well that is the question(s) i have, it stalled in my last thread at that point. so if any one would please be so kind and explain this to me. thank you in advance.

 

Chamber size affects compression ratio, plug angle affects header fitment.

 

ok thank you, straight to the point...umm is it possably to dumb it down for stupid me? well i guess my question is actually what should i look for in a new set of heads? this is what the engine is at:
the basics:
70s truck 350
t-5
rear end: 3.42s

what i am doing:
ARP rod bolts installed and resized
bored next size over
hypereutectic pistons with about 12-16cc dish, or flat top (depends on heads im told)
block zero-decked

what i am putting on/in it:
fi induction, http://www.azspeed-marine.com/chvofuinsy.html
cam/lifters, http://store.summitracing.com/partde...2&autoview=sku
headers, http://store.summitracing.com/partde...5&autoview=sku
exhaust, having a machine shop build me a true dual 3in exhaust

im told i should stay around the 180-190cc intake and i would like alumumion heads, but iron would be ok it i dont hav a choice.

 

The "problem" with Vortec-style intakes is that you are limited to a Vortec style head. Only ones off the top of my head are GMPP, Edelbrock, and RHS. If you want aluminum, there's only GM fastburns, or Edel's E-Tec (which is the only Vortec head from Edel).

 

In theory, angled plugs help make a more efficient burn, making more power. In reality, if there is actually any improvement, its basically unnoticeable. Under 3hp. The problem with angle plugs, is they can severely limit which headers you can use, and sometimes even require oddball 'shorty' plugs.

Your best bet is to get a straight plug head, and avoid all the problems that angled plugs bring with them.

Chamber size dictates compression ratio... smaller = more compression. 64cc will have higher compression than a 72cc chamber (the piston is squeezing the same volume of gas into a smaller space with the smaller chambers).

The 'standard' chamber size for a performance small block is 64cc, thats the size most people will go with (they can vary by manufacturer from about 62cc to 67cc, but thats still close).

With a 350's 4" bore and a set of flat top pistons, a 64cc head will give you right around 10:1 compression ratio, which is just right for a strong street engine.

I would recommend staying under 200cc intake port size for a street driven 350. Most stock heads are between 160-170cc. Heads with intake port sizes between 180-200cc typically work very well on street engines, though 200cc is getting on the big side.

 

oooo ok...well i was at RHS and found a set, http://www.compperformancegroupstore...ry_Code=VORTEC, but i dont think its really what im looking for... so what makes it the fact that only vortec heads will work? is it like the angle of the intake? or something... and thank you every one for helping. i will look for some heads now that i have a better idea of what to look for, but if its ok i would like to post what i find and make sure that its the best bang for the buck.

 

Raised intake runners and a different number of intake bolts.

You've looked at the RHS heads already.

I think AFR also makes a set, but be ready for $$$ for them. GMPP makes a 185cc intake version, iron, for just over a grand per assembled set. The Fastburns (GMPP alum.) are 210cc intakes, and about 1300 per assembled set. The E-Tec's are available in both 170 and 200cc intake formats. Those will set you back just under 1200 and just over 1200, respectivly. Those are pretty much your primary choices.

Comes down to how badly you want aluminum and what you're willing to pay. All would be good head choices.

For cams, look for more of an EFI-type grind. Most generic off the shelf cams with 110 LSA are designed for use with carburetors. A grind with a wider LSA, like 112-114, will be easier on the tuning aspect.

 

dam, leave it to chevy to make things complacated. well i deffently cant afford a grand per head...so would this be the best deal then, http://www.compperformancegroupstore...ry_Code=VORTEC,? and iron cant be that bad for my build, can it? i mean iron is heavy but stronger right? trying to justify going with iron heads lol.
and isnt the cam i have selected good for this? wait what is LSA? and i dont suppose you got a recommend cam/lifter kit then?
and it appears i will be going with flat top pistons

 

actually scratch that head set, i think i like this one better and think i will go with these,http://store.summitracing.com/partde...5&autoview=sku, for a little above 1200 for a pair, i can swing that, barely.
so flat top pistions with this one right?
and as for the cam...i think i might be able to find one, maybe ill need help on the cam thing for sure.

 

Since you're getting a flat tappet cam, you need p/n 12410-01 (01 indicates heads set up for flatt tappet, 02 is hyd. roller).

There is nothing wrong with iron heads. People have run them for years, and will run them for years.

You can stick to the same lobe profiles. Comp offers an EFI friendly grind, just a wider LSA: http://store.summitracing.com/partde...4&autoview=sku

The nice thing about the RHS setup, getting them assembled, they already have all the recommended hardware that Comp suggests for that particular cam. I.e. That cam recommends 742-16 valve springs. Those RHS heads come with 742-16 springs.

 

well, which heads would you recommend? i only wanted aluminum heads bc im told they are the best and such...or will it be one of those personal options?

and if i do go with the aluminum heads i saw should i use that cam you found or how bout this one, http://store.summitracing.com/partde...0&autoview=sku,? again i suck at finding the right parts for my needs, lol?
also for the help
ps i dont have to have that kind of cam, thats just the one recommended, doesnt the cam depend on the head style?

 

Aluminum is lighter, can run a higher compression ratio (to make up for the fact that aluminum conducts heat away from the combustion chamber faster/better than iron). Aluminum is also more expensive. But, in theory, if you have the same intake port design, one aluminum, the other iron, they will flow similarly. Iron vs. aluminum, argument doesn't really make much of a difference, as long as the engine was planned out correctly.

Looking at both the RHS heads and the E-Tec 200's, I would be inclined to choose the RHS heads. They show better airflow; more air. Unfortunately, flow charts don't usually say all the specific details at which the head was flowbenched with, so exact cfm ratings can be a bit off from eachother. But the basic fact that RHS has better numbers all across the board remains the same. Airflow is the basis of horsepower. Can't make power if the engine can't breathe.

I would stick to Comp. They have some of the best lobe profiles. More aggressive ramp rates which opens the valves sooner. Again, back to the more air thing. Summits lobe profiles are outdated. Very very lazy ramp rates (valve gets to higher lift figures slower, stays at higher lift figures for a shorter amount of time).

 

ok, so even tho the etec has more airflow in, it doesnt nessacry flow as good as the iron 1? but thank you very much for helping me. now with these iron heads(decided to go with these) i need flat top pistions and flat tappet lifters correct? and i believe i have everything else in order...

 

The E-Tecs have larger intake ports than the RHS, but the RHS moves more air through the intake ports. When it comes to airflow, it's not how big, but how much. You will be happy with the RHS stuff. I've had personal experience with them a few times and had great results every time.

Yep, you'll need flat tops, which will yield you around 10:1 compression, which will do well.

Get a cam and lifter kit. I just linked you to the cam, but there is the CL kit (cam and lifter) available, which is what you will need.

Are you planning to zero deck the block?

 

ok
great
and ok, shouldnt b to hard for me to find the kit
and i was told i should, but when i went to price it the guy said i shouldnt worry bout it unless i am going to add a super charger, which i wont. but i think theres something else behind having it zero decked...so at this moment im open to suggestions.

 

http://store.summitracing.com/partde...4&autoview=sku this is the kit, these kits dont really come with anything do they.

 

Knowing the deck height is a big factor in getting an exact compression ratio. Most motors I do usually get decked for compression and quench reasons.

Taking into account everything that calculates compression ratio, all else being equal, if the only thing you changed was the deck (stock vs. zero'd), it comes out to be about .6 compression ratio differences. Most flat tops you'll look at in a kit have about 5 or 6cc's of valve relief, so you're looking at either 9.7ish or 10.3ish. I am getting these numbers with a 64cc combustion chamber, 4.100 x .040" head gasket, +030" bore, and stock stroke.

You would be just fine having the deck cut (if needed) to ensure flatness.

That's the CL kit, and yep, it's just the cam and lifters. You would still need a timing set and pushrods.

Edit, now that I think about it, I am fairly certain Comp offers cam/lifter/timing set kits.

 

ya push rods shouldnt be hard to get, and im thinkn bout getting a double roller chain
ya im keeping the crank, possable getting it turned, and i have a high flow oil pump...i think i have a complete engine now

 

http://www.flatlanderracing.com/compcams-sbc01e.html

Very last thing on that page, the SK12-268-4 kit. Cam, lifters, timing set, and assembly lube. Everything needed.

Look into Summit's engine kits. Pretty much everything required to redo a motor in a convenient box. From bearings to assembly lube, including pistons and rings.

 

what kind of timing chain is in the kit tho? i assume regular...but i would be afraid it would break so i was thinking a double roller chain, yay? na?

and i will look into the kit, as long as there is instructions i think i can do it after i get it back from the machine shop...actually i might need some help there to...

 

Should be Comp's 2100 Magnum double roller that's included.

Kit isn't that hard, really. It has more to do with the ability to put an engine together than anything else.

 

ok cool and i got to the genral area to search but which pistion materals would be good? and then the piston ring size, ect ect. and i actually do now how to put the thing together, lol its just getting the right parts that i have a hard time with

 

Hyper's would be fine. You're not planning juice or boost. Nothing radical as far as compression goes.

The correct piston rings would be supplied with the pistons.

EDIT- the only thing you would need to know before ordering the engine kit is if you need any undersized bearings. Quick trip to the machine shop would be able to tell you this.

Double edit: http://store.summitracing.com/egnsea...=KeywordSearch

That's the Fed. Mogul stuff. The first is the +030 with std mains and rods. The rest is various combinations of undersize bearings.

 

but theres different sizes and different numbers that im not totally sure about also isnt forged stronger? or am i getting it mixed up?, sorry.
and just checking but the heads im gona get, they do come with all the springs n valves androcker arms and such right? theres no pic of it so i cant see for myself.


edit: undersized bearings... umm?
double edit also, lol: ok that link is very helpful, bc once i now the size of the underbearing then i can pretty much get the right kit, correct?

 

hey your in michigan to! im in ypsi, lol sorry to keep you up so late with these questions.
and the rebuild kits do have the connecting rods correct?

 

Yes, forged is stronger, but also around twice as much. There's nothing radical enough about your engine build that screams forged pistons are required. You'll be fine with hypers.

The heads come with valves, springs, retainers, locks, guides, seals, rocker studs, and guideplates. You will need rocker arms seperately.

No con. rods. They are assuming you're just replacing the slugs, reusing the crank and rods. If you wanted stronger rods and/or crank, then you're getting into rotating assemblies.

Yea, I'm in GR. Not keeping me up, I'm working. Well, I call it multitasking.

 

ok, even at lets say 8ooo rpm? even tho my motor wont go that high...
ok just the rocker arms right? 1.6 good? or is there osmething special bought those?
and the rods would be cast iron i think, so thats strong.
and your working, well mutitasking!? at 3am! sounds like a good job lol.
when the block goes to the shop, they will check the crank and rods correct? make sure they are good and straight

 

Check your PM's.