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Re: Thoughts on mild 383 [Re: furious70] #2802910
07/30/20 02:09 PM
07/30/20 02:09 PM
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Originally Posted by furious70
I've done back to back comparisons, same car, same engine, same tires with OEM and SD intake. SD intake and 3.91's, barely spin tires on idle stomp. OEM intake and 3.23's, much more spin from idle stomp. That's proof positive of low end difference.

This was a basically stock magnum 383 spec motor with 268H cam and 906's with normal 3 angle VJ, headers, 750 holley, nothing fancy at all.


I've got that same basic set up. Runs strong and pulls hard. Good street set up with 3:23's and a TCI Breakaway converter.

Re: Thoughts on mild 383 [Re: furious70] #2802985
07/30/20 04:48 PM
07/30/20 04:48 PM
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Originally Posted by furious70
I've done back to back comparisons, same car, same engine, same tires with OEM and SD intake. SD intake and 3.91's, barely spin tires on idle stomp. OEM intake and 3.23's, much more spin from idle stomp. That's proof positive of low end difference.

This was a basically stock magnum 383 spec motor with 268H cam and 906's with normal 3 angle VJ, headers, 750 holley, nothing fancy at all.
i had the exact same experience working on two 383's. the one 383 car with the 3.91's and single plane was a total turd. the stock 3.23 geared 383 would have clobbered the other in a 1/4 mile.

Re: Thoughts on mild 383 [Re: BSB67] #2802992
07/30/20 04:52 PM
07/30/20 04:52 PM
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Originally Posted by BSB67
Originally Posted by HP2
Originally Posted by BSB67

A mechanical cam is the only cam I'd put in a 383 application if you want to mazimize street friendly power. Unless you really don't care about power and performance, and only low end torque put some tiny cam in it and go ahead and keep it hydraulic.



Explicate why a mechanical cam would perform better in the lower rpm range. I have honestly never digged into that field. I have used mech cams in high revving street/strip engines but not in something like this.


I think you my have missunderstood my point, but my my wording was poor as well.

In short, maximizing power (track performance), and low rpm torque (the low speed "feel" of the motor) is hard, paticularly with a 383. These things compete with one another in a 383 more so than 440s. You also made a statement about 4500 rpm, and not sure what to infer from that. A stock 383 is pretty happy at 5500.

Anyways, to have your cake and eat it too, you need to put a cam in it that moves the valves fast, but will still keep the valvetrain happy to 6000 rpm. The fast rate hydraulic cams (or lifters) usually struggle at higher rpm. A faster rate solid cam can do both. Also, loosening the valve lash will sharpen-up the low throttle response noticably on a 383. The faster you move the valves and slap the valvetrain around, the harder it is on parts. It's always a compromise.
with all things equal a solid cam is more flexible and will do everything a hydraulic will do and more. i'm with bsb67 on this one.

Re: Thoughts on mild 383 [Re: HP2] #2803030
07/30/20 06:57 PM
07/30/20 06:57 PM
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Andrews,In. U.S.of A.
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This got off into the weeds pretty quickly. If you are really going to run a stock converter, stock ex. manifolds 3.23:1 gears in a 383, forget the single plane manifold. Build as much compression ratio as your budget allows, use a dual plane intake of your choice with a 650-750V.S. carb., and don't over cam it. I have run stock manifolded 383's in 2 different 4 door (66& 68) Newports. Both ran mid 15's at 90ish m.p.h. with less than 8:1 compression,2.76-3.23 gears & stock heads.. I used a cam dynamics 266 energizer(.440" 266 210@.050") and a Crower 260 H.D.P. ( .456"-477" 260-267 212-218@.050). I liked the energizer better as it had tighter lobe sep. and better low end.A 230@ .050 cam and a single plane will be a turd below 3000-3500 R.P.M.

Re: Thoughts on mild 383 [Re: lewtot184] #2803130
07/30/20 10:58 PM
07/30/20 10:58 PM
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Originally Posted by lewtot184
Originally Posted by furious70
I've done back to back comparisons, same car, same engine, same tires with OEM and SD intake. SD intake and 3.91's, barely spin tires on idle stomp. OEM intake and 3.23's, much more spin from idle stomp. That's proof positive of low end difference.

This was a basically stock magnum 383 spec motor with 268H cam and 906's with normal 3 angle VJ, headers, 750 holley, nothing fancy at all.
i had the exact same experience working on two 383's. the one 383 car with the 3.91's and single plane was a total turd. the stock 3.23 geared 383 would have clobbered the other in a 1/4 mile.


We’ve reached absurdly here. Intake swap cost like 100 ft pounds off idle. Yeah or whatever. Dyno results right in this thread show a variation of about 3% one way or another in favor of one manifold or another at various rpms. But with a simple intake swap you guys killed off triple digits of power. That takes some skill.


I want my fair share
Re: Thoughts on mild 383 [Re: 67_Satellite] #2803196
07/31/20 09:11 AM
07/31/20 09:11 AM
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Originally Posted by 67_Satellite
This got off into the weeds pretty quickly. If you are really going to run a stock converter, stock ex. manifolds 3.23:1 gears in a 383, forget the single plane manifold. Build as much compression ratio as your budget allows, use a dual plane intake of your choice with a 650-750V.S. carb., and don't over cam it. I have run stock manifolded 383's in 2 different 4 door (66& 68) Newports. Both ran mid 15's at 90ish m.p.h. with less than 8:1 compression,2.76-3.23 gears & stock heads.. I used a cam dynamics 266 energizer(.440" 266 210@.050") and a Crower 260 H.D.P. ( .456"-477" 260-267 212-218@.050). I liked the energizer better as it had tighter lobe sep. and better low end.A 230@ .050 cam and a single plane will be a turd below 3000-3500 R.P.M.


I agree, we ended up far out in the weeds LOL
Yes, I'm really gonna do what I stated from beginning. Maybe not the DP4B since it's not for spreadbore, which I'm gonna use.
I have never even considered a single plane for this build. This engine will need long runners.

I'm going to keep the compression pump gas friendly. We can get 93.5 oct here in Sweden (<5% ethanol). Cylinder pressure around healthy 160-170 psi is what I'm aiming for, that will leave some margin.

What I asked for was camshaft input for this specific build.
My thoughts of a cam are duration around 220 and maybe a little more on exhaust, lift as much as .500 and LS around 110. Talking hydraulic flat tappet now. But what do I know? LOL
It would be interested in some input - what cam and why?


70 W100 Power Wagon. 318 4-spd
70 Sport Fury 440 2dr HT
71 Duster 340
71 Charger Super Bee - 383/727
72 Charger "Sabotage" - 440/727 - Street/Strip
78 Warlock in beautiful patina
Re: Thoughts on mild 383 [Re: HP2] #2803200
07/31/20 09:18 AM
07/31/20 09:18 AM
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Posts: 24,562
Brookeville, Md
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Originally Posted by HP2
Originally Posted by 67_Satellite
This got off into the weeds pretty quickly. If you are really going to run a stock converter, stock ex. manifolds 3.23:1 gears in a 383, forget the single plane manifold. Build as much compression ratio as your budget allows, use a dual plane intake of your choice with a 650-750V.S. carb., and don't over cam it. I have run stock manifolded 383's in 2 different 4 door (66& 68) Newports. Both ran mid 15's at 90ish m.p.h. with less than 8:1 compression,2.76-3.23 gears & stock heads.. I used a cam dynamics 266 energizer(.440" 266 210@.050") and a Crower 260 H.D.P. ( .456"-477" 260-267 212-218@.050). I liked the energizer better as it had tighter lobe sep. and better low end.A 230@ .050 cam and a single plane will be a turd below 3000-3500 R.P.M.


I agree, we ended up far out in the weeds LOL
Yes, I'm really gonna do what I stated from beginning. Maybe not the DP4B since it's not for spreadbore, which I'm gonna use.
I have never even considered a single plane for this build. This engine will need long runners.

I'm going to keep the compression pump gas friendly. We can get 93.5 oct here in Sweden (<5% ethanol). Cylinder pressure around healthy 160-170 psi is what I'm aiming for, that will leave some margin.

What I asked for was camshaft input for this specific build.
My thoughts of a cam are duration around 220 and maybe a little more on exhaust, lift as much as .500 and LS around 110. Talking hydraulic flat tappet now. But what do I know? LOL
It would be interested in some input - what cam and why?


FWIW my buddy had a 68 Charger, 383 2bbl motor with over 150k on it. He used the Summit 465/488 cam, headers, DP4B, Demon carb, 2.5 exhaust, auto w/ a mild stall. He ran 13.90's shifting like grandma. He did have 3.55's I think.


[IMG]http://i66.tinypic.com/pui5j.jpg[/IMG]
Coming soon!!!!
Re: Thoughts on mild 383 [Re: HP2] #2803214
07/31/20 09:57 AM
07/31/20 09:57 AM
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Northeast Indiana
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I don't understand the infatuation with the DP4B over a Performer 383... maybe because its old & people don't like change.

A Performer 383 intake IS and updated DP4B casting flipped 180 degrees with more favorable features, like mounting the coil in the right spot, the ability to mount a spreadbore, and the option of hooking up the factory choke.

IMG_1123.JPGIMG_6103.JPG
Re: Thoughts on mild 383 [Re: SomeCarGuy] #2803236
07/31/20 10:52 AM
07/31/20 10:52 AM
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Originally Posted by SomeCarGuy
Originally Posted by lewtot184
Originally Posted by furious70
I've done back to back comparisons, same car, same engine, same tires with OEM and SD intake. SD intake and 3.91's, barely spin tires on idle stomp. OEM intake and 3.23's, much more spin from idle stomp. That's proof positive of low end difference.

This was a basically stock magnum 383 spec motor with 268H cam and 906's with normal 3 angle VJ, headers, 750 holley, nothing fancy at all.
i had the exact same experience working on two 383's. the one 383 car with the 3.91's and single plane was a total turd. the stock 3.23 geared 383 would have clobbered the other in a 1/4 mile.


We’ve reached absurdly here. Intake swap cost like 100 ft pounds off idle. Yeah or whatever. Dyno results right in this thread show a variation of about 3% one way or another in favor of one manifold or another at various rpms. But with a simple intake swap you guys killed off triple digits of power. That takes some skill.


I mean, I think I can read, but maybe not. That article shows a 37lb-ft difference at 3000rpm between the SD and the performer. 38 to the Action Plus. If they had tested down lower then that gap would surely increase. It wouldn't take 100lb-ft to make the difference I observed and shared in this thread.
I appreciate your compliments as to my skill in things mechanical as well as reading ability.


70 Sport Fury
68 Charger
69 Coronet
72 RR
Re: Thoughts on mild 383 [Re: HP2] #2803241
07/31/20 11:30 AM
07/31/20 11:30 AM
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I've been thinking of how I should put it to make you understand of how I see it.
If you'd had a chance to log the throttle position for a season on a street driven car (such as a 71 'Bee) I'd swear you never go WOT more than a few percent. Probably very very few.
The idle portion would be quite a big number, depending on the traffic situation at your location of course.
If I make a wild guess of the throttle opening you actually DRIVE your car I'd say it's mostly between idle and half throttle. At least that's how I drive my cars. Using a set of 275 BFG takes only a few minutes of pedaling! LOL

The engine I'm planning to build is for a driver.
Looking at dyno numbers are always fun, but I don't know anyone who puts his street car in gear, floors it from 2,500-3,000 and wait 'til the power ends. Well, if he goes to the track, but that's a completely different story.

A dyno can't give the information of how the engine works in a street car. How responsive it is, and what will happen if you give 3/4 throttle at 2,000 rpm's. A chassis dyno can do it better, but not fully.

I want my street driven 383 to be long lasting, ready for long trips on winding sideways or a trip to the town to lay out some smokescreens and no unburned fuel wiping off the oil film from the cylinder walls.
I want it to be snappy and happy, have muscle car characteristics with a bit lumpy idle and grunt from bottom so I don't have to wait for it to happen.

If it wouldn't have been a matching car I would have used the 67 440 I have sitting, or maybe built a 400 stroker. It would have made it easier to achieve my goals, but that's not an option now.
If I had too much money or lived in the US I would have considered building a stroker out of the matching block, but that's too risky with today's situation. Shipping overseas sucks these days...
As said before, a 383 is not the best start - but now it has to be a 383, and I will try to make the best of it.

I'm gonna try to use the parts I have and do it all by myself at home. Do it and build it someway I stated from the start. Be painstaking with the details, jetting and timing.
What I'm asking for is cam input from people who built something similar. Anyone?

Sincerely regards!


70 W100 Power Wagon. 318 4-spd
70 Sport Fury 440 2dr HT
71 Duster 340
71 Charger Super Bee - 383/727
72 Charger "Sabotage" - 440/727 - Street/Strip
78 Warlock in beautiful patina
Re: Thoughts on mild 383 [Re: HP2] #2803258
07/31/20 12:12 PM
07/31/20 12:12 PM
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Prospect, PA
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Solid flat tappet. Comp cam: XS268S. Pretty mild, and easy on parts.

This is an internet amatur's recommendation from a catelog. I would suggest calling a professional.

Re: Thoughts on mild 383 [Re: HP2] #2803259
07/31/20 12:13 PM
07/31/20 12:13 PM
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Warren, MI
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in terms of the cam i'd be looking for a mopar .528 cam, i always liked the torque the cam had down low and always liked the way it drove. i think in terms of bang for your buck you really cant beat it in a street car.


Superior Design Concepts
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Troy MI 48083
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Re: Thoughts on mild 383 [Re: BSB67] #2803276
07/31/20 12:46 PM
07/31/20 12:46 PM
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Originally Posted by BSB67
Solid flat tappet. Comp cam: XS268S. Pretty mild, and easy on parts.

This is an internet amatur's recommendation from a catelog. I would suggest calling a professional.


I have also been looking at that one, it's mechanical. Very close to Hughes SEH2024BL-11 but more duration and a little less lift. Plus I'm not sure Comp grind their Mopar cams for the larger .904 lifters...


70 W100 Power Wagon. 318 4-spd
70 Sport Fury 440 2dr HT
71 Duster 340
71 Charger Super Bee - 383/727
72 Charger "Sabotage" - 440/727 - Street/Strip
78 Warlock in beautiful patina
Re: Thoughts on mild 383 [Re: HP2] #2803372
07/31/20 05:18 PM
07/31/20 05:18 PM
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something to think about on solid cams is their advertised duration ratings. you need to look at how much lobe lift the seat timing is rated at. using the xs268 as an example I believe it is rated at .015" lobe lift, but the recommended lash setting is .016". to get 268 degrees on the seat with a true 1.5 rocker you'll need .022" lash setting. .016" lash setting is going to get you 8-10 more degrees on the seat. will that kill off some low end torque?, probably. looking at the 270 solid it's rated at .015" lobe lift but has .022" lash setting. would the 270 be more versatile?, perhaps. either way look before you leap. what got me into looking at this stuff is I bought a solid cam that was "rated" at 280 degrees. what I didn't know at the time was the 280 was at .020" lobe lift, but recommended lash was .020". long story short is my 280 cam actually has 295 degrees running duration at recommended lash. the only saving grace is the solid tappet. 295 hydraulic degrees would have been miserable for what i'm doing.

Re: Thoughts on mild 383 [Re: HP2] #2803404
07/31/20 07:03 PM
07/31/20 07:03 PM
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Bend,OR USA
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Originally Posted by HP2
Originally Posted by BSB67
Solid flat tappet. Comp cam: XS268S. Pretty mild, and easy on parts.

This is an internet amatur's recommendation from a catelog. I would suggest calling a professional.


I have also been looking at that one, it's mechanical. Very close to Hughes SEH2024BL-11 but more duration and a little less lift. Plus I'm not sure Comp grind their Mopar cams for the larger .904 lifters...

I'm going to tell you that I have been told, and saw it on here also, that Hughes has Comp grind al their cams for them so that being said I'm sure that all the cams Cp sells are designed around the .904 lifter size up scope


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Thoughts on mild 383 [Re: HP2] #2803431
07/31/20 07:45 PM
07/31/20 07:45 PM
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Idaho
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Originally Posted by HP2
Originally Posted by 67_Satellite
This got off into the weeds pretty quickly. If you are really going to run a stock converter, stock ex. manifolds 3.23:1 gears in a 383, forget the single plane manifold. Build as much compression ratio as your budget allows, use a dual plane intake of your choice with a 650-750V.S. carb., and don't over cam it. I have run stock manifolded 383's in 2 different 4 door (66& 68) Newports. Both ran mid 15's at 90ish m.p.h. with less than 8:1 compression,2.76-3.23 gears & stock heads.. I used a cam dynamics 266 energizer(.440" 266 210@.050") and a Crower 260 H.D.P. ( .456"-477" 260-267 212-218@.050). I liked the energizer better as it had tighter lobe sep. and better low end.A 230@ .050 cam and a single plane will be a turd below 3000-3500 R.P.M.


I agree, we ended up far out in the weeds LOL
Yes, I'm really gonna do what I stated from beginning. Maybe not the DP4B since it's not for spreadbore, which I'm gonna use.
I have never even considered a single plane for this build. This engine will need long runners.

I'm going to keep the compression pump gas friendly. We can get 93.5 oct here in Sweden (<5% ethanol). Cylinder pressure around healthy 160-170 psi is what I'm aiming for, that will leave some margin.

What I asked for was camshaft input for this specific build.
My thoughts of a cam are duration around 220 and maybe a little more on exhaust, lift as much as .500 and LS around 110. Talking hydraulic flat tappet now. But what do I know? LOL
It would be interested in some input - what cam and why?


I wish I could tell you what cam was used in this 383 engine but I cannot. Most likely it was some stock replacement hydraulic cam. The engine was built in 2002 and had about 10 miles it.

However we did run it on our engine dyno today 7/31/2020.

Fired it up with the stock iron 4150 type dual plane intake with a casting number ending in 301 and then changed to a Holley Street Dominator. The carburetor used was a 1406 Edelbrock.

RPM......Iron 301 TQ/HP......Street Dominator TQ/HP

2500.....349/166..................308/147
2700.....343/176..................310/159
2900.....351/194..................330/182
3100.....364/215..................343/202
3300.....361/227..................349/219
3500.....356/237..................350/234
3700.....349/246..................350/246
3900.....338/251..................350/260
4100.....336/262..................351/274
4300.....325/266..................348/285
4500.....315/270..................344/295
4700.....312/279..................338/303
4900.....298/278..................328/306
5000.....284/276..................320/305

END TEST

Re: Thoughts on mild 383 [Re: Cab_Burge] #2803499
07/31/20 10:35 PM
07/31/20 10:35 PM
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WI
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Originally Posted by Cab_Burge
Me thinks your goal of running in the 8 with a 383 in your car are unobtainable tsk twocents
All kidding aside, that car is heavy and those motors are limited on how much cheap power you can make with them, been there done that(multiple times) whiney
Can you find a usable 440 crankshaft? If so I would use it by turning down the mains to 383 size and have a set of pistons made for using the stock 440 rods in your 383 , you will have to do some work, grinding the edges, on the crankshaft counterweights to clear the main webbing but increasing the stroke to 3.750 in a low deck is a really good way to help on the low end torque.
Being in Sweden has to limit your ability and choices on parts for this project so I can feel your pain and frustrations work good luck up


Listen to this guy! Put a crank in it and enjoy the low end that it will provide! I have a 470" low deck with a mild solid roller cam. Idles nicely at 900 rpm, looks like a 383, rpms like a chain saw and pulls like a freight train!!

Re: Thoughts on mild 383 [Re: Dcuda69] #2803547
08/01/20 02:19 AM
08/01/20 02:19 AM
Joined: Sep 2004
Posts: 523
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Originally Posted by Dcuda69
Originally Posted by Cab_Burge
Me thinks your goal of running in the 8 with a 383 in your car are unobtainable tsk twocents
All kidding aside, that car is heavy and those motors are limited on how much cheap power you can make with them, been there done that(multiple times) whiney
Can you find a usable 440 crankshaft? If so I would use it by turning down the mains to 383 size and have a set of pistons made for using the stock 440 rods in your 383 , you will have to do some work, grinding the edges, on the crankshaft counterweights to clear the main webbing but increasing the stroke to 3.750 in a low deck is a really good way to help on the low end torque.
Being in Sweden has to limit your ability and choices on parts for this project so I can feel your pain and frustrations work good luck up


Listen to this guy! Put a crank in it and enjoy the low end that it will provide! I have a 470" low deck with a mild solid roller cam. Idles nicely at 900 rpm, looks like a 383, rpms like a chain saw and pulls like a freight train!!


I've been thinking of how I should put it to make you understand of how I see it.
If you'd had a chance to log the throttle position for a season on a street driven car (such as a 71 'Bee) I'd swear you never go WOT more than a few percent. Probably very very few.
The idle portion would be quite a big number, depending on the traffic situation at your location of course.
If I make a wild guess of the throttle opening you actually DRIVE your car I'd say it's mostly between idle and half throttle. At least that's how I drive my cars. Using a set of 275 BFG takes only a few minutes of pedaling! LOL

The engine I'm planning to build is for a driver.
Looking at dyno numbers are always fun, but I don't know anyone who puts his street car in gear, floors it from 2,500-3,000 and wait 'til the power ends. Well, if he goes to the track, but that's a completely different story.

A dyno can't give the information of how the engine works in a street car. How responsive it is, and what will happen if you give 3/4 throttle at 2,000 rpm's. A chassis dyno can do it better, but not fully.

I want my street driven 383 to be long lasting, ready for long trips on winding sideways or a trip to the town to lay out some smokescreens and no unburned fuel wiping off the oil film from the cylinder walls.
I want it to be snappy and happy, have muscle car characteristics with a bit lumpy idle and grunt from bottom so I don't have to wait for it to happen.

If it wouldn't have been a matching car I would have used the 67 440 I have sitting, or maybe built a 400 stroker. It would have made it easier to achieve my goals, but that's not an option now.
If I had too much money or lived in the US I would have considered building a stroker out of the matching block, but that's too risky with today's situation. Shipping overseas sucks these days...
As said before, a 383 is not the best start - but now it has to be a 383, and I will try to make the best of it.

I'm gonna try to use the parts I have and do it all by myself at home. Do it and build it someway I stated from the start. Be painstaking with the details, jetting and timing.
What I'm asking for is cam input from people who built something similar. Anyone?


70 W100 Power Wagon. 318 4-spd
70 Sport Fury 440 2dr HT
71 Duster 340
71 Charger Super Bee - 383/727
72 Charger "Sabotage" - 440/727 - Street/Strip
78 Warlock in beautiful patina
Re: Thoughts on mild 383 [Re: LaRoy Engines] #2803548
08/01/20 02:29 AM
08/01/20 02:29 AM
Joined: Sep 2004
Posts: 523
Right here
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Originally Posted by LaRoy Engines
Originally Posted by HP2
Originally Posted by 67_Satellite
This got off into the weeds pretty quickly. If you are really going to run a stock converter, stock ex. manifolds 3.23:1 gears in a 383, forget the single plane manifold. Build as much compression ratio as your budget allows, use a dual plane intake of your choice with a 650-750V.S. carb., and don't over cam it. I have run stock manifolded 383's in 2 different 4 door (66& 68) Newports. Both ran mid 15's at 90ish m.p.h. with less than 8:1 compression,2.76-3.23 gears & stock heads.. I used a cam dynamics 266 energizer(.440" 266 210@.050") and a Crower 260 H.D.P. ( .456"-477" 260-267 212-218@.050). I liked the energizer better as it had tighter lobe sep. and better low end.A 230@ .050 cam and a single plane will be a turd below 3000-3500 R.P.M.


I agree, we ended up far out in the weeds LOL
Yes, I'm really gonna do what I stated from beginning. Maybe not the DP4B since it's not for spreadbore, which I'm gonna use.
I have never even considered a single plane for this build. This engine will need long runners.

I'm going to keep the compression pump gas friendly. We can get 93.5 oct here in Sweden (<5% ethanol). Cylinder pressure around healthy 160-170 psi is what I'm aiming for, that will leave some margin.

What I asked for was camshaft input for this specific build.
My thoughts of a cam are duration around 220 and maybe a little more on exhaust, lift as much as .500 and LS around 110. Talking hydraulic flat tappet now. But what do I know? LOL
It would be interested in some input - what cam and why?


I wish I could tell you what cam was used in this 383 engine but I cannot. Most likely it was some stock replacement hydraulic cam. The engine was built in 2002 and had about 10 miles it.

However we did run it on our engine dyno today 7/31/2020.

Fired it up with the stock iron 4150 type dual plane intake with a casting number ending in 301 and then changed to a Holley Street Dominator. The carburetor used was a 1406 Edelbrock.

RPM......Iron 301 TQ/HP......Street Dominator TQ/HP

2500.....349/166..................308/147
2700.....343/176..................310/159
2900.....351/194..................330/182
3100.....364/215..................343/202
3300.....361/227..................349/219
3500.....356/237..................350/234
3700.....349/246..................350/246
3900.....338/251..................350/260
4100.....336/262..................351/274
4300.....325/266..................348/285
4500.....315/270..................344/295
4700.....312/279..................338/303
4900.....298/278..................328/306
5000.....284/276..................320/305

END TEST


Very good you did that test! It proves what we already have guessed - in this particular case the SD intake will start walking away first after 3,700 rpm.
Dual planes will always beat single planes in the lower rpm's.
Single planes will always beat dual planes in pure power. But you will need revs to get it.
It is the Law Of Physics.


70 W100 Power Wagon. 318 4-spd
70 Sport Fury 440 2dr HT
71 Duster 340
71 Charger Super Bee - 383/727
72 Charger "Sabotage" - 440/727 - Street/Strip
78 Warlock in beautiful patina
Re: Thoughts on mild 383 [Re: Cab_Burge] #2803549
08/01/20 02:48 AM
08/01/20 02:48 AM
Joined: Sep 2004
Posts: 523
Right here
HP2 Offline OP
mopar
HP2  Offline OP
mopar

Joined: Sep 2004
Posts: 523
Right here
Originally Posted by Cab_Burge
Originally Posted by HP2
Originally Posted by BSB67
Solid flat tappet. Comp cam: XS268S. Pretty mild, and easy on parts.

This is an internet amatur's recommendation from a catelog. I would suggest calling a professional.


I have also been looking at that one, it's mechanical. Very close to Hughes SEH2024BL-11 but more duration and a little less lift. Plus I'm not sure Comp grind their Mopar cams for the larger .904 lifters...

I'm going to tell you that I have been told, and saw it on here also, that Hughes has Comp grind al their cams for them so that being said I'm sure that all the cams Cp sells are designed around the .904 lifter size up scope


I have also heard so. That Hughes let someone else grind their cams is no surprise. You need to be effective and grind a lot of cams all day long to make money.

My question then would be if Comp really design their Mopar grinds to take advantage of the bigger lifters in a way that make the cams make more/better power?
Dave at Hughes claim they do so, and I'm willing to believe him. Hughes are Mopar only and can put all their effort in maximizing their cam grinds.
Do Comp have resources to put their best engineers to design cams for Mopars only?
Some time ago I tried to compare Comp to Hughes grinds. Not scientifically but as well as I could just studying duration, lift and LS. It always seems like Hughes have steeper ramps and that makes me suspicious.


70 W100 Power Wagon. 318 4-spd
70 Sport Fury 440 2dr HT
71 Duster 340
71 Charger Super Bee - 383/727
72 Charger "Sabotage" - 440/727 - Street/Strip
78 Warlock in beautiful patina
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