Cam Choices?

Cam Choices? - 04/25/09 01:59 AM

so, putting together a list of parts i need to buy to get the motor finished.

wondering about cams, now that i know more about what i will be running.

itll be the stock 72 short block, with like 9-1 compression, probably less. with the edelbrock performers with the 84cc chambers.

itll probably have either a 650 holley my boss gave me, or ill rebuild the old carb my dad ran which is like a 750 but could be an 850, idk.

id like to keep it a sold cam, seeing as we already have the hardland sharp rockers.

so, what would run good in a combo i need to find out what cam some friends ran who had the same combo and ran 10.20's.

also, where can i get new rings for the stock pistons? not sure where to look...

John

Posted By: Bob_Coomer

Re: Cam Choices? - 04/25/09 02:55 AM

Hello
I would let the experts order up a good cam tailored for your combo. Like a SQ lobe from Comp Cams. That engine would be easy to over cam. If your looking at a shelf cam.... The 557 MP would work excellent and be about a max cam for the engine IMO. And should clear fine even with stock pistons. I assume the converter will be up to snuff also, do you know which one you have, or going to get? What intake do you plan to run or have? These will play a important roll on cam selection too.
Rings can be had through Summit etc. Get a good set of +.005 rings and file fit them for the bore.
It would be nice to get the compression up another point or so. Pump gas will be no problem even with a full point more compression.
If the budget allows, give Dewayne Porter a call and mull it over a bit. He has quite a bit of experience with similar combo's...
I know you probably already have, but if not check out the Tech Archives Default 500HP combo...

Posted By: Quicksilver440

Re: Cam Choices? - 04/25/09 03:42 AM

Quote:

so, putting together a list of parts i need to buy to get the motor finished.

wondering about cams, now that i know more about what i will be running.

itll be the stock 72 short block, with like 9-1 compression, probably less. with the edelbrock performers with the 84cc chambers.

itll probably have either a 650 holley my boss gave me, or ill rebuild the old carb my dad ran which is like a 750 but could be an 850, idk.

id like to keep it a sold cam, seeing as we already have the hardland sharp rockers.

so, what would run good in a combo i need to find out what cam some friends ran who had the same combo and ran 10.20's.

also, where can i get new rings for the stock pistons? not sure where to look...

John

No offense...but nobody ran 10.20's in the 1/4 on the motor with the combo your describing.

Posted By: SealockRacing

Re: Cam Choices? - 04/25/09 10:09 AM

no offense taken, just stating what i was told, not saying it will, but it will be a nice reliable combo i think.

now, cam choics...

Posted By: S/ST 3040

Re: Cam Choices? - 04/25/09 11:27 AM

I'm no BB guy but, I've seen several low-buck 440s respond pretty
good to the MP 312/.590 cam and Edelbrock RPM heads. It should
break 10.90s in an A-body.

Posted By: blownzoom440

Re: Cam Choices? - 04/25/09 12:06 PM

what was the piston to valve clearance again?

Posted By: RemCharger

Re: Cam Choices? - 04/25/09 06:02 PM

I think 8.0:1 is what you'll likely end up with. You could measure the deck height with a ruler and some feeler gauges , start with about .150. I went with a .528 in mine, but at the time I was running a 3500 stall so I needed the 60 degrees overlap to build some cylinder pressure and make torque.
If you had a higher stall, like 4800-5000 then you can get a real camshaft. I would have tried the .590 , I've heard that it would fit with those pistons. The only problem is how high do you want to spin that unbalanced, stock rod, cast piston motor? I imposed a 6500 rpm limit on myself, I figured thats the safety zone. Beyond that ....well it depends how attached you are to that motor. There were alot of combos listed in the smogger 440 thread in the archives.

Posted By: SealockRacing

Re: Cam Choices? - 04/28/09 12:10 AM

carbs going to be an 850 holley, intake is an old weiand. converter, no idea, but its been 10.30's in this car, and 11.00's in a dart. headers are like 1 and 5/8's or something, pretty big.

i dont plan on spinning this up any higher than 6500.

the motor has about 30 minutes of runtime on it, so i think ill be checking the bearing clearances with some plastigage, and probably reusing the bearings. same with the rings.

also, another question, do arp rod bolts have to be professionally installed, or could i do it with a press at work?

im trying to do as much of this as possible, why pay for something i can do myself?

John

Posted By: Old School

Re: Cam Choices? - 04/28/09 12:15 AM

headers are like 1 and 5/8's or something, pretty big.

are you serious?

Posted By: dartman366

Re: Cam Choices? - 04/28/09 12:31 AM

Quote:

carbs going to be an 850 holley, intake is an old weiand. converter, no idea, but its been 10.30's in this car, and 11.00's in a dart. headers are like 1 and 5/8's or something, pretty big.

i dont plan on spinning this up any higher than 6500.

the motor has about 30 minutes of runtime on it, so i think ill be checking the bearing clearances with some plastigage, and probably reusing the bearings. same with the rings.

also, another question, do arp rod bolts have to be professionally installed, or could i do it with a press at work?

im trying to do as much of this as possible, why pay for something i can do myself?

John

if it has only 30 minutes of run time and it has/had good oil pressure then why mess with it, as far as rod bolt's yes you can replace them your self but you will need to re-size the big end of the rod, 1.625 is not big for that motor, that is smallblock size, I would go with a 2" header at the very least.

Posted By: SealockRacing

Re: Cam Choices? - 04/28/09 01:22 AM

you guys do understand im 18 years old, and have not been involved with building a big block, let alone putting together my own car right?

i am just eyeballing stuff, ill measure them, whatever size they are, they look big, if i had to guess, id say the collectors are 3.5 maybe even 4 inch...

why do the big ends have to be resized when you install new bolts?

also, ive been told you cant install main studs without having the block line bored.

to me, i dont see the problem, but, im not an engine builder, nor do i have experience with this stuff.

i just know most of the time, a stud is stronger than a bolt.

so i should just check the bearings, make sure everythings in order and stick it together?

Posted By: MR_P_BODY

Re: Cam Choices? - 04/28/09 01:47 AM

Quote:

carbs going to be an 850 holley, intake is an old weiand. converter, no idea, but its been 10.30's in this car, and 11.00's in a dart. headers are like 1 and 5/8's or something, pretty big.

i dont plan on spinning this up any higher than 6500.

the motor has about 30 minutes of runtime on it, so i think ill be checking the bearing clearances with some plastigage, and probably reusing the bearings. same with the rings.

also, another question, do arp rod bolts have to be professionally installed, or could i do it with a press at work?

im trying to do as much of this as possible, why pay for something i can do myself?

John

First off... the converter you got might have gone
10.30s with a strong engine... but the converter
isnt going to stall anywhere near what it stalled
with a high torque engine. The headers are small
but a small header helps to make torque down low
and you will need the help. Pay a shop to install
the rod bolts that way they can re-size them. Forget
the plastigauge... your at a shop, correct, borrow
the proper equipment to check it.... but if its only
got 30 minutes on it, just open a couple bearings
and look at them. But I think your pulling this
engine apart just because you want to... if the engine
has 30 minutes on it and it ran you should be set
(if you truly know about the engines history)... JMO

Posted By: SealockRacing

Re: Cam Choices? - 04/28/09 10:04 AM

thing is i really dont know the history of the motor. all i know is it is a 72 440.

a highschool class dropped it in an old dodge ram. part of their project was to have it rebuilt. they couldnt get it running right, so they gave it to my dads friend, and he ended up buying the truck, and selling us the motor.

thats all i know about it...

Posted By: GTX MATT

Re: Cam Choices? - 04/28/09 04:49 PM

If youre going to re-use the stock pistons why not buy some out of an earlier engine to up the compression? I would think the compression drop in '72 is due to a shorter piston, combustion chambers were the same size.

Theres a guy in the big block parts for sale section with a bucket full of them for like 40 bucks. You could probably acheive near 11:1 compression if you shave the heads as well, you will have to take a bit off but I'd say its probably doable.

Posted By: SealockRacing

Re: Cam Choices? - 04/29/09 02:48 AM

thats another option, but i really just want to get some seat time before i start going fast...

ive never driven this car, nor a car with big tires, and a big block...

ive driven an 11 second smallblock dart, which was plenty fast, but i was 17 at the time.

just want to get something together, get it running pretty good, have some fun, and get used to it. im not going to half [Edited by Moparts - Keep it clean] it, but not going to break the bank just yet...

my next motor will hopefully be alot meaner...