1969, 186 Camel Hump head question - Team Camaro Tech
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post #1 of 9 (permalink) Old Sep 3rd, 18, 06:56 AM Thread Starter
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1969, 186 Camel Hump head question

I have a nice set of virgin 186 heads for my 69 Camaro. They have never been touched. They have the original 1.94 intake valves. When I talked to my machinist about installing 2.02's he is advising me against it. He says there's a good chance to cut into the water passages. Isn't this a common practice to do with these heads? Any professional advice would be appreciated.
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post #2 of 9 (permalink) Old Sep 3rd, 18, 08:04 AM
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Re: 1969, 186 Camel Hump head question

My opinion on engine building:

Heads determine your potential horsepower. The better the heads breath the more power you will make. If you want fuelie heads because of how they "look" then that tells me you are willing to restrict your power level to those 1956 technology head designs. As such do not risk cracking the valve seat at the point where it is closest to the exhaust valve by thinning the casting at that point due to increasing the valve size. Larger valves increase the ability of a head to breath, but not as much as the effect of the port design (consider the nail head Buick, or a BBC that has tiny valves compared to a SBC).

Second rule is a cam doesn't do much more than to shift where in the RPM operating band that the engines makes it's power. The higher you spin the motor the more power strokes per minute that the motor will make. The more lift you can grind into the lobe the more power you will make, but physics gets in the way of a tappet and poppet valve: limiting max lift for a given cam lobe slope.

Because air is a fluid it responds to all of the mechanical limitations of a fluid (inertia), as such you must increase the duration (time the valve is off the seat) if you want air to move at high engine speeds. Duration kills bottom end and mid range power because you can not make power with the valve open. As such you have to choose if you own a race car or a street car; as you can not have both in a push rod motor without variable valve timing. I have no sympathy for those that put a race cam in there street car and complain about the affects of long duration on street manners, but as an engine builder I had to allow my customers to handicap their cars despite my advise.

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post #3 of 9 (permalink) Old Sep 3rd, 18, 08:22 AM Thread Starter
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Re: 1969, 186 Camel Hump head question

I appreciate the quick and professional response. His recommendation is to cut in hardened exhaust seats, replace all valves, replace all guides and mill the surface. Do you have any thoughts on that scope of work? Also, what kind of valve seals are best to use on these heads? He recommends rubber umbrella. I know there are better materials out there today. Thanks again!
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post #4 of 9 (permalink) Old Sep 3rd, 18, 08:47 AM
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Re: 1969, 186 Camel Hump head question

The last I checked it was around $1000 to do SBC iron heads

Personally I would not put a dime into 1950 technology heads and would go with new Aluminum heads for the same money.

unless it an all original thing you're going for.
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post #5 of 9 (permalink) Old Sep 3rd, 18, 10:06 AM Thread Starter
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Re: 1969, 186 Camel Hump head question

I like the looks of the engine on a 69 Z28. I have a bone stock 327, 4 spd Camaro that will look nice with a stock set of camel humps, aluminum intake and Holley 4 bbl. Not looking to make a Z28 clone. I have already gone with all the aftermarket power monger parts on my 454, 70 Chevelle.
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post #6 of 9 (permalink) Old Sep 3rd, 18, 12:44 PM
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There is a company out there that makes aluminum heads with the old double hump casting on the ends. Might be worth looking into.

X-77 keith
1969 x-77 Z/28 orange/ white stripes, named by my daughter "Clementine ", M-22 close ratio, 4:10 12 bolt, CE 302. Hugger orange with white stripes. White standard interior. Restoration complete May 2018
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post #7 of 9 (permalink) Old Sep 3rd, 18, 12:57 PM
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Re: 1969, 186 Camel Hump head question

That company is Trick Flow, Many machine shops now are willing to weld up accessory holes on aluminum heads and machine the ends of the heads in a five axis CNC machine to look like early 1957-'67 Fuelie heads.

These are AFR heads that have been machined to look like 1968-'72 fuelie heads:



A coat of Chevy orange engine paint and no one is the wiser.

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post #8 of 9 (permalink) Old Sep 3rd, 18, 02:05 PM
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Re: 1969, 186 Camel Hump head question

I like the look of the Trick Flows, but didn't have the funds to support em.. Bought a set of unmolested 186's and for $300 had em dipped and checked, then had hardened seats and 202's put in them. They've been a good head with no issues for the past 15 years. If I could have swung the $$$ for AFR's milled to look like the camel humps I'd have gone for it. Would have kept the mostly stock appearance but with increased output.

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post #9 of 9 (permalink) Old Sep 3rd, 18, 06:13 PM Thread Starter
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Re: 1969, 186 Camel Hump head question

Great information. Thanks for all the feedback. I'll look into the AFR heads.
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