What aluminum heads on gen 1 sbc?

[Guest terraview]

Hello all,

 

What heads are you using on your small blocks?

I've got a new gm crate motor, but I'd rather put some aluminum heads

on it before I install it.

 

Are 200cc heads too big on 2500lb street cars?

 

patrick

[jt1]

Lots of choices on heads. Edelbrock, Dart, Brodix, Canfield, Trickflow, and the GM heads. It really comes down to what you want what the budget allows. 200's are fine on a street car as long as the rest of the combo supports them. I'm running 195 Canfields with a light cleanup, makes for a fairly quick motor.

 

Determine your budget and time frame, then choose parts.

 

John

[Guest TeamNissan]

lsx heads are alum no?

 

http://forums.hybridz.org/showthread.php?t=128137

[Hey_Allen]

When I was shopping for some replacement heads for my 1st gen SBC, I ended up getting a set of Summit branded heads.

 

In the size I got, (and in cast iron, not aluminum) they were just small intake runner versions of the Dart Iron Eagle heads.

 

I don't know if they offer the aluminum versions, but if you're not looking for peak HP, and a little better torque curve for daily driving, you might look at the Summit house branded offerings.

[grumpyvette]

post the rest of your combo, displacement, cam,intake, cpr,etc.

including the trans used, rear gear ratio and stall speed if its a auto trans

we can assist you in sellecting a decent head to match the combo....IF you don,t have a clue, read thru these as a guide

 

http://www.rustpuppy.org/chp/Welcome.html

 

http://airflowresearch.com/articles/article031/A-P1.htm

 

http://www.chevyhiperformance.com/techarticles/148_0306_chevrolet_406_big_block_torque/index.html

 

http://www.ryanscarpage.50megs.com/combos1.html

 

http://www.chevytalk.org/fusionbb/showtopic.php?tid/131229/

 

http://airflowresearch.com/articles/article085/A-P1.htm

 

http://www.chevytalk.org/fusionbb/showtopic.php?tid/142298/

 

a great deal of your engines power potential lies in the volume of airflow you can pass thru the cylinders EFFICIENTLY,and the pressure curve above the piston that results from burning that mix in as controlled manor, and the rpm range at which it can be done effectively

think about this a cam does nothing much but control the timing and lift of the valve in the ports, a valve is basically a door to the cylinder and an intake is basically the hall way to that door, it doesn,t matter all that much if the hall way is just slightly or much bigger than the door and if the door opens 3/4 or 7/8the of the way if the door and enterance way immediately infront of that door, (the cylinder head port and valve) is so small its restricting the flow into the cylinder even if its fully opened

intake port and intake runner flow should match or slightly exceed the heads max port flow and cross sectional area at the MAX POTENTIAL VALVE LIFT

having an intake that can flow 270cfm and heads that flow less than 200cfm is far from ideal, and no matter how high/long the valves open it won,t significantly increase the cylinder volumetric efficiency before you find the dropping effective compression ratio is becoming a restriction as the durration increases, and that as the rpms increase the head flow restriction becomes a critical barrier to filling the cylinders

 

http://www.rbracing-rsr.com/runnertorquecalc.html

 

http://victorylibrary.com/mopar/intake-tech.htm

 

http://www.dw1977.cz28.com/photo2.html

 

http://home.earthlink.net/~hennad/results.html

 

 

here’s a chart FROM THE BOOK,HOW TO BUILD BIG-INCH CHEVY SMALL BLOCKS with some common cross sectional port sizes

(measured at the smallest part of the ports)

...........................sq inches........port cc

edelbrock performer rpm ....1.43.............170

vortec......................1.66.............170

tfs195......................1.93.............195

afr 180.....................1.93.............180

afr 195.....................1.98.............195

afr 210.....................2.05.............210

dart pro 200................2.06.............200

dart pro 215................2.14.............215

brodix track 1 .............2.30.............221

dart pro 1 230..............2.40.............230

edelbrock 23 high port .....2.53.............238

edelbrock 18 deg............2.71.............266

tfs 18 deg..................2.80.............250

 

Potential HP based on Airflow (Hot Rod, Jun '99, p74):

Airflow at 28" of water x 0.257 x number of cylinders = potential HP

or required airflow based on HP:

HP / 0.257 / cylinders = required airflow

 

http://www.tmossporting.com/tabid/1805/Default.aspx

 

 

theres only about a 3% increase in CROSS SECTIONAL AREA between the two differant heads , even without a supercharger its not a huge change in low rpm tq or responsiveness,in fact its generally almost not noticable as its about a 200 rpm shift in the tq curve,and a supercharger easily more than compensates, infact its easily able to increase the volume significantly even at low rpms

 

 

ITS A COMON MISCONCEPTION, ITS NOT the port area at the enterance , you need to use in the calcs, ITS the MINIMAL port cross section at the SMALLEST point in the port, usually near the pushrod area.

LIKE a funnel, its not the largest part of the opening but the smallest thats the restriction to flow

 

use these to measure

 

then keep in mind that normal ports flow under negative pressure while a supercharger produces at least minimal possitive flow at low rpms

[Guest terraview]

GMPP short block (basically 350/290 without heads). L79 hyd flat tappet

New style performer with 600 afb but after it is broken in will be replaced

with holley 950 mpfi and megasquirt I have already built. Unilite distributor.

Small tube full length headers.

 

3.08 gears wide ratio 4spd

Street and twisties car, not 1/4 mile, so flexibility is fairly important.

 

I have a set of dart pro 1 64cc heads(200cc, pre platinum) that I cleaned up but never used.

The only gm heads I have are some old 327 station wagon heads so if

the darts don't work I'll buy new heads but I would rather spend the money

elsewhere if possible.

I am certainly open to camshaft suggestions. CR should be about 9 to 1

with the 64cc heads.

 

I've been thinking the L79 with 1.6 rockers and the decent springs on the

darts might give me nearly 6k to play with(?)

 

thanks again

[Kevin Shasteen]

Is your 4spd an automatic or standard trans? If standard, which one? If it is an automatic, which one?

 

If flexability is a requirement then you need a broad torque curve. With an SCR of 9.0:1, I would keep your Aluminum Heads in the 185 cc and nothing bigger for the 350 displacement.

 

Again, if flexibility (broad turque curve) is your desire; any cam in the 260 duration cam or a 270 duration cam. Either duration cam would need a 112 LSA and .450" to .475" will make for a very sensible well mannered street engine on 89 Octane pump gas. That is only around 36 degrees of overlap with the 260 cam and 46 degrees overlap w/the 270 cam; which is a very minimal amount of overlap as far as modern performance engines go.

 

If you are stuck on the 9.0:1 SCR, the 260 cam would be best for lower octane pump fuel. If you want to use the 200 cc Darts then you will need to consider a higher SCR than 9.0:1 or volumetric efficiency will suffer.

 

Can I ask why you have chosen 9.0:1 SCR? If you want a peppy street engine and plan on using aluminum heads, why not go a little higher to benefit from the aluminum; say in the 9.5:1. At the very least consider 9.25:1 SCR.

 

As far as which heads to purchase, any of the top brands that jt1 listed should work fine. They are the brands that flow the best. If you want to know what your paper engine will put out simply read the articles grumpy posted and follow their instructions.

 

With flexibility in mind; keep your engine components mild as well. You really cant go wrong w/any of the top brand aluminum 185 cc heads, the 260 duration cam w/112 LSA and .470" lift, if you are certain about keeping w/the 9.0:1 SCR, then these mild parameters should work great for you.

 

Are you looking for a mild peppy street engine or are you looking for an H/O street/strip engine?

 

Are you really wanting to rev to 6k and when you say "flexible", exactly how flexible are your wanting it to be? Do you want a choppy engine, are you wanting to run on lower octane fuel or are you planning on using higher pump gas 92 or 93 octane fuel?

 

Kevin,

(Yea,Still an Inliner)

[Guest terraview]

Hi Kevin,

forgive me but this is,umm, well, not exactly a datsun. The transmission is

a 4sp porsche 930 (there just are not that many forums to discuss small

rear drive cars with 5 or 6 liter V8s around and you folk seem pretty

switched on)

 

The 9 to 1 is what I come up with for my 64cc heads, possibly closer to

9.5 if I use felpro .015 head gaskets, more if I skim it.

 

I talked to Comp cams today and they suggested

(@ .050) 230 236

0.490 lift

108 lobe sep

advanced 2 degrees

ground on XE lobes

 

This is a toy street car that gets autocrossed every now and then. Mostly

I just drive around and grin. I am limited to 91 octane around here.

Flexibility to me is usable in traffic and a wide enough power band to

be able to drive a fairly tight canyon road (I live in the sierra nevadas

and cannot leave home without driving a tight canyon road) in one or

two gears keeping in mind the gears are very widely spaced in this box.

If I can get a clean power band from 2500 to near 6k it would probably

work just fine.

I have several hours in these dart heads that were going on a bigger

motor that never happened so since I have them I am trying to figure

out if they can be made to work on this car instead....

 

 

Is your 4spd an automatic or standard trans? If standard, which one? If it is an automatic, which one?

 

If flexability is a requirement then you need a broad torque curve. With an SCR of 9.0:1, I would keep your Aluminum Heads in the 185 cc and nothing bigger for the 350 displacement.

 

Again, if flexibility (broad turque curve) is your desire; any cam in the 260 duration cam or a 270 duration cam. Either duration cam would need a 112 LSA and .450" to .475" will make for a very sensible well mannered street engine on 89 Octane pump gas. That is only around 36 degrees of overlap with the 260 cam and 46 degrees overlap w/the 270 cam; which is a very minimal amount of overlap as far as modern performance engines go.

 

If you are stuck on the 9.0:1 SCR, the 260 cam would be best for lower octane pump fuel. If you want to use the 200 cc Darts then you will need to consider a higher SCR than 9.0:1 or volumetric efficiency will suffer.

 

Can I ask why you have chosen 9.0:1 SCR? If you want a peppy street engine and plan on using aluminum heads, why not go a little higher to benefit from the aluminum; say in the 9.5:1. At the very least consider 9.25:1 SCR.

 

As far as which heads to purchase, any of the top brands that jt1 listed should work fine. They are the brands that flow the best. If you want to know what your paper engine will put out simply read the articles grumpy posted and follow their instructions.

 

With flexibility in mind; keep your engine components mild as well. You really cant go wrong w/any of the top brand aluminum 185 cc heads, the 260 duration cam w/112 LSA and .470" lift, if you are certain about keeping w/the 9.0:1 SCR, then these mild parameters should work great for you.

 

Are you looking for a mild peppy street engine or are you looking for an H/O street/strip engine?

 

Are you really wanting to rev to 6k and when you say "flexible", exactly how flexible are your wanting it to be? Do you want a choppy engine, are you wanting to run on lower octane fuel or are you planning on using higher pump gas 92 or 93 octane fuel?

 

Kevin,

(Yea,Still an Inliner)

[jt1]

Ultima????

 

Post up some pics!!!!!

 

If it's a rear engine car, I would use what I had, ie the darts. Skim them to true them up, use a steel shim head gasket to bump the comp some, and let it rip.

 

You can tighten the ratios in a 930 trans, but like anything Pcar, it's pricey.

 

John

[Zfan1]

Whats the octane levels in your neck of the woods. Keep that in mind when choosing heads if the octane is 90-91 for super I would keep it in the 9.0-9.5 arena.

 

Maybe with a set of aluminum heads you could go 10.0 but I sure wouldn't go any higher. In Texas we still have 93 octane and I have approx. 11.0 to 1 compression but run only 32 degree's of total timing and would be screwed if they drop the octane levels a few points.

 

Oh, and my vote is for AFR heads:burnout:

[DavyZ]

If you are going to be driving in the Sierra Nevada mountains, I hope your engine is boosted. I lived in Tahoe for years and every car seemed like it had half the motor it did just due to the altitude. My vote is for AFR heads and EFI with boost Can I spend more of your money?

 

Davy

[Kevin Shasteen]

I have to agree about the pictures thing, if you have them we need them; lots of them!

 

Kevin,

(Yea,Still an Inliner)

[Guest terraview]

No not an Ultima

It's a 914. I had the ring and pinion flipped in the 930 box.

The 327 is a bit worn out so I bought a gmpp crate motor to

replace it. And since I had the dart heads from another project that

I sold, I figured I could save 50lbs and bolt them on a new short block.

 

Don't have many pictures on this 'puter, but here's the 930 and cable

shifter and engine.

 

 

 

Ultima????

 

Post up some pics!!!!!

 

If it's a rear engine car, I would use what I had, ie the darts. Skim them to true them up, use a steel shim head gasket to bump the comp some, and let it rip.

 

You can tighten the ratios in a 930 trans, but like anything Pcar, it's pricey.

 

John

[Guest terraview]

I think I am going to spring for some new afr 180s. Thanks for all the

advice. (and anyone want a good deal on some unused dart pro 1 200cc

heads?)

 

patrick

[getZ]

I think I have those same heads you have. The Dart Pro 1 200cc's with a moderate cam 230 @.050 and .480 lift in the car has a nice broad torque band. My engine is a 383 with about 10:1 compression (also a 3.9 final gear ratio) My only complaint with those heads was the final finishing. It took a couple of hours into the head to clean up casting flashes, recheck thread holes and smooth the inside chamber. If I was to do it over again I would have gotten the 195 or 200 AFR's for another few bucks, but I'm happy with the power the heads are making. The car is light enough I was thinking of tightening up the convertor from a 2300 stall to around 2000. The dart heads can make bigger power with a raunchier cam if you don't want as much torque. Other then that those heads should work fine in a 350, unless you are worried about emissions.

[jt1]

V8 914's are max cool cars. A friend used to have one with a 302. It was a real terror, but stayed broke a lot. I'm pretty sure he was using a 901 trans.

 

What's this thing gonna weigh, 21-2200#? It's going to be a ball to drive, for sure.

 

John

[dr_hunt]

There is nothing wrong with 9:1 compression. I don't know why everyone always wants to have more compression. If you spring for the better heads the more efficient combustion chamber design will make more power than a 0.5 increase in compression IMHO!

[Pyro]

I think if you do the math more carefully you will find 64cc on that gm crate engine will have 9.3:1 cr. I helped a friend set one up and that what it was.

 

717cc/cylinder

64cc heads

flat tops (kind of, but had 10cc worth of voids)

9cc head gasket (0.040")

3cc piston under the deck 0.015

 

(717 + 64 + 10 + 9 + 3) / (64 + 10 + 9 + 3) = (717 + 86)/ 86 =9.34

 

I would avoid the xtreme series lobes. They are much more prone to go flat. Sure they make a little more power but the lift rates are overly aggressive for a flat tappet cam (IMO). I would use the compcam 260H high energy cam. Plus, you don't need a cam with more exhaust duration with those dart heads because they have a really good I/E flow ratio.