Ok, so I figure the best route before I start buying parts at random is to come up with a complete gameplan and start assembling it as money comes available. So here are the specs for a future 383 build I've been thinking about. Any input would be appreciated!

GOAL:
383 Stroker
450+HP/450+ ft/lbs TQ
Has to be able to run on pump gas (92 octane)

Intake:
Rochester Quadrajet 750cfm
Edlebrock Performer RPM Q-Jet # 7104
AFR 195 Eliminator Street Cylinder Heads 65cc
--274cfm intake @ .500 / 207cfm exhaust @ .500

Rotating Assembly:
Eagle Street Performance Internally Balanced Kit:
--Cast Steel Crankshaft
--"SIR" 5140 Steel Connecting Rods
--FM244 Aluminum Alloy Hypereutectic Pistons -12cc Dished (9.9:1 Comp w/64cc Head)

COMP CAMS XE274H
--Duration @ 0.050": 230° / 236°
--Max Lift w/ 1.5RR: .490" / .490" Lobe Separation: 110°
---OR---
LUNATI VOODOO 268/276
--Duration @ 0.050": 227° / 233°
--Max Lift w/ 1.5RR: .489" / .504" Lobe Separation: 110°

Drivetrain:
Bowtie Overdrive Stage III 2004R w/ 2200 stall and 3.36 gears

Misc:
All Felpro Gaskets and ARP Bolts
Hooker Sidemount Headers

I’m ultimately looking for a monster that can also be taken on an occassional cruise (hence the overdrive and 3.36 gears). I also want to stay flat tappet due to affordability and figure the extra cubes will help tame the cam a little. Maybe throw some 1.6 RR on there for a little extra lift from those cams since the heads breathe so well.

Thanks in advance!!!

 

I think your cam is bigger than what your stated goals require.

I would call compcams (heaven help you if you actually do call them), crane, cammotion, isky, or crower and talk to them.

Your probably looking for a 1800-5800 rpm range. So something along the lines of 224/230 will do the job nicely I think (my opinion which is worth squat)

 

You're correct on the RPM range since I'm only looking to spin this to 6k. So should I look for a cam with a lower duration and higher lift profile? I was thinking the XE284H was a mild cam for a 383 compared to what some are running.

This won't be a daily driver, but I'd like to be able to take it to Carlisle or Bowling Green once a year without having to spin the motor over 3k RPMs the whole way there.

 

I think the cam is going to be way different than what you are expecting.

Give a reputable cam grinder a call, and ask their tech about it, give all your car details to the guy and he can tell you whats right.

My money is on a 224/230 or 230/236 at .05 with a 110 or 112 LSA

 

Yeah, I would definately give a call to the manufacturers before doing anything but was hoping to do any major troubleshooting on here before they tell me my heads or something else wont work with the kit as a whole.

I downloaded Crane's Cam selector program and I'm assuming this thing is pretty generous with the numbers it spits out?

I tried the setup with the following cams and got these results with a 10.5 compression ratio and AFR 195 Eliminator Street flow numbers:

XE262H
--Duration @ 0.050": 218° / 224°
--Max Lift w/ 1.5RR: .462" / .469" Lobe Separation: 110°
449 HP @ 5500
485 FT/LB @ 4000

XE268H
--Duration @ 0.050": 224° / 230°
--Max Lift w/ 1.5RR: .477" / .480" Lobe Separation: 110°
466 HP @ 6000
481 FT/LB @ 4000

XE274H
--Duration @ 0.050": 230° / 236°
--Max Lift w/ 1.5RR: .490" / .490" Lobe Separation: 110°
474 HP @ 6000
474 FT/LB @ 4000

All three of these recommend a stall in the range of 2300-3300. Maybe the XE268H or an equivilent cam would be better?

Any input from the professionals? I'm just an amateur trying to learn. How does the rest of the combo look?

 

Have the block clearanced to unshroud the intake valves and have the manifold gasket matched. You may also add a lifter valley splash shield while you are in there. Small mods add up.

 

I applaud you for working toward a comprehensive plan.

suggest:

gas quality ain't what it was & I expect it to decline: build accordingly.

more attention be paid to compression ratio and quench height.

off the shelf chamber size with no milling.

6" rods.

0.028" thin COMPosite gasket such as gm 10105117 or 14096405 for use with soft aluminum heads.

off the shelf dish or reverse dome piston to achieve desired compression ratio. Suggest one with thin ringpak.

deck block ... cut off in range of 0.012" - 0.016" to achieve proper quench ... that, in concert with gasket & with how far "down in the hole" NEW piston dwells in bore when @ TDC (aka dck height), determines quench height. About 0.035" - 0.040" QH good for fresh street motor.

FYI ... afaik, Eagle does not make pistons. Find out who makes piston before you choose. You'll find folks who're not fans of KB hypereutectic.

After you've established a practical static CR for your use, then decide on a cam for your use. Suggest do not get caught up in much discussion of dcr.

 

If theres any way you can save a little more to go roller do it..Those heads (dont go bigger) can handle plenty more lift.
Maybe a solid flat tappet at least. Careful about asking the speedshops for advice, most of them are $12 and hour kids reading from a chart in a book. Crower, Isky, etc would be good places to get some real life experience.

 

what is the maximum compression I could run on premium gas (92 octane)?

 

This does not answer your Q directly ... but, looking ahead, I'd hold it under 10:1. I'm sure others will not concur but I stand by it.

Please don't be led astray by some NEW gas cars' scr in the 11:1 even 12:1 range ... they all have very sophisticated computer-driven fuel injection & ignition & variable cam phasing ... some with "direct" injection that cools the chamber w/ pulsing.

 

Thanks for the suggestion. So how would I keep it under 10:1 with the AFR195s? Do I go with a larger chamber (IE: 74cc) or is it cheaper just to get a set of -12cc dished pistons. The AFRs come in either 65cc or 74 cc so what piston would be required to keep this thing under 10:1? Sorry I have so many questions. Thanks again in advance.

 

I run 10.6 to 1 compression in my 385 motor. I do run a pretty large solid flat tappet with 252/260 @ .050 dur so I can run that kind of compression. The compression has a lot to do with the head material, type of chamber and the duration of the cam. I run on 92 all day long. I did by mistake get some 89 in mine once and that was bad. 92 is the least I can run.

 

Many ways to skin a cat. My preference is dish piston ... dunno if cheapest ... afr heads very nice but dart may be just as adequate for your app ... dart & most others' most common chamber is 64cc. Frankly, me thinks your 383 project's hp/tq goal is attainable with w/ iron vortec heads & dish piston. Maybe this for your 72 and it does Not have numbers match? ... perhaps you might consider acquiring&building a later block that's already setup for OE roller cam-lifters? A great starting point is a core vortec 350 motor from '96-'01 GM trk with VIN code's eight'th character "R" ... $if bought right$.

I dunno which cr calc you use ... I use this one from TRW/FedMog ... it's quite accurate & easy to use ... I usually add 1.7cc to the chamber volume ... that's a close approximation to compensate for most pistons' chamfer and land gap.

http://www.21cgt.com/FMWebCatalog/frmConversion4.aspx

 

You can run 11:1 with an efficient combustion chamber, anywhere in the 10s is plenty safe.

 

I would have to agree with some of the above posters that 240 duration is to high a power band to work best with 3.36 sure the low gear ratio and stall will work out in low gear but what about that high of rpm range on the cam through the rest of the gear range ?? that 3.36 will be pretty high geared when the overdrive is factored in. cruise rpm would be to high on the cam.

hers an example a 236 .050 hydraulic flat tappit with 110 LSA
the cruise rpm range 3800-4200.

 

I'm leaning more towards a XE268H style cam with only 224/230 duration so would you recomend 3.08s and a lower stall?

 

high gear
3.08 X .067 = 2.00
3.36 X .067 = 2.20
3.55 X .067 = 2.30
3.70 X .067 = 2.40

Low gear
2.74 X 3.08 = 8.43
2.74 X 3.36 = 9.20
2.74 X 3.55 = 9.72
2.74 x 3.70 = 10.13

if you have a choice in rear gearing consider 3.70 or 3.55.

 

With head that flow near 280cfm that cam will be a waste of time. I ran a solid roller 242/248 with .600" lift with heads that flow 280cfm and got 550HP.

With 3.08 rear end it was pleasure to drive it on the street. It was a 406ci but still a 383 with those heads can handle some cam. Put a mans cam in it and you will be happy, that cam above is great in motorhomes

Run flat top pistons and 10.5 to 11:1 cr .

 

Here"s a calculator http://www.wallaceracing.com/gear-speed.php
figured with 26" tires 336 rear gear an .67 o/d your looking at 2000 rpm @ 70 mph
I agree with jackson, keep it just under 10:1 to be safe.
At 750rpm that xe284h pulls 5-7 in of vacume, so when they say pulls good vac they must idle it up a little
Here"s my setup an comp recommended the xe284h
First i told them i wanted a hyd cam
355 ci.
dart pro 1 heads 180cc 74cc chambers
.125 dome pistons
compression is 10.1:1
370 rear gear
4 speed trans

I later found out i only have 308 rear gears an this is not a problem at all. Drives great with 308"s
At 5000 rpm this engine makes 1 hp per cubic inch
The xe284h is rated 2500-6500 (only turn mine 6000) the cam pulls hard from 2000 but that may be because of the 180cc heads an the holley contender dual plane intake

 

Ok, I updated the original post with a few changes: (XE274H ,10:1 compression, dropped the stall to a 2200)