Cam selected for hot 383. Curious what you think.

F

FinallyGot1

Member
Joined
Feb 11, 2015
Messages
93
Reaction score
32
Location
Troy, MO
New engine is coming together. Pistons are off at Swain Tech being coated and I'm still trying to decide on a cam. I think I've got it narrowed down to this one: http://www.crower.com/camshafts/mopar-383-440-b-supercharger-hydraulic-cam-304-hc.html
236* duration @ .050", 114* LSA, .534" lift with my new 1.6 roller rockers. Got me some Edelbrock E-Street heads and KB162 flat top pistons for a 10:1 compression. Ultimately, I plan on adding a couple of turbos making 6-10 psi of boost. Might consider switching to E85 at that point if water injection can't control detonation. I plan on taking the old girl out to Silver State at some point but she will see regular street use. It's a heavy car with 2.75 gears so I'm not really concerned with launching off the line. High speed highway runs is where it's at for this build.
So waddya think? My DynoSim really likes this cam both with and without the turbos.:3gears:
 
Though the simulator likes that cam, have you tried a dual pattern or even a custom grind?

You have many options, though they may not seem conventional - turbo builds are definitely different than N/A builds.

Have you tried one size larger cam with 1.5 rockers on the intake and 1.6 on the exhaust? On a custom grind have you tried 2 degrees or 4 degrees wider on the LSA?
 
That is a lot of cam for a heavy car. You are going to need a lot more gear too. Sorry to say that it will be a dog until you get to 3500 rpm's or so...
 
. High speed highway runs is where it's at for this build.
Click to expand...
Did you know when travelling even at 80 mph you only need less than 100 hp?
You seriously need to examine what you need.
You're short on cubic inches in a huge barge with highway gears.
 
Not to mention that you'll be starving for vacuum and will have a problem with brakes especially in traffic.
 
Don't be too scared of the cam, I run a similar one in my '68 with a single plane M1, 2800ish stall and 3.91 gears........ The cam is part of a package, just make sure your package works. Unfortunately the only way to build a package that works is to try components.

Remember; 383s are not torque monsters - they like rpm and can pull hard 3,500-6,000 you just need to build a package that supports this in the weight of your vehicle
 
commando1 said:
Did you know when travelling even at 80 mph you only need less than 100 hp?
You seriously need to examine what you need.
You're short on cubic inches in a huge barge with highway gears.
Click to expand...


Hence the turbos. Think of it as a 547 motor at 6 psi. and a 654 at 10 psi. At least when I stick my foot in it and the boost builds. On-demand displacement.
450 lbs-ft of torque at 2000 rpm without the turbos and just a hair over 550 lbs-ft at 2000 with them adding 7 psi. I expect it'll be adequate when I want it to be.
 
1978 NYB said:
Not to mention that you'll be starving for vacuum and will have a problem with brakes especially in traffic.
Click to expand...

114* LSA and very low overlap should preserve vacuum down low, along with the dual plane manifold and 650cfm carb.
 
1978 NYB said:
That is a lot of cam for a heavy car. You are going to need a lot more gear too. Sorry to say that it will be a dog until you get to 3500 rpm's or so...
Click to expand...
Hoping to take care of that with a low gear set for the A727 during the rebuild. Low gears at low speeds and I still get to keep my long legs in third.
 
commando1 said:
So, like the Ford EcoBoost....
Click to expand...
Only because they're both turbo motors. Turbos, being dependent on load rather than engine speed can build boost & add "displacement" at relatively low engine speeds IF you stick your foot in it and add load. Light throttle = no/low boost. Wide open throttle = max boost pretty quickly (depending on how the turbos are sized).
 
Top Heavy said:
Though the simulator likes that cam, have you tried a dual pattern or even a custom grind?

You have many options, though they may not seem conventional - turbo builds are definitely different than N/A builds.

Have you tried one size larger cam with 1.5 rockers on the intake and 1.6 on the exhaust? On a custom grind have you tried 2 degrees or 4 degrees wider on the LSA?
Click to expand...
Played around with cam profiles quite a bit. I reach coil bind at .590 lift so trying to stay a bit below that. This cam gets me real close at .534. A wider LSA seems to soften the motor down low (below 4000 rpm). This engine seems to like single pattern profiles best with these heads. Factory heads are another story. Tighter LSAs make the motor snappier at lower speeds but overlap goes up and I lose vacuum....but top end power is good. Of all the many profiles I've tried, this one does the best both with and without boost. 550 hp @ 5500-6000 rpm N/A and 700 hp @ 6000-6500 rpm with 7 psi boost. Retarded the cam 4* to get those numbers and surprisingly that didn't kill my bottom end like I thought it would.
 
icon_crazy.gif
 
Have you done any of these mods yet or is in still on the drawing board?
 
1978 NYB said:
Have you done any of these mods yet or is in still on the drawing board?
Click to expand...
Motor is being built by Creason Racing Engines. Pistons are off at Swain Tech being coated. (Thermal barrier coating on the crowns and friction reducing coating on the skirts.) When the pistons come back, the whole rotating assembly will be balanced and dropped in place, along with the bottom end girdle I got from 440 Source. I'll be ordering the cam this week, as well as the timing set. Block is all machined and ready for parts. Heads will go on later after I get the chambers and valves coated. All other parts have been purchased, with the exception of the turbos themselves.
 
1. What is this engine going into again?
2. And the HP numbers are coming from the simulator software?
 
commando1 said:
1. What is this engine going into again?
2. And the HP numbers are coming from the simulator software?
Click to expand...
Going in my '68 Newport. Yes, all numbers are from DynoSim 5. Interesting that all my numbers went DOWN after the most recent update to the program. For reference, I entered the data for my factory stock 383 2bbl and DynoSim shows 260 hp @ 4000 rpm and 416 lb-ft of torque @ 2000 rpm. Seems pretty close to me. Got the cam specs from my FSM.
 
Last edited:
Please post pictures when you assemble. It'll be interesting with turbo's.
 
1978 NYB said:
Please post pictures when you assemble. It'll be interesting with turbo's.
Click to expand...
Will do. After the short block is assembled, I'm going to get the motor back from them and put it on a stand. I'll put the heads on and then get all the accessory mounts needed. I want to leave my original engine as un-molested as possible and I want to retain the factory A/C. Nothing like racing through the desert with the A/C blowing. Sounds like fun to me.
 
You must log in or register to reply here.
Back
Top