »
I advanced the timing to 11 deg btdc.You can still see the red glow in the daylite but at nite the ex manifold and tail pipe is cherry red to with in a foot of the end of exhaust pipe...and this is on easy going as we dont have 6 inchs of snow here yet!!!THIS CANT BE NORMAL but this is the first ford engine I have ever owned OR IS IT????

Offline Averyman

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Re: exhaust manifolds
« Reply #4 on: December 22, 2008, 09:05:55 pm »
I'm not familiar with the Ford 300 but I had the same situation with a gas engine in a combine. Problem was the tappet clearances were set too tight. If the 300 has hydraulic lifters this may not apply but if its newly overhauled it could have been set up too tight..

Offline Cranman

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Re: exhaust manifolds
« Reply #5 on: December 23, 2008, 12:57:53 am »
When timing is retarded the gas doesn't get a chance to do a total job in the cylinder and the late ignition in the exhaust causes a red hot manifold. Apparently some guys have got away with as much as 14 deg but I don't know if you could get away with that much without too much pinging. I've changed the counter weights on the distributor of GM's to get more. If a timing light is used there is sometimes confusion as to the timing marks on the 300 Ford. There is apparently two marks and the one you chaulk is the smaller one?? On the Chrysler six I don't use timing light, I just keep advancing until I start to get pinging under load in high gear. Driving in 8 inches of new snow is ideal. It's ok to hear some pinging at peak load but I try to find the point it just goes away. I find this gives the most power and gives best gas mileage. I've heard a clogged catylitic converter can cause this also but not to worry about this in bombardiers. On the other hand,our bombardiers don't have any back pressure unless we put baffles in so this may be a concern. In my hotrodding days when we made our own staight headers they ran red hot too. It may be a combination of factors at play here.

Offline bluetoque

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Re: exhaust manifolds
« Reply #6 on: December 28, 2008, 08:24:53 pm »
Timing change makes little difference...the next time someone is out at nite check your exaust manifold and ex pipe on your 300..tell me if its red hot!!

Offline chopperguy

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Re: exhaust manifolds
« Reply #7 on: December 29, 2008, 12:19:13 pm »
I run a 300 six in my narrow gauge and I know my timing isn't spot on but I never notice my exhaust getting that hot that it glows....wow I'll have to check next time I'm out.

Offline Averyman

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Re: exhaust manifolds
« Reply #8 on: January 11, 2009, 09:33:57 pm »
bluetoque
If timing changes make no difference then I would still suggest that your valve clearances are too tight...ie: burning exhaust gases are  escaping from the cylinders through  exhaust valves which are not completely closing. .  I am told that engine has adjustable tappets and hydraulic lifters. You could remove the valve cover and back off each exhaust valve  adjuster one turn and see what happens. Can't hurt to try... Clarence

Offline bluetoque

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Re: exhaust manifolds
« Reply #9 on: January 15, 2009, 08:11:12 pm »
The jury is still out but I think it may be as a result of a faulty clutch fan....I dont think there is enough air movement with a thermosatic controled fan to disapate the heat created in the engine compartment. We installed an exhaust fan simmilar to Skenmans and it does help for sure. We are going to change it to a direct drive fan and try that .

Offline the old trucker

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Re: exhaust manifolds
« Reply #10 on: January 22, 2009, 10:12:17 am »
  I got an email the other day about the 251 engine specs. I thought it may help.
 
    here is some specs for the engine.  spark plug gap .035  point gap .020  firing order 153624.   timing is 0 degrees b.t.d.c.     valve adjustment     exhaust  .010h    intake .010h

The email below is about manifolds.

the 251 engine is the same one that is used in the cars and trucks.the only difference in the industrial engine is that it has 4 ring pistons and the car-truck engine had 3 ring.there were different manifolds made for those engines but they will all fit.
after covering a few acres of prime real estate.

Offline Averyman

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Re: exhaust manifolds
« Reply #11 on: March 06, 2009, 07:21:13 pm »
bluetoque... have you found a cure for that red hot manifold ?

Offline bluetoque

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Re: exhaust manifolds
« Reply #12 on: March 11, 2009, 06:07:52 pm »
I removed the clutch fan and installed a conventional fan,there is alot more air movement now so hopefully will help .We are going up to the rally so will be able to show the bombardier guros first hand of red hot exhaust pipes.

Offline the old trucker

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Re: exhaust manifolds
« Reply #13 on: May 07, 2010, 04:08:23 pm »
The jury is still out but I think it may be as a result of a faulty clutch fan....I dont think there is enough air movement with a thermosatic controled fan to disapate the heat created in the engine compartment. We installed an exhaust fan simmilar to Skenmans and it does help for sure. We are going to change it to a direct drive fan and try that .

  bluetoque, I was talking to a mechanic today & he thinks with the fan hauling in cold air, & the engine giving off so much heat at the same time, it's hard for the air to circulate properly. He was thinking if there was a big enough fan pushing out air out through the rad the fresh cold air should draw in through the motor doors. Any thought on that idea ??                                           

  BTW : Thanks again for the info you sent to me.                      The Old Trucker
after covering a few acres of prime real estate.

Offline bluetoque

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Re: exhaust manifolds
« Reply #14 on: May 07, 2010, 08:22:06 pm »
OT   You cant reverse the fan  to push air back thro the rad . It sounds good and its used in various applications but not on any bugs that I have ever seen.If Woodsy reads this I hope he will comment as those kind of guys put these machines to the test year after year.The 300 I put in my narrow ga steel runs hot when its working hard.I use strong antifreeze and a 17# cap...It runs in the red but does not boil over .We use a plastic jug as a collector from over flow tube and with this if it blows off it will reguritate the antifreze so you dont have to add unless you get her real steamed up.In my experience when I blocked off the air flow to the front It only makes matters worse when its tough going..it might be so hot inside you cant breathe but at least you are still going..another thing turn every heater on you got it cant get any hotter inside.  Keep the beer up front!!