383 q's

[Hot_Rodder]

As posted in the proven engine build big block section:

I ran across this article in a Car Craft magazine about a 383 Mopar build-up.  It's really bolt ons and a cam. Made some good power.  Seemed like the kind of info a lot of folks would be interested in. Maybe a pretty common build. Here are the details:

Bone stock 383--stock-bore
K-B hypereutectic replacement pistons--9.0 to 1 compression   Pump gas special.
Unmodified  906 heads
Comp XE285 HL Cam  285/297* gross duration  or  241/247* @ 0.050
The lift is 0.581 intake and exhaust with 1.6:1 rockers---hydraulic lifters
Mopar Performance  M-1 intake
Demon 750 cfm carb
1 7/8 headers

This combo produced the following Horsepower and Torque

Horsepower peak is  455.7 @ 5800 rpm
Torque peak is 457.4 @ 4900 rpm

This research was done by Comp Cams and the entire story can be found in the Winter 2003 Car Craft Mag

     ...................Oldschool

Here's what me and a friend of mine were wondering for a street only driver, mostly cruising car. The car will be a '72 B body, and my friend has bought a 383, but it has not been touched as far as checking casting #'s other than knowing it's a 383. We have not even checked the year yet... Anyway, I was looking at this build, and was wondering what would happen if you did change a few things. First before I continue, I will say there's gonna be a lot of "assuming this and assuming that" because of the lack of unfortnate knowledge of the motor. But we can use this as a general guideline...
-383 block, + .030
-Stick with the KB pistons, somewhere around a 9-9.5:1 comp.
-Hopefully it will have 906 heads, but if so then this is what I have in mind, gasket match both int/exh ports, bowl port
              also, install bronze valve guides, and hardened seats, have 2.14/1.81 valves here are the two sets of
              valves that I'm concidering:   These are Summit Racing part #'s
              Intake: MIL-45275-8           Exhuast: MIL-45266-8
              valve springs will be matched to the cam
-I've been looking at the Lunati Voodoo cam's and have a few good things and a couple of not so good things.... But
              more good than bad, if these will make better vacuum then I'd rather focus on this line up, we were thinking
              of maybe something like this: LUN-60302
-The intake will probably be an Edelbrock Performer RPM
-Use the same carb, but it's got to have an electric choke
-Use the same headers with a 3" collector and maybe 3" pipes all the way back with X pipe and maybe Hooker
              Aerochamber mufflers
-Will be using an electronic ignition conversion
-Aluminum water pump housing with high flow aluminum water pump with a 180*F thermostat
-March Performance serpentine belt conversion kit
-Run an electric fan assembly with one of these: http://store.summitracing.com/partdetail.asp?autofilter=1&part=FLX%2D31165&N=700+4294924500+4294839058+4294860934+115&autoview=sku just in case the link doesn't work here's the part # FLX-31165

So anyone got any comments?

[Chryco Psycho]

I feel 3" exhaust on a 383 is overkill , 2.5 will work better
 the Viscous clutch fan will be more efficient than an electric fan   
 Tha March serp belt is more looks than performance
 I am not a fan of the KB piston , for not a lot more you can get a Good forged Speed Pro piston or other Like Ross or Diamond & if you want more power later on no rebuild needed , also the 906 heads will not offer good quench charicteristics & tend to actually cause pinging if you push much past 9.5 compression , I would use 1.81 exhaust & hard seats in the heads with 2.08 intake valves
 other than that it looks good

[moparnut]

where do you buy a Viscous clutch fan???

[moper]

Here's a similar twin to what you're thinking: Car is '70 RT challenger, #s block, 4sp, 3.55s, goal of pump gas, decent street manners, and faster than stock for minimal budget.
Stock block +.060 over (was .030 already), stock main cap bolts reused
KB flat top hypers set to zero deck (as delivered witha  blueprint deck, they will be down int he bore .015-.020")
Stock crank truned .020/.020 and polished
stock rods, resized with ARP bolts
906 heads w/stock ports, redone with 2.18/1.81 valves, guides, unleaded seats, cut for teflon seals, milled to 74cc
FelPro blue gaskets
reused factory rockers and shafts
Comp XE268 cam w/matching springs, retainers, and locks
Comp pushrods
MP conversion w/orange box
re-used Edelbrock Torker single plane intake
Holley 3310 750 vac secondary
re-used Hedman 1 3/4 primary headers
custom bent 2.5" exh with H pipe and factory tips

The engine idles at 700rpm smooth with 14" of vaccum and just a hint of lumpy. It runs on pump 92 or 93 very happily. The car had an MP 509 and 4.10s previously, and had all kinds of issues besides that. The new engine runs in his words " faster than I wanted, but better, and with street manners and even with the mild gears." The car is a blast on the street.

[Hot_Rodder]

I feel 3" exhaust on a 383 is overkill , 2.5 will work better
 the Viscous clutch fan will be more efficient than an electric fan   
 Tha March serp belt is more looks than performance
 I am not a fan of the KB piston , for not a lot more you can get a Good forged Speed Pro piston or other Like Ross or Diamond & if you want more power later on no rebuild needed , also the 906 heads will not offer good quench charicteristics & tend to actually cause pinging if you push much past 9.5 compression , I would use 1.81 exhaust & hard seats in the heads with 2.08 intake valves
 other than that it looks good

Thanks Chryco I've made noted of this, and will let him know, and see what he thinks.

Oh yeah, btw, any suggestions on ign setup? He says he doesn't want to spend the $ on an MSD setup, so I was thinking maybe the M.P. electronic ign conv kit with orange control box?

[ViperMan]

where do you buy a Viscous clutch fan???

I don't know of any main-stream, "high end" places, but I'm pretty sure Advanced Auto Parts has 'em for various models and applications.  There's really nothin' fancy about a viscous clutch fan.  I think usually you can swap the fans on the actual clutch.

[Stacked440]

I bought my fan right from the local Dodge dealer for not to bad of a price if I remember right.

[todd383]

I would  go with  3" x-pipe exhaust, it made a lot more power than my 21/2 set up, I basically have the same set up u mentioned but used a hughes he3038 cam, and made over 500 HP!!!!

[ViperMan]

So how much do you think a setup like that would run someone?

No idea why I might be asking....   

Jeff

[Hot_Rodder]

Hey I got a bit of a question, hopins (and assuming) that the heads that are on this 383 are the 906 (once again, have not done anything to the motor yet), does anyone know what the combustion chamber cc's are? I think it's like an 84 or 86 cc chamber, but I was wondering what they are supposed to be in factory form? Here's some links to some pistons that will probably be considered for the engine rebuild:
1: http://www.rosspistons.com/uploads/chry_big_blck_flt_top.pdf
2: http://www.campbellenterprises.com/mopar_speed_pro_trw_forged_pistons.htm   - Mopar Piston link
          http://www.campbellenterprises.com/parts.php?type=search&query=fml2315f-30   - 383 Piston link
3: http://www.diamondracing.net/Diamond2007.pdf


So does anyone know what the factory combustion chamber CC's are on the 906?

[moper]

Factory size says 84-88cc. It's more like 89-93. The biggest I heard of was 94cc.

[Kapteenikosmos]

I measured my set of 452 heads and the chambers were approx 94cc on those. (I think that the chamber is the same kind as used in 906 too).

[PlumCraZRT]

Hey I got a bit of a question, hopins (and assuming) that the heads that are on this 383 are the 906 (once again, have not done anything to the motor yet), does anyone know what the combustion chamber cc's are? I think it's like an 84 or 86 cc chamber, but I was wondering what they are supposed to be in factory form?

"However, the 906 was cast with open combustion chambers (typical factory volume 88 cc)." -Mopar Muscle:

http://www.moparmusclemagazine.com/techarticles/5115_cylinder_heads/

[moper]

right. They got that from a manual. Actually measure a set of four on one stock untouched head...

[Hot_Rodder]

Jeeze.... Ross's listed 383 piston on the above link lists an 86cc chamber of a comp of 9.5:1.... Wonder what a 90 + cc chamber would be....
Hmmmm.... Speed Pros listings are as follows under a 88cc chamber
                          +.030= 8.94:1
                          +.040= 8.98:1
                          +.060= 9.01:1
 

As for Diamond.... Once there link uploads.... I'll be abe to say what they list....
Mopar Pistons start on page 41 for reference....
There piston ranges from 8.8:1 - 9.6:1

Man oh man.... Here I am trying to keep the comp between 9:1 and 9.5:1 for this guy, and looks like some shaving may be in order? So if anyones got some ideas on what to do to try and up the comp ratio to within these spec's without going to a dome piston, please say something. He wants to stick with a flat top for better flame travel.