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  #1  
Old 01-14-2009, 03:35 PM
MrChemist MrChemist is offline
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Default Port my EddyÂ’s or stroke it

IÂ’m getting ready to reassemble my 360, but IÂ’m not sure what would benefit my ETÂ’s the mostÂ….buy a crank and pistons to stroke it to a 408, or have my Edelbrock heads fully ported. Not enough money to do both.

The rest of the combo / parts:
360, Scat I beam rods (new)
Comp solid roller, XR286R, 248/254 duration with .576/.582 lift (new)
Air-gap intake, 750 dp
727, 8 inch PTC converter (new)
4:10 gears, 3250 lbs with driver in 67 Barracuda.

IÂ’m leaning toward porting the headsÂ…but I just donÂ’t know. The car is 80-90% race with some weekend street use. Thanks in a
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  #2  
Old 01-14-2009, 08:22 PM
valiant64 valiant64 is offline
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Do the heads. At least if you later decide to do a stroker short block, you'll already have heads that will keep up with the extra cubes. Heads are key.
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  #3  
Old 01-14-2009, 10:20 PM
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Agreed....
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Old 01-14-2009, 11:23 PM
passing you passing you is offline
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This is a good question, what do ya do?
I mean porting the heads will definitely increase the flow=HP/torque 25-40 each and would be great on a 360ci motor.
And putting in a 4' stroke crank will definitely increase the HP/TQ as well with more emphases on the TQ to the tune of around 65+ or so ft lbs and would be pulling the soul out of those eddys as is, which I'm not sure how much material will be removed in the port job your describing but I wonder if it will be enough to get enough port volume to properly feed that stroker in the long run, Maybe do the stroker and later buy W2's would be the best bet ?
I don't know this is a tough one....
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  #5  
Old 01-14-2009, 11:48 PM
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I'd stroke it first. That way the hard parts over with. You can pull the heads without removing the whole engine at anytime. If you do the heads now, then want to stroke it you have to pull the whole thing back out and just about start all over again. Less work to stroke it now and rehead the thing later on.
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Old 01-15-2009, 12:28 AM
DonCarr DonCarr is offline
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stroking will raise the compression up to where you need it with aluminum heads + that cam ?
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  #7  
Old 01-15-2009, 02:11 AM
DartGT66 DartGT66 is offline
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What is hte current state of your 360 short block? Which pistons etc? I agree with DWC43, first get the short block done, everything else is easily changed later without having to tear the whole thing down. If your current 360 short block is recelntly built with good quality parts, I would leave it as it is. If it needs rebuilding, definitely go with the big arm crank. You have a pretty serious cam in there, and might do better with a single plane wether you stick with 360 cu in or go with 4" stroke.
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  #8  
Old 01-15-2009, 04:00 AM
TeamDart TeamDart is offline
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Depends on the porter.....
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Old 01-15-2009, 06:06 AM
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agree...stroke it! you will get alot of tq in the low rpm! but you will not reach a 408`s full potensial with eddys untuched!
the eddys hardly reach 300cfm ported with $$$$(correck me if wrong) and I believe 300 is the lower limit for an 90% race 408!

it all comes down to the combo: engine,converter and rear + tiresize.

if you stroke it and leave the eddys as is, you have an engine that stops pulling before 6k, but you have ALOT more power before the 6k limit

if you port the heads you will have a 360 that can make power past 7k,
but it will not pull as hard as the stroker in the lower rpm-s.
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Old 01-15-2009, 06:22 AM
buckneccid buckneccid is offline
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Gonna drag race? Stroke it. The extra torque will move you off the line faster, faster 60 ft times, and put you out front sooner. If you port the heads first, you're gonna put your power up high, and have the engine pulling at the end of the race. Port the heads later, there's no substitute for cubic inches...
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Old 01-15-2009, 11:06 AM
passing you passing you is offline
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I knew that would spur some thought.
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  #12  
Old 01-15-2009, 11:26 AM
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Theres also a RPM issue.
The cam isn't that big. Once in the stroker, which eats up cam duration a bit due to the increased size, the port volume of the head will only be good to a certain RPM because of it's size. And then the rest of the combo comes into play to limit it's abilties. Most strokers peak @ 6000 rpm and that cam isn't pushing any bounderies.
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Old 01-15-2009, 02:11 PM
43 purestock 43 purestock is offline
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If it were me, I would just port the heads, your other option sounds like a "new buildup" If its running and racing now, the porting will pick up some power, building a new engine will cost alot more. The stroker motor will make more power, but you still need to port your heads with the stroker, see what I am saying?
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  #14  
Old 01-15-2009, 05:51 PM
TeamDart TeamDart is offline
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Depending on the head porter....

I would build the short block with the stroker.... but if you have any other "assembled" heads then I would choose to run those... possibly some J or X heads sitting in the garage?

Save up for the heads to be ported, and have a cam cut for your application and heads....

Once money and time permits, do a weekend install of the Eldy heads and new cam, very little down time with less work involved, and you bring your potential out in your motor...
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  #15  
Old 01-15-2009, 08:04 PM
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Hard to beat 'pubic inch'=torque, see what I mean.lol
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  #16  
Old 01-15-2009, 08:17 PM
valiant64 valiant64 is offline
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Quote:
Originally Posted by 43 purestock View Post
If it were me, I would just port the heads, your other option sounds like a "new buildup" If its running and racing now, the porting will pick up some power, building a new engine will cost alot more. The stroker motor will make more power, but you still need to port your heads with the stroker, see what I am saying?
I 2nd that. The stroker will net you less than 50 more inches over the stock stroke 360, and without the headwork to support the extra inches & probably larger cam profile, you're not going to get the potential out of the shortblock. I could understand if all you had to do was wait another month or so before you had the $ to port the heads for your stroker, but I doubt thats the case. Probably be a bit longer than that I'm guessing, like most of us, you probably dont have money to burn. Think of it this way, say you have a 383 with ported heads & a decent cam installed. Now, say another guy has a 440 with stock heads. The cubic inch difference between the two engines is about 57 inches. Guess which will probably make the most power? What I'm saying is for the cash outlay, a well ported set of heads should make up most of the difference output wise between the 360 & 408. And, you'll definitely need these heads ported to make the most of that stroker when you do build it.
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Old 01-15-2009, 08:48 PM
passing you passing you is offline
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It's the port volume & int/exh ratio, not the flow that limits the rpm.
You bet it will take a lot of material removed to get the port volume correct for the cubes, thats why I said W2.
You bet with more swept volume that he will be getting every bit of that 260cfm that the stock eddys have to offer.

While you do need horse power you have to have torque first.

Horsepower sells cars, torque wins races.JMO

I guess I am the only one.....
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  #18  
Old 01-15-2009, 09:04 PM
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Quote:
Originally Posted by passing you View Post
It's the port volume & int/exh ratio, not the flow that limits the rpm.
You bet it will take a lot of material removed to get the port volume correct for the cubes, thats why I said W2.
You bet with more swept volume that he will be getting every bit of that 260cfm that the stock eddys have to offer.

While you do need horse power you have to have torque first.

Horsepower sells cars, torque wins races.JMO

I guess I am the only one.....

But porting creates torque too.... but which one will produce more?.... depends on the porter
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  #19  
Old 01-15-2009, 09:05 PM
valiant64 valiant64 is offline
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...So put some stock heads on YOUR 408!lol jkn
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  #20  
Old 01-16-2009, 07:54 AM
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2.02\1.6 valves is too small for 4" stroke!the valve size vs time vill choke the engine at 5500rpm on a pretty good bumpstick. @.500 lift @ valve, and since there is no room for bigger valves,the only thing that can get more air in is lift! pipemax tell me to use .700+ lift to get the choke up to ~7000rpm... and 700 lift is a pretty wild roller! and in my world too much for the street!


check it out... 660hp , 260\268@050 roller.... guess this "little" baby scream

http://www.popularhotrodding.com/eng...410/index.html
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  #21  
Old 01-16-2009, 08:19 AM
DartGT66 DartGT66 is offline
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Just take your current engine wiht the J-heads to a "magazine dyno" at Westech, and be happy. There is no way anyone would want to use much over 0.6" lift with the RPM heads, they have short valves and low spring installed heights and the SB mopar valvetrains pushrod angles really arenät best suited for extremely high lifts and rpms. We just recently built a 4" stroekr with rpm heads and rpm intake, the cam was a solid flat tappet, with close to the same lift that's in your street roller. It made 455 true hp at 5800 rpm with 1 5/8" headers and a 650 cfm carb. The heads were homeported, not really anyhting wild, and the engine had excellent low end torque, pulling very strong from 2000 & up and making 490 ft-lb peak at 3800
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  #22  
Old 01-16-2009, 08:40 AM
Century Cp Guru Century Cp Guru is offline
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Stroke it first.
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  #23  
Old 01-16-2009, 03:27 PM
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Quote:
Originally Posted by powerdodge View Post
2.02\1.6 valves is too small for 4" stroke!the valve size vs time vill choke the engine at 5500rpm on a pretty good bumpstick. @.500 lift @ valve, and since there is no room for bigger valves,the only thing that can get more air in is lift! pipemax tell me to use .700+ lift to get the choke up to ~7000rpm... and 700 lift is a pretty wild roller! and in my world too much for the street!
With good porting, a 408 with Eldy heads can easily make power up to 6500rpm before dropping off, with 2.02" valves. And with valvesprings available today it's not difficult to make 0.650 lift cam live for thousands of racing miles. But then again I don't consider a 0.700" a wild cam either.

Quote:
Originally Posted by DartGT66 View Post
Just take your current engine wiht the J-heads to a "magazine dyno" at Westech, and be happy. There is no way anyone would want to use much over 0.6" lift with the RPM heads, they have short valves and low spring installed heights and the SB mopar valvetrains pushrod angles really arenät best suited for extremely high lifts and rpms. We just recently built a 4" stroekr with rpm heads and rpm intake, the cam was a solid flat tappet, with close to the same lift that's in your street roller. It made 455 true hp at 5800 rpm with 1 5/8" headers and a 650 cfm carb. The heads were homeported, not really anyhting wild, and the engine had excellent low end torque, pulling very strong from 2000 & up and making 490 ft-lb peak at 3800.
Very true, to take full use of a "good" RPM head you need longer valves, and of course rework the guides. I agree with using J heads to start out with.... then start getting work done to the Eldy's while the motor is running. Our dart motor makes 500lbs of torque @ 3000rpm, Peak torque of 600lbs @ 4500rpm, while still rev to a "decent" 6000rpm.... with the right combinations of parts it can be done. PM me if you have any questions
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Old 01-16-2009, 06:14 PM
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Quote:
Originally Posted by TeamDart View Post
With good porting, a 408 with Eldy heads can easily make power up to 6500rpm before dropping off, with 2.02" valves. And with valvesprings available today it's not difficult to make 0.650 lift cam live for thousands of racing miles. But then again I don't consider a 0.700" a wild cam either.

Very true, to take full use of a "good" RPM head you need longer valves, and of course rework the guides. I agree with using J heads to start out with.... then start getting work done to the Eldy's while the motor is running. Our dart motor makes 500lbs of torque @ 3000rpm, Peak torque of 600lbs @ 4500rpm, while still rev to a "decent" 6000rpm.... with the right combinations of parts it can be done. PM me if you have any questions.

well, I`m only a younggun with little experience, so I will shut up

but can I ask for your opinion about why most of the 408s peak before 6k?

and about .700 wild...I talking about street-driving whitout tearing down the engine every sec winter...
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Old 01-16-2009, 06:32 PM
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Quote:
Originally Posted by powerdodge View Post
well, I`m only a younggun with little experience, so I will shut up

but can I ask for your opinion about why most of the 408s peak before 6k?

and about .700 wild...I talking about street-driving whitout tearing down the engine every sec winter...
Why make a motor turn more RPM's than needed? I was just saying with the right heads, and cam, a 408 will have no problem revving to 6500-7000rpm... of course figuring you're bottom end has a good combination. RPM's kill motors, but also like you said higher lift cams can kill valvesprings.... unfortunately there's just so many different variances in these stroker builds, with different parts from all over.... it's hard to group them in a "general" 4" SBM can do this but can't do that category.
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Old 01-16-2009, 07:49 PM
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Quote:
Originally Posted by TeamDart View Post
With good porting, a 408 with Eldy heads can easily make power up to 6500rpm before dropping off, with 2.02" valves. And with valvesprings available today it's not difficult to make 0.650 lift cam live for thousands of racing miles. But then again I don't consider a 0.700" a wild cam either.



Very true, to take full use of a "good" RPM head you need longer valves, and of course rework the guides. I agree with using J heads to start out with.... then start getting work done to the Eldy's while the motor is running. Our dart motor makes 500lbs of torque @ 3000rpm, Peak torque of 600lbs @ 4500rpm, while still rev to a "decent" 6000rpm.... with the right combinations of parts it can be done. PM me if you have any questions.
He already has the Ed RPM heads. Why would he switch to factory iron heads and eventually pay to have both sets ported? Unless I'm misunderstanding your post...
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Old 01-16-2009, 08:08 PM
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Good answer TeamDart.

Quote:
Originally Posted by powerdodge View Post
but can I ask for your opinion about why most of the 408s peak before 6k?

and about .700 wild...I talking about street-driving whitout tearing down the engine every sec winter...
Most stroker engines peak before 6,000 rpm because of the stroke. The longer the stroke, the earlier the torque and hp peak. Theres also piston speed to deal with, and the rest of the engines perameters and parts.

You can cam the sucker to death, but, that doesn't give it an automatic ticket to 7500 rpm. All the rest of the parts need to be in sync and up to par.

Valve lift. Is a funny thing. You can get a cm to lift this high with as many duration numbers as there are lift numbers in all the catologs you can find.
Generally speaking, .700 lift would be considered a heck of alot for a street engine. Then again, it may not be a whole lot for a crazy full throttle strip car.

The thing that wears out springs on a head is lift and the amount of abuse it sees.
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Old 01-16-2009, 08:10 PM
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I thnk he was trying to say, use the iron heads for now while the edel.'s get ported.
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Old 01-16-2009, 08:13 PM
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Quote:
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I thnk he was trying to say, use the iron heads for now while the edel.'s get ported.
Yessum
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Old 01-17-2009, 04:39 AM
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but WHY does longer stroke make the peak come earlier?

(my theory) it`s because the longer stroke make the piston travel further, and if the piston travel furter, you need to get more air in to fill it completely! and there is simply not enough room + time with a 2.02 valve to get in enough air with a decent street camshaft.it is the pumping part that does most to get air in to the cylinder. (picture) duration does little to widen the pumping area... but lift and valve size do!

but I agree....we dont want more than 6.5k...speed kills!
in my world it is better to have a strong engine up to 6500, and then stop it with a rev-limiter rather than use a choked engine as the rev-limiter...

(sorry for my bad english, hope I make myself understandable :-) )
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