Big Block team AASSSEEEMMMBBLLLEEE! (have a 454 performance question)

[86Peter454]

So im looking at what im wanting to do to build my 454. it will be a while before im ready to build it but im one of those people who plans out what i want to do so i can dream about it for a while.

anyway the problem im having is figuring out how im going to get the compression i want.

the 454 i have is from a 70s truck and has like 8 or 8.5:1 cr. i would like around 9.5:1 no higher than 10 no less than 9.

the heads im wanting to use have a 110cc combustion chamber (they are edlebrock heads. im open to others but i want them to be aluminum)

i would also like to do this without doing any machine work. as in id like to stay with 4.250" bore if possible and no decking the block if i dont have to. though am willing to mill heads if i need to.

im just having trouble finding pistons that will bring my compression up that high. ive found some that claim they are 9.5:1 with 110cc heads but when i put the dome height and comp height into compression calculators they say they are like 8.5:1. as far as i can tell that the piston manufacturers dont add in the head gasket thickness or the fact that most of the pistons comp heights put them .020" in the hole.

anyone have any ideas on how to get to that compression with .020 in the hole and 0.39 head gasket? suggestions on piston brand or anything? ive seen not to go over .150" dome but i need like .500 dome to get to the comp im looking for.

any help is much appreciated.

 

[4WDKC]

Are you set on using the edelbrock heads?

 

[shiftpro]

Why not deck the block? It's not a big extra cost and with a bbc I feel it's an absolute. Just like grooving those lifter bores.
This imo is generally where engines lose massive efficiency.
If you do decide to deck it down, do that last. After the block is bored or honed whatever, clean it up just enough to install crank and one piston to measure where the deck height is.
I prefer to install 2 psitons, #1 and #8. Then if there is any taper from one side to the next it will be obvious and a good machinist will know exactly what to do. I'm pretty sure that decking would just deal with this issue anyway, as they use the crank center line to line up for shaving down the decks.

 

[86Peter454]

Why not deck the block? It's not a big extra cost and with a bbc I feel it's an absolute. Just like grooving those lifter bores.
This imo is generally where engines lose massive efficiency.
If you do decide to deck it down, do that last. After the block is bored or honed whatever, clean it up just enough to install crank and one piston to measure where the deck height is.
I prefer to install 2 psitons, #1 and #8. Then if there is any taper from one side to the next it will be obvious and a good machinist will know exactly what to do. I'm pretty sure that decking would just deal with this issue anyway, as they use the crank center line to line up for shaving down the decks.

main reason is trying to keep from pulling the engine. im not 100% against it if its a must have. but trying to keep it cheap and in the truck. planned to just quick hone on it with a bubble hone then new pistons and rings if thats what i need to get compression up. if i need to deck it i will. is it no problem decking them .020" to get pistons setting at 0? or is there a certain amount i should not deck off of it?

Are you set on using the edelbrock heads?

not 100%. im open to other so long as they are aluminum and affordable.

horsepower goals are very mild like 500-550 so im not looking to put a lot of money or work into it. (like i thought about 496 and building the piss out of it but then i was like. i just want a mild amount of power so it really isnt worth it.)

 

[shiftpro]

Well considering the amount of work you're looking at, it's not much more to pull the mill out and do it properly.
Leaving the block in place and honing the cylinders is possible but to me that's more like an emergency repair.
Your brake booster will be in the way to do a proper hone job on #7. And you will never get all the grit and grime out either.
If you're going to spring for new pistons, you really should check all the cylinders for taper. Again, not much more to hone up
to the next oversize piston.
And maybe you have a bad crank journal...? Adding more power and compression to the top end will only help finish off a worn bottom end.
So don't get a boob job if you have a saggy baggy ass.
Back to the possibility of a bad crank journal... if you have to grind the crank... not much more for a full stroker kit you know.
And a 496 is umm, another animal!

Most if not all cast iron BBC can use .020 off the deck at the least.

 

[86Peter454]

Well considering the amount of work you're looking at, it's not much more to pull the mill out and do it properly.
Leaving the block in place and honing the cylinders is possible but to me that's more like an emergency repair.
Your brake booster will be in the way to do a proper hone job on #7. And you will never get all the grit and grime out either.
If you're going to spring for new pistons, you really should check all the cylinders for taper. Again, not much more to hone up
to the next oversize piston.
And maybe you have a bad crank journal...? Adding more power and compression to the top end will only help finish off a worn bottom end.
So don't get a boob job if you have a saggy baggy ass.
Back to the possibility of a bad crank journal... if you have to grind the crank... not much more for a full stroker kit you know.
And a 496 is umm, another animal!

Most if not all cast iron BBC can use .020 off the deck at the least.

well really if im going to pull the engine ill likely to a 496. if im gonna get it bored 30 over may well do 60 and just stroke it.

thanks for the info. got a head you like that isnt AFR? lol they are to rich for me.

 

[OkieFishMan]

As for the heads, no way would I spend $1500 for Eddy heads when I could spend $2200 and have AFR heads. The AFR 265 heads are badass on 454 or a street 489/496.

As to the stroking it, do it. No replacement for displacement. If you have to grind the crank you can kick in $300 and gain 30 cubes. That's cheap power right there.

On the overbore, keep it .030 and leave some meat in the cylinder walls. Helps with engine cooling a bit too.

If you want to go cheap, just go back with some oval port heads with the stroker kit and enjoy a level of torque most only dream about. Stock heads will still pull hard as hell to about 5,000 rpm. That's plenty to have a hell of a good time.

 

[Honky Kong jr]

As for the heads, no way would I spend $1500 for Eddy heads when I could spend $2200 and have AFR heads. The AFR 265 heads are badass on 454 or a street 489/496.

As to the stroking it, do it. No replacement for displacement. If you have to grind the crank you can kick in $300 and gain 30 cubes. That's cheap power right there.

On the overbore, keep it .030 and leave some meat in the cylinder walls. Helps with engine cooling a bit too.

If you want to go cheap, just go back with some oval port heads with the stroker kit and enjoy a level of torque most only dream about. Stock heads will still pull hard as hell to about 5,000 rpm. That's plenty to have a hell of a good time.

Well said. Damn it I tried to stay out of this lol

 

[shiftpro]

I'm happy with a ported 781 head. Larger exhaust valve and open the bowls, especially that restrictive exhaust side.
I don't have any experience with aftermarket heads so sorry nothing to say about that.

 

[86Peter454]

i think i want to go aftermarket on heads. based on how much it cost to get 1 aluminum head ported (honda engine) 2 iron heads will cost just as much to buy them get work done to them to make them good as it would to get some aluminum after market heads.

looking into brodix right now just to see what they are like and they seem to be pretty good and affordable. anyone have words to say about them?

i know AFR would be ideal but again too spendy and with my light goals just not necessary.

 

[Honky Kong jr]

Run a good set of fast big ovals and use the money from the aluminum heads to go towards a roller valve train. Cam, retro lifters, rockers and proper springs. Don’t get huffy @shiftpro lol

 

[74 Shortbed]

Instead of spending a bunch of money on high dollar ****, why not spend time on making the engine efficient which would make it about as good without all that high dollar fancy stuff, one example= piston .020 down in the hole is HP down the crapper no matter what heads and cam you use, zero deck the block and get the squish area as tight as possible, if the compression is a tad high, there are ways to drop it and make things more efficient again at the same time. A note on aluminum heads, nice to save weight but aluminum dissipates heat, iron holds heat which in turn makes power, spend a few hours on a set of 781's, right cam and induction for the street and you'll have enough torque to break all the parts you want right off idle with just a 468, and the best part you won't spend a ton of money...

 

[4WDKC]

horsepower goals are very mild like 500-550 so im not looking to put a lot of money or work into it. (like i thought about 496 and building the piss out of it but then i was like. i just want a mild amount of power so it really isnt worth it.)

you can pick up the 96-01 454 vortec iron heads that feature 99cc chambers, bigger ports than the peanut but, smaller than the oval ports for $250 on craigslist. This will up the compression provide better flow and come in under budget. You dont want to pull the engine but you are talking about replacing the pistons? Your goals are possible with these heads, heres just a quick idea of the ballpark you could be in http://www.superchevy.com/how-to/en...power-on-a-junkyard-454-with-simple-cam-swap/

 

[QBuff02]

X2 on oval port reworked heads. The trouble I always see is people want to throw the biggest this, the baddest that, the largest one onto something.. Not that it's always entirely bad! But the reality is, look at where you do 75-90% of your driving.. and Keep in mind, looking at the flow numbers of a head and x's it by 2 is usually a pretty good indicator of the horsepower they'll support. But that's in a Maxed out, Ultra high efficiency World. And the only way to harness big flow numbers and the like is to turn big rpm's with a way high lift cam (as a rule) and for most of what we do with these things that's just not the case. In my opinion, if I'm going to do the majority of my driving in a 1,500-5,000rpm range, I'm going to build my engine accordingly. I get the weight savings side of things from aluminum heads, but if the majority of your driving is "street" oriented, build a torque monster with a matched setup. the right head/cam/compression/intake combo can be the worlds difference between "she sounds mean and runs pretty good' and "oh my god my eyeballs just kissed the back of my skull and there's nothing left of the tires".. I'd save the money on the high dollar heads and build somewhere between the stock 454 and 496 with zero deck height, massaged factory heads a streetable c.r. and the right valve train that can feed it the charge.

 

[QBuff02]

main reason is trying to keep from pulling the engine. im not 100% against it if its a must have. but trying to keep it cheap and in the truck. planned to just quick hone on it with a bubble hone then new pistons and rings if thats what i need to get compression up. if i need to deck it i will. is it no problem decking them .020" to get pistons setting at 0? or is there a certain amount i should not deck off of it?
not 100%. im open to other so long as they are aluminum and affordable.

horsepower goals are very mild like 500-550 so im not looking to put a lot of money or work into it. (like i thought about 496 and building the piss out of it but then i was like. i just want a mild amount of power so it really isnt worth it.)

Heck, if 500-550 horsepower is your goal, you could do that with a set of factory peanut port heads!