Building the 318/390 stroker

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limelight72

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So I'm going with the 318 bored .030 over, 4340 forged steel 4.000 stroke crank, 6.123 H-Beam rods, and forged step dish -23cc will be 9.8:1 when all said and done with aftermarket aluminum heads.

Anyway I've been looking for a cam for it and found this. It will be a weekend warrior.

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=651&sb=0

Not very good at building motors, but is this a good cam choice? Will 1.5 rockers be a good choice with these?

Let me know if you need anymore info.

Also wil a 750 double pumper with mechanical secondaries and electric choke be good for this combo or will I need a bit bigger?
 
X2^^

Also said nothing about the definition of "weekend warrior" to some that means spending the whole weekend at the dragstrip, to others, cruising the local sonic and pissing off the neighbors with loud pipes.

What stall and gear ratio? Tire height? What car/weight?
 
I think it would be a decent choice for 90 percent street/ 10 percent race.
The rocker arm choice looks good too. Might be hard on fuel.
 
I never said you had to copy someone else's...but if you search through here and read a couple dozen threads on cam selection in stroker engines, it should give you an indication of what cam would work well for your application based on your parts selection and desired outcome.

Depending on what [brand] converter you go with, I'd honestly say you need more...like 3k...and like many on here will tell you, don't skimp--good converters cost and are worth every penny.

The Edelbrock heads are nice, but you still didn't say if you're going to have some work done to them at all, and if you're really planning to use that cam, you might want to invest in better springs. Hydraulic roller cams are slinging heavy lifters and they require more spring pressure to stave off valve float...there's a thread up right now concerning just that.

Another thing, what intake do you plan to use? RPM? or Single plane? Port matched to heads?
 
txstang84 said:
I never said you had to copy someone else's...but if you search through here and read a couple dozen threads on cam selection in stroker engines, it should give you an indication of what cam would work well for your application based on your parts selection and desired outcome.

Depending on what [brand] converter you go with, I'd honestly say you need more...like 3k...and like many on here will tell you, don't skimp--good converters cost and are worth every penny.

The Edelbrock heads are nice, but you still didn't say if you're going to have some work done to them at all, and if you're really planning to use that cam, you might want to invest in better springs. Hydraulic roller cams are slinging heavy lifters and they require more spring pressure to stave off valve float...there's a thread up right now concerning just that.

Another thing, what intake do you plan to use? RPM? or Single plane? Port matched to heads?
Click to expand...

Weiand action pro dual plane probably get that ported and yes I will port the heads and get better springs. So i'll pick up a 3k then. Thanks. Although the eddy heads come with dual springs. Max lift on them are .600 I'll upgrade to titanium retainers also.
 
I stand corrected--I didn't completely view the ad, I saw Edelbrock heads and assumed the standard hydraulic flat tappet versions. All the same, it would pay in the long run to have them looked at by your machinist and make sure there's enough open pressure (the lift limitation is a pretty arbitrary number based on coil bind) for that cam and your roller lifters.
 
The Action Plus might actually hold you back a little bit with the enlarged displacement...even getting it ported may not be enough to match up to the breathing requirements of a 390" engine. You have to keep in mind, you're essentially building a big block displacement engine in a small block package...good breathing is imperative.

EDIT: you may actually want to wait a couple days for some more seasoned folks to come on here and recommend other cams...with the longer stroke, you really have to be more discriminating with cams...they eat up lots of duration.
 
I suggest a single plane intake like the M1.
Torque will be massive with a 4" stroker, so you want that thing breathing best at higher rpm's.
 
I am personally targeting a 348 stroked 318. I currenlty have the heads and cam and intake and carb to best suit it. Of course, everyone will suggest a 4" stroke for the same money.....except it is NOT the same money. Not when my heads would then need more work, cam is too short, intake manifold is not up to the task, etc.
 
txstang84 said:
Here's some other reading for you:

http://www.forabodiesonly.com/mopar/search.php?searchid=8009592

...please read through a few of them...there are several members here who've done the 390 build and with proven results. Again, I'm not saying you need to copy one of them, but you may glean something resourceful from their experiences.
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Thanks for everything and ya I'm going to have the place im taking them to look at them. I'll take a look at the M1 intake. Would that one have to be ported? Might go for a high rise tunnel ram intake.
 
I wouldn't run a thmpr in that engine. I'd go with something more along the lines of the big extreme energy HR cam or something like that if you want an hydraulic roller engine.

XR-286-HR
XR-292-HR

Make sure the springs that come on the head are suitable. Look at pep boys for a 25% off coupon code then have summit match it if you want to buy from them or buying a bunch of stuff at once.

Run an ede air gap or a victor 340 with a 1" spacer. The action plus is not a good choice IMO. I'm not a fan of the m1 intakes.

The 750 will work if you have it, it will likely will want more carb.

Don't spend money on titanium retainers. A good steel retainer is fine and preferably a 10*
 
crackedback said:
I wouldn't run a thmpr in that engine. I'd go with something more along the lines of the big extreme energy HR cam or something like that if you want an hydraulic roller engine.

XR-286-HR
XR-292-HR

Make sure the springs that come on the head are suitable. Look at pep boys for a 25% off coupon code then have summit match it if you want to buy from them or buying a bunch of stuff at once.

Run an ede air gap or a victor 340 with a 1" spacer. The action plus is not a good choice IMO. I'm not a fan of the m1 intakes.

The 750 will work if you have it, it will likely will want more carb.

Don't spend money on titanium retainers. A good steel retainer is fine and preferably a 10*
Click to expand...


x2. Except I like the M1s with a spacer and plenum cleanup. Air Gap would be my 1st choice for something you have to drive, but put a real carb on it. Either an 870 Avenger or 950HP.
 
moper said:
x2. Except I like the M1s with a spacer and plenum cleanup. Air Gap would be my 1st choice for something you have to drive, but put a real carb on it. Either an 870 Avenger or 950HP.
Click to expand...

So one of the 750 ultra dbl pumpers with electric choke and mechanical secondaries would be out of the question?
 
crackedback said:
I wouldn't run a thmpr in that engine. I'd go with something more along the lines of the big extreme energy HR cam or something like that if you want an hydraulic roller engine.

XR-286-HR
XR-292-HR

Make sure the springs that come on the head are suitable. Look at pep boys for a 25% off coupon code then have summit match it if you want to buy from them or buying a bunch of stuff at once.

Run an ede air gap or a victor 340 with a 1" spacer. The action plus is not a good choice IMO. I'm not a fan of the m1 intakes.

The 750 will work if you have it, it will likely will want more carb.

Don't spend money on titanium retainers. A good steel retainer is fine and preferably a 10*
Click to expand...

x3....and Yes, the 750dp will work, but you might be leaving some power on the table...might being the operative word...hard to say. My 410 has a 750dp on it and does just fine...but more than a few folks have told me that my car appears to be the exception to the rule, so take what you want from that.

For a 50/50 street/strip car I would go with the Airgap. I have had both the Victor and the Airgap on my stroker, the Airgap with a 1/2" open wood spacer + a 1" tapered spacer had the best throttle response and best torque (better for street driving). My car is more like 90/10 Race/street, so I currently run a Victor intake.
 
flyfish said:
x3....and Yes, the 750dp will work, but you might be leaving some power on the table...might being the operative word...hard to say. My 410 has a 750dp on it and does just fine...but more than a few folks have told me that my car appears to be the exception to the rule, so take what you want from that.

For a 50/50 street/strip car I would go with the Airgap. I have had both the Victor and the Airgap on my stroker, the Airgap with a 1/2" open wood spacer + a 1" tapered spacer had the best throttle response and best torque (better for street driving). My car is more like 90/10 Race/street, so I currently run a Victor intake.
Click to expand...

Thanks very much for the info on the carb and intake.
 
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