What set of heads can I buy and bolt on and run? People have told me that any new heads have to be reworked before you can use them! And what would be the correct heads for a 318ci bored 30 thousands mild cam Tri headers 904 automatic! 69 Dart gt! Thanks
New heads
- Thread starter Mr GT
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Tho I run stock heads on my 318,lots of guys are going with Speedmaster because of price.
Too many horror stories about out of the box heads having flaws is why many pull them apart and check them out completely. Even good names such as Edelbrock and Trickflow .
I bought a set of Mopar Performance big block heads and out of the box each head had different pressure valve springs.
That was 20 years ago. Quality Control was as bad back then as it is now.
Too many horror stories about out of the box heads having flaws is why many pull them apart and check them out completely. Even good names such as Edelbrock and Trickflow .
I bought a set of Mopar Performance big block heads and out of the box each head had different pressure valve springs.
That was 20 years ago. Quality Control was as bad back then as it is now.
You don't list your intake or carb., but unless you NEED aluminum heads much could be said about a set of J heads cleaned up.
If your able to do the swap your able to check them out yourself.
moper
Well-Known Member
You can do that with any of them. But, you are rolling the dice that they will work as advertised. If you’re spending $1000+ just for the heads To get the benefits, another $3-400 to have them checked and corrected will ensure you get them. You don’t have to. But there’s risk taken on with not doing it.
mario03srt
Well-Known Member
I have had 2 cases where cyl heads either new or rebuilt that needed work. Mainly exhaust valves that were not seated completely. Some burrs and debris. Small core shift on ex port. Valve springs that were set way to light and needed shims.
Marion
Marion
Both sets of Edelbrock head I got were very good OOTB.
I purchased a set of ProMaxx chink castings heads that were bang on perfect.
The wife purchased Trick flow heads that were bang on perfect.
The machinist will make quick work out of less than perfect heads but garage heads will require a bit more time and money.
As said above, cleaned up 360 heads will work great. So would edelbrock heads. It’s really not about the bore size but about the combination.
The wording, “Mild Cam” really means nothing without know what the cam is or there specs. Do you have the cam card available or know exactly what cam it is?
I purchased a set of ProMaxx chink castings heads that were bang on perfect.
The wife purchased Trick flow heads that were bang on perfect.
The machinist will make quick work out of less than perfect heads but garage heads will require a bit more time and money.
As said above, cleaned up 360 heads will work great. So would edelbrock heads. It’s really not about the bore size but about the combination.
The wording, “Mild Cam” really means nothing without know what the cam is or there specs. Do you have the cam card available or know exactly what cam it is?
I recommend bolting on NO ONE's new heads out of the box. I haven't seen anywhere where anyone said to have them "reworked". It is always recommended to take them to a machine shop and have them checked out. Why in the world would you want to bolt them on totally unknown on top of a PILE of money? Take a chance the valve job isn't quite right? Maybe a valve guide or 16 are too tight? Think of how expensive the consequences are if something goes wrong. That's a LOT of money to be out just trying to be cheap and cut corners. Do you want to do the engine build twice?
On a 318 you can get all the head you need with some cleaned up iron heads. Regardless of the part number they are all basically the same with a little porting.
Iron makes more power than aluminum because it keeps more heat, and heat is power. This is not to say you can't buy aluminum heads, but for that size of engine you can do a lot with
some good old stock iron castings.
Tom
Iron makes more power than aluminum because it keeps more heat, and heat is power. This is not to say you can't buy aluminum heads, but for that size of engine you can do a lot with
some good old stock iron castings.
Tom
True that!
Oh no! Here come the debates!!!! You’re wrong, I’m right. No! You’re wrong I’m right. You have no idea! No! YOU have no idea!
Aluminum!
Cast iron!
Aluminum!
Cast Iron!
Aluminum!
Cast Iron!
Continue for 40 more pages ……
I got heads for a 318 from Aerohead - a division of Indy, that came complete with 360 (1.88 valves in new seats) for very good price a few years ago. These were rebuilt factory 318 iron heads.
I have a set of brand new Edelbrocks sitting on my desk right now. I could throw them on my 318 without doing anything, but I would have several headaches to deal with: loose casing flash that could cause issues with the oiling, a raised helicoil that would cause an exhaust leak. I need to check the valve guides for proper clearance too, but its nothing that can't be overcome with a little care... point is, these heads are REALLY cheap for their volume compared to factory stuff that has to pass an oem warranty, so you are going to have to deal with the quality issues no matter what. Edelbrocks, Speedmaster, Trickflow, etc. has to pass on some of these issues to us for them to be remotely affordable.
Buy a set of aluminum heads, but expect that you need to check things out. If you have no experience with engines, you can still catch a lot of the issues like flash, things that would cause a leak etc. Even the valve guides, you would likely notice a valve that is way too tight and would stick just by feeling.
Buy a set of aluminum heads, but expect that you need to check things out. If you have no experience with engines, you can still catch a lot of the issues like flash, things that would cause a leak etc. Even the valve guides, you would likely notice a valve that is way too tight and would stick just by feeling.
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Lol, yep similar answers posed differently
No I know nothing about cam! engine was in car when I bought it! Thanks for info!
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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your question, as posed, is, IMO, as good as impossible to answer.
what are you expecting out of a head-swap?
How far down in the bores are the pistons?
Not a chance would I install any open-chamber head on a 1969 street 318, with an automatic.
So that leaves closed chamber heads.
and if you do that, then you have the Quench issue to deal with.
Alloy heads will cost you the equivalent of somewhere between one half and a full point of compression by virtue of their excellent ability to pull heat out of the chamber. Heat is power, so; this means that with a simple swap to alloy heads with no other changes, you are likely to lose ~4% power, everywhere in the rpm band from stall to peak power and over the nose. With 318 pistons usually down in the hole, you can't afford that. This power-loss will be most noticeable at lower rpms. which, unless you have racegears in the back, is gonna very noticeably soften the performance below 3000/3500 rpm.
The overbore helps nothing, unless, during the rebuild, the piston tops were sent to the top of the bores.
The shorties are a high-rpm design, but in all seriousness, for street, are only half a header, not being tuned for the rpm that most streeters drive in. But worse is that those shorties will pretty much kill the overlap period of any cam you install; so that also kills the top end power. So really, all they do is provide a clean place for the pistons to push the exhaust gasses into, which unless the throttles are wide open, is of almost no consequence.
At this point, the mild-cam, at sub 3500 rpm, may actually be costing you power. Alloy heads will just make it worse.
The 69 engines were rated at 9/1 Scr, which demands a total combustion chamber volume of no more than 81.5cc
IIRC the 1969 heads were about 60cc and the steel gasket at a tic over 4cc, for a total of say 64cc. that means the balance, 17.5cc comes from the shape of the piston tops and the deck volume. I'm pretty sure the 69 pistons were flat tops with no eyes, so that puts the pistons down at ~.089 I sortof remember the spec was .057/11.2cc, so the pistons must have the missing 6.3cc. It doesn't really matter, since the Quench is outta sight either way, between .077 and .109, both with closed-chamber heads. which just means this combo should not be detonation prone, at 9/1 Scr.
The thing is, the .020 headgasket is gonna be a special order, and the ones that come in the rebuild kit are like .057, and the fire-rings are like 4.18 inches in diameter for a net of 12.6cc as compared to the steel shim around 4cc. So if that gasket gets installed with flat top pistons .090 in the hole, this jumps the total chamber volume to 90.58@ plus .030, and the Scr becomes ~8.2 so, If you install 60cc alloy heads on a combo like that, then it will perform like 7.2Scr in most of the working range of the throttle openings, the rpm below the torque peak, and it will be severely hampered by a stock stall, and say the common 2.76gears of the day.
Now I know you didn't ask these questions, and for all I know your engine has been decked to ZERO, or close to it; But it seems to me, you wouldda mentioned it, cuz it is probably the most important part of any 318 street-build.
And you may have 4.10 gears and and a 3000 stall, IDK, but you didn't mention that either.
The point is that all of us are just pissing in the wind, cuz your question, as posed, is as good as, impossible to answer.
Losing power going Aluminum was a Big worry that you'd lose power when aluminum heads started becoming popular, I wouldn't say the evidence against is conclusive but there been a few test when companies offered a cast and aluminum version no one found any loss, and like worrying if a stoker gonna wear your engine out, it seem to be an old concern most don't care about anymore, aluminum heads seems to work for 90+% of the aftermarket and the car industry as a whole.
Magnum heads are a nice upgrade if you happen to have a set or can find some at the pull a part. Yes, most would have an exhaust seat cracked but they will run fine. Not everyone's cup of tea, but if you dont mind finagling the intake bolts they are near perfect for a street able low buck 318.
340six
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Years ago i bought one of the 1st sets of Edelbroken heads.
The machinest checked them out were fine out the box. Did say he would do a better valve job.
They would have been fine. Quality sucks now.
I ended up having port work done, new springs to match my cam etc.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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to the OP:
These are my opinions, top to bottom, interspersed with my experiences.
................ just try to run the same 195psi with iron heads on 87E10, that can easily be run with alloy heads; good luck.
I mean making the pressure, to make the torque, to make the Power, is the whole point for the existence of an internal combustion engine.
So if yur not running the pressure up,
then you're missing the entire point of running alloys;
air-flow not withstanding.
Said another way;
If the pistons in your already-built short-block, are down in the holes, in the usual places, it will be impossible to make decent pressure with any head period, and so, IMO, spending good money on alloy heads is a waste.
I'm not saying impossible to make decent POWER, which is a function of rpm;
just impossible to make decent pressure.
At the best, with an Ica of 62*, the pressure will come in around 150/155psi; at the BEST! More likely is 140ish
Without the pressure, the bottom end will go soft, forcing you to increase the stall and the rear gear, in that order.
_____________________________________
Notta chance would I screw an engine together with alloy heads; and not address the Quench, and not run the cylinder pressure up to near the max, for 87E10, to enjoy both power and economy of operation, and the fun factor.
I mean 195psi versus 165 is a night and day different engine.
To get the pressure up with a typical 268* cam, with alloy heads, is gonna require the Scr to be in excess of 11.2/1 , maybe closer to 11.4, depending in the actual ICA.
For a 318, 11/4 is gonna require a total chamber volume of no more than 63.7 cc; and therein lies the problem, how to get down that low. To run the rock-solid-dependable Felpro .039s the pistons will need to pop up to get the Q down to say .030. But those pistons will need to then be machined for valve clearance.
Say the net on that is 5 less 2 is 3cc, and the gasket is 8.6 for a total of 11.6. Thus the heads have to be down at
63.7 less 11.6= 52.1cc
If you try to use the .028s chances are they will blow into the valley at this pressure.
In any case, this is gonna run the machining costs up, because nearly everything is gonna have to be machined and custom fitted together.
Whereas,
for iron heads to get to 160psi @9.7 Scr is nearly a bolt-together effort. Total chamber volume @ 3.94 bore is 76.1cc, (versus 63.7cc for the alloys), which is a huge deal. This allows ~64.5cc heads on the above block. Or with the pistons down at .057(11.2cc) and the .028 gaskets(6.2cc) now, the need to be ~58.7. A quick deck-swipe will bring that to a standard 60cc head, or at least close enough..
But in the end, she is still down 30psi from the alloy heads which bring the potential of increased airflow with the same cam.
I know
what I would do, and I know what I wouldn't do.
It's so much easier and cheaper to do with a 360, to get the same power with so much less cam, and then sip 87E10 at the rate of some 30% less, at hiway speeds, than the HO 318; and maybe a total of say 50% less if taken advantage of, by gearing the 360 to match the second-gear road-torque, with say 20% less rear gear.
And I guarantee that having a 360 under the hood, you will never say; " I shouldda built a 360."
With a 360,
What you save in machining costs, and not having to buy a higher stall convertor, nor big street gears, and not having to run 91 gas at every fill-up, and all the while idling down the hiway, will easily pay for a 360 short and some nice alloy heads, in less than 12,000 miles. At least that was my payback period, less than two summers.
If I was forced by circumstance,
to use a 318 block, I would likely bore it out to use a 340 piston, which already comes with a high-enough compression ratio, to use those sick .053 headgaskets that come in the gasket kits, which are accumulating in my rafters.......
hmmmmmmmmmmmmmmmmm maybe next winter.
----------------------------------------------------------------
Facts, in my 367;
>I have run up to 195psi on 87E10, with no detonation.
>I have geared it to run 65mph@1600rpm and gotten 32mpg (USg) on a certain day-trip.
>The lowest pressure I have run is 177psi, with the engine now tired and having over 125,000 hard hard miles on her.
>Just 4* of later-closing intake valves is already noticeable.
I see
no reason that
> a sweetly built 318 cannot match this in every way except absolute power................. but is starts with having the pressure.
> Lack of Pressure is like a powerlifter not working out for a week or two, then coming to the station, loading up with his usual weight, and NADA.
Please coach, take off 10% and let me try again,
and still NADA,
please coach ........... take off another 10%
and so on.
> I know you have a 69 car, which should be a 9/1 Scr engine, but it's the piston height and chambers that made it a 9/1. Without knowing
where the pistons are, relative to the decks, and
the size of the combustion chambers, and
when exactly the intakes closes;
it's like watching a blind-man trying to find the loo, in a strange place. There's gonna be a lotta banging around in the hallway, and maybe he never gets there in time......
These are my opinions, top to bottom, interspersed with my experiences.
................ just try to run the same 195psi with iron heads on 87E10, that can easily be run with alloy heads; good luck.
I mean making the pressure, to make the torque, to make the Power, is the whole point for the existence of an internal combustion engine.
So if yur not running the pressure up,
then you're missing the entire point of running alloys;
air-flow not withstanding.
Said another way;
If the pistons in your already-built short-block, are down in the holes, in the usual places, it will be impossible to make decent pressure with any head period, and so, IMO, spending good money on alloy heads is a waste.
I'm not saying impossible to make decent POWER, which is a function of rpm;
just impossible to make decent pressure.
At the best, with an Ica of 62*, the pressure will come in around 150/155psi; at the BEST! More likely is 140ish
Without the pressure, the bottom end will go soft, forcing you to increase the stall and the rear gear, in that order.
_____________________________________
Notta chance would I screw an engine together with alloy heads; and not address the Quench, and not run the cylinder pressure up to near the max, for 87E10, to enjoy both power and economy of operation, and the fun factor.
I mean 195psi versus 165 is a night and day different engine.
To get the pressure up with a typical 268* cam, with alloy heads, is gonna require the Scr to be in excess of 11.2/1 , maybe closer to 11.4, depending in the actual ICA.
For a 318, 11/4 is gonna require a total chamber volume of no more than 63.7 cc; and therein lies the problem, how to get down that low. To run the rock-solid-dependable Felpro .039s the pistons will need to pop up to get the Q down to say .030. But those pistons will need to then be machined for valve clearance.
Say the net on that is 5 less 2 is 3cc, and the gasket is 8.6 for a total of 11.6. Thus the heads have to be down at
63.7 less 11.6= 52.1cc
If you try to use the .028s chances are they will blow into the valley at this pressure.
In any case, this is gonna run the machining costs up, because nearly everything is gonna have to be machined and custom fitted together.
Whereas,
for iron heads to get to 160psi @9.7 Scr is nearly a bolt-together effort. Total chamber volume @ 3.94 bore is 76.1cc, (versus 63.7cc for the alloys), which is a huge deal. This allows ~64.5cc heads on the above block. Or with the pistons down at .057(11.2cc) and the .028 gaskets(6.2cc) now, the need to be ~58.7. A quick deck-swipe will bring that to a standard 60cc head, or at least close enough..
But in the end, she is still down 30psi from the alloy heads which bring the potential of increased airflow with the same cam.
I know
what I would do, and I know what I wouldn't do.
It's so much easier and cheaper to do with a 360, to get the same power with so much less cam, and then sip 87E10 at the rate of some 30% less, at hiway speeds, than the HO 318; and maybe a total of say 50% less if taken advantage of, by gearing the 360 to match the second-gear road-torque, with say 20% less rear gear.
And I guarantee that having a 360 under the hood, you will never say; " I shouldda built a 360."
With a 360,
What you save in machining costs, and not having to buy a higher stall convertor, nor big street gears, and not having to run 91 gas at every fill-up, and all the while idling down the hiway, will easily pay for a 360 short and some nice alloy heads, in less than 12,000 miles. At least that was my payback period, less than two summers.
If I was forced by circumstance,
to use a 318 block, I would likely bore it out to use a 340 piston, which already comes with a high-enough compression ratio, to use those sick .053 headgaskets that come in the gasket kits, which are accumulating in my rafters.......
hmmmmmmmmmmmmmmmmm maybe next winter.
----------------------------------------------------------------
Facts, in my 367;
>I have run up to 195psi on 87E10, with no detonation.
>I have geared it to run 65mph@1600rpm and gotten 32mpg (USg) on a certain day-trip.
>The lowest pressure I have run is 177psi, with the engine now tired and having over 125,000 hard hard miles on her.
>Just 4* of later-closing intake valves is already noticeable.
I see
no reason that
> a sweetly built 318 cannot match this in every way except absolute power................. but is starts with having the pressure.
> Lack of Pressure is like a powerlifter not working out for a week or two, then coming to the station, loading up with his usual weight, and NADA.
Please coach, take off 10% and let me try again,
and still NADA,
please coach ........... take off another 10%
and so on.
> I know you have a 69 car, which should be a 9/1 Scr engine, but it's the piston height and chambers that made it a 9/1. Without knowing
where the pistons are, relative to the decks, and
the size of the combustion chambers, and
when exactly the intakes closes;
it's like watching a blind-man trying to find the loo, in a strange place. There's gonna be a lotta banging around in the hallway, and maybe he never gets there in time......
MOPAROFFICIAL
Oogliboogli
You sure typed a lot for a question you say is impossible to answer.
MOPAROFFICIAL
Oogliboogli
The Speedmaster heads are okay, I would just say that the guides are a hair on the loose side, and I'd add that the valve job is garbage at two angles and in order to get it right you need to put it down/sink it about .030 to get the proper top cut with 3 or 4 angles.
Magnum heads from speed master are absolutely not usable out of the box.
Magnum heads from speed master are absolutely not usable out of the box.
Why use 62* a comp cam xe275h is a 63* there's a lot more reasonable cams then that for a 318. Like xe250h, 51* or xe256h 54* are a more reasonable choices even the xe262h 57*, xe268h 60* are less then your eg..
I imagine you could fine similar cams to xe250h or xe256h on 108-107 for even closer lvc to the stock 48* and or change the install angle.
How much do you think you can get away with changing the lvc, how many degrees from stock 48*?
Eg. Like comps xe250h it's got to worth going 51* to gain 30-40hp.
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