i have a 454 witch i bought and dont know if it has round or oval ports, i want to buy a new set of heads for it but dont know what kind to by, can i get some help, also what kind of heads hould i look at getting,
If it's a first generation BBC (70's-80's) it probably has oval port heads-rectangular port heads were early 396/427/454 HP units. The later generation engines were different. Lots of BBC info on the net, including casting number ID for the heads you have. Make sure the head port (oval or rectangular) match your intake.
www.mortec.com Check your head and block casting numbers with this site. You will get a ton more information than you provided us here. And of course, mortec is down. Sure fire way is to pull the intake manifold off and look.
Street cars looking for torque over HP usually used the smaller oval ports with big valves cut in. But that was years ago using factory stuff. Nowadays aftermarket heads are plentiful and relatively inexpensive. That is, the cost of rebuilding old heads along with new valves, springs, machine work etc. really isn't worth it
You really need to give more information for anyone to make a useful suggestion. What are you putting it in, intended use, year of production and any casting numbers on the engine/heads would be helpful. A guy I know got ripped badly on a car with a new "502-502" in it that was really a dressed up late model, low compression 454. I hope you got a deal on yours but you should always run the numbers first.
Hi, Oval port heads say "Pass" on them for pasenger car and rectangular port heads say"HP" on them for high performance. Unless you have a stroker motor stay with the oval port.
Look for the last three numbers of the casting # on the heads. Two of the popular oval port castings are 049 or 781. Square port castings are fine for racing but really too big for the street unless you are going to run between 4000 and 7000 rpm all of the time. I have a pair of peanut port castings off of a truck that say hi performance on them so you cant really rely on that. Look for the casting number and look them up on the net. It gives you all the info you need.
BBC's have a heck of a bunch of heads to choose from so please do your homework. Intake ports.............. 1. Peanut port that have wider than tall intake ports. They range from right at 200 cc's up to maybe 230 cc or so intake port size. 2. Regular large oval have taller than wide intake ports that can be anywhere from about 230 to 262 cc intake port size. 3. L-29 Vortec heads are around 230 cc's and are true, but small port large oval. They have right at 100 cc heart-shaped, fast-burn chambers so are good to raise the poor CR up on the old pick-up 454 engines that actually have like a 7.9 to 8 to 1 CR.! 4. large oval smog chambered heads that have the exhaust quench "squared-off" over almost in line with the intake vave quench. Way open chambered design, but they can range fromm 112/113 to above 122 cc chamber size so you really have to cc them to know for sure as also ALL BB heads!! 5. GM/E-brock aluminum "rovals", really are short rect port heads. Never made in cast-iron that I am aware of. They range from 110 down to 100 cc open chamber size. Valve sizes.................... Range from----- .........1.84"/1.94"/1.66" that are actually in regular large oval castings so these rare heads can be reamed out and regular sized .........2.06"/1.72" valves can be installed. .........2.19"/1.72"/1.84"/1.88" valves are in rect port heads. And GM sold a .........2.30" intake valve but never installed it in a production head. Chamber designs----------- 1. Early true closed large oval port down around 96.7 to 98 cc's. 2. Semi-closed that have the sparkplug quench bullnosed back. 3. Open that range's from 112/113 to above 122 cc's and the afore mentioned 4. Squared-off Smog chamber. And I'm almost positive that years ago Bill Mitchell/World Products made a cast-iron, 218 to 219 cc open chambered, regular large oval 290 cc intake port head that was called a "VR" design. I wish these would be made again except with 100 cc chambers!! Should sell like hotcakes to the 454 P/U engine guys and gals if reasonably priced, imho!! pdq67
Chamber designs----------- 1. Early true closed large oval port down around 96.7 to 98 cc's. 2. Semi-closed that have the sparkplug quench bullnosed back and can range from 100 to 101 cc's or so chamber size. Sorry about that.. pdq67
Sorry, i forgot few things. i am putting the motor in my 50 fleetline, bolted u to a 700r4 tranny, i am trying to put claysmith cam in it, i just want it to cruse in but sound loud ad choppy, the casting numbers on the motor are 3999289 some web sites say its out of a vette others chevelle and other a truck, http://www.ajgeneral.com/bbc_block_casting_numbers/ this one says it came out of one of the 3, also web site say its a 2 bolt others 4 bolt, and i belive that i got a good deal on the motor only paid 250 for it, i have a forum that i posted called "get a load of this" it has pics of the motor the post is closed but cn still be seen.
I would stick with the oval ports. Since you are just going to go mild and running an overdrive just rebuild what ya bought for 250.00. Put ya a mild cam in it, good aluminum intake and a good carb. Will be fine. As far as ovals go 781's you can find pretty cheap are good. Rectangulars are a factory Hi-po heads. I have merlin rect. ports on my setup. Just got my engine back from the machine shop.
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