i have a set of #15 that would get you into the realm your looking for. the domed pistons shouldnt be ruled out as they would improve compression. they are although not without issues as jim stated. the pistons would be hotter on the dome than the lower surfaces due to the raised areas of the piston. they would however work well with the lower compression heads if you plan to add nitrous or a blower. goes to quench factor for more reasons. burns the fuels better over a wider surface of the piston. when you start talking about modifying an engine your speaking of a whole different animal in and of itself!!! a daily driver would due good with a valve job to those heads and a good cam. take the exhaust side to 1.77 and port match the heads. go with a RA cam and you would be good in the fun factor department!!!
Andy
due to budget cutbacks, the light at the end of the tunnel has been disconnected for non payment.
As was stated earlier, use flat tops and get the right heads to begin with. A dome on the top of the piston will lose power compared to an engine with flat tops and the same compression ratio. A worst case scenario would be big chamber heads and big domes, losing up to 20 hp over a proper combo.
Only use domes if you have no other way to get the compression and you absolutely have to have the extra compression - not usually the case for street engines.
Aluminum heads with identical flow to a set of iron heads need about half a point more compression to compensate for the heat lost through the aluminum - which is why you can (and should) run an extra half point of compression with aluminum. In both cases the limiting factor is the octane rating of the fuel. The air-fuel mixture can only handle a certain amount of temperature and pressure before self-igniting and causing detonation, and that happens at the same point (in terms of cylinder pressure and temp) whether the heads are aluminum or iron.
Aluminum head advantages: lighter, easier to port, easier to repair (welding and such), no paint to peel (think centre ports on Pontiacs!), you can buy new ones if needed, sometimes have more options for chamber sizes, almost always have better flow because of advances in port design over 30-40 year old heads. Disadvantages: cost, heat loss, higher expansion rate (heat cycling on high output engines can "punish" head gaskets), warp easier when overheated, not original.
OK, Last time I said anything about how much for some heads that someone out there might have I included some poorly place humor SO, Just the facts. Who has some better heads and how much? Thanks Eldon
Eldon, You need to pick a fuel source(octane). And then, from that, pick a compression ratio. From that, pick a head chamber size(cc). And from that, pick out heads that will have that chamber size. Then go 'Head Huntin'. That's the way it's done.
Do you want to run the cheapest 87 octane fuel, or are you fine with filling up with 93/94? If you don't mind spending the extra 20 cents or so a gallon, you can choose heads that will deliver around 9.5:1 in iron heads (approx. 96cc) or 10.5:1 aluminum. And you can install a cam that will provide good power with these heads.
You also need to take into account what exhaust system you'll be running (stock iron logs, iron long branch, small tube or large tube headers, open or closed exhaust) and the rear gear ratio in order to pick the right cam for your use. If you normally don't take it over 3500 rpm, you don't want a cam that starts making good power until 4500.
Jim Hand wrote a very good book about building a 455. He built for maximum power, but there are a lot of good tips for any kind of build.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
I really would like to just run lowest octane pump gas. My wife will be driving this car more than me and power is not as important as she isn't left on the side of the road because the 400 hp monster is not running right. Eldon
Then it works out to somewhere just above 100 cc's to burn the regular pump gas. You could have a machinist mill some off your 4x heads(@114cc) and you will be good to go... Or leave them be for a very mild build.
on my 400 I have 5C heads with 88CC (milled to that), I can run regular, but most of the tme use "plus" just in case.... and its no 'slouch', even though no "drag car"
Bjorn, On a 455 those same heads give more compression. The 455 has more 'squeeze' than the 400. Different bore and stroke makes for a different recipe.... Here's a link to a compression calculator. LINK: http://www.csgnetwork.com/compcalc.html
Then it works out to somewhere just above 100 cc's to burn the regular pump gas. You could have a machinist mill some off your 4x heads(@114cc) and you will be good to go... Or leave them be for a very mild build.
Mill SOME off? That is more than some to remove 14cc's..That is MAJOR.
We charge $50 to clean up or true the deck..up to 10 thousandths. After 25 thousandths, you have to mill the corresponding intake surface for proper head to intake geometry. For laymans sake, he needs 70 thousandths removed. According to the rule, 5 thousandths is 1 cc. He is going to need 14 cc's removed. That is $350-400 a head ($750 total) for machine labor for both the intake and deck milling alone WITHOUT rebuilding these 4X heads (valve job, valves, springs, disassembly, guides, locks, retainers etc.) Add another $5-800 for rebuilding the heads. Milling 14 cc's off a head is a total waste of money. And if he was bringing them to me? I would not mill them and waste his cash.
Find a set of 6X4's (98 cc) or a set of 96's (96cc). Cores usually run $150-250 for the 6X4's and 96's $250-400.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
Then it works out to somewhere just above 100 cc's to burn the regular pump gas. You could have a machinist mill some off your 4x heads(@114cc) and you will be good to go... Or leave them be for a very mild build.
We charge $50 to clean up or true the deck..up to 10 thousandths. After 25 thousandths, you have to mill the corresponding intake surface for proper head to intake geometry. For laymans sake, he needs 70 thousandths removed. According to the rule, 5 thousandths is 1 cc. He is going to need 14 cc's removed. That is $350-400 a head ($750 total) for machine labor for both the intake and deck milling alone WITHOUT rebuilding these 4X heads (valve job, valves, springs, disassembly, guides, locks, retainers etc.) Add another $5-800 for rebuilding the heads. Milling 14 cc's off a head is a total waste of money. And if he was bringing them to me? I would not mill them and waste his cash.
You say he 'needs' .070 milled. I disagree. He could leave them be and still have good power for what he wants. Or he could get a small amount, say .020-.030 milled for a little more 'zip'. I really don't think they would charge all that much for that. And he says he has a good budget to work with....
If the 4X are usable as is with no work, use them. They are very low compression heads. If they need any work, replace them. There is no shortage of good heads, and matching numbers does not matter, just the right specs.
If those heads are worn out and you want a set of fresh machined rebuit 7M5 114cc, I can get you a set from my machinist for $350. The 114cc heads are cheap because no one wants them for performance builds.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
If the 4X are usable as is with no work, use them. If they need any work, replace them. There is no shortage of good heads, and matching numbers does not matter, just the right specs.
Agreed. Have a shop check them for cracks, ect. And just for kicks, ask them what they would charge to mill them .o25. It will help the grin factor.
5cc is 5cc. A little more compression doesn't hurt in that range. And it wouldn't cost that much. It's a quick job for any good machinist. I could do it in an hour(or less).
5cc is 5cc. A little more compression doesn't hurt in that range. And it wouldn't cost that much. It's a quick job for any good machinist. I could do it in an hour(or less).
20 minutes to set up the machine and 5 minutes a pass of 3-4 thousandths at a time PER HEAD.
That is a $300 bill minimum for nothing. 5cc's at that compression equates to no performance difference except a lighter wallet that is faster (and lighter) to remove from his back pocket.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
5cc is 5cc. A little more compression doesn't hurt in that range. And it wouldn't cost that much. It's a quick job for any good machinist. I could do it in an hour(or less).
20 minutes to set up the machine and 5 minutes a pass of 3-4 thousandths at a time PER HEAD.
That is a $300 bill minimum for nothing. 25cc's at that compression equates to no performance difference except a lighter wallet that is faster (and lighter) to remove from his back pocket.
$300! I've never been on the collecting end like that. Always did it by the hour for GM. And I would take more than .003 per pass. But you can't fault someone for being careful. And I've seen many people spend much more money for less HP gain. At least this gain is for sure. You can't deny it on paper.
114cc + valve reliefs, standard bore, standard compressed gasket thickness, no zero decking = approx. 8.0:1.
109cc + valve reliefs, standard bore, standard compressed gasket thickness, no zero decking = approx. 8.3:1.
Not significant. Compression is so low it will have little effect on power. If it bumped it up a full point to 9.0:1, yes, that would have a significant effect.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
And I've seen many people spend much more money for less HP gain. At least this gain is for sure. You can't deny it on paper.
Again, at that compression ratio of 8.2 (114 cc) by spending $300 and taking the heads to 109 cc, compression has raised to 8.4. Not even close to noticing anything, again I say "at that compression ratio" and for the record, at any compression ratio. It would be like me spending $300 on a 85mm Granatelli throttle body expecting a 20 hp gain when the remainder of my motor is stock. If the remainder of my/his motor had many performance mods, maybe 20 hp, but the throttle body alone (as in the milling we are discussing) has absolutely no seat in the pants feel/difference and a total waste of money.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
Jim, yes , I know, i was just showing that with an engine 400 or 455, with the right heads to start with you can figure out how to mill them to the correct CR so you can run regular pumpgas..I know he cant use 5Cs milled like mine..possibly 5C`s un milled? they usually are round 105ccs? arent they?or are they in the 98`s?
Watch out for overinflated shipping, as "per head". I shipped a pair of heads to Dallas for $35 each..Some of those guys are charging $65-90 per head.
The 96's I have look better than the ones shown in the pics, are baked, Ampro blasted, threads chased, small parts tumbled, cleaned and inspected, heads magnafluxed and new freeze plugs installed. Just need to be rebuilt. And you get all the parts that came from them. If you were to buy a pair and have them disassembled and checked, plan on another $125-150 a pair.
Unsure if these are 6X-4's, but not a bad price for rebuilds..Would be similat to your 4X's if these are 6X-8's, but they have been rebuilt.
Jim, yes , I know, i was just showing that with an engine 400 or 455, with the right heads to start with you can figure out how to mill them to the correct CR so you can run regular pumpgas..I know he cant use 5Cs milled like mine..possibly 5C`s un milled? they usually are round 105ccs? arent they?or are they in the 98`s?
Right. I knew you had yours milled to the cc's you wanted. Just wanted to point out the head difference on a 455. Every change you make is a little 'magnified' on a 455 as compared to a 400. You don't have to mill as much with a 455. And the simple factor of all that displacement makes the engine more powerful without all that compression. Eldon, I wouldn't take those numbers that were thrown out there as 'Gospel'. I would check with your builder on how much he would chanrge to get those 4x milled. I know a great head builder in Texas that I bought a set from and his work was dirt cheap and perfect. He may even have set that is right for you. I'll see if I can dig up his contact info.
Good cores run $250+. Those are good used heads in need of rebuild.
Rebuild can run $250 for a simple disassemble/clean/inspect/lap/reassemble. But it's the rare set of heads that doesn't need more. I've been paying $500-700 for full rebuilds on my cores with guides, valves, springs, seats ground, etc.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
Fbody69, Let me know if you find that shops number. Thanks Eldon
P.S. Vikki, The last few post went way over my head. If I added anything I would be talking out of my skill level. This has turned out to be much more informative than I thought it would be. Thanks to everyone. I have taken the 455 apart, down to the shortblock, and will take it to the machine shop next week. Lots to figure out on the head thing and soon.
And much more exciting! You're learning first hand about how some fairly straight forward questions and answers can become several pages longer than needed! But that's sometimes how more info comes out!
Jim, at the risk of being called names or accused of having a hidden agenda or belonging to a secret Get Jim club, sometimes it isn't about you, just the info you're presenting - Mr. Namecaller!
And much more exciting! You're learning first hand about how some fairly straight forward questions and answers can become several pages longer than needed! But that's sometimes how more info comes out!
Jim, at the risk of being called names or accused of having a hidden agenda or belonging to a secret Get Jim club, sometimes it isn't about you, just the info you're presenting - Mr. Namecaller!
I really would like to just run lowest octane pump gas. My wife will be driving this car more than me and power is not as important as she isn't left on the side of the road because the 400 hp monster is not running right. Eldon
All the more reason to build the 400 around 8.75-9:1 All you'll get from a 8:1 455 is a gas burner. All those extra low compression cubes are doing nothing for you in a daily driver except burn more gas. Jim's right, if you want to burn lower octane fuel and take advantage of performance gains, aluminum heads will help there. You'll put $1000 in doing Iron heads right anyway, $500 just to get them in decent condition and raise the compression on the 455. There is no right decision, there are just several options, it's your decision. Good luck. And I'd stay clear of domed pistions, a stock overbore flat top is much cheaper as well.
Wanting a Custom fit in an off the rack world.
I don't have time for a job, I just need the money.
Thanks Gordon! I don't know where these people get off saying 'opinions' are wrong. They should present their opinions and let the asker decide what he wants to do. This 'bullying' is a bunch of crap and it doesn't work...period.
If bullying is wrong, then why do you do it, Jim? You call names, stick out your tongue, repeat yourself endlessly, and jump up and down with joy if someone agrees with anything you say.
Why not show a little open-mindedness and listen too?
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
If bullying is wrong, then why do you do it, Jim? You call names, stick out your tongue, repeat yourself endlessly, and jump up and down with joy if someone agrees with anything you say.
Why not show a little open-mindedness and listen too?
For example, I say aluminum heads are an option. Instead of letting it stand and present something else that you may have thought of, you attack the idea. I present head milling, which several members have done successfully, Bjorn for one, and you attack it too. Use your brain power to think of original things instead of attacking my plausible options.... It will work better for all.
5cc is 5cc. A little more compression doesn't hurt in that range. And it wouldn't cost that much. It's a quick job for any good machinist. I could do it in an hour(or less).
20 minutes to set up the machine and 5 minutes a pass of 3-4 thousandths at a time PER HEAD.
That is a $300 bill minimum for nothing. 5cc's at that compression equates to no performance difference except a lighter wallet that is faster (and lighter) to remove from his back pocket.
I just had my block decked .028 and both heads milled .010 and the intake sides .010, total bill was $250
Wanting a Custom fit in an off the rack world.
I don't have time for a job, I just need the money.
5cc is 5cc. A little more compression doesn't hurt in that range. And it wouldn't cost that much. It's a quick job for any good machinist. I could do it in an hour(or less).
20 minutes to set up the machine and 5 minutes a pass of 3-4 thousandths at a time PER HEAD.
That is a $300 bill minimum for nothing. 5cc's at that compression equates to no performance difference except a lighter wallet that is faster (and lighter) to remove from his back pocket.
I just had my block decked .028 and both heads milled .010 and the intake sides .010, total bill was $250
Gordon points to another instance of where my post was attacked. And he also shows where it was attacked with false information, an overquote just to make my advice useless.... Now, milling IS an option. Where, before this, milling and decking were thrown in the trash as worthless.
Wrong iron heads machined to work then rebuilt to 8.5:1: $1000, no significant gain.
Aluminum heads ready to bolt on, 87cc (equivalent performance to 9.5:1 iron heads): $894.95 EACH plus rockers $1890. Headers for raised roof port aluminum heads: est $400. $2300, good performance, pump gas.
Iron heads ready to bolt on, 96cc, 9.5:1: $1000, good performance, pump gas.
My opinions are based not on flash but on substance, on price and performance, on practicality. Billet does not make a car go faster, I don't recommend it as a necessary upgrade, but it makes no difference to me if someone else likes it and installs it. Same with other options, I am against spending money in excess of what is required to gain the desired results.
HO428, why were the intake sides milled? Was it just to clean up surfaces, or were the heads previously milled?
Jim, prices and workmanship vary. The shops that Tom and I quote are high end race building shops, they don't do services for the general public. High volume shops can have lower rates, but I am absolutely confident that I get the right results when I drop my parts off.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
Wrong iron heads machined to work then rebuilt to 8.5:1: $1000, no significant gain.
Aluminum heads ready to bolt on, 87cc (equivalent performance to 9.5:1 iron heads): $894.95 EACH plus rockers $1890. Headers for raised roof port aluminum heads: est $400. $2300, good performance, pump gas.
Iron heads ready to bolt on, 96cc, 9.5:1: $1000, good performance, pump gas.
My opinions are based not on flash but on substance, on price and performance, on practicality. Billet does not make a car go faster, I don't recommend it as a necessary upgrade, but it makes no difference to me if someone else likes it and installs it. Same with other options, I am against spending money in excess of what is required to gain the desired results.
Stick to your own ideas. When I present a build idea it's either something I have done personally or something I've seen a close acquaintance do successfully.
That's the way it's done. 
