What are the best heads out there for a 305? I'm going with the xer 218/224 112 with the LT1 intake and 1 5/8 headers with a 5sp with 3.42 gears. I was thinking about the Sportman II heads or maybe some brodix heads. I'm trying to keep this as cheap as possible.

Thanks,
Jeremy

 

I am told that ..... with the smaller bore ... you are really limitewd to your choices . I keep hearing about World Products S/R ( stock replacement ) tourqer heads . But everything else ....... the valves seem to be too crowded . This eats up any gain you would have gotten form the heads to begine with .


something like this ....bear with my bad graphics


combustion chamber
____V__________
l < 4.00" > l
_________________l__ __l_____________
deck surface l l \
l l \
l l \
l l \
< 3.9x" > \

**** follow this up.....this is THE problem ....that ledge ruins any gained flow by the heads

hope this helps

 

oh well , for some reason the stupid text thingy wont let my ( wanna be ) diagram look right ..

oh well I tried .....just remember your heads combustion chamber (width or diameter , or whatever it's called) should not be bigger than your bore . Also you will fry that ring part of your head gasket , due to the fact it is exposed to the combustion charge


I am no expert but .... just don't do it

 

Since you plan on using a LT-1 intake you will not be using your EGR so I would use the Corvette alum heads. They have the small 58 CC chambers and 1.94 and 1.5 valves that clear the 305 bore. The head should work well with your 305.

 

Im going with the SR heads. i cant seem to find a nice set of corvette alum heads for the price of SR heads.. plus the SR's flow more (i belive) and there springs can handle the ZZ4 cam im gunna drop in. The reason you cant use regular 350 heads, is cause the valves being shrouded (sp?). The will hit the deck surface. You can get reliefes(sp?) milled into the top of the deck so that the valves can be useful. Also the 64cc chamber will be wayyy to big for the 305.. you will lose a ton of compression.. in that case, you will need to mill the head surface down so that the combustion chamber can be around 60cc.. i would not go larger then that.. SR heads are not alum. and if u want to lose weight with them, there good, but remeber there from the factory. Anything from the factory cant flow as well as aftermarket heads.. and the SR arent really standard repalcments.. the runners flow more, and the valves are bigger.. but still have the 58cc chamber hope this helps ya

 

hmmmm..... I know the corvette aluminums are 58 cc ..... but I thought they were still too wide ( combustion chamber ) for the smaller bore . But I don't actually know . I need heads BAD ! I am putting in the ZZ4 aswell , along with the new intake ( thats all good ) but the heads are REALLY going to hold me back . I will have to see what's best for this setup .

 

With a 305, you're really limited on what will work. I know guys who have used the Trick Flow twisted wedge, and someone here says he is using Edelcrocks with no problem. The vette heads work fine, ask Willie. Then too there is the SR, and AFR will setup their $$$ heads for a 305 if you want. But in any case, you cant just pick a head you like and throw it on there without doing some research to make sure the valves clear the bore.

 

Im pretty sure willie has AFR's on his, but milled down and his block is notched for the bigger combustion chamber valves. He could get away with AFR's if he could get the valves to fit, because the bigger 64cc chamber would give him a low compression so he can run the supercharger.

 

I found a pair of 8113 vette heads, complete and shipped for $350.00. Essentially I will have a total of $700.00 into the heads and wil lhave trick heavily ported aluminum heads with the lt4 hot cam kit.

This means that for less than the SR torquers I have heads that flow near the 180 / 190cc AFR heads. ANYONE will tell you that the SR torquers MUST have work done to them out of the box, which than jacks the price up. They are also old technology, and weigh a ton. I can go on and on why you should go with these heads if you are on a budget, but read around you will hear others saying it too.

PS last time I checked willie was running the vette heads, but I could be wrong.

 

willie doesn't run vette heads anymore.

ANd for a certain year they did make 58cc Chambered Vette heads, with are a direct bolt on and no modificatiosn are necessary, other than the usual porting/polishing.

I cant remember the 58cc head part number for the life of me.

 

It's casting number 113 for the 58cc head. There's another one too, but I don't know it. The 113 is almost identical to an LT1 head.

 

the SR head is a WAY big improvment over stock heads. What kind of work are you talking about? the runners flow more, the valves are bigger, and they come with the same technology thats on there now. There isnt any "high-tech" heads for a 305. The L98 alum heads need as much work to them as any stock head would, work thats already been done to the SR's. the Alum heads are also rare, and whenever i find a set, there usualy around the same price as SR's. If i could get a set of l98 alum heads with screw in studs, intake runners increased to 180cc, and come with valves and springs for a mild lift cam, then i will pick it up, but untill then i am gunna go with the SR's.

 

Research the site. I don't think that anyone will take the SR torquers over the vette heads. The vette heads flow better STOCK than the SR torquers do, and you WILL have to do at least bowl work on the SR torquers to make them work. You also very much misconfused "old technology" as far as the heads go. I believe they were designed late seventies??? with the update for the centerbolt intake manifolds. Also you can buy NEW vette heads for the same price as you can buy NEW SR torquers.

So for the same price you can:

1. Run .85 more compression on the same octane as the SR's - more power
2. Save 50lbs of weight - more power (.10 for every hundred pound loss, so you should see a .05 better time just from the weight savings alone)
3. Get better flow stock vs stock - more power
4. Vette heads will flow better after being worked over than the SR's. - more potential power
5. Same compression as the stock heads

If you can't find any vette heads your not looking hard enough. Check the classifieds on this site. I probably see vette heads once a week on there. Also check corvetteforum in the c4 section. If you want a list of places to check out PM me and ill let you know.

I didn't know willie wasn't running vette heads anymore, probably wanted to get into the 11's on a streetable 305. good stuff. however, I believe he hit low 12's with the vette heads on a 305. Need to check his site.

 

Given the same price, I would take the S/R Toquer 305 heads over the L98 heads. People can go back and forth on the aluminum versus iron head thing, and most often times do, so I am not going there, but if you are talking flow numbers, these might be worth a look.

http://www.worldcastings.com/tech/RTorquer305Tech.pdf
http://users.erols.com/srweiss/tablehdc.htm
http://www.topher.net/~bearman/gmheadcomp.html
http://home.columbus.rr.com/richlish...es/zz4head.htm
http://www.chevyhiperformance.com/te...98/index4.html

 

From what I can see there is a very limited difference, not anywhere near enough to make up for the weight distribution, detonation, and cost. The vette heads are still cheaper, $350.00 - $450.00, is always cheaper than $600.00 - $800.00, I don't care how you count it up.

When ported side by side al heads are hands down better IMO. But like I said it's up to you.

If you think going fast is ALL about 13 cfm more flow at .500 lift (especially on a 305), than spend more money and go with the iron heads, but before you do that I would ask those guys ripping out their interiors, and using AFR 190cc heads over comparable iron eagles, why they do it. If it is all about flow than everyone should just use 220CC heads and be done with it.

It is all about proper part matching and weight distribution. Another plus to the vette heads is the fact that they can convert over to a 350 if you ever go that route. Heck that is really waht they were built for, they are just great for the 305 as well. I wouldn't say the same with the sr torquers. But it is all just my opinion. SR torquers will make your car faster, but if you do go that route make sure you get at the very least some bowl work done to them.

 

I personally am going with Vortecs most likely. I am just fueling the debate a bit.

 

Remember once you go vortec that is it. Unless you get all new heads, and an all new intake. I would rather have AFR 190's, but those vortech are really nice, just don't like being stuck with their intake and stuff

 

What bowl work? Thwy will be just fine right out of the box, and also, i need to keep my egr, so the vette heads are out. I dont feel like fabbing up a bunch of stuff just to get my egr to work. I am presently looking for a cheapper alternative to the SR's, and i like the alum heads, but the SR's is everything that i want. New valves, screw in studs, 1.94/1.50 valves, hi lift springs, and 58cc chamber. Yea the alum heads are good, but there is to much work to make them work the way i want them, plus if i get the SR's, they are brand new, where the vette heads are used and could have something wrong. I like the vette heads and i wish i could get a set, but the egr is standing in my way and i dont feel like doing the vette egr mod. I rather slap on a set of heads that are all ready to go, and work well with my cam. The only thing i could think of is if i could get the ZZ4 heads (L98 heads) from somewhere, but i saw the prices on thoes, and there more then the SR's. And what vortecs fit a 305?

 

Vortecs fit 305's w/o an issue. Just use the right intake, rockers, etc. You can mill them to 58 cc if you want, but I may just leave mine at 64cc as I am building a 350 down the line.

 

I would.

Aluminum L98 #'s @ .500" 195/155
S/R 305 #'s @ .500" 213/166

Where??? I wouldn't mind picking up a set then.

Well actually their static compression ratio will be the same but the L98 aluminum heads will have less effective compression because of the heat loss due to the aluminum composition.

Yes true using aluminum will get you better times because of the weight difference. Hopefully you don't lose much horsepower from your compression loss and be able to run faster with the lessened weight.

Very true. Stock versus stock there's more flow on the intake side because of the 0.1" bigger valve.

Got some flow numbers to back up that statement?
Refer back to #1.

Personally if you want the best power making opportunity go with Vortecs. They have all the power characteristics already worked in. With equal amount of work, they will make the most power.

 

lol if you think SR torquers are good out of the box, you REALLY need to search these boards. Ask five7kid if these heads are really ready to be bolted on right out of the box. Search for torquers and five7kid, you will see what I mean. Also SDPC sells an EGR kit for the vette heads.

Did you also happen to notice what state I am in? California, if vette heads can pass here, they can pass anywhere. Talk to kevin91z who is running these heads and passes visual. Dynodon, his father, fabbed up the pieces for him, maybe he can sell you a prefabbed up kit. Not sure he is really busy.

Also the ZZ4 heads, I believe comes with the complete LT4 hot cam kit, which will handle more lift than those out of the box SR torquers could ever dream about. Like I said heads that belong on a 350, but will do wonders for your 305, or heads that only belong on a 305... It really is up to you.

Since the vette heads are less money and offer better performance AND pass smog, I would think the choice is clear, but it's your decision. Also for another clincher, IMO, :hail: Lingenfelter uses these same heads on his super ram 383 putting out 430hp. Ask him if he could or would do the same with the sr torquers, but hey it's your car your money bro. As long as you are happy with the decision that is all that matters.

 

I have never heard of anyone saying that a 58cc to 58cc is a compression loss. There would be no compression loss, just different heat distribution. The "pressure" for the compression is all going to be the same. Apple to apple. However, you can run more compression with the same AL head on the same octane. I have never heard of anyone saying that you need to increase compression when going from AL to iron because you will lose power, but I have heard everyone and their mother talk about how you can gain extra power by moving up the compression.

By your statement you would be moving up compression to stay at the same power range as the iron heads. Im sorry I just dont believe that. Apparently neither do piston or head manufacturers

Unless you can show me where they give a different compression ratio for AL heads and Iron heads, I am going to stick to my guns.

http://flatlanderracing.com/trwchevy350.html


I dont see an iron vs aluminum change there anywhere.

 

http://www.chevytalk.org/threads/sho...fpart=all&vc=1

http://www.camaros.net/forum/Forum4/HTML/006014.html

 

rockind, thanks for those links, great information, but I guess those posts even show it all goes back to differing opinions.

We can all agree to disagree

I just really feel that if aluminum was so bad, you wouldn't have guys like lingenfelter using them on his 383 (which was the engine brought up in one of those posts) and you wouldn't have a company like AFR known as the best heads around, at least on this board and most camaro boards I frequent.

I would think people would jump all over the iron eagles, canfields, etc... and just put a heavy port job on them, but they don't they use the AFR's or trickflows, etc...

I do want to say that this is such a great site where we can have mature technical discussions. Good stuff .

 

I had world tourquer 305 heads on my 305. They kicked ***. Made the car really fast and louder. They are the same dimensions as vette aluminum heads but they worlds flow better and have an egr port. Best part is you can pick them up for about $300-400 each

 

Well to me the difference is that you can pickup a set of vette heads for the price of one torquer. I was under the impression that the vette heads are $800.00 for SDPC? or $400.00 a piece.


http://www.sdpc2000.com/cart.asp?act...id=277&pid=147 - I stand corrected, however these are not the 8113's.

 

the Worlds are cheaper but they are also cast iron. The vettes are lighter but the Worlds flow better. The world heads will also keep your emmisions stuff working so you can still pass emmisions. It is pretty much a toss up.

 

You can keep EGR, just not plug and play EGR

 

Im gunna go with my original plans for a set of world 305's.

 

No problem, but anytime you want to go to the track to test them against the AL l98's let me know. My buddy's RS would like to show you the power that is aluminum j/k

 

Read it again carefully. Let it sink in.

 

Theoretic compression and "real" world compression I would venture to say is a little bit different.

Time travel is theoretically possible, but have you done it?

No flame intended, though your rebuttal was a bit condescending

 

I don't think Iroc22 was trying to be condescending. I'm kinda hard at explaining this, but I will try to build on what Iroc22 is talking about. The energy released during combustion in the chamber is what what powers the motor. It is also characteristics of that combustion process that gives a motor its horsepower and torque characteristics (well, mostly anyway). With iron heads, the energy released during the combustion of the air/fuel misture is more immediately contained to the chamber, due to the thermal characteristics of iron, channeling the energy to the pistons and providing power. This same process occurs with aluminum BUT some of that energy released during the combustion process is bled off due to the rapid heat loss characteristics of the aluminum. To compensate for this loss, many/most people will bum the compression up a point or so.

I don't know if I explained this appropriately or not, but this is MY interpretation of it.

 

I understand what you and iroc22 are trying to say, but than why does everyone make an aluminum head and does why does everyone use an aluminum head. Everything I have read either on thsi site, in a magazine, or just picked up from people is that you CAN up the compression up to a full point (actually most say .85) more on aluminum heads than iron and still run the same octane gas because you will not run into detonation. No where have I ever heard that you will make less power. Kind of boggles my mind that AFR, trickflows, and other would be so powerful if aluminum really sucked that bad as a performance head. Just kind of my observations.

 

Man you pretty much nailed it on the head.

 

Well, Alum as a head isnt bad if you are running a high compresion engine, but incase of a lower compression engine, Iron will make more power then alum. Iroc and Rock both explained the heat trasfer thing 100 times. I have read up on a lot about alum heads, and if you are running 10.1CR and above, the alum will help with the heat disapation. But on a lower CR motor, iron will make more power. Its been proven by tons of people. My 305 isnt gunna raise a CR point with these heads, and iron will do just fine! Yes, alum. heads will be good on a race motor thats running 12.1:1, but not on my 305 thats running a around 9.3.... i would gain more by using the iron heads over the alum heads.

 

Aluminum heads are popular because of their ease to manufacture. It is easier to work with aluminum than with cast iron. This would include any port work done, repair, etc. Not everyone uses the aluminum heads. Very many people do, and in the end, I may as well, but for me, cost will be an issue as well. If you look at some of the best heads out there, including Dart, Pro Action, AFR (not sure about that one), and the well known Vortecs, (I will acknowledge there are others, I just can't think what they are right now) they are iron for the most part. Sure, some aluminum castings are available from the above manufactureres, but the iron counterparts would not be produced if there were not a market for them. Keep in mind also, that casting material is probably only part of the detonation issue. If you pit the L98 heads against a set of Vortecs, you may find that the Vortecs are almost (if not just as) detonation resistant as the L98's despite the iron versus aluminum issue. This is due to the more modern combustion chamber offered by the Vortecs. Lingenfelter does make outstanding power with the L98's, but he I would think that he really has to work those heads over to get that kind of power. Now, if you are goin with a worked set of L98's, then you need a different intake system to take advantage of the better flow afforded by the heads. Time to buy a new intake. In that case, you have the Vortec option avaliable again. I personally would rather buy a good set of Pro Action Vortec heads, buy the intake and run with those. If the heads flow at least as good as stock, then you are already in the neighborhood of 230-240 cfm flow. Pro ACtion is claiming even better flow.
Run the L98's. They have a lot of potential, and are probably better than my stock 305 heads, but that is all the credit I will give them. There is a large variety of better cylinder heads on the market.

Quote:

Everything I have read either on thsi site, in a magazine, or just picked up from people is that you CAN up the compression up to a full point (actually most say .85) more on aluminum heads than iron and still run the same octane gas because you will not run into detonation.

Actually, many will tell you that that bump in compression is REQUIRED to keep up with the iron heads. As a friendly piece of advice, I would recommend you not believe everything you read on this (or any other) site. Keep in mind that just because you are asking the opinions/advice of others, and it is given, doesn't make it correct. It is given to use at YOUR discretion. If you truly want to keep ahead of the game, keep reading literature that is accepted as true. Don't even take what i have stated above as true, it might not all be. My memory isn't always 100%. Looking stuff up for yourself and applying it often proves to be the best teacher of all.

 

aluminum heads are lighter and disapate heat better that is why people like them as well

 

I was talking to the local engine machinist about 305 options for my car....

He pretty much said what everyone else here has been saying about the 305 & it's power prohibitive bore size. You can throw as much money into an engine as you want, but sometimes you have to be sensible. I want to be sensible, and get a good performance to dollar ratio.

He suggested that my best bet is him working my stock 305 heads. $400 is all it would cost me. This included all the tricks (port, polish, bowl work, valve work, etc). He said I would probably see about a 30HP gain or maybe >. He also said the intake system (plenum, runners, base) would needed to be opened up to take greater advantage of the head work too. This sounds very nice for the price if you want my opinion.

So, my vote goes for working the factory heads since it's a 305.

 

I might have my 305's ported and have screw in studs put in... but also i want to have my seals done.. i gotta ask around for how much thats gunna be, and i need to find a good shop to do it.

 

If you really want to save money find some old heads at a yard and port them yourself.

I ported, had a 3 angle valve job done and new valve guidess/seals where needed for under $250.

And it gained some SERIOUS horsepower!!

 

let me borrow your air compressor, die grinder, and other tools and ill do it myself. Dude, if i could, and i knew what i was doing.. i would do it. But if i f*ck up, then i have to spend money on a new set of heads anyway...

 

Actually I didnt know what i was doing. i just got some info form magazines (car craft) and stuff and went at it. I probably didn't do it as good a job as an aftermarket place like AFR but **** - its good enough for me.
Its your call though - it can be an intimidating project at first.

 

dont bother porting your 305 heads...they dont flow good at all and they are to small...get aftermarket world 305 heads, you wont regret it but you will if you take the time to port 305 heads and get little gain

 

There is no way to make this statement correct, no matter how you read it. Compression (static or dynamic aka"effective") is mechanical, end of story.

The heat loss and related power loss is an entirely different issue.

 

:hail:

 

Was the above incorrect?

I was under the impression that the potential energy given off in the form of heat is what causes the power loss because it is no longer applied to the piston. Is this line of thinking wrong? You've got me curious now.

 

If I remember back to simple high school physics correctly (I was only in class like half of the year) "Energy cannot be created nor destroyed; only transformed into another type of energy". In this case the mechanical energy (in the form of the compression stroke) gets transferred into thermal energy in the power stroke. Energy is lost because of the poorer heat retention properties of the aluminum element (although it's not pure in a cylinder head). The element iron has better heat retention properties than that of aluminum and can transfer the energy better into the power stroke.

And as far as I know (which isn't a lot, I'll admit that) static compression ratio is a constant because of its standard calculation used to obtain it ({swept volume + total chamber volume}/total chamber volume [right??]) but I'm unclear of a calculation for effective (or dynamic as you referred to it as). Is there actually a calculation for that? I know it's very important for boosted applications to determine their effective compression ratios so they know how much psi to run. But as far as determining a dynamic ratio I'm not entirely sure. I understand though that a dynamic compression ratio calculation helps you determine a camshaft that will work the best in your paticular application. I'm here to learn man.

 

I thought you decided against them after the price increase?

 

:: looks around ::
are you following me? :: gets gun ::

hehehe well its still up in the air about that. They seem to be the best IRON heads for the job. Porting out my 305 will not bring the same kind of power as these will, plus the SR's will be new and have all that im looking for. I have to keep in mind the semi-high lift of the ZZ4 cam and i need the springs and rockers to do so. Its gunna come down to budget and see if i cant get a set somewhere for cheap. Ill post again after this summer and my lil 305 has all its parts in.