64mopar
Well-Known Member
Wrong.
The 302 heads are closed chamber and will help raise compression.
They will flow fine on the 318,they will help with low end and throttle responce.
Need 318 help/advice
- Thread starter Claude C
- Start date
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The 302 heads are closed chamber and will help raise compression.
They will flow fine on the 318,they will help with low end and throttle responce.
MOPAROFFICIAL
Oogliboogli
Yeah and if this were a big block that would be like taking off your 906s to put on some 516's. The 302 head flows less than a regular open 318 head without a considerable amount of work.
If compression were everything we would all be driving diesels.
The 302 doesnt flow the peak till a lot higher lift...because it's like a gopher trying to stick its head out of a hole.
I'm not into plugging my youtube...but I flow it in a video and then do a better valve job and relieve the chamber around the short turn. It's a big difference.
Whatever you read about you better read again. That head as cast is a piece of ******* ****. I hate sounding like this but dude I've been here and done this, I have many names... if you read ...I dont lie.
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64mopar
Well-Known Member
It is not a big block.
Good thing it is not a gopher.
Again, those heads will flow fine for a 318 street motor.
I ran those heads on a 318 truck and would spin a pair of 295 50 15 tires with ease.
Did I not read about a 400 hp build with those heads on a 318,I think,yes.
The 302 head shines best when we’ll ported.
Otherwise, stick with what ya got on top.
Otherwise, stick with what ya got on top.
MOPAROFFICIAL
Oogliboogli
He doesn't get it. He is one dimensional.
MOPAROFFICIAL
Oogliboogli
For you to be pushing so hard your advice it's sad you don't even know what I'm talking about. Way back when I would call you a brain dead cumfart and taunt you until you cried to a mod.. but I'm past that now. You don't know, but when you're ready... you'll get it. Best of luck in your learning curve. I'm being sincere. I don't want you to believe fallacy.
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dirty white boy
50 yr old Juvenal delinquent
im a big fan of 302 heads when use for what thay are!! but gotta say keep them X heads!! might pull them off and cc them then have them shaved depending on there cc!! what ever cam you go with, degree it! if you dont know how, learn! ....it ant a mack, and mack's ant known fer HP or speed!
MOPAROFFICIAL
Oogliboogli
This x10.
Some of us don't mind living with a little too big of a cam while others cannot stand it and dont like driving around the cam range manual shifting autos and rolling starts.
I like that right cam for the combo, I dont wanna leave any power on the table or get caught out of my range
Dartswinger70
Well-Known Member
Ehhh...the life of a 318,guy, isn't enough to have the engine but then ya hafta figure out what cam,heads, then take it apart and swap it around,even if it runs good with stock heads and Carter2 barrel...
MOPAROFFICIAL
Oogliboogli
Drill jets and solder n refinish rods...play with the step up arm and spring.
MOPAROFFICIAL
Oogliboogli
All most of them need is a good tune up.the 4 brl mostly just picks up the 4000 and up...which is near the top of the cam range.
Road Grabber
Well-Known Member
I had a 1970 318 with heads I ported myself with a cam relative to a stock 340 cam. I ran across an old Hot Rod magazine that mentioned the use of a 273 four barrel carb which I still have. It ran great. It had great bottom end torque.
People couldn’t believe it was just a 318 in a heavy 1969 Charger. Is maybe the carb too much causing it to bog?
I also had a stock 360 in the car with a four barrel out of a 1973 dodge polara. Unbelievable torque that put you back in the seat. Sometimes too much is not that right fit for the street.
I had a friend with a dodge van with a 318 and the 360 heads that was impressive.
I have the 273 carb for sale if you are interested. Good luck.
People couldn’t believe it was just a 318 in a heavy 1969 Charger. Is maybe the carb too much causing it to bog?
I also had a stock 360 in the car with a four barrel out of a 1973 dodge polara. Unbelievable torque that put you back in the seat. Sometimes too much is not that right fit for the street.
I had a friend with a dodge van with a 318 and the 360 heads that was impressive.
I have the 273 carb for sale if you are interested. Good luck.
1) any clue what pistons are in there? 2)why in the hell remove the torque converter? Unless a really inefficient old one, that should've stayed for this cam, & the new one ain't good for much.Bought a 1970 318cid. Engine has 340X heads, new Holley Growler 600cfm, electronic ign., 3.23 sure grip. Had a cam that was too big for what I wanted (didn't want to idle, exh. smelled like unburnt fuel due to what I was told was the cam overlap?, and was doggy on take-off)and had 3,200 stall conv. Inquired here and was recommended Comp Cam #20-224-4 (.488 lift/274 duration). Had this cam installed and changed stall cov. to 1,800-2,200. Sounds nice and goes nice down the road, but still doggy with no initial take-off, will barely chirp the tires. Just wanted to make it (1966 Barracuda) a weekend driver to drive around with the kids.... and maybe squeal the tires at a light if needed!I haven't had the time to do any of the work so have had a couple local mechanics doing the work. I am just wondering if they are missing something? It seems like the engine has all it would need so I am seeking opinions here . Wondering if it could be fuel/ignition. I had to jump start it yesterday and alternator wasn't charging well. Full-fielded the alternator and jumps way up. Could possibly be poor ground at regulator?..and this issue would probably cause weaker spark/ignition? I am tempted to switch back to old distributer with points & condensor. Opinions welcomed. Thanks-Claude
3)yes low voltage can hurt output, of course check ground/correct issue.
4)not knockin' the guy, but don't assume because they've "been around" means they're good at it. I've worked with guys older than Me I wouldn't let put a bicycle chain on.
5)that cam's a tad beefy for Your intent @236deg at .050, needs squeeze and more stall....
6)plenty of ??? Timing, cam centerlined/correct, carb adj esp float level high enough/correct, ......
8formulas
Well-Known Member
Hey Claude C, are you confused yet?
MOPAROFFICIAL
Oogliboogli
A bunch of parrots and actuall folks testimonials, both pro and con...
Let's analyze this some and break it down to groups.
1.Those who have run them on the street.
2.Those who just parrot what they've heard or been sold.
3.Those who have modified and run them and made great power with time slips to prove it.
4.Those who have flow tested them and other heads for comparison and have modified and verified the improvements at track on a flow bench or on a dyno.
The only meaningful opinions are from 3. & 4.
Not out of disrespect,l to 2 and 1
... only because "butt dynos" vary... a lot more than a time slip , flow bench or actual dyno will. It is just like the old saying of "300 hp is another mans 400hp".
People want "x" amount and don't realize that "w" ..was plenty, for them.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Pressure is power, especially at low-rpm.
Consider how a diesel makes low-rpm power, with a fuel that has less energy in it per pound than does gasoline.
Or how does a turbo/supercharger work? It stuffs more air into the cylinder so you can add fuel ...... to increase the pressure.
The very last thing you want to do to a gas engine destined for street duty, is to reduce it's pressure.
This goes triple for a low-pressure 318.
The fastest way to lose pressure in any engine, is to bolt on some bigger-chamber heads, and the second fastest is to stuff a cam into it that has a later-closing intake valve.
These are the two things that most often get done to a 318. And these two things; with no other changes, when done to a nominal 8/1Scr 318, will immediately make the bottom end (say below 3000/3500rpm) very very soft.
It sorta worked, back in the day when the 318 was a nominal 9.2/9.0 engine , because we had never even heard of 2.20 or 2.45 gears, and our 318 cars already had 3.91s/4.10s because that was the fastest way to performance, back then; and we all knew it. So the next step was always to bolt on the 340 top-end.
But that crap don't fly for a Smoggerteen, that altho advertized at 8.0 Scr, never was, and when you take out the .020 318steel shim gaskets, and swap in .039/4.18diameter composites, it only makes a bad situation so much worse.
Now, your 1970 model 318, probably came with a 9.0 Scr so that would give you some wiggle room. But that was 50 years ago so who knows what Scr it is sporting today, which is why I suggested to start with a Compression test ..... to see how bad it really is.
If you had a true 9.0 318LA, your Total chamber volume would be ~81.5cc..
Just the headgasket change will add about 5cc to your total chamber size. And say your valves have receded, adding another 1.5cc; and so the total chamber size has grown to 88cc.
The net effect of just these two, is that your 9.0 engine is now, just 8.4..
Given this as gospel, your 318LA at sealevel, is likely to make about 147psi.
By a more typical elevation of 800ft this has dropped to 143 psi. Now there is a performance factor that combines pressure and volume, and spits out a whole number that is useful to compare engines of various displacements, as to low-rpm performance. In the case of the 8.4 318 at 800ft, the formula spits out a P/V of 118.. Read about it here;
V/P Index Calculation
Adding the X-heads at 72cc, over the 60cc 1970, 318LA heads adds another 12 cc . Yes 12cc.
Your new Scr with a total chamber volume of 100cc comes to 7.5, and your pressure is predicted to fall to 123psi and the P/V to 101. That is equivalent to a 14% loss of low-rpm performance
Next; lets install that 340 cam, with it's Ica of 64* (compared to the 318 cam at 50*). The pressure falls to 101psi and the P/V to 80. At P/V of 80, compared to a starting P/V of 118, you are now down 32%
BTW P/V of 80 is LESS than a stock 225 slanty puts out.
I don't care what anybody tells you; with no other changes
this is exactly what happens in real life; your 9.0 advertised 1970 318LA will turn into an azz-dragging turd, until that 340 cam starts waking up at about 3800 rpm.
With 3.23s and 26" tires, that is about 31mph
With the stock TC, that mightabin a 2200@PV of 118; but might now be a 2000@ PV of 80, it will just be a horribly embarrassing turd of a combo until it gets to around 3800rpm.
I have done this just once for myself, and twice for idiot buddies, at their insistence, and can testify to the lunacy of doing this.
And there have been several FABO members over the years, that have been brave enough to step forward and concur, that this is what happens in real life. And the only way to band-aid such a sad situation is with a hi-stall TC and "race gears" like 3.91/4.10s .
BTW
A good P/V number is 140 or more. But I don't think you can get an iron-headed 318LA up there, and still be able to floor it.... with a 4bbl..
Consider how a diesel makes low-rpm power, with a fuel that has less energy in it per pound than does gasoline.
Or how does a turbo/supercharger work? It stuffs more air into the cylinder so you can add fuel ...... to increase the pressure.
The very last thing you want to do to a gas engine destined for street duty, is to reduce it's pressure.
This goes triple for a low-pressure 318.
The fastest way to lose pressure in any engine, is to bolt on some bigger-chamber heads, and the second fastest is to stuff a cam into it that has a later-closing intake valve.
These are the two things that most often get done to a 318. And these two things; with no other changes, when done to a nominal 8/1Scr 318, will immediately make the bottom end (say below 3000/3500rpm) very very soft.
It sorta worked, back in the day when the 318 was a nominal 9.2/9.0 engine , because we had never even heard of 2.20 or 2.45 gears, and our 318 cars already had 3.91s/4.10s because that was the fastest way to performance, back then; and we all knew it. So the next step was always to bolt on the 340 top-end.
But that crap don't fly for a Smoggerteen, that altho advertized at 8.0 Scr, never was, and when you take out the .020 318steel shim gaskets, and swap in .039/4.18diameter composites, it only makes a bad situation so much worse.
Now, your 1970 model 318, probably came with a 9.0 Scr so that would give you some wiggle room. But that was 50 years ago so who knows what Scr it is sporting today, which is why I suggested to start with a Compression test ..... to see how bad it really is.
If you had a true 9.0 318LA, your Total chamber volume would be ~81.5cc..
Just the headgasket change will add about 5cc to your total chamber size. And say your valves have receded, adding another 1.5cc; and so the total chamber size has grown to 88cc.
The net effect of just these two, is that your 9.0 engine is now, just 8.4..
Given this as gospel, your 318LA at sealevel, is likely to make about 147psi.
By a more typical elevation of 800ft this has dropped to 143 psi. Now there is a performance factor that combines pressure and volume, and spits out a whole number that is useful to compare engines of various displacements, as to low-rpm performance. In the case of the 8.4 318 at 800ft, the formula spits out a P/V of 118.. Read about it here;
V/P Index Calculation
Adding the X-heads at 72cc, over the 60cc 1970, 318LA heads adds another 12 cc . Yes 12cc.
Your new Scr with a total chamber volume of 100cc comes to 7.5, and your pressure is predicted to fall to 123psi and the P/V to 101. That is equivalent to a 14% loss of low-rpm performance
Next; lets install that 340 cam, with it's Ica of 64* (compared to the 318 cam at 50*). The pressure falls to 101psi and the P/V to 80. At P/V of 80, compared to a starting P/V of 118, you are now down 32%
BTW P/V of 80 is LESS than a stock 225 slanty puts out.
I don't care what anybody tells you; with no other changes
this is exactly what happens in real life; your 9.0 advertised 1970 318LA will turn into an azz-dragging turd, until that 340 cam starts waking up at about 3800 rpm.
With 3.23s and 26" tires, that is about 31mph
With the stock TC, that mightabin a 2200@PV of 118; but might now be a 2000@ PV of 80, it will just be a horribly embarrassing turd of a combo until it gets to around 3800rpm.
I have done this just once for myself, and twice for idiot buddies, at their insistence, and can testify to the lunacy of doing this.
And there have been several FABO members over the years, that have been brave enough to step forward and concur, that this is what happens in real life. And the only way to band-aid such a sad situation is with a hi-stall TC and "race gears" like 3.91/4.10s .
BTW
A good P/V number is 140 or more. But I don't think you can get an iron-headed 318LA up there, and still be able to floor it.... with a 4bbl..
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Part of the advice "scatter" is that Claude C has been unable to provide critical details about what cam He started with, what actual compression this thing has w/X heads, what size headers, etc., etc., the things that can have a dramatic effect on the low end. One of the effects of those heads is that the extra flow will make the 'teener more sensitive to being over-cammed, particularly if nothing was done to put the squeeze where it belonged. I had a former co-worker that raced a mid '70's Nova w/a 454 ran 12.40's, put a new set of headers on & lost 4 tenths, wondered WTF? lol! I said, "those look like 2&1/8", bigger than the old ones...", yep...sent them back & got a smaller set and back came the .4 sec., point is even big blocks are sensitive to "too big" syndrome.
To give good advice, one has to gather all of the relevent information first, then know precisely what the person wants.......IF they even know.....
Dartswinger70
Well-Known Member
That explains alot. In my 318 with stock heads and the summit .444 cam, it would run up to a point then sorta "level off" in the pulling power...it was like it was done at 5000-5500 no point in flooring it any more...itd be doing 100 miles an hour though with 3 91s...
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