Gibson

okay, before anyone says 'ohh, just put a 350 in it'...screw you guys, i already have a 50k mile 305 sitting in my car, this isnt a full rebuild.

1989 lb9 iroc, converted to carb.

going to port stock heads, and possibly have em skimmed to bring me from 9.3 to 9.5:1 compression ratio thinking 1.90/1.55 valves, the 5.3 lsx motors run that same size valve on the same size bore as the 305, and they run like ****'s. with a set of well ported heads with those valves, im thinking the comp cams 503 grind will put me in the power level i want. looking to shift at 6200 rpm. would this put me around 330ish crank hp? if its more than that, great, no such thing as too much power. the rest of the short block is gonna stay stock, no need to rebuild a 50k motor.

this car isnt a daily, more of a tool to teach me more about driving fast, a step up from my miata turned drift car if you will. fuel mileage and low end torque are not a concern, im used to having to shift all the time (my miata has 4.88 gears)

Night rider327

iTrader: (13)

You can't compare a LSX to a gen 1 sbc.
The LSx has a 12-13.5* valve angle or head angle where a gen 1 sbc has a 23* angle.

The diff in the angle is what helps the LSX engine heads flow so great.

FRMULA88

A fool and his money are quickly separated.

Damon

I wouldn't throw a bunch of money into 305 heads. Get a set of 350 Vortec heads, have them milled down a few thou, add a matching Vortec intake and you'll make a lot more power than mildly ported 305 heads.

305 heads have ~58cc chambers, but many are closer to 60cc if you measure them.

350 Vortec heads have 64cc chambers but in reality are closer to 62cc. So not much difference in compression in the real world. And the stock 1.94/1.50 valves will fit down the 305 bore no problem.

They will flow SO much better. Even if you lose a smidge of compression it won't matter- they'll still make more power everywhere. PLUS you get to use them over again on a 350 later. And they have some resale value where 305 heads have none, regardless of what you have done to them.

Gibson

if i could afford vortec crap, i would, but around here, vortec anything comands a premium cause all the rednecks just recently found out what vortec heads can do. im not throwing a bunch of money at em, im porting em myself, and have a friend helping me out with machine costs. the only real money spent will be on the valves. plus the 1.94 valves in the vortec heads will be shrouded by the cylinder wall. 1.90/1.55's wont be shrouded, and should help equal out the flow on the exhaust side of the head

and instead of calling me a fool, why not offer up some advice, instead of wasting bandwith on the server? back in the day, this website USED to be full of helpful people, but i guess they all moved on...pitty.

Night rider327

iTrader: (13)

You don't search around a lot do you? Not trying to talk down to you or talk you into another route but take a look

$250 obo core 350 vortec engine, knocking rod http://pittsburgh.craigslist.org/pts/4891312188.html Talk him down to $175 to 200.. Snag the heads, sell the roller cam 350 block for $150 (or heck rebuild it and swap it into your car)

2001 complete vortec chevy 350 motor with 160xxx miles $450 obo http://pittsburgh.craigslist.org/pts/4890540162.html Again, get it for $375-400, resell the short block for $300

That was from a very quick 90 sec. search..

2005Impalla

Being that the 305 lacks a little torque compared to a 350 I would do a mild cam and bolt ons. "Mild stuff though". High energy 260 cam, performer air gap Q-jet intake, tune a good Quadra jet carb to work with the set up, headers ect... I would install some lower rear gears and being that your talking about shifting I am going to assume its a 5 speed correct?

FRMULA88

A 4.00 bore Gen 1 SBC with good aftermarket 23 degree heads.

or

if you are really cheap find a complete junkyard LS engine
They make CARB conversion kits for the LS engines IF EFI is cost prohibitive. What you are paying for is the cylinder head technology..

Either choice will run circles around anything you try to do on a
POS 305 Chevy with outdated cylinder head design, no amount of home porting can fix poor design. I don't care if it has 50,000 , 5,000 or 150,000 miles it is simply poor choice when you have better options that will cost the same money. cams and beehive springs... all a waste of time and money on outdated cylinder heads

FRMULA88

Before you start a tread telling the 350 people to "screw off" you better know what you are talking about... You really have alot to learn, helpful and education are not the same.

You have no concept why the LS engine "runs like a ****"

You just assume because the bore is same as the gen1 305 SBC that there lies the secret to the LS engines success. You are clue-less my friend. See post #8... that is all the help you need and all the attention this post deserves. I was wrenching when you were crapping diapers...

AIN"T NOBOBY GOT TIME FOR THAT !

DeltaElite121

and this is exactly why these threads need to be locked right away.


Might want to leave those heads alone before you REALLY mess something up. Breaking out your dremel and going to town is NOT porting.

Gibson

of course headers and 3.45's are in the cards(already sitting in my garage), thats a given, we're talking about the engine itself here, not hte whole package

if i wanted a 350 or an ls, i would have bought a 4th gen of some sort for the same money as i paid for my car. i dont give a shlt what will run circles around me, i wanna see what I can build out of this stock motor. a 350 or lsx will blow the t5 sky high with my right foot, and i dont have the money to swap in a t56. agian, if i wanted these parts, i would have bought the car that came with em stock.

im telling the 350 people to screw off because i really dont feel the need to go out and buy a worn out 350, and spend a grand rebuilding it when my engine has really good compression #'s and is #'s matching to the car (yes, that maters to me even though im devaluing it by changing things.) im not looking for something that makes massive amounts of torque at low rpm, i could care less about the 45 cubes im missing. im not assuminging the bore size is the secret to the 5.3 lsx is the secret, im using that as insinuation for my exhaust valve choosing as pretty much all stock SBC heads dont flow worth a **** on the exhaust side, minus swirl port heads, and they flow like crap on the intake side. instead of assuming that im a clueless fool, why dont you fwcking ask why im thinking these things, and actually be helpful, and not a douche nozzle who thinks that just because you have 9 billion posts means you know infinitely more than i.

ive done about 5 sets of heads and more intake manifolds than i can count, i learned the old school (very old school, think 1940's) way of doing it by hand with various types of hand files and stones, then moved up to the air tools, im not your idiot ******* ******ed incest freak who thinks a dremel and a couple sanding rolls will make me 68 extra hp. hell, i have a set of 088 big block heads sitting on my bench right now that im gonna start porting tomorrow

now, will someone helpful, not someone who says '350, lsx, vortec heads...you all can go suck on a giant rooster that starts with a C) please tell me about what i should expect out of what im planning on building? im going to build it anyway, regardless of what anyone says,i just want to know what to expect out of it. before anyone else says dont waste my money on those heads, ill have 200 into machine work, and 300 into the valves im getting from a good friend. sure, i could put differant heads and 350 and a monkey giving regis filban a bj in my car, but i want to see what i, me, myself, can build out of a 'junk' motor'. if our dont want to help me out in the way im asking, do not post or ill be a hostile *******.

Mystyk_Wynds

IMHO..
Whatever your going to do to your 305....Just make sure that its "transferable" to a 350....Should you ever decide to go that way...This way your Investment isn't totally lost and salable if need be.

Things I would stick to are basically the heads and valve train. Gains are going to be less incremental than a bigger bore (WE all know this), but by no means shouldn't you do it.

Should you get 300+ out of it, you will have a surprisingly competent motor.

Thing with the 305, is if you want greater power, your gonna have to turn more rpm.
Look into lighter rods and Lighter cranks. At least have the ability to turn higher, even if you rarely use it.

The intake will stop you from using higher rpms, so look into the LT1 or baby LT1 (262 intake (Caddilac, caprice, impala intakes)).

Heads, if your gonna stay low rpm, don't over look the vortecs...Ironic as they are the best bang for the buck.
Higher rpm, look into modding a set of LT1 heads or 083 heads.

If your shop is good, you may be able to take your irons and have the valves offset, move them away from the bore a few thousandths, and reangle them a few degrees 23 stock to like 21-18.

The rest, rockers, cams, studs etc is a given. 1.6 rollers are found on most lt1s, However if your not impartial to non self aligning, go with the LS series of 1.7 rockers (You don't need the girdles period - self aligning is a matter of awesome welding skills)
If your worried about the trunions...I'll give a few tips on that.

Do what you can and make 'er run like the dickens.

3rdgenmaro

iTrader: (9)

Depends on which rating you want to go by. I think 330 would be about right with a better set of heads, but if you are decent at porting, I think 300 would be a better guess. I would probably go with a smaller cam and a good dual plane (dont recall seeing if you mentioned the intake you have).


Prime example of why I hate some threads on here. You get threads like this that bait people in and those that just cant keep their mouth shut and not fan the fire. Sometimes its best to just let people do what they want to do regardless of what is better. Even easier to tell these people apart by how they respond to criticisim. This is one of those times.

FRMULA88

Unless you have a flow bench and actual data to back up your porting skills.
I would try to keep your attitude in check.

Little boys who use "crude talk" do not impress me.


ps... when you can DO THIS... versus typing smack talk on forum get back to me.



have fun

FRMULA88

My CNC ported cylinder heads flow over 390CFM, what about yours?

I don't 9 need billon posts..
ALL I NEED IS MY CAR TO DO THE TALKING FOR ME

douche nozzle... that's funny, but I left the school yard a long time ago.

if that is all you have then we are done here.

God bless you in all your endeavors.

Orr89RocZ

iTrader: (20)

To answer your question

If you were able to do the valves and light port bowl rework and flow around 220 cfm which would be good for those heads and valves, you should make 330 ish crank with a 503 cam.

Cam only may get you 300

Formula 305

6200 RPM on a stock LB9 bottom end, lol. Good luck with that one buddy. Keep dreaming and running your mouth, punk. Asking for advice and then going off with your trucker mouth are a real good way to make enemies around here. Classic case of more money than brains....

And the extra 45 C.I. isn't as much the key to why 350s are better and 305s are good boat anchors, but the key is that the larger bore lets the valves breath better, they aren't as shrouded by the cylinder wall. Maybe you should do your homework before you run your mouth.

And if you don't like the advise you get on this site you are more than welcome to leave.

Orr89RocZ

iTrader: (20)

The butthurt is real in this one lol

Formula 305

Also, you haven't mentioned any exhaust work. Without a full exhaust system any modifications to the motor will gain you... pretty much nothing. The factory exhausts on these cars flow about as well as trying to breath thru a stir stick.

dmccain

iTrader: (2)

Lost me at the "screw you guys" in the first sentence. Punk a%&* kid.

FRMULA88

yes the less than 4.0 bore on the 305 block combined with the 23 degree valve angle (standard for any gen 1 small block chevy head) is a poor combination for optimum performance.

All the porting in the world cannot correct the valve angle, and the small bore of the block limits the size of valves you can use with that combination of cylinder bore and cylinder head valve angle..

HENCE why the LS design with a 3.8 cylinder bore has cylinder heads with valves @ 12 degree angle to the combustion chamber "runs like a ****".
The revised valve geometry greatly improves the air flow of the heads while unshrouding the valves, despite the smaller bore size. The larger bore LS engines work on the same principle.

Just like the original OHV gen 1 SBC surpassed the flathead Ford (because of improved cylinder head flow / valve geometry = more HP & TQ and more efficient).

The problem is you can only use LS heads on an LS block.. not a big deal since the aftermarket makes plenty of heads for the 4.00 + bore Gen 1 SBC with altered valve geometry.. 18, 12, even 10 degrees ! but they cost more than OEM if you go the used LS engine route..

hey if you want to play and hone a craft there is nothing wrong with that.. porting is an art / science so good for you.
Just don't expect home ported heads based on 40+ year old design to outperform anything new from the factory or high-end aftermarket parts that are CNC ported. ALOT of R&D went into the LS and aftermarket.sorry but if you were that brilliant GM would have snatched you up already LOL..

Formula 305

Thanks, I learned something new today. When referencing the valve angle (23, 12, ect ect.) is this with respect to the cylinder center-line?

Orr89RocZ

iTrader: (20)

Aftermarket sbc 9-18 deg heads are usually large port large valve and really only good for 400+ inches up to 8000 rpm or more or smaller motors that turn 8500-10000 rpm. There are only few smaller port heads in the 18 deg range that could be used on street motors with success but still wouldnt put them on anything less than 4.125 bore and ideally 3.75 stroke or higher

Formula 305

Well I don't plan on reving my engine to 10K anytime soon, and I have a pair of 350 Vortec heads already that should suit my needs.

Or maybe I could take a trip to Pittsburgh... A pair of 350 Vortec heads would fetch a premium a week before race wars

FRMULA88

Obviously you have to plan your build accordingly.

mine is a max effort NA drag engine so I bought the best heads I could afford at the time.

I only need to rev to 6700-6900 to make max HP but I take it to 7200-7300 at the track (optimizing the shift point)

I have run it on the street without any ill effect, the only issue is 110 cost 8$ gallon LOL so by no means is this a daily driver.

FRMULA88

FRMULA88

with respect to the deck surface of the head.

here is great article to explain

http://www.trickflow.com/articles/18degree_hp/

Formula 305

Great info! Thanks

Gibson

i'd like to **** off as many mustang guys as possible.

i got a mazda miata to go from a 17 second car to a 15 second car with intake porting and removing the muffler and power steering. it ran dead even to my car when my car was completely stock, which ran 15.05 on dry rotted bfg's...spinning 150 feet out of the hole. the plan is a dual plane air gap style manifold.


excellent. thank you sir. thats goes exactly in like with my thoughts. i want around 300 at the wheels, so 330 at the crank is spot on

if you dont like my attitude, your more than welcome to leave my thread. go act important else where.

when i drop the motor back in, i have hooker 2460's, going to have a custom y pipe made. currently has 3" bullet race muffler where the cat was, 3" cutout behind that, ls1 2.75" exhaust with a flowmaster 80. not gonna argue with a free cat back system, and its not rotted out. with the cutout, it gained a fair amount of power, and the race mufler took out the 'gluggyness' that all sbc's seam to have, and it got rid of that flowmaster drone

the whole idea of playing with this 305 is practice. if i blow it up, ill build something bigger faster and stronger. thats how hot rodding is. if i wanted an lsx, i would have bought something with one in it. this is to improve my existing skils, develop new ones, and have fun with something every one seams to hate. you can get a good running 305 for less than $100 around my neck of the woods, where as a 350 i would consider serviceable is more like $3-400. if i wanted to work for a large corporation, i would have stayed with goodyear. i like knowing who's making money off my work and the freedoms that comes with working for small companies.



anyone else wanna bad mouth me and call me a punk @ss kid, ill gladly take that as a complement.

Mystyk_Wynds

Be weary of those who talk softly, for they carry a big stick.

As far as valve angles....Reality is this. if nothing else changes, just the valve angle, then what actually changes?
Most manufacturors change a SERIES of inputs, to get the effect they want. Combustion chamber design, Port angle, port entry angles, port geometry, shape, higher/lower; valve placement..These factors, if ANY are changed, WILL change the outcome.

As far as this article goes....I remember a saying..."Its the sum of ALL the parts"
http://www.trickflow.com/articles/18degree_hp/

-"boost the engine's compression ratio"

-"Trick Flow 18 degree head is 56cc versus the 64cc chamber"

-"In 18 degree heads, the valves are right on the cylinder bore centerline. The valves are also relocated to position the intake valve closer to the bore center, and the exhaust valve closer to the cylinder wall. This unshrouds the intake valve at maximum lift and allows the use of bigger valves."

-"The Trick Flow 18 degree heads are machined for 2.150 in./1.625 in. valves, and can accept intake valves up to 2.180 in."

-"18 degree heads have raised intake runners; the runners on the Trick Flow heads have floors raised 1.150 in. from the deck."

-"18 degree head's intake manifold mounting flange is angled at five degrees (standard is 10 degrees) to accommodate the raised intake runners. That requires a special 18 degree intake."

-"The 18 degree heads are also taller than their 23 degree cousins, and require longer valves and special head studs. Eighteen degree pistons with domes and valve reliefs matched to the combustion chamber shape and valve locations are needed. And then there's the big kicker--18 degree heads must use shaft mount, offset rocker arms and mechanical roller cams with offset lifters."

Don't claim that something is better, if all the variables are changed specifically to alter the outcome that is wanted. This would be considered an illusion.

For the record, what these head accomplish, are not much different than what '70-'90s' racers were orginally doing to their stock heads. They just put it into one neat lil package, that all.

Fast355

iTrader: (2)

You guys act like a 305 is built weaker than a 350 or something Stock rotating assembly of a 305 or 350 will survive intermittently to 6,500 rpm and beyond. The 312 in my Vette gets shifted at 6,500-6,800 rpm and has seen 7,000 rpm a few times. It is the production crank/rods from a 1983 G20 van granted it had a steel crank and "X" rods and .040" over cheap rebuilder. The hecho en mexico GM Goodwrench crate L31 in my Express van gets shifted at 6,200 rpm and has seen 6,500 rpm numerous times as well. Once you take care of the springs and valvetrain 6,500 rpm is not a problem even with a 2 bolt main and factory rod bolts.

ddeennis

I can look past the attitude, but I do question the whole story of spinning 150 feet out of the hole and still running 15.05, you better have some really high mph trap speeds for spinning that far to make up some time, on top of that anyone with any track time or experience just would not hang it all out to spin for 150 feet off the line no matter the tires/track. Specially when you say it was STOCK, so total b.s. on your part on spinning that far and having that time, sure maybe 5, 10, 15 feet but not 150 ft and still run a 15.05 STOCK....lol.

Now the whole 305 deal, here's a little back to back example if you will of a 1985 trans am.

tore a 1985 305 apart and cleaned it and put the original bearings and rings back in, did a slight bowl blend on the 305 heads and put those back together with factory seat with z28 springs and tossed the rotators, compression was around the 9.0 to 1 mark, no more then that at best and tossed in a 204/214 @ .050" cam flat tappet ( eddy performer cam), eddy performer intake, 600 vs holley carb, cheap 1 1/2" shorty headers open at the track, 10" jegs converter 2700-3000 stall, th350 tranny and 2.73 gears, about 250 bucks in the engine all together. the tranny and stall was installed because we knew a 350 would be dropped in soon, but wanted my boy to practice with a 305 at the track.

after about 3 outings to the track, car went from 15.80's @ 87 mph to 15.2@93mph with a 2.07 60 ft time with some timing and carb tuning.

With a 4.10 gear it would have ran low 14's easy no question about it, car had lots of pulling power to top end, but the hole shot was weak with the 2.73 gears, 2.07 60 ft is all it had really, some tuning was left maybe 2 tenths worth on the table in the engine.

So my son wanted to go quicker so we built a budget mind 350, total was just a tad over 900 bucks, new cheap pistons, rings and bearings and so forth.

350 bored to 355
10.2 to 1 compression 234/244@ .050" cam
well used vortec heads with a very slight bowl blend, still used the stock valves ad stock seats was not touched put back together with alexspring kit, cheap procomp air gap clone.

same carb and headers as 305, same tranny and gears. the car ran 13.59 @ 103 mph first outing with 2.06 60ft. having some traction issues spining off the line 5-10 ft with slicks.

Anyways with a few changes, long tube headers, roller tip rockers, .080" thick pushrods, 750 carb and 4.10 gears, some suspension parts to get the car to hook better, same car and engine ran 12.63 @ 108.41 mph 1.78 60ft hooks ok with maybe 1/2 turn of the tire off the line much better.

And the tuning is not done yet, this car should be in the 11's by the end of the summer with the carb dialed in and the timing, work on launch and few other mild changes.

you would be hard pressed to get a 305 to these times with basic bolt ons, the vortec heads are so much better then stock, I built the same engine with same everything but used older heads something like the 882 and it ran 13.2 at 103 mph, so the vortec heads have proven to be well worth it.

I have spent my life at the race track as much as possible and watched many cars go down the track, I have driven many as well and now my sons 85 TA showing him how to build and run down the track, for someone to spin 150 ft or more would have monster power, a little stock 305 would never.

Have the attitude all you want, just don't lie about things, your going to be called out on it, even the worst track days, traction isn't all that bad, specially for a stock 305 engine.

Even I can manage to get my blown bbc on down the track on regular street radials without blowing the tires off that far on a no prep track. And that wheeling about 700 hp at the crank and I'm being modest on that number.


hope this helps in some way.

Es_91rs

You do know this is just a forum and no ones opinions on here actually matter, right? You asked for other peoples input. Careful what you wish for...



Aside from that, I'll be honest. Having worked with a 305 5 speed third gen do NOT expect your trans to last very long with 300hp. Especially if you plan to shift above 4500 rpm or do any hard launches. The t5 was a fun and nice transmission before I started modding my car. It quickly gave up on my car after only 120,000 miles on it, and I ALWAYS shifted before 3500 - 4000 rpm. See the attached pictures to see what you'll be looking forward to if you don't take it easy with that trans. The t56 is well worth the investment, I promise. And no, upgrading the clutch and changing the fluid won't make it last longer. Mine blew about 6 months after getting a new clutch and full service.

As for the engine. Yes a 305 is fun, I thoroughly enjoy mine. However, if you're looking to use this car as a tool to drive fast muscle cars, that's not the engine for you without heavily modding it. An intake, cam, and head work are going to barely scratch the surface of what you want, especially on a motor that was only getting around 200 crank hp from the factory.

If you read the list of what I've done to my car, I've easily put $6,000 into the car after buying it. I will be the first to admit that with what I've done, everything other than modding the internals, I am no where near 300hp at the crank, let alone the wheels.

If you're concerned about the cost of the mods please enjoy the nice cruiser that you have now while you collect money and parts to make a real HP generator.

FRMULA88

[QUOTE
For the record, what these head accomplish, are not much different than what '70-'90s' racers were orginally doing to their stock heads. They just put it into one neat lil package, that all.[/QUOTE]



No racer can alter the cylinder head valve angle in their home garage.

A machine shop can't even do that...

You have no idea what you are talking about.

Fast355

iTrader: (2)

That intake and cam are about the absolute worst you could use in a 305 to be honest and that trans/converter/gear is **** poor as well.

A performer RPM intake with a 218/218 @ .050, .458/.458 cam on a 108* LSA advanced to a 104* ICL and 1 5/8" primary headers, and 3.73s would have really woken that 305 up. A pair of ported ZZ4 style L98 aluminum heads would have also been great on that 305. A good quality 10" converter setup to stall 3,000-3,400 rpm behind the 305s torque output rather than a healthy 350 would have also helped tremendously. That 305 should have been able to turn a 15.00 pretty much stock and would have run the low 13s, high 12s correctly built. An 85 350 built the same way as your 305 wouldn't have been nearly as quick as your 350 Vortec build.

Mystyk_Wynds

No racer can alter the cylinder head valve angle in their home garage.

A machine shop can't even do that...

You have no idea what you are talking about.[/QUOTE]


Just because you haven't done it, or because someone hasn't made it known that he did it..
Doesn't mean it can't be done.
Machine shops won't do it..And yes they actually can if they wanted to...Because the Buy it vs make it is helluva difference in cost.

(Simplest Method) Angle mill the head on the exhaust side.

FRMULA88

Angle milling the head on the exhaust side is not going to change the valves' angle relative to the deck surface of the block.

but go ahead and do that.. get back to us when your exhaust manifolds no longer fit

The 23 degree, 18 degree, etc refers to the valves' angle relative to the deck surface.

You simply cannot take 23 degree heads and make them 18s... IMPOSSIBLE. You have to change the angle of the valve seats, which also changes the location of the valve stem holes, push rod guide holes, etc, altering all this geometry you will hit water passages, etc which is why the aftermarket heads with altered valve angles are different castings.


But I digress, I encourage you prove the impossible is possible. Go to town with a die grinder and milling machine; you will wind up with a bunch of chips and a set of junk heads.

My advise to you is don't tread into waters you cannot traverse, keep your floaties on and stay on the shallow end or try reading up on the subject matter
to educate yourself, before posting ignorant comments and getting called out on them.

Mystyk_Wynds

First off I'm not gonna hijack a thread any farther beyond this. But just to prove a point.
However, if you want to understand how angle milling a cylinder head, can actually change the geometrics of a single point, relative to a fixed position...Then I would recommend relearning geometry.

This basic concept can actually be applied directly to the valve and its angle without altering the cylinder head deck surface...(But will require altering just about everything in relationship to it.)

If you want, just so you and others can understand, with or without math on exactely what and how it can be done. One being a hypothesis/theory, the other being proven.
But I digress, you most likely won't get 18deg, but you could get 22-20 mayhaps more if your creative.

Fast355

iTrader: (2)

You are missing the point, while angle milling would slightly change the shrouding of the bore, it will not change the angle at which the intake port bowl intersects the intake valve, which is where the flow comes from. For the most part the straighter the angle through the valve, the higher the flow and air changing direction causes turbulence and reduced flow.

Mystyk_Wynds

Fast355- my point was made in relation to this comment. Which any descent engine builder with knowledge of geometry knows is false.

Second, early I made my point or a statement about all variables being (changed) to prove a "wanted" outcome.

Just like this.... "X heads have X flow and can give X HP/TQ gains over stock heads....
**Disclaimer** Head where equipped with 2.05/1.70; 1.6 full roller rockers; cam was x/x dur, x/x lift; etc, etc etc."

See you can't really define the heads ability to create power, if all variables were changed to fit the wanted outcome.

Now in this article which explains better than what I can:
http://www.hotrod.com/how-to/engine/...ylinder-heads/

Int his is both pratical and very hidden piece of information...(Very commonly overlooked (helps solve some associated problems) and basically tells how to change valve angles..Without Angle Milling the head.)

Orr89RocZ

iTrader: (20)

Well obviously the whole head port is a system that has to work together. Valve angle is one aspect.

But the fact is the straighter the path of airflow to the cylinder the higher the velocity of the stream can be while staying out of choke flow. Air doesnt like to turn at high speeds. More potential for airflow when laying the valve over to those smaller angles, 18, 15, 13, 12, 9 etc. whole port changes to take advantage of what the angle gives you

FRMULA88

[QUOTE=Mystyk_Wynds;5900251]Fast355- my point was made in relation to this comment. Which any descent engine builder with knowledge of geometry knows is false.
QUOTE]

Extreme angle changes require more work, including moving the dowel pins, recutting the bolt holes, and fiddling with the water passages.

Read more: http://www.hotrod.com/how-to/engine/...#ixzz3WfuOvbwE
Follow us: @HotRodMagazine on Twitter | HotRodMag on Facebook





no one is going to bother with this work on OEM 40 year old outdated head designs to gain 1-2 degrees valve angle when for the same amount of money (or less) you can buy a lot more power out of the box...

tell you what bring a set over to a dyno and do a comparison with a modern set of aftermarket heads... HOT ROD won't guess why?!

That sandal wearing jack-@$$ Freiburger ruined Car Craft over 10 years ago now he's the big shot at Hot Rod... gimme a break.. most of his junk sits in the yard and don't run. but his dumbed down vision of Rat Rod magazine will tell you all about antiquated "speed secrets" .. crack out your 327s and 3/4 race cams.. boys.. we got some real power secrets here!