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What would cause this???

jims427400

Well-known member
Joined
Jun 7, 2005
Messages
763
Location
Temperance Michigan
Corvette
67 427 tripower,68 427 tripower,04 Z16, 62 340hp
A friend of mine just installed a fresh 327 300 all stock with a holley 650 in his 66 coupe. started off just fine,he ran for about 20 min and noticed on both sides of the intake(freshly painted orange) in the middle where the choke attaches about 5 inches in diameter the intake is burned black and bubbled almost all the way to the carb. He said it was extremely hot. He thought the car was running normal temp but didnt have temp guage hooked up. Can someone determine what would cause the intake to do this from my brief description.
Thanks, Jim
 
There is an exhaust passage going through the intake below the carb that allows exhaust gas to pass through from the right side to the left side when the heat riser valve is closed on the right side exhaust manifold during a cold start. This hot gas will burn or discolor the paint on the intake. A good grade of high temp engine primer and paint will slow down the burning but after time it will still discolor.
 
Jim, Have your friend confirm that his heat riser is working properly, ie, opening after a few minutes of the engine operating. Bill
 
There is an exhaust passage going through the intake below the carb that allows exhaust gas to pass through from the right side to the left side when the heat riser valve is closed on the right side exhaust manifold during a cold start. This hot gas will burn or discolor the paint on the intake. A good grade of high temp engine primer and paint will slow down the burning but after time it will still discolor.


Yup what he said. Normal.
 
Jim, Have your friend confirm that his heat riser is working properly, ie, opening after a few minutes of the engine operating. Bill

And...........................not installed upside down.
 
my 64 365hp did not really run very well with that heat riser butterfly valve between the exhaust manifold and the exhaust pipe. Car usually didn't want to idle worth a darn until really warm.

Then I bought side pipes for it and the butterfly valve was taken out and straight through to the side pipes....all I can say is WOW, what a difference. The car would idle great right off the bat as well as it seemed to pick up more HP.....it was a different car with the side pipes....I am glad we made that change.
 
Hi Herb,
Haven't seen many pics out of Norwalk for awhile.
I kinda wonder why anyone keeps that flapper intact. After I get the 427 rebuilt, I'm going to put the spacer in the exhaust before I reinstall it. I'm hoping the magnaflow exhaust that comes out the back will be less restrictive. Side pipes are not an option now.
 
Hi Herb,
Haven't seen many pics out of Norwalk for awhile.
I kinda wonder why anyone keeps that flapper intact. After I get the 427 rebuilt, I'm going to put the spacer in the exhaust before I reinstall it. I'm hoping the magnaflow exhaust that comes out the back will be less restrictive. Side pipes are not an option now.
got busy with getting the 37 Ford back on the road.....took extra weekends....it is really a tight fit....if you want to change the serpentine belt or the blower belt you have to take the front end apart and pull the radiator to get to anything....it is tight...in my case I had the motor redone, in fact we pitched the 502 and went with a bored and stroked 396. Much better in a number of areas, but it was a real SOB to get apart and back together....
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Sharon helped out by putting together the engine stand...
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you can see the '63 in the back ground of the photo below....
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here is how the car looks when it is together...
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between the big block, whine of the supercharger and the exhaust, you can hear this car coming down the road and can tell there is power under the hood....

Now that I have it back together and drove it last weekend for the first time in a long time, I am turning my attention to the '60. I am getting the hardtop restored to show the car at Autorama this year. So that will keep me going for a while.

I got the trunk redone on the '60 this past summer....
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and put the hardtop on for a while to take some photos and do some photoshopping of the hardtop in two colors...
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will be going with the RED top....

went to Summit Dragway for Super Chevy Show and walked away with some hardware...
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we bought a house on 4 acres up in Kennebunkport, Maine for a summer house and that ate up some time....

made some stickers for my trailer and vent windows...
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we were going to take the '37 on the Hot Rod Power tour but after I cooked the engine 5 days before we were going to leave, I had to get the '64 going and it hard carb problems that took my attention....
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of course it wouldn't be the HRPT without some rain
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Sharon told me next time to make sure we had Mickey Mouse hands to wave at people as we drove by....

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and then I was trying to help the shop that painted the '60 and worked a deal (even though I had no intention now to do this) to have them paint the '63 numbers matching car. I was able to help them stay open and bridged them to their next several jobs. Ultimately in recent time, I talked to Harry and the jobs dried up and they did have to lay everyone off....it is tough everywhere for sure.

I pulled the chrome and trim off the '63 and Harry and his guys worked their magic on it...
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so other than that and traveling (Sharon's thing) I haven't had time to do squat on the '63 restorod....I got the radiator, intake coming from Kinsler and soon we will stick the motor and tranny in the car and get it to Stainlessworks to get the exhaust completed.....you know my full time job gets in the way, that is what Sharon says anyways and the way the weekends get eaten up and vaporize I am beginning to believe her!

That was our summer.....not much going on.....:rotfl ;LOL :rotfl

oh yeah almost forgot, took the '60 back to Carlisle and got pretty wet from the rain there too.....ugh....
 

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