Better heads

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To me the 302 heads are very hard to beat on a 318, I have a set on the 322 engine that makes an average of 466 HP and peak HP is 501 on pump gas and 535 on alcohol. Last time out I ran a 7.384 @97 MPH lifting as I caught the guy at half track and just road with him to the finish line. On this run the engine put 355 HP to the ground but theres more left in it yet. The air flow in the heads show to be good to about 375 HP net. This is with a air correction of 1.051 for HP, so 355 X 1.051 = 373 HP which means I'm getting about all you can to the ground from a set of 302 heads. Without any aftermarket parts.
 
BJR, here's what I've got in mind.

I'm planning a warm street build for driving around town and on the highway. I don't anticipate any track time with this car but don't want a dog either (I'd like to be able to get into the 12s if I can).

I have a couple of 318 blocks in the garage that I need to do something with before my wife kills me. I also have on hand a 3.58" stroker crank and a set of low-comp 318 cast pistons (0.040" over) that should put me at zero deck with a little block clean-up.

Both the 302s and EQs have reported chamber volumes of around 62cc so by my calculations, even with valve reliefs of 5cc machined in, I will have about 10.5:1 CR (which several folks say they are running with iron heads given proper quench distance).

I think the 302s are a little low on port volume "as is" for a 350 CI stroked 318 but should they should produce plenty of torque. Looking at the ported 302 flow numbers that you gave in another thread, they should be plenty good for what I'll do with the car. I'm leaning toward 1.88/1.60 valves since I have the additional CIs, and will probably use Comp's XE268H cam.

Maybe I'm going about my head selection all wrong for a mild 350 CI stroker. It would be alot cheaper to just thow on some good 340/360 heads and go with it, but I like the idea of a modern closed chamber head.

Any advise is greatly appreciated.
 
I would still preface those numbers with "Your results may vary" Bobby..lol. Your heads, on your car, with you machining, and you tuning, and a car that is a drag race and sorted combo. I also dont feel really great about 207cfm. Good numbers for the valve size and volume surely, but not enough for what I see being considered for the OP's 318, or 1967's 350" engine. I'd rather run a milder cam with a bigger port than a small port. I just get a better result that way on average. My own feeling is the 302s are a bonus in terms of cash outlay and least invasive. But they will limit both combos in the real world of compromises in conditions.
 
Wow, lots of great feedback. My car is more of a cruiser. I drive it quite a bit in warm weather. Maybe once a year it see's a few passes on the strip. I think the highest rpm I have had it at was 5,500. But more often see's 4,500-5,000 when out having fun. But thats about it. I was just throwing around ideas to get some more power out of it. Lot's of choices though. The more I look at things the more expensive things seem to get once everything is added up. But then again I wouldn't be doing this for several months in the future. Just something to think about.

Thanks for everyones feedback. Lots of great info!
 
BJR Racing said:
To me the 302 heads are very hard to beat on a 318, I have a set on the 322 engine that makes an average of 466 HP and peak HP is 501 on pump gas and 535 on alcohol. Last time out I ran a 7.384 @97 MPH lifting as I caught the guy at half track and just road with him to the finish line. On this run the engine put 355 HP to the ground but theres more left in it yet. The air flow in the heads show to be good to about 375 HP net. This is with a air correction of 1.051 for HP, so 355 X 1.051 = 373 HP which means I'm getting about all you can to the ground from a set of 302 heads. Without any aftermarket parts.
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What kind of intake manifold do you run on that thing?
 
moper said:
I would still preface those numbers with "Your results may vary" Bobby..lol. Your heads, on your car, with you machining, and you tuning, and a car that is a drag race and sorted combo. I also dont feel really great about 207cfm. Good numbers for the valve size and volume surely, but not enough for what I see being considered for the OP's 318, or 1967's 350" engine. I'd rather run a milder cam with a bigger port than a small port. I just get a better result that way on average. My own feeling is the 302s are a bonus in terms of cash outlay and least invasive. But they will limit both combos in the real world of compromises in conditions.
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True, I was going to suggest a small valve 340/360 head 1.88/1.60 that comes from the factory at 150-152 cc's. Sure the chamber is larger but with that cam and the lack of overlap on it, this will increase the cylinder pressures a good bit. Also too doing a cleanup cut and the thin head gaskets will help in running the pump gas. I would do a good VJ and a bowl cut on both sides and some light duty hand blending and he should have 230 cfm's or so on the intake side and about 180 or so on the exhaust side. This should be more than enough for what he wants to do.
 
A 344/349 engine really needs this size head on it, just due to the amount of stroke that the engine will have. Also to the cam has alot to do with what size head is used.

Something in the 272/276 @ .050 with a 104 CL can use the small 302 head to the engines adavantage, due to the large amount of overlap the cam has and the loss of port velocity and cylinder pressure. This is why I say that not every head will work on every engine. To me it's more of a specific head for a given engine. I guess I science my engines out too much, so true others may not have the same results that I get, but then hey anything I have is for sale. LOL
 
BJR,
Thanks for the info regarding head choice for a 318/349 stroker combo. What port volume and cfm do you generally consider optimal for a 318 head and for a 340-360 head?
Thanks again!
 
67,
Once again it's build dependant for head choice. For a given 318 .030 with KB167 pistons I would use a 302 head with 136 cc's of intake port volume and 225-235 cfm's and this is achievable with a 1.78 intake valve. Just like I just flowed a head for another customer and the exh. flowed over 200 cfm's with a 1.50 valve.

As for a 318/349 combo I would use something like 155 - 160 cc's of intake port volume with a 1.88 and a 1.60 valves that should flow in the 240-260 range and the exh. should go in the 180-210 range. But as I've said before it really depends on the cam and compression that the engine will end up with. This is why it's very build dependant as to modifications done to the heads. I hope I'm not being too vauge but every engine is different, just as machininst's are and the equipment that they use. But good quality should still be good quality reguardless of what it is or how it's done.
 
BJR were those 318 magnums you referred too as "the biggest dogs you'd ever seen" in stock trucks with original computers, etc? Reason I ask is I had a 93 Dakota I bought new with a 318 mag and when I got it it ran adequate but wasn't all that impressive. I added short tube headers with dual exhaust and a Mopar perf. computer and nothing else. It was like a whole different truck. With a peg leg 3.55 rearend it ran a best of 14.46 @ 96 mph and 14.60 consistently spinning 10-20' out of the gate. I found it was the computer that really made the diff. Apparently they had the timing very conservative from the factory. I have throughout the yrs. known numerous guys with 70's LA 318 Dodge pickups, a few of which I helped tune for best perf. and none of them came anywhere close to the way mine ran. I'm not trying to make it sound like I had some sort of a race truck but rather stating that in comparison my 318 magnum with it's ports that you say are too big for a 318 would run circles around the older ones. I have also driven one other 318 magnum full size Ram (short bed , reg. cab. all stock) and it ran stronger than my Dak did when mine was stock. I know you know more than I do about heads and perf. in general but to say the 318 magnum is the doggiest 318's ever I can't agree with. JMHO
 
I find that statement "Biggest Dogs Ever" a surprise myself. The ports may be a bit big, but I can't see it dogging the engine down that much.
 
hi, from all the big flow numbers shown here, what test pressure they taken at? was that 7'38 in the 1/4 mile? or 1/8 mile? just curious. big numbers sell.
 
perfacar said:
hi, from all the big flow numbers shown here, what test pressure they taken at? was that 7'38 in the 1/4 mile? or 1/8 mile? just curious. big numbers sell.
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perfacar,
It was in the 1/8 mi.. The test pressure is 28".
What some think is that this engine is all tricked out, this couldn't be farther from the truth, as this engine has all stock parts, except for replacment pistons and a M-1 intake and holley carb and a cam from Comp cams, I did go to shorty hedders though.
 
fishy68 said:
BJR were those 318 magnums you referred too as "the biggest dogs you'd ever seen" in stock trucks with original computers, etc? Reason I ask is I had a 93 Dakota I bought new with a 318 mag and when I got it it ran adequate but wasn't all that impressive. I added short tube headers with dual exhaust and a Mopar perf. computer and nothing else. It was like a whole different truck. With a peg leg 3.55 rearend it ran a best of 14.46 @ 96 mph and 14.60 consistently spinning 10-20' out of the gate. I found it was the computer that really made the diff. Apparently they had the timing very conservative from the factory. I have throughout the yrs. known numerous guys with 70's LA 318 Dodge pickups, a few of which I helped tune for best perf. and none of them came anywhere close to the way mine ran. I'm not trying to make it sound like I had some sort of a race truck but rather stating that in comparison my 318 magnum with it's ports that you say are too big for a 318 would run circles around the older ones. I have also driven one other 318 magnum full size Ram (short bed , reg. cab. all stock) and it ran stronger than my Dak did when mine was stock. I know you know more than I do about heads and perf. in general but to say the 318 magnum is the doggiest 318's ever I can't agree with. JMHO
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Yes that what I was referring to, in the stock form. But then with what you added to yours it should have picked up something but then so would the earlier version engines with the same amount of mods done to them.

For a comparision to your 318 magnum engine in your truck, we have a old version 318 with a standard bore and a .501 comp cams cam and 3675 set of heads with stock valves and a M-1 intake and a set of hedders on pump gas and the car weighs in at 3330 lbs. and just last week even being out of tune ran 7.89 @ 88 mph in the 1/8 which this puts the old style 318 engine in the low 12's or upper 11's. The heads have a good VJ and a 75* bowl cut only and have been gasket matched on the intake side, the exh. was left untouched other than what the machine cut at the VJ. Were looking for some low 7.70's or upper 7.60's this week, with the carb jetting that we did.

You also have the advantage of being double quenched in the heads and we have a open style chamber, which this is a advantage for you and for comparision sake would be closer to the 302 heads. So yes I in my own opinion I personnally wouldn't ever use a magnum head on a 318 engine. And my reason for this is too much port volume, too big of intake valve, the bowl in the heads are too large for short stroke and small bore engine. This is where the 5.9/360 engine works much better with the magnum heads. Because they have everything that the 5.2/318 engine doesn't in reguards to bore and stroke. My personal opinion is that they tried to pattern the magnum head after the likes of the 440-1 head when they first came out. The bowls were so large that they wouldn't make any power til you turned the crap out of them. They are also in the 160+ cc range from the factory which doesn't bode well for Tq on a NA engine of this size and bore.

The reason that they work better on the 360/5.9 engine is the piston speed is much faster and the larger bowl will work better, something along the lines of a BBC engine. Now this isn't to say that they wouldn't work well on a 349 style engine as the stroke would be much longer and could make better use of the larger port volume, and piston speeds. Once again similar to the BBC.

Also to in your comparision to the older version engines that your friends have is that your also fuel injected which should be a gain on any engine. And you never mentioned weather the older engines had small 4 bbl carb or 2 bbl carb on them. So were not really comparing apples to apples here.

Sorry for being so winded but IMO I won't use the magnum head on any 318 that comes from me. Maybe thats why I'm getting the performance that I do. But this is MPO.
 
BJR Racing said:
Yes that what I was referring to, in the stock form. But then with what you added to yours it should have picked up something but then so would the earlier version engines with the same amount of mods done to them.

All I added were short tube headers and dual exhaust and the mopar computer would only do the same job as super tuning an older engine i.e. maximizing timing and fuel curves.
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For a comparision to your 318 magnum engine in your truck, we have a old version 318 with a standard bore and a .501 comp cams cam and 3675 set of heads with stock valves and a M-1 intake and a set of hedders on pump gas and the car weighs in at 3330 lbs. and just last week even being out of tune ran 7.89 @ 88 mph in the 1/8 which this puts the old style 318 engine in the low 12's or upper 11's. The heads have a good VJ and a 75* bowl cut only and have been gasket matched on the intake side, the exh. was left untouched other than what the machine cut at the VJ. Were looking for some low 7.70's or upper 7.60's this week, with the carb jetting that we did.

I'm sorry Bobby but that's not much of a comparison IMO. Mine had the stock cam which is a bunch smaller than yours. Stock valve job with no bowl work or port matching. Short headers vs. your long tubes. And your M1 will make a ton more upper power than my stock magnum beer barrel that flattens out at 4500 rpm. And my truck weighed nearly 400 lbs more and of course has terrible aerodynamics compared to a car. Also mine had the stock 3.55 geared single leg rearend and a stock converter. Yours certainly should go allot faster.
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You also have the advantage of being double quenched in the heads and we have a open style chamber, which this is a advantage for you and for comparision sake would be closer to the 302 heads. So yes I in my own opinion I personnally wouldn't ever use a magnum head on a 318 engine. And my reason for this is too much port volume, too big of intake valve, the bowl in the heads are too large for short stroke and small bore engine. This is where the 5.9/360 engine works much better with the magnum heads. Because they have everything that the 5.2/318 engine doesn't in reguards to bore and stroke. My personal opinion is that they tried to pattern the magnum head after the likes of the 440-1 head when they first came out. The bowls were so large that they wouldn't make any power til you turned the crap out of them. They are also in the 160+ cc range from the factory which doesn't bode well for Tq on a NA engine of this size and bore.

You are correct that a fairer comparison is to the 302 head due to chamber design. You are quite possibly right about them being too large for a small 318 engine but I can't help after seeing many of them easily run mid to low 14's in a truck with the aerodynamics of a brick think their not all that bad.
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The reason that they work better on the 360/5.9 engine is the piston speed is much faster and the larger bowl will work better, something along the lines of a BBC engine. Now this isn't to say that they wouldn't work well on a 349 style engine as the stroke would be much longer and could make better use of the larger port volume, and piston speeds. Once again similar to the BBC.

Also to in your comparision to the older version engines that your friends have is that your also fuel injected which should be a gain on any engine. And you never mentioned weather the older engines had small 4 bbl carb or 2 bbl carb on them. So were not really comparing apples to apples here.

Your right about the diff. in intake/carb differences in most cases that the fuel injection did help but to make it honest I'll compare mine against my buddies 78 short bed pickup with a 318 and 72 340 intake and thermoquad. Mine was only 50 lbs. less but yet consistently ran over a full second faster. The only advantage mine had over his was shorty headers and 3.55 gears vs. 3.21 gears which I doubt will make a truck go over a second faster. Please refer to post #6 where I mentioned his truck and you'll see where I said his had the 4 barrel and carb.
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Sorry for being so winded but IMO I won't use the magnum head on any 318 that comes from me. Maybe thats why I'm getting the performance that I do. But this is MPO.
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I understand you have to use what works for you and if you think stock magnum heads are junk then by all means don't recommend them or use them but I just can't agree with the statement that they "are the biggest dogs ever". For me and allot of other guys I've seen they do work well right out of the box with no fancy valve jobs. JMHO

Thanks for your reply Bobby.
 
fishy,
I agree that we have to use what works best for each of us.

On your statement on aerodynamics, I don't think that a 71 Duster qualifies for being the slickest aero car out. LOL
But better than a truck, I agree. But for point sake and the 400 lbs difference of yours and our duster that 14's and 12's don't compute. Cam and intakes are only worth about 1/2 a sec. or so. As the faster you go the more power it takes to go faster.

We had a bone junkyard stock 318 2bbl engine in the duster a few years back and it ran 8.88 / 8.89 in the 1/8 as this is what most tracks here run. This should be 14's in the 1/4 since 7.99 = 12.99 and 8.49 = 13.99 according to NHRA.

To me MPO the thermoquad carb is close to the Edlebrock carb for metering fuel, there good for emissions and street performance but not performance orenited enough to get real performance HP. And the Holley's are a much better choice.

I guess we'll have to agree to disagree on the heads, and as you say we each have to use what works for each of us. Sorry to hijack the thread, and if I offended anyone about the magnum heads. As I'm sure that there are some good ones out there.
 
hi, I see you don't think much of T.Q. carbs. how is it the stocker and super stockers go so fast with them? being as how they have to run them. lots people don't like Qjets, but they can be made to work very well. just curious.
 
Hey I said that MPO that the T.Q. and the Edlebrocks are close on metering fuel, I never said that I didn't think much of them. But when I go for performance I don't usually look at a Edelbrock or a T.Q. carb for a race application. Anything can be made to work, but would it be cost effective. From my stand point, I use whats most plentiful and what most want on there cars. But this is just my preference. Most engines that I've seen that make very good HP other than a highly sophisticated stock or super stock engines don't run them. But then we can't compare a 20K/40K engines and call them stock either. No one here would by one for a street car,(stk/ss engines) let alone why would they. Once again this is a matter of preference for myself, I personally don't care what whoever runs this is up to whoever.

I don't mean this to sound sarcastic, but more of a question of why, or is it a correctness thing for the purest. Because I'm surely not a purest. I'd rather use what works the best for the $$$$$ spent than to be politically correct. LOL
 
BJR Racing said:
For a comparision to your 318 magnum engine in your truck, we have a old version 318 with a standard bore and a .501 comp cams cam and 3675 set of heads with stock valves and a M-1 intake and a set of hedders on pump gas and the car weighs in at 3330 lbs. and just last week even being out of tune ran 7.89 @ 88 mph in the 1/8 which this puts the old style 318 engine in the low 12's or upper 11's.
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What gear ratio is this? Not wanting to get involved in this disagreement, just curious.

Fishy: I think someone slipped a 5.9 in your truck when you weren't looking. LOL! Lots of the R/Ts around here barely run what yours does.

Thanks

Steve
 
it's not a purist or political correct, its what it required on stockers and super stockers. as for cost, they can be made to work for less than some of those holleys. they flow from 750 to 850 cfm.
 
perfacar,
I don't run stock or super stock so it really doesn't matter to me. And I won't run any less than a 750 cfm on a 318. My engine runs a 1050 cfm carb and loves every bit of it. It started out as a 750 cfm holley DBL pumper thats now been very well race prepped. I paid $400.00 to have it prepped over the cost of the carb, and I bought the carb used, I think I had $100.00 in it.
 
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