pistons, heads, both?

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THE STEVE

THE STEVE

"part-time wheelman"
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springville, indiana
in highschool abt 4 years ago i built a 360 for my duster. its a 77 block out of a van. its stock bore, stock dished pistons, stock heads ported with bigger springs (dont remember the spec) the cam is an erson 480 lift 292 duration.
it has an edelbrock victor intake and a holley 650 double pump.

i know the cam is alittle big for my setup. i would like to raise the compression ratio. my question is: should i change pistons and keep my heads? change pistons and heads? or just put a set of edelbrock performer aluminum heads on?

i would like to have a compression ratio of around 10.5

what do you think? kinda new to this, so any info would help.

all in all, what i want to do is increase power. but id like to keep the cam i have.

thanks.
 
IMO If you have stock 360 1.88 intake valves I would look @ swapping to 2.02s as well as higher compression pistons.
 
ok, so edelbrock aluminum heads and flat top pistons? what piostons do you recomend?


itll take awhile to save the dough for all the parts but right now i just want to have an idea what i want.
 
Flat top pistons with RHS or eddy heads your choice (I'm using eddy heads on my 340 , it sucks because I was gonna use my x heads which were upgraded and rebuilt but can't use them).
 
If you're on a budget I would zero deck the block and run magnum heads with pistons. You'd need AMC lifters and maybe custom pushrods. You'd run higher valve lift instantly with the 1.6 rockers, better head oiling, bigger valves. Of course, you'd need an intake or find a machinist to drill the heads to accept an LA intake.
 
THE STEVE said:
ok, so edelbrock aluminum heads and flat top pistons? what piostons do you recomend?


itll take awhile to save the dough for all the parts but right now i just want to have an idea what i want.
Click to expand...

I used Ross racing pistons in my motor they are forged alum
 
T56MaxTorq said:
If you're on a budget I would zero deck the block and run magnum heads with pistons. You'd need AMC lifters and maybe custom pushrods. You'd run higher valve lift instantly with the 1.6 rockers, better head oiling, bigger valves. Of course, you'd need an intake or find a machinist to drill the heads to accept an LA intake.
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come to think of it.. i do have a set of magnums laying around. i dont know the specs on them. they are out of a 99 dodge 2500. would it be worth it to put them on? would it bring the compression ratio up? should i just wait and spend the money on aluminum heads?
 
Put the 340 cam in it. It will haul ***.
 
id like to keep the cam i got. my goal now its to get more air in/out and have a higher compression ratio. im just aiming for 10-10.5, id like to still drive it on premium
 
The magnum heads have smaller chambers so yes they will increase compression along with the zero deck. The compression ratio is up to you with your piston choice. A step dish piston would net you roughly 9.3:1, more if you shave the heads a bit. Which would be nice with iron heads.
 
Most likely, yes. Your machinist should take into consideration how much the block was decked and how much was shaved off the heads to get your desired compression ratio and then shave the intake side of the heads or the intake itself.
 
Use a new set of rhs heads.
They have a closed chamber design to boost your compression and will handle the cam that's in your engine as far as the valve springs go.
You could bowl port them and go to a 2.02 valve if you wanted to.
They come stock with a 1.94 /1.60 set of valves.

Sounds like you want to go faster???
Raising your compression is a great idea but so is making the hole cars drive line work together.

What converter and gear do you have in it????
 
IMO, if you're on a budget, and want to start going fast now, use what you've already got. It sounds like you've already got a solid bottom end. I'd take the magnum heads into a machinest and have them rebuilt, milled, ported, polished, and drilled to accept you're existing manifold. That way all you have to buy is lifters and pushrods.
You will get a SERIOUS increase in power, and spend less than you would on a set of new heads. The other big bonus is that you're car will only be down for a day because you won't need to tear into it until the heads get back from the shop and you have all the nescessary parts.
Don't forget all the extra costs aside from just the cool parts. You're gonna need a head gasket set, oil, and antifreeze at a minimum. When I swap heads, I usually to a full tune up and oil change at the same time (It seams cheesy to me to put old plugs in new heads, or new oil into an old filter). It can be done cheaper for sure, but ,my experience has been that changing heads for me usually costs a couple hundred bucks in tune up, oil,antifreeze, filters, gaskets, and misc. supplies.
 
thanks for all the info. im familiar with engine building. its just the mopar specific details that i want to make sure about. ill probably use the magnums. i can do all the machine work at work. i ve built a few engines but im still new to performance. the stall im running is a 2200 b&m. the gears right now are 3.55s. id also like to go to a lower gear. maybe 3.90s or 4.10s. i also have larger tires for the rear to compensate alittle. the intake i have is a victor single plane. im on a college budget so id like to use as much as i got. theres no way i can afford to drop $1500 on a set of heads. the magnums i got for free and they are on a running engine (has a knock tho) so id really like to use those.

thanks
 
THE STEVE said:
id like to keep the cam i got. my goal now its to get more air in/out and have a higher compression ratio. im just aiming for 10-10.5, id like to still drive it on premium
Click to expand...

Doing what I recommended is the cheapest, easiest method of "raising" the compression. That mammoth camshaft you have in it now is bleeding off tons of cylinder pressure. Cylinder pressure that 8.2:1 motor ain't got to begin with. It is probably more like an honest 7.6:1 like all the rest were. By installing the 340 camshaft, you will make the cylinder pressure skyrocket, essentially raising compression. I bet in a situation like yours, it would not be impossible to add as much as 30-50 HP with just a simple camshaft change. Because the camshaft you have is so exponentially mismatched to the rest of your engine, the difference would be astounding. Certainly cheaper than changing out the pistons......and would also actually make it worth the extra money to run premium. Because then you'd have the cylinder pressure to probably justify it.
 
Don't mention it. I only persevered because it is the most cost effective option.
 
I hate advertised duration. Do you have the cam card specs?? I agree, 292 sounds extreame for the rest of the setup.
 
I think the Erson is a 292/.449 with 214° @ .050 on a 112 LSA. It's not a bad cam if that's what was used. They don't have the larger 292s with 240+ @ .050 type profiles. I think if it was me I'd either leave it as it is, and plan to upgrade (rebuild) the thing in the future, or do the rebuild now and expect to re-use the rods, crank, block, heads, and tin. You need pistons to get any real compression, and with them comes the "might as wells" that will end up making you rebuild it anyway... Just my $.02
 
If the camshaft has 214 duration (which sounds about right with .449 lift) I would seriously consider just adding your magnum heads and zero deck the block and take advantage of those bigger valves and quench design. Your cam produces excellent low end torque and works with your stall speed, keep it. Really, how often do you see over 5500 rpm? Along with an intake (eddy air gap or simular), new valve springs, and pushrods, you should look into headers if you don't already have them. Mag heads flow worse than some la heads. Although you can easily gain a few cfm at home by cleaning the bowl and port of the heads.
 
T56MaxTorq said:
If the camshaft has 214 duration (which sounds about right with .449 lift) I would seriously consider just adding your magnum heads and zero deck the block and take advantage of those bigger valves and quench design. Your cam produces excellent low end torque and works with your stall speed, keep it. Really, how often do you see over 5500 rpm? Along with an intake (eddy air gap or simular), new valve springs, and pushrods, you should look into headers if you don't already have them. Mag heads flow worse than some la heads. Although you can easily gain a few cfm at home by cleaning the bowl and port of the heads.
Click to expand...

i figured i would clean the bowl and gasket match the heads while i was in there.

i couldve swore that the spec was 292. but i could be wrong, it was 4 or so years ago.

i do have headers, they are flowtechs. later on ill get something better but they work for now. i think right now ill swap the mag heads on and see how it runs. then later consider a cam swap. after college i plan on buiding a 408 stroker. i was just looking for the making more power with what i got now. thanks guys
 
If the cam was advertised with .480 lift its got to be the 230 duration @.050 version,just like the lunati braketmaster 292 .480 which are both very similar to a comp 280-BUT,I believe that was a chevy grind only so it probably is the 214 @.050 .449 lift.
 
If the block doesn't get to see a machine shop..measure how deep the pistons are in the hole and compensate to achieve your desired compression ratio and a .040-.060 quench (piston to cylinder head clearance) with head gasket thickness.
 
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