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The motor in my boat is a rebuild. I got it real quick and cheep. I dont know anything about it. Just thats its 2 carbs (found out yesterday they are 750's) High rise, Tunnel ram, 460, rebuild. Reps show short block exhange for just over $500. Two valves repaired. No other info. I found a number on my heads. Its "20439" Anybody know what that means? Under the valve cover it says "DOOE-R" Whats that? I have a pic of the valve train, Can you tell what valve was cahnged?? :rolleyes: http://www.***boat.com/image_center/...hp?photo=16248
Any comments on this? Whats the diffrence in the rockers?
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Your valve train looks good adjustable and guide plates.I am pretty sure those part numbers are the cobra jet heads and if so they are good!I did notice the screw in studs so they are def an earlier head.
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Congratulations Dan.
D00E-R The fabled Cobra Jet and Super Cobra Jet castings.
Combustion chamber volume comes in slightly smaller at 71 to 75 cc's 11 to 1+ compression ratio with 429 flat tops, or with the dished 460 pistons.
About 1/2 point lower on '72 and up blocks.
Cobra Jet engines built before 11-'69 had adjustable valve train. They were non adjustable after that date.
All castings came with pushrod guide plates,sled fulcrums and stamped steel 1.73 to 1 rocker arms
Adjustable valvetrain used non shouldered rocker studs. Non adjustable valvetrain used positive stop shouldered stud with 3/8" fine pitch threads on top..
All Super Cobre-Jet engines used a solid lifter camshaft.and adjustable valve train.
Valve sizes are 2.24" intake and 1.72" exhaust.
Intake ports are larger at 2.51" x 2.11" ovals
Exhaust ports are also larger at2.25" x 1.30" rectangular oval port shape
Although the exhaust ports are larger they share similar architecture with the passenger car castings. Removal of the thermact-air boss along with blending of some of the weird casting bumps will help flow measureably.
All of the 385 series castings suffer from a very poor intake/exhaust flow ratio.
This due to the fact that shock towers in the intermediate line up neccesitated tucking the exhaust manifolds as close as possible to the engine for clearances' sake
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I measured the exahust ports. I dont have a caliper but I have small scale in 10th. The ports are 1.30 by 2.2 or 2.25. Squirtcha, you gave me a ton of info.....too much. Are you saying I have Super Cobra-Jet heads??? Is the good? :confused: Do I have a good valve train? ( dont laugh, remeber I am new) I was thinking about putting in a cam, the one in there is a stocker, or close to it. How big can I go without tearing too much apart? Dose the cam go in form the pully side of the motor?
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Here's the skinny. As I understand it........the only difference between Super CorbraJet and Cobrajet head is this.
Cobra Jet engines built before 11-'69 had adjustable valve train. They were non adjustable after that date (that would be most of em).
All Super CobraJet engines used a solid lifter camshaft and an adjustable valve train.
I can't get the picture that you posted to come up, so I don't know what you have for studs n rockers. I'm assuming that they're adjustable though. Someone has probably changed them out over the years to a Chevy type stud and roller type rockers. That's what most guys do with em. You'll need the valve train to be adjustable for just about any cam that is more aggressive than a stock, or near stock cam profile.
As far as cams go, there are lots of things to consider. Solid lifters, hydraulic, roller, etc.
Someone else can jump in here that knows more about cams but my take is that
The roller cams can make more horsepower because the roller lifters can follow a more aggressive cam lobe profile, but they're more expensive, have more moving parts and require more maintenance, having to be adjusted a couple times a year or so.
Hydraulic are pretty much a set it and forget it type deal and are probably more forgiving and definitely less expensive.
I don't know squat about solid type cams.
Jump on in here motor guys.
Dan, I'd recommend that you buy yourself a book. It'll at least familiarize you with the internals of your motor. You might want to consider one of the BBF performance books as opposed to a stock rebuild manual. The stock books are o.k. if you don't intend to do anything other than a stock longblock, but that's about it.
[ April 22, 2003, 08:10 PM: Message edited by: Squirtcha? ]
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Yo Hercules,
You have a set of rare heads. These are perhaps the most high performance cast iron cylinder heads that Ford ever offered for the 429/460 engine family. They are indeed the Cobra Jet cylinder heads as designated by the D0OE-R casting. People pay a lot of money for those heads and they are capable of producing lots of horsepower.
Your heads have a combustion chamber volume of about 72 cc's. Most Ford passenger car heads have chamber volumes of 76 cc's and 92 cc's, so you can see that your heads offer the highest compression. Also, your heads have the biggest intake valve size of 2.25" (vs. 2.08" for standard heads). Finally, the ports are the most agressive offered in a cast iron head by Ford.
You mention that you want to install a camshaft. This is very involved as the camshaft is usually the very first component installed into a V8 during assembly. And so you will need to remove your tunnel ram intake manifold and carbs, complete valve train, front timing cover and pulleys and timing chain. If you are not experienced in this, then I strongly recommend that you seek the assistance of somebody that is.
Finally, you must do more evaluation of you engine before selecting a cam. You at least need to know what pistons are in your motor. Also, if you get a super-radical camshaft, the huge intake and exhaust valves in you heads have been known to touch each other during valve overlap unless some precautionary measures are taken.
I don't mean to discourage you. It would be a shame to lose those heads due to a simple oversight. Do your homework and get some help.
LO
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hey, squirtcha, remeber how I was told I hit 70? Is it possible that that reading is correct after seeing what heads I have? Do heads make that big of a diffence?
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wana trade those heads for my good ones that give me good gas mileage ? Good catch on those heads, you won the lottery.
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Here is a slightly diffrent view. I will get better pics tomorrow. Thanks for all the help! :D i am a happy man!
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Here is a slightly diffrent view. I will get better pics tomorrow. Thanks for all the help! :D i am a happy man! http://www.***boat.com/image_center/...hp?photo=16260
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I went to a shop near buy where I get my stuff. I was talkin to him and showed him the pics too. Re recommeded a couple of cams. What do you guys think?
RPM range 1000 to 5200
In take 262 514 lift
exh 268 524 lift
or
rpm range 2000 to 6000
intake 280 530 lift
exh 280 330 lift.
By the way, I dont want to change springs if i dont have to. I am gonna change that one rocker for sure!
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By the way, the 2nd cam ehx lift is 530, not 330
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I'd think that if you're already running 5500 rpm that first one's gonna run out of steam on ya with a 1000-5200 rpm.
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[img]http://www.***boat.com/image_center/data/500/467rockers.JPG[/img]
