small block heads

[bambam]

Are the heads from a 1987 360 motor a direct bolt-on to a 1970 318?

[dwc43]

Yes, but not as good as the older X,U,and J heads. Make sure to fit them with 2.02 intake valves while you have it apart for more performance. Also take .035 off the heads to raise the compression ratio up a bit.

[eric414]

If the casting # is a 308 get the heads done and bolt them on and forget the old,old school x and j's

[mopar_nocar]

i'd NOT install 2.02 valves for a street driven motor. race only, yup, 2.02s all the way. cut the heads between .035 and .040, try to get between a 58-60cc combustion chamber.

if you just want to see if they will work to get ya' down the road, they will, just bolt 'em on, but get ready for some VW bug type compression.

btw, what intake/carb combo do you plan to use with it?

sb

[fastback340]

Sell them and buy a set of 93-200 Magnum heads. they flow better, have better velocity for more torque and have smaller chambers for more compression.

[dwc43]

They also have a bottle neck in the intake that you can't port around that wastes HP over the older X,J,and U heads. They use a valve train that causes flex and harmonic problems as well. You'll need a stud girdle, if they are even making them yet. Not worth the trouble.

[TK]

HoooBOY! the good ol magnum vs old head debate! I just cant resist!

Now, as far as the bottleneck effect? dwc is right, there is no way around it. Same as the rockers, you can abuse them in everday use, but they are not as good as rockershafts, so why have good when you can have great?
(I)would go with the 308 heads before the magnums, close to the same performance as the magnums, but they have rockershafts. (I would use them since you have them)
Make sure you cc your 318, and deck it before you mill the heads (piston in hole=wasted horsepower)
As far as the old heads? If you have a set of J's or X'es, use them, they build more HP for the same work. (no 2.02's on a 318)
Question!?
where are your 318 heads? A 70 318 has awsome heads for the street! Just install 1.88/1.60's, and some minor bowl/port work! (675 castings?)

[mopar_nocar]

i can attest to the 675 castings working really well. i did exactly what dodgetruckboy is talking about and whooo-wee that little small block would sing. scaird the farmer next door something terrible when we went for a ride!! 8-)

[70AARCuda]

Throw it all away..and buy a set of Edelbrocks.....

And make sure you run a Thermoquad...

[TK]

Originally Posted by 70AARCuda

Throw it all away..and buy a set of Edelbrocks.....

And make sure you run a Thermoquad...

LOL!!!!!! I wish I could too!


UH OH. I see LA360 dart lookin at this thread (LOL!)

[George G. Leverette]

The best small block head for the money is the Mopar P4529574, these heads are machined for 2.02 I 160 E and features the latest swirl port technology. I replaced the Eddy RPM heads and intake with 750 Holley with the 574s, stock intake, and Thermoquad on a Duster 340. The 340 in a 72 Duster is much faster in all ranges than the Mopar short block 360 in a 74 Duster equipped with the parts removed from the 340. The 574s cost much less through the dealers than the eddys.

[LA360Dart]

I have used both "X" and Magnum heads and there is a lot of good to Magnum heads. The pinch at the intake is very similar to the "X" head but the port uses other ways to make power. The velocity is better, balance between intake to exhaust is close to 80%, the "X" head is approxamately 60% at best This can be overcome with split pattern cams. In the 35 years since LA "X" head, port sceince has advanced some.

I wonder if this was a big block if you'd say to run 906 casting or 915 over all the newer big block stuff and run 30 plus year old technology. Maybe with all that dirt track racing experience and the limits placed on Mopars thats all you can use, is the 30 plus year old LA heads. There are better heads than "X" heads in modern times.

Steve D. from Mopar Muscle made 400 hp on a 318 with stock magnum heads no porting at all, a small comp cams cam 230 @ .050 try that with "X" heads and made torque as well, and not have the middle of the power band weak....

[TK]

somewhere here, there is a link to a article where they made over 400HP with small port 318 heads on a 318, with a mild cam, I might go find it.
That does prove your point on the velocity, but, there is a bigger botleneck on the magnum heads, hands down! The roof can be raised more on the X and J heads too.
(675 318 heads can be ported to match the 360 J head flow in stock form, with WAY better velocity)

LOL!!!!!!!!!
nice to see ya keepin us in line still 360 dart! :jackbox:

[LA360Dart]

My 73 Dart Sport340 is 3645 lbs and runs 8.20's at 85 mph in the 1/8th at Mopars at the Strip on Friday morning was it's best pass and at 3500' AD was 13.29 at 101.87 which is 12.83 at 105.6 for sea level thats 425 Hp at the crank with 340 at rear wheels for the MPH being run, not bad for a 850 rpm idle in gear and 15" manifold vacuum. Magnum heads mild porting and unshrouding of valves. Cam is 230 @ .050 with .511 lift, dual plane M1, 650dp speed demon, 727 with 166K mopar converter(2400rpm) and 3.55 and sure grip, G60X15 American Racer tires, not a race car set up at all. I have had other 360's and none run as well as this with similar setups most ran in the 13.7's at 96 The only difference is the Magnum heads...

[dwc43]

Originally Posted by LA360Dart

I have used both "X" and Magnum heads and there is a lot of good to Magnum heads. The pinch at the intake is very similar to the "X" head but the port uses other ways to make power. The velocity is better, balance between intake to exhaust is close to 80%, the "X" head is approxamately 60% at best This can be overcome with split pattern cams. In the 35 years since LA "X" head, port sceince has advanced some.

I wonder if this was a big block if you'd say to run 906 casting or 915 over all the newer big block stuff and run 30 plus year old technology. Maybe with all that dirt track racing experience and the limits placed on Mopars thats all you can use, is the 30 plus year old LA heads. There are better heads than "X" heads in modern times.

Steve D. from Mopar Muscle made 400 hp on a 318 with stock magnum heads no porting at all, a small comp cams cam 230 @ .050 try that with "X" heads and made torque as well, and not have the middle of the power band weak....

We can run any cast iron head we want to including the W2. It may be an old head, but it still makes mroe power and has a valve train that's ten times better than the magnum. Using the chebby junk is going backwards, not forwards. Even chebby racers look to shaft mounte Jesel and other brands. Go look in the circle track section where some are wanting to try magnum heads, but there looking for shaft mounted rocker systems. And set up right, the X wont be 60% off by any means. I wished I could turn loose of some numbers, but I can't do that. Secrets are no longer secrets if you tell everyone everything ... LOL!!

By the way, we were racing 318's making over 400 hp on X and J heads years before that article came out, but we did move on to the 360 since they were available and make ever more torque and hp with the higher rpms. 400 hp is not that hard to come by.

[fastback340]

Bottle neck or not the Magnums still out flow all other factory small block heads. He's building a 318 for the street he needs velocity not a huge port. If hes not planning on porting who cares about the bulge in the intake port wall. The port still flows better then a X head intake port.

[rumblefish360]

Good ol DW still giving advice on to big valves on old heads on small engines.
I have not brought this one up in awhile, but here Mr. Wests 318 build page.
http://www.geocities.com/alwest_83/318
With my fav. part is the last parragraph. Bottom right.

330 horse power @5750rpm. 290 hp with 360 heads.

The heads recieved 1.88/1.60 valves with a valve job and home touch up porting.

[TK]

thank you rumble! thats what I was lookin for!

[TK]

Originally Posted by fastback340

Bottle neck or not the Magnums still out flow all other factory small block heads. He's building a 318 for the street he needs velocity not a huge port. If hes not planning on porting who cares about the bulge in the intake port wall. The port still flows better then a X head intake port.

axactly! so why throw a bottlenecked magnum head in there that outflows a X? (wich it doesnt on the intake side, cant be hogged out as much, cause ya cant port dead air)
besides, it sounds to me like he has 308's, and the stock 318 heads (im assunming).
Rumble got what I was lookin for!

[LA360Dart]

Hi All;

The shaft mounted rockers used by chevrolets is mainly on high RPM small blocks 7500 RPM and above. The AMC style set up used by Mopar is capable of out RPM'ng the 59 deg. lifter angle of the cam for street use anyhow. So that argument is out the window about shaft mounted rockers.

On the X heads exhaust being better than 60% of intake flow even Mr. Bob Mullens best heads that were not completely reworked (read welded) was in the Mid 70% range. Also check Shady Dell's site on J heads and were only 72% of intake flow. They do nothing but port cylinder heads, think that they might have found more flow if it was there. Just my 2 Cents ....

[fastback340]

Heres some flow numbers

These are all off of Ryan J. from shady dells bench.

J heads with 2.02 1.60 valves
LIFT------ASCAST---------PORTED
.100”----62.1/46.6---------62.1/51.8
.200”----112.1/99.4-------135.2/103.5
.300”----156.6/128.3-----198.7/135.2
.400”----193.2/137.3-----239.8/158.7
.450”----200.1/138.3-----253.9/169.7
.500”----200.1/139.7-----258.4/182.9
.550”----200.1/140.8-----264.9/186.3
.600”----200.8/141.5-----254.6/186.3

magnum heads with 1.92 and 1.62" alves
LIFT----AS CAST
---------IN/EX
.100"--67.3/N/A
.200"--131.3/97.3
.300"--185.6/132.5
.400"--212.5/144.9
.450"--213.9/146.3
.500"--212.2/146.3
.550"--212.5/146.3
.600"--213.9/146.6
.650"--214.2/147.3
.700"--215.3/147.3

LIFT------IN/EX
.100"--67.3/N/A
.200"--132.8/115.6
.300"--196.0/156.6
.400"--225.0/172.2
.450"--238.1/174.3
.500"--250.5/176.6
.550"--257.1/178.0
.600"--259.1/180.8
.650"--259.1/180.8
.700"--259.8/180.8

The Magnums flow better stock then the Js. Fully ported the Js barley take the lead. So much for the bottle neck.

Plus the Magnums chamber is a much better shape, smaller size and higher rocker arm ratio.

So free cam lift, free compression, better flow and 25 year newer

[dwc43]

1st off, you can't race a flow bench. Good for fine tunning, but that's it, it's just a tool. The rocker set up on the mag heads are the weakest ling ever. On our X,J,U heads we have more rocker ratios than the stock mag head if need be. We can also offset the ratio between ex. and int. sides. Dual pattern cams, etc. etc. etc. And a few tricks I wont tell. You can still do better with the old heads if you know what your doing and there's no bottle neck in the intake to get around either. Go run what you like, we will keep winning with what we know works in real life and not on a bench.

[TK]

you guys are also missing the torque that the X,J,U heads make BECAUSE of the smaller exaust port.
The original question was 308 heads on a 318, MY question is, why put the 308's on it IF he still has the 675 heads to mess with.
So.......also..........what is better, the bottleneck port that flow's XXXXX or, the non bottleneck port that flows the same, or a bit more? Ill stick with my old heads, but, also, may I bring up that THIS IS A 318!

[TK]

Originally Posted by fastback340

If hes not planning on porting who cares about the bulge in the intake port wall. .

cause you cant get rid of the bulge by porting.

[bambam]

I have an 87 dodge pickup going to waste and thought I would pull the heads an stick them on the Challenger (1970 auto with a 318) just for poops and giggles. Only spending $ on gaskets.

Thanks for all the help

Chris

[rumblefish360]

Originally Posted by dodgetruckboy

you guys are also missing the torque that the X,J,U heads make BECAUSE of the smaller exaust port.
So.......also..........what is better, the bottleneck port that flow's XXXXX or, the non bottleneck port that flows the same, or a bit more? :

Your fist sentence is baffffaling.
According to flow work at the sheadydell shop, the bottle neck heads your trashing flow better than your heads your keeping.

[TK]

If anyone knows that flow isnt everything, its you Rumble. The bottleneck heads do have a bottleneck, therefore, behind that bottleneck, there is going to be a loss in velocity (the one that the bottleneck created) wich is not good, for fuel mixing, and torque.
As far as the exaust? The smaller exausr port helps keep torque, and not everyone will benifit from hogging it out to outflow the magnums. (I wouldnt unless I was REALLY serious) But, if your esaust flows almost the same, you got same duration cams, ect,ect to keep torque, but that is another thread eh?
I was refering to the as cast numbers, because most people seem to just slap em on.

[fastback340]

Did you ever look at a Magnum head ? The have smaller exhaust ports then LA heads, not larger. So you pretty much just proved my point. The smaller port not only out flows the X and J heads they have better velocity too.

Take a good look at a magnum head some day. The ports and combustion chamber are just better designs.

DCW, you can get more rocker arms for magnums then you can for LA engines and at half the cost. All you need is a set of screw in studs and you have your choice of 1000s of small block chevy rockers.

Im not saying the X and J heads are no good, Just that the magnums offer a number of advantages at a lower cost. For a 11 to 13 second street strip car its hard to beat them if you want to use a factory head.

[73scamp318]

Originally Posted by dwc43

1st off, you can't race a flow bench. Good for fine tunning, but that's it, it's just a tool. The rocker set up on the mag heads are the weakest ling ever. On our X,J,U heads we have more rocker ratios than the stock mag head if need be. We can also offset the ratio between ex. and int. sides. Dual pattern cams, etc. etc. etc. And a few tricks I wont tell. You can still do better with the old heads if you know what your doing and there's no bottle neck in the intake to get around either. Go run what you like, we will keep winning with what we know works in real life and not on a bench.

HAHAHAHA, the only reason the new heads a junk to you is beacause you don't use them nor know anyhting about them, You are telling me that 8 rockers on a shaft each doing there thing has no problems, flex, harmonics at all? you have no grip on physics.

How much are you able to buy x or j heads for? just about the same price of magnum r/t heads,have you seen those numbers? lets just say that they flow just as good as the w5 heads at .300 and they flow over 300cfm at .600 lift.

FLOW #’s 2.02” Version

LIFT-----AS-CAST--------PORTED
.100”----72.5/N/A--------74.1/N/A
.200”----131.1/117.3-----138.3/105.3
.300”----189.8/158.7-----200.1/151.8
.400”----231.2/175.9-----245.0/186.3
.450”----245.0/179.4-----265.7/193.2
.500”----255.3/181.1-----282.2/198.3
.550”----258.1/182.9-----296.7/202.0
.600”----254.6/184.9-----303.6/204.6
.650”----252.5/186.3-----301.9/207.4
.700”----246.7/186.3-----293.3/209.1

All #’s at 28” water
2.02”/1.625” MP 8 MM Valves
Intake Valves Have Proprietary Back Cut Angle.

FLOW #’s 1.92” Version

LIFT-----ASCAST--------PORTED
---------IN/EX----------IN/EX
.200"--135.6/110.4---148.4/111.8
.300"--194.9/154.9---208.7/155.3
.400"--227.4/173.5---243.2/189.1
.450"--233.9/177.3---252.5/194.6
.500"--239.4/179.4---255.6/197.7
.550"--244.9/180.8---259.1/199.8
.600"--245.0/181.8---268.4/201.2
.650"--245.0/181.8---276.0/203.2
.700"--241.5/183.2---281.2/203.2

man 186 of flow for the j-heads (ex.) and well over 200 for the r/t...hmmmmm which heads would i want? the r/t and thats why im getting them.

you can have the xor j heads, as they are way over priced, have bad exhuast port, and people praise there golry that was back in the 70's. this is like saying that the w2 heads is the best race heads made...(small block)

and what secrets do you have about making the numbers better that the some of the beast heads porters don't know, because if you do you need to get into just porting x and j heads im sure you woul

[TK]

Originally Posted by fastback340

Did you ever look at a Magnum head ? The have smaller exhaust ports then LA heads, not larger. So you pretty much just proved my point. The smaller port not only out flows the X and J heads they have better velocity too.

Take a good look at a magnum head some day. The ports and combustion chamber are just better designs.

DCW, you can get more rocker arms for magnums then you can for LA engines and at half the cost. All you need is a set of screw in studs and you have your choice of 1000s of small block chevy rockers.

Im not saying the X and J heads are no good, Just that the magnums offer a number of advantages at a lower cost. For a 11 to 13 second street strip car its hard to beat them if you want to use a factory head.

Now, the slight problem, you dont want velocity on the exaust side, because velocity means more back pressure, or we would be running 1 1/2 exaust pipes and 3/4" headers, right?
Back to what I said first off, the magnum heads dont make the torque.