Overspray on exhaust manifold questions....

[Steve Wallach]

I have a 67 427 / 390 Roadster that I am always doing a little more work to.
I am trying to get the overspray on the exhaust manifolds correct and have a couple of questions.

1. Should the dipstick mounting tab (bolted to the manifold) be sprayed or was it installed after the engine was painted?

2. are all the exhaust manifold bolts sprayed, I seem to recall only the bolts at each end were installed when the engine was painted, but I'm not sure of this?

Thanks for any help,

Steve

[Verne Frantz]

Re: Overspray on exhaust manifold questions....

I expect a very detailed answer from Mike H. after Carlisle......

[Barbara S.]

Re: Overspray on exhaust manifold questions....

You 67 BB guys will have to chime in, but for 67 SB's, there is no overspray on the exhaust manifolds.

Tony

[Phil P.]

Re: Overspray on exhaust manifold questions....

if it had 100 miles on it (from the day it was born)any one would expect to see something ? of over spray, i know i'm not conveying what i want to say politically correct--these are 30 year old plus old cars---barn finds are a joke---after 500 miles and 30 years there is little to no paint left on a hotter than %&%&%**%*exhaust manifold---if ncrs is looking for this type of car to put a gold medal on they are living in the twilight zone along with those that live the same premise and try to "pass" a car off as it the same as new low mile (lost and found)or as something it is not---totally respect someone that has restored a car to "original" but quit the fly **** in pepper program because it is like taking grandma and making her into to a super model--she is old and does'nt fly---apologize to any and all offended---JMO

[Wayne W.]

Re: Overspray on exhaust manifold questions....

Yea, but, The so called overspray was more than overspray. It was plain old spray. Take a look at factory pictures the coverage was extensive. And, Near the bolts and the exhaust ports the temperature was not much greater than the block itself. The paint on those areas lasted for a very long time.

[Michael H.]

Re: Overspray on exhaust manifold questions....

Steve,

Your 427 engine would have left the Tonawanda engine plant with all of the exhaust manifold bolts and end cyl lock straps (if so equipped) in place and painted. The entire engine was painted with these bolts and straps so a generous coating of orange would have been on all of these pieces.

The dip stick tube was installed at the St. Louis assy plant so it would have no orange paint. However, the original exhaust manifold bolt that was installed and painted at Tonawanda was removed and reinstalled after the dip stick tube was added so it would retain it's orange coating, or at least most of it.

As far as "overspray on the manifolds" goes, it would actually be more accurate to describe the coating on the side of the cyl head as "overspray", and the coating on the side of the manifold as a "direct hit". There was actually more paint on the manifold than there was on the side of the head between the manifold runners. That's because the paint spray equipment that was used at the engine plant pumped out so much material, so quickly, that it would have been impossible to paint just selected areas without covering the entire area around the target. The painter just made one quick pass down the side of the head that covered everything. In some earlier posts, John Hinckley described the actual process and said that the entire engine paint operation was done in something like 13 seconds. Not much time to pick and choose targets. It was "pull the trigger and run".

Most of the orange would have burned to black within a few hours of run time but the flange area that mates to the cyl head will stay orange for decades. Hope this helps.

[Michael H.]

Re: Overspray on exhaust manifold questions....

Phil,

While it's true that no restored old Corvette will ever be exactly the same as it was when it was new, the target, for many, is to get it as close as possible with the parts we have available today. It's all in how much fun a person has duplicating, exactly, the way a component was made or completed on the assembly line. It's a continuous research project that never ends. Many restorers find this as enjoyable as any other part of the restoration. It all depends on what you want as a hobby.

Others enjoy the finished product instead, and some of the details along the way, such as exhaust manifold paint, really aren't important. I agree with both directions. There's room for both here.

By the way, my 66 big block still has quite a bit of original factory applied orange on the manifold flanges after 40 years and 55,000 miles.

[Steve Wallach]

Re: Overspray on exhaust manifold questions....

Hi Michael,

Yes, that's the info I'm looking for! Thank You,

Cheers,

Steve

[Steve Wallach]

Re: Overspray on exhaust manifold questions....

Michael,

Another quick question I have is the small black phosphate clip that mounts under one of the Intake Man. bolts that holds the steel vaccume advance line in place, does that get painted Orange also? Was it in place when the engine was painted, or was it added when the carb was installed?

Thank You again!

Steve

[Michael H.]

Re: Overspray on exhaust manifold questions....

Steve,

I THINK it was painted orange but I'm not sure. Wish I could give you a definite answer on this but I can't remember if it was installed/painted along with the engine at Tonawanda or added at the St. Louis plant later. I don't have a 67 AIM handy but if it's like the 66 AIM for the L36, there will be no mention of the clip, OR the hose for L36. It's shown for the L72 425 HP but that's a completely different clip that mounts to a carburetor stud instead of an intake manifold bolt. Hopefully, someone with an unrestored 67 390 HP can help. Is there a good pic in the Noland Adams book?

I don't remember this clip in the same location as the clip for the vacuum advance unit. I thought it was mounted further forward, under the 2nd intake manifold bolt, but I'm not sure.

[John H.]

Re: Overspray on exhaust manifold questions....

Steve -

That clip was installed at Tonawanda, and should be painted orange.

[Steve Wallach]

Re: Overspray on exhaust manifold questions....

Thank You John,

I appreciate your help!

Cheers,

Steve