Running a 383 @ 8000rpm....what do I need for a good reliable shortblock

[Fury Boy]

When I rebuild the 383 I am gonna build it to run @ 8000 rpm. I want to run a 3.5 in stroke. want about 12 to 1 comp. what do I need for a crank, rods, oiling, cooling and ignition. top end consist of Hughes Stage I porteed '516s(66 cc combustion chambers), Engle K10 hyd. cam(.260 dur @ 50 and .550 lift), 1.6 ratio roller tip rockers, a Torker intake(might trade for a tm6 if I can fing one)and how about some Rhoades lifters?
I will use a rebuilt Electronic dist. and am looking at the Chrome ECU. The car is of course my '63 Fury(will weigh about 3100 lbs race weight) w/ a 4000 rpm converter and 4.30 or 4.56 gears. I am looking for about 525 to 550 HP. Do you think I should Have a knife edged crank? I am planning on using a balanced OE forgedsteel crank(383 strokeed to 3.5)

[fat bastard]

Well, I think you'll need alot of work with your oiling, a very good harmonic balancer, aftermarket rods and bolts (if you really plan on spinning at 8 g. r) I like the new MSD 6 digital for spark. Right now it sounds like the motor isnt together, so I would consider stroking the 383 block for more cubes and torque.
F.B.

[Warren J]

Fury Boy, you will have to do much more than you think to run to 8000rpm. Instead of the chrysler electronic box you will need a good msd as one of the other members said. You can forget the hyd cam, you will need a solid with good roller rockers and good push rods, your talkin a roller cam. You will need to modify your oiling system, restrict oil to rockers. You will need a good set of forged rods and lightweight pistons and a really good crank. You will need better head porting than stage one, and get a lot more convertor than a 4000 stall, more like 5000-5500. You will probably need crank trigger pickup and forget the dist you plan on running. I think you need to rethink what you really want to do with your 383.

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[Dr. Righteous]

Not to sound too course Fury Boy,
But it sounds like you are getting advice on 'what you need' rather than solid research and reading of good tech manuals.
When you are talking about running an engine at 8 grand the stock configuration of everything goes out the window. You even have to consider is the BLOCK itself strong enough. You may need to revaluate your performance goals. If you really want 500+ HP you would be money ahead to start with more cubes (more stroke ) than your 383.

(not dogging a 383; that is what I have)

[Streetwize]

First off, WarrenJ is right on the money regarding the cam and the oiling system.
your converter and gearing is going to depend on your total combination, so I won't go there. Definately a 1/2" pickup and a good Milodon pan and hardened drive. I've turned 383s 7200-7500 without hurting anything using mopar rods, so 8000 shouldn't be too hard if you keep the crank mass low and have enough head on the car. You'll need a good rocker arm assembly, I'd talk to Dan Dvorak down in Fla to get his prefered set-up. Since Dan runs the same vintage B bodies and 413-426" RB motors, he can also help there, too. I'm thinking a 4.88-5.13 with a 29.5" tire may be better, BTW.As for the rest of the block:

Trade the 383 for a 400, you'll have a 4.375" bore instead of a 4.31" (383 +.060)
This will further unshroud your valves and give you 424" cubic inches with a 3.525" Stroke. (see below). The block itself will want steel caps and ARP studs which means you'll need it allign honed afterward.

Have your crank rod journals offset ground down to a BB Chevy sized 2.200" taking the stroke from 3.375" to 3.525" (+.150"). The smaller journals both reduce the crank mass and reduce both oil demand and friction, all good for higher RPM. I'd highly recommend Pauls Crank Shop (Paul@devtex.net). He Builds/rebuilds top fuel cranks and is one of the most precise and knowledgeable people I have ever dealt with in my over 20yrs of building motors. Very reasonable pricing and his precision and attention to detail is unmatched.

For connecting rods, use the 6.765" Manley #14279, which are Mopar width and BBC big end w/bushed .990" pins. This will give you a 1.92 rod/stroke ratio which will help you keep the heads flowing at the high rpms. If you have the funds, use the same size BME Aluminum rods.

For Heads, I'd use the Indy S/R's which can flow 340/235 with very little work. The bigger bore of the 400 block will really help the 2.19" intake do its thing. Use an M1 with the popsicle sticks and the dominator flange; I'd definately use a 4500 series carb of at least 900 cfm.

There's more, (like cam specs, headers, etc)but I haven't had my coffee yet this morning!!

It's doable, and 424" of lightweight short stroke is a great combination; It's not usually done because you can built a 470" motor using only a 440 crank w cut down mains and have the same power at lower (read: better Longevity) RPM. But with the right attention to detail, precise machining
and a good lightweight combination, why not.

Good Luck, sounds like a screamer (literally)

Wize 1


[This message has been edited by Streetwize (edited January 21, 2001).]

[This message has been edited by Streetwize (edited January 21, 2001).]

[cuda66]

Easy....
write me a check for $30-40K and you can have one on your porch in about 2 months.

You could buy a Hemi Crate Motor and send me all the extra cash for my project...Dear Sponsor.......

[Fury Boy]

OK, I can see that it is quite a project to make a motor turn to 8 grand reliably. I am not in for that so what if we tuned down the cam and gave it a little more head(like Stage II 902 heads) and the cam is more like .252 dur @ 50 and .540 lift. I think I could still see 520 HP. Maybe run like a 4500 rpm stall. make the motor so it tops out about 7400 rpm, external oiling system, rev limiter of course, What else can I do to make the crank STRONGER. I though I read in Mopar Action some time that align honing a 383 caaused major weaknesses in the block. I know all you think I should just buy a 451 stroker but I thnk of this as an expensive way to get cubes and it is not good bang for the buck. If I could have my .060 over 440 pistons lightened and I used some sixpac rods would I be in good shape for the rod area? I see all the muscle motors kits about these $2500 kits and that is with factory rods. could I just stroke the 440 crank to 3.9 without problems? I still love the 383s! I like the power band, the way it revs, I just like it!

[HOLESHOT]

A BAG OF MONEY AND GODS INTERVENTION!!!!

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[Streetwize]

If all you want is 525HP, the 424" combo would work, just limit your rpm to about 6800-7200.
You can then skip the steel caps, just use ARP studs. If allign honing weakened the 383, they must have allign BORED it to 440 size 2.75" from 2.625". Honing itself takes out very minimal material. I'd still use a 400 block, 100 bucks for the extra cubes and better valve flow is worth it. Pistons will cost the same. You can get Paul (paul@devtex.net) to nitride .030" into the the Crank for around $175 bucks. (see E-mail text to me below)
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Bobby, read a question from a guy on MoparChat, Perf. if a crank needs to be
nitrided. No it does not for normal use and if you put your engine together
clean. The metal on a regular crank, say a 440, is hard enough to do the job.

Say you want to spend some extra cash and are racing or running all out then
you can nitride. It will make the journal about 60 rockwell hardness, that
is very hard, Hard Chrome is 62. It is very wear resistant. You can put a
new polishing belt on a nitrided survace and it will hardly touch it.

What is nitriding, the germans used it very successfully in WWII on their
plane and tank engines. Made them last much longer in the sand in Africa.

To nitride you put the crank in a nitrogin athmospere at a constant 700
degrees. Each hour it is in this athmosphere the hardness goes .001 deep. To
get a dept of .030, which is what dept most go to, it must stay in the
cooker for 30 hours.

When a crank is nitrided it will increase in size from .0005 to as much as
.0008, so if you want the crank journal to be 2.199 you must grind it to
2.1985 and after it is nitrided it will be close to 2.199.

You may explain that to the guy on chat, I did not know how to do that.

Also if you have a crank that is nitrided, it can be ground .010, 0r .020
without nitriding it again as the nitride is .030 deep, if you grind it .030
then you better re-nitride. They say you have to re-nitride a porsche, I
have ground many and never re-nitride as it is not neccessary if you only
cut it the first two sizes.

I did a stroker like yours for a guy in Calif. for a motor home and he
wanted it nitrided. I charge $175 extra to do it. Paul
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Keep the M1, use an 830-850 Annular 4150.

I'd use an Ultradyne Solid Flat tappet with about 255-260 @ .050. Mildly ported Iron Stage V's like mine (285I/210E)would run about $1300-1400 complete w 2.19"/1.81" and would be more than adequate.

That should get you in the right direction and not bust the bank, or make your pistons swap holes, for that matter

Wize

[Rex Jr]

Why all the talk about turning the 383 so high just for 550hp?You should be able to do that between 6500-7000rpm with right cam and heads.we just got finished running a 406 on dyno,it made 553hp at 6300rpm and 519 ft/lbs at 5000rpm.

[Streetwize]

The most important think with short stroke motors IMO is not so much peak power but where your motor pulls down to on the 1-2 shift recovery. assuming your running a 727 with a standard 2.45/1.45/1.00 ratio at say 10% past a peak HP of, in Rex's case 6300 makes 6900 shift point. Now,if you shift at 6900, the 1-2 gear change is going to try to instantaneously try to pull the motor down to around 4100rpm. If you don't have close to your peak torque at this RPM the car may momentarily lose momentum until it gets close to and past the torque peak. This is generally why short stroke motors like tighter gear spacings (as with a manual tranny) to keep the revs up. It's a lttle harder (though not impossible)to get a broad flat torque curve with a proportionally shorter stroke. A shorter stroke tends to raise the RPM at where peak torque is made and the (general rule of thumb) 90% of peak torque range (above and below the peak) tends to be over a narrower band of rpm. A broad flat torque curve can be an advantage in drag racing because it makes the optimum shift point just a little more "tunable/adjustable" for tight or loose track conditions. Short stroke motors are generally more sensitive to induction changes as well. Again, a bit of oversimplification here, but the gist is there for conversation.

There is a great book on this subject called "The design and tuning of competition engines". The Author's name was Phillip H. Smith. Don't know if it's still in print, I read it in College.

Wize 1

[Fury Boy]

Is there a close ratio gear kit for 727 transmissions. I also have thought about having the pistons and stuff coated

[Rex Jr]

streetwize,you are correct about needing a broad torque and hp curve for dragracing,especially in bracketracing.I think the short stroke engine we built has that.The tq only changed 15 ft/lbs from 4300 to5400.HP only changed 10 from 5800 to 6800.

[Streetwize]

Rex,

That's great! I'd like to know in more detail about your Intake, Carb, compression and cam timing as well as your Cylinder head flow. Are you running longer than the 6.36" "B" rods? That torque curve sounds awesome, looks like a STR or "Rat roaster"
(similar to a Max Wedge or an SS/AA Hemi style configuration, for those who may be unfamiliar with the "old" terminology).

Then again, maybe your running a DFI system?

I calculated the 424 combo I outlined with 280/215 heads would make an Easy 545 at right around 6000 with only about 10.2:1 and be basically streetable. Taking it out to 305/225 (still within Stage V's port range) and 11;1, I get 591 @6250 and 577 peak torque @ 4800, which is real close to your 553 with 406 inches (hp/ci-wise). The torque stays above 480lb/ft from 3800 to 6500, not quite as flat as yours. Kind of stumped, it's tough to get that flat and broad a curve with a short stroke and a single plane X Manifold and a Carb, as you probably know. My 108 centerline needs to widen and/or switch to a solid roller. How about a sheet metal Tunnel ram....hmmmm.

Wize 1



[This message has been edited by Streetwize (edited January 21, 2001).]

[Sport]

Fury boy, I think the idea of a 8000 rpm motor is cool. But being cool will burn up alot parts, and $$$$$$$$$$$$$. Unless you have the budget of John Force ,Warren Johnsen
etc. etc .Then go for it but really you can get a lot of power more cheaply with less rpm. And a motor that lasts a long time.I admire the fact that your going with the the 383 ,that was one of my first motors, in a 1969 charger.Sport

[Fury Boy]

Well, if anyone knows were I can get a 431 rotating assembly for under $1000 I would probably go that way

[Rex Jr]

SRTEETWIZE, it has manley RB rods with Diamond racing pistons. It has 13.5 compression, also home ported INDY SR heads don't know what they flow.It has 950hp carb&M1 mopar singleplane intake.The cam is relatively small,but I think it is reason TQ is so good,it is a609 lift comp roller with a split duration 272/276 at .050 and 304/308 adv.I think it would benefit with more lift.This is a new combo we just wanted to try so far so good,looking foward to putting it in the car and tring it out.