461 head Question

[Jim S.]

I was visiting a friend over the weekend looking at his various cars when the discussion came around to a set of 461 heads he had purchased.

He sucked me in with "Your the Vette expert so tell me if these are indeed Corvette heads " . Taking up the challenge , I Knew enough to tell him they were in fact Flint heads because of the lack of a T inside , and because the double humps were machined , and they had the circular broach marks on them.

The two questions I could not answer were:

(1) Why they machined the double humps ?

(2) Why one head has both sides of the single oppisite hump machined, and the other head has only one side of the single hump machined while the other side is left untouched ?

So now an inquiring mind whants to know ! What was the reason for the machining of the double humps and more importantly, why machine the other (single hump ) sometimes, but not always ?

Jim

[Jack H.]

Re: 461 head Question

I was visiting a friend over the weekend looking at his various cars when the discussion came around to a set of 461 heads he had purchased.

He sucked me in with "Your the Vette expert so tell me if these are indeed Corvette heads " . Taking up the challenge , I Knew enough to tell him they were in fact Flint heads because of the lack of a T inside , and because the double humps were machined , and they had the circular broach marks on them.

The two questions I could not answer were:

(1) Why they machined the double humps ?

(2) Why one head has both sides of the single oppisite hump machined, and the other head has only one side of the single hump machined while the other side is left untouched ?

So now an inquiring mind whants to know ! What was the reason for the machining of the double humps and more importantly, why machine the other (single hump ) sometimes, but not always ?

Jim

Jim, hopefully you won't mind if I pile on a bit...

Is this hump machining for Corvette and not machining for non-Corvette identification also the case for the '67 462 heads???

[William C.]

Re: 461 head Question

OK, this is in the archives, but it really came down to the machining processes in Flint and Chevy Buffalo. Flint machined the front boss to use as a registration surface for alignment during processing. The Chevy Buffalo plant did not use the same areas for location during processing, therefore had no need to machine the area of the "humps" and now 50 or so years later leaving us with an easy way to tell a Flint head from one machined in New York. As to the 462 question the same answer applies, with the exception of the "corvette" statement. Passenger cars with flint built engines used the identical process, and outnumbered Corvette versions, maybe 30 to one?

[Jim S.]

Re: 461 head Question

OK, this is in the archives, but it really came down to the machining processes in Flint and Chevy Buffalo. Flint machined the front boss to use as a registration surface for alignment during processing. The Chevy Buffalo plant did not use the same areas for location during processing, therefore had no need to machine the area of the "humps" and now 50 or so years later leaving us with an easy way to tell a Flint head from one machined in New York. As to the 462 question the same answer applies, with the exception of the "corvette" statement. Passenger cars with flint built engines used the identical process, and outnumbered Corvette versions, maybe 30 to one?

Thanks Bill,

That answers most of the question. I am still somewhat vague on the oppisite side (single hump ) part. If the double hump was used for alignment, it makes sense that they ground all of them. Why however did they grind none , some , or all of the oppisite side single humps ? Did some indeed stick out that much more than others , thus affecting alignment as well ?

By the way I did go to the Archives first . Spent an hour looking through them before I posted . However I could not find any explanation ,just a lot of info . There are a ton of postings on 461 heads.

JIm

[Jim S.]

Re: 461 head Question

I know this isn't all that important in the overall scheme of things,but now that I have it in my head , I can't let it go.

In an effort to understand what bill was saying yesterday , I looked at the 3 heads I have .The two originals and the one replacement for the one that had a crack in it . If I line them up as if all were to be used on the "left side " I come up with all three having both the double hump and the oppisite single hump ground off in the front , and only the double hump ground off in the back.

So if I understand what bill said , this would be the way they were alligned from the front. So far so good . However if they did not care about the rear lining up why did they grind off the double hump back there.That would be just one unneeded extra step . Further this is only the three I have , and does not tell me if they were all that way. Nor does it explain why I saw at least one where the oppisite single hump was ground down on both sides. Perhaps Bubba did it ?

Are the three I have the typical way most of yours look ? Does anybody have any where both sides of the single hump were ground off as well ?

Still confused,

Jim

[Timothy B.]

Re: 461 head Question

Jim,

Help me understand what you are talking about. My 63 (461) and 67 (462) head double humps appear to be machined the same on both ends. I don't think it matteres what side of the engine they go on.

[Jim S.]

Re: 461 head Question

Jim,

Help me understand what you are talking about. My 63 (461) and 67 (462) head double humps appear to be machined the same on both ends. I don't think it matteres what side of the engine they go on.

Hi Tim,

My double humps are machined on both sides as well . I am speaking of the "single hump" on the other side of, or across from the double hump .To the left on the enclosed picture.

As you can see from it , this one is ground off , however on the bottom , or the reverse side , it is not , and still shows the sand cast appearance. All three that I have show the same pattern. However over the weekend I saw two others , one with both sides of the head having the "single Hump " machined , while the other had one of each.

I hope this makes more sense .


What do yours look like in that area ?

Ps. No comment on the slippers please !


JIm

[Jim S.]

Re: 461 head Question

Jim,

Help me understand what you are talking about. My 63 (461) and 67 (462) head double humps appear to be machined the same on both ends. I don't think it matteres what side of the engine they go on.

Tim,

I just got home so I took a picture of both heads together. Notice the difference of the "single hump" from one to the other. I might add that if I turn these two over they would show the same difference, one ground off and one left alone.

Jim

[Jack H.]

Re: 461 head Question

Tim,

I just got home so I took a picture of both heads together. Notice the difference of the "single hump" from one to the other. I might add that if I turn these two over they would show the same difference, one ground off and one left alone.

Jim

Hmmm, this is very interesting. I'm going to have to check my 461/462 heads when I get home. I never noticed this difference before.

Oh, and I liked the slippers better than the dress shoes, but maybe it's just me.

[Timothy B.]

Re: 461 head Question

Jim,

You know, I never noticed that difference before. I will check tomorrow and post what the 461X and 462 (67) heads look like in this area.

I vote for the slippers also, my feet get warm just looking at them..

[Jerry W.]

Re: 461 head Question

My guess is that the facing of the lone single hump is incidental to the facing of the double hump dependant upon the depth of cut taken to cleanup the double hump bosses....My 2 cents

[Jim S.]

Re: 461 head Question

My guess is that the facing of the lone single hump is incidental to the facing of the double hump dependant upon the depth of cut taken to cleanup the double hump bosses....My 2 cents

Jerry ,

That's a good guess , but wrong.

I put a level to them last night .The sides where both the double and single humps were machined are indeed level to each other and cut to the same depth . However on both sides where the single hump is unmachined , the single hump is in fact much higher than the double hump.

Jim

[Timothy B.]

Re: 461 head Question

Jim,

I wanted to post back that both my 67 with 462 heads and 63 coupe with 461x heads are exactly as you describe.

Is there any logical reason for that machining process..

[Clem Z.]

Re: 461 head Question

Hi Tim,

My double humps are machined on both sides as well . I am speaking of the "single hump" on the other side of, or across from the double hump .To the left on the enclosed picture.

As you can see from it , this one is ground off , however on the bottom , or the reverse side , it is not , and still shows the sand cast appearance. All three that I have show the same pattern. However over the weekend I saw two others , one with both sides of the head having the "single Hump " machined , while the other had one of each.

I hope this makes more sense .


What do yours look like in that area ?

Ps. No comment on the slippers please !


JIm

i was wondering if the slippers were steel toes in case the head fell over.

[Timothy B.]

Re: 461 head Question

Ouch!!!!!!