While examining my car's 1967 cylinder heads (3904391), dated C 15 7 and C13 7, I discovered that the cylinder head's valve springs had purple paint dabbed on two sides of each spring (see attached photo). Does anyone know if the paint would have been applied at the factory? If so, what was the reason for applying the paint? Thanks for your help.
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Re: 1967 3904391 Cylinder head
Hector-------
The purple dye stripe you see on the springs was applied at the spring manufacturing plant and is part of the GM identifier for the valve springs used on your engine. The other side of the spring should show a red stripe. These two colored stripes were the identifier for the GM #3859911 valve springs used for most 1965-69 big block applications.
By the way, this spring is VERY problematic and often breaks, sometimes with disastrous results. I would NEVER have these springs on big block of mine. Never. Ever.
DSCN3117.jpgDSCN3118.jpgIn Appreciation of John Hinckley -
Re: 1967 3904391 Cylinder head
Then Joe which springs to use?Comment
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Re: 1967 3904391 Cylinder head
Thanks Joe. As usual great information. Would the dye wear off eventually?
Reason I ask is that I'm looking for all clues as to the my car's mileage. I've been able to establish beyond any reasonable doubt that the car had 14,539 miles on 7-9-91, 14,800 miles on 12-13-96 and approximately 14,990 miles in 2004. I know that the car was part of a car collection dating back to 1985 and the previous two owners. Don't know much about it's history prior to that. Working on it. Know it was sold new in Florida. It now has 15,102 miles on it.
It is in remarkable original condition with the exception of several parts like the fuel pump, radiator hoses and radiator Wittek clamps. The Wittek clamps are original but dated 84/2. As a side note, it still retains its original flame arrestor hose with original Wittek clamps dated 66/3. Had to mention that since I just discovered it this past Saturday.
The list of original parts is extensive, including all original interior. In regard to the interior, you name it, it is original and probably born with parts.
In regard to the valve springs, I was not aware of the problems with these springs. I believe they've been on the car since 1967 along with most of the cars parts. The car is a joy to drive although I've only driven it approximately 100 miles. I've had no issues with it so far. It turns over immediately and does not overheat.
Would you expect the dye to still be on the valves at 15 thousand miles? The Cylinder heads and exhaust manifolds look like they have never been removed. I will look into getting the valve springs replaced but I'm making every effort not to replace parts on this car unless absolutely necessary. I do want to drive the car.
If you can think of any other parts I should be weary of, please let me know. Thanks again.
HectorComment
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Re: 1967 3904391 Cylinder head
Thanks Joe. As usual great information. Would the dye wear off eventually?
Reason I ask is that I'm looking for all clues as to the my car's mileage. I've been able to establish beyond any reasonable doubt that the car had 14,539 miles on 7-9-91, 14,800 miles on 12-13-96 and approximately 14,990 miles in 2004. I know that the car was part of a car collection dating back to 1985 and the previous two owners. Don't know much about it's history prior to that. Working on it. Know it was sold new in Florida. It now has 15,102 miles on it.
It is in remarkable original condition with the exception of several parts like the fuel pump, radiator hoses and radiator Wittek clamps. The Wittek clamps are original but dated 84/2. As a side note, it still retains its original flame arrestor hose with original Wittek clamps dated 66/3. Had to mention that since I just discovered it this past Saturday.
The list of original parts is extensive, including all original interior. In regard to the interior, you name it, it is original and probably born with parts.
In regard to the valve springs, I was not aware of the problems with these springs. I believe they've been on the car since 1967 along with most of the cars parts. The car is a joy to drive although I've only driven it approximately 100 miles. I've had no issues with it so far. It turns over immediately and does not overheat.
Would you expect the dye to still be on the valves at 15 thousand miles? The Cylinder heads and exhaust manifolds look like they have never been removed. I will look into getting the valve springs replaced but I'm making every effort not to replace parts on this car unless absolutely necessary. I do want to drive the car.
If you can think of any other parts I should be weary of, please let me know. Thanks again.
Hector
Hector------
The dye stripes usually last quite awhile. Eventually, engine heat usually causes them to discolor but some vestige of the stripes usually remains indefinitely. I suspect that the reason yours are still as-original is because of the low mileage on this car. It's also probably why the original springs are still on the engine. However, it could be that one or more of the springs did break and was replaced. The GM #3859911 was discontinued in November, 1970 and replaced by GM #3970627. So, if a broken spring occurred after that time it would not have been replaced with a 3859911 (and, the replacement spring would not have had the same color dye stripes). In this regard, if the springs were replaced with the 3970627, that spring also has a purple dye stripe but no red dye stripe. Also, the 3859911 is a single spring with damper. The 3970627 is a dual spring with no damper.In Appreciation of John HinckleyComment
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Re: 1967 3904391 Cylinder head
Gary------
The best choice is the GM #3970627. However, it's GM-discontinued. Aftermarket springs of similar specifications would be one choice. In the case of big block springs, there's a special problem that's created. That's because most 1965-69 and 73-74 big blocks used a single spring with damper AND used an umbrella type seal in conjunction therewith. When a double spring is used, the conventional umbrella seal, originally GM #3866612 and later GM #460527, will not work. So, with most aftermarket double springs, different seals must be used. One option is going with positive seals like Perfect Circle type all Teflon seals but these require machining of the valve guides. Another option is going with a high quality aftermarket single spring with damper and using the stock-type umbrella shield. The unique integral retainer/seal used with the GM #3970627 was never and is not now available in the aftermarket. The 3970627 was used in PRODUCTION for all 1970-72 big blocks and was SERVICE for most 1965-69. It's possible that the 3970627 was also used for very late 1969 big blocks.
I'll be posting some information on big block valve springs and related parts in the near future. I've been planning to do this for quite some time but I just haven't got around to it as of yet.
In Appreciation of John HinckleyComment
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Re: 1967 3904391 Cylinder head
A few more photos of the 3970627:
DSCN3123.jpgDSCN3124.jpgDSCN3125.jpgIn Appreciation of John HinckleyComment
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Re: 1967 3904391 Cylinder head
We've been kicking around the early big block valve spring issue on the TDB for years. Until a couple of years ago, the ...627 was the solution, but once those became unavailable no one has ever come up with durable replacement spring/seal lsystme that doesn't require removing the heads for machine work. I'm glad I don't have a big block that needs a refresh, but there must be an answer, and I think we are looking for you, Joe, to come up with an acceptable replacement.
Given all the big blocks that were built in that era I'm really surprised that the aftermarket like F-M or Dana doesn't offer an exact replacement for the ...627.
DukeComment
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Re: 1967 3904391 Cylinder head
So we can visualize the options, circa 1971, from "How to Hotrod BB Chevys"
cComment
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Re: 1967 3904391 Cylinder head
That book along with "How to Hot Rod Small Block Chevys" are great reference books. At the time they were written in the seventies, most of the early problems with both engine families had been solved with better OE parts.
If you're contemplating a rebuild get the book that applies. I don't think they are in print anymore, but used copies should be available on ebay and Amazon.
They both have very good chapters on blueprinting OE engine components and excellent chapters on head head massaging and multi-angle valve seats. The emphasis is on identifying the best OE parts and reworking OE parts (like cylinder heads and some simple checks and work to blueprint the OE oil pump) for best performance and reliability. The emphasis is on OE, not aftermarket parts, which makes them great references for building a reliable engine that looks and acts OE other than having more top end power and another 500-1000 useable top end revs, which is primarily gained from head massaging.
DukeComment
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Re: 1967 3904391 Cylinder head
Thanks Joe. For clarification, can you tell from my photo whether the spring is a GM #3859911 or GM #3970627. I'm pretty sure all springs have purple dye stripe on both sides and not a red stripe. I'll check the photos again later. Thanks again.Comment
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Re: 1967 3904391 Cylinder head
It's tough to see in the photo what's inside the outer spring. If what you see inside the outer spring appears to be another spring of round section wire, then they are probably ...627s. If what's inside is a thin rectangular section wrapped into a helix, it's a damper - like on SB springs - so they would likely be the early single spring/damper setup that is prone to failure.
Refer to the photos in post #9 for reference and let us know your conclusion.
DukeComment
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Re: 1967 3904391 Cylinder head
How much do you think a set of NOS GM 627 Springs in the Original boxes would be worth at this time???
JRComment
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