383 / 432 Mopar stroker for the Challenger

Author Topic: 383 / 432 Mopar stroker for the Challenger  (Read 31786 times)

Offline femtnmax

  • Full Member
  • ***
  • Posts: 997
383 / 432 Mopar stroker for the Challenger
« on: February 19, 2013 - 08:02:06 PM »
Decided to build a new engine for the Ebody.  Found a good used 383 engine out of a 1969 Chrysler Newport for $225, had 80k miles on it and still turned over.  The engine had never been apart...main and rod bearings date coded 2-69, engine block date code 5-5-69.  The Scat stroker kits thru Flatlanderracing offer a 383 bore with 440 stroke basic kit that includes crank, rods, and pistons.   To go with the flat top forged pistons I will have moly top ring with napier 2nd ring for better oil control.  The main bearings will be half groove just like what came from the factory, again to keep excess oil off the cylinder walls.  Note that the Chevy LS7 had to make changes to control oil thrown off the crank.  I might run the OEM cast iron 906 cylinder heads until funds allow for aluminum heads.  The 906 heads are in remarkable condition, beautiful contact patterns between valve faces and seats, not too much guide wear. 
Running the iron heads with a .039 thick felpro head gasket gives 9.8 static compression.  Aluminum heads with some milling can also use the thin .039 thick Felpro gasket for 10.5 static compression/8.26 dynamic.  So the 383 build can easily go iron or aluminum head with same flattop piston. 
With aluminum heads, intake manifold, water pump & housing the 383 weight is about equal to a 360 small block, but the 383 stroker will have much more torque:)
Should be a great project.

UPDATE!!!!
March 2014    Finished building the long block.  Here are some thoughts on the build.

There are several stroker kits sizes available for the 383, and more choices for the 400.  Kits are available from 440 Source, and Flatlander Racing to name a couple.  I have purchased from both and had excellent service either way.
Your altitude location above sea level has an effect on engine output.  For every 1000 foot elevation, there is a 3.7 % reduction in Torque and Horse Power.  So for my 5000 foot altitude that is over 18% loss in performance.  So in hindsight going to a larger cubic inch stroker can make up for the performance loss.
If using OEM Mopar 440 crank cut down, or Scat forged with 383 main journal size; either way the crankshaft counterweights need to be cut down to clear the 383 engine block cylinder bottoms.  Research says the Mopar crank needs .125 inch cut off the crank counterweights, that is .125 radius.  The Scat forged 383 crank needed 0.1 radius cut off, might as well be .125 also, because when balancing with I-beam connecting rods and forged pistons the Scat crank still needed a lot of weight removed (holes drilled) to achieve internal balance.   The Scat forged 383 crank does have the correct 383 sized main bearing journals, but my guess is this crank starts as a 440 crank forging then has the mains cut down to 383 size; thus the need to reduce the crank counterweight diameter to fit into a 383 block.  Reducing the crank counterweight diameter means no need to die grind clearance cuts in the engine block.
Everything else in the long block was typical engine rebuild, your choice of 1 bolt or 3 bolt timing chain gearset.  Oil pump pickup tube for 383 block is 3 / 8  inch from the factory, some folks run it as is, others drill the block out to 1 / 2 inch diameter (hemi) size.
For cam selection most users suggest a faster lobe ramp rate typical of Lunati Voodoo or Comp Cam extreme (XE) series.  Choice of cam for street runs from XE262H to XE280ish, with RPM limited to around 5500-6000 for hydraulic cams.  Higher rpm use for street/strip goes up to at least  XS282 solid and still have somewhat acceptable idle quality for street use at lower elevations.  Your choice.
Cylinder heads.  I spent  $1000 to completely go thru factory iron heads with new everything.  For the old iron do at least a 75 degree bowl cut or the Mopar templates for improved performance.  For aluminum heads the 440 stealth or Edelbrock RPM are commonly suggested Next Level Up.  Either choice should include a complete tear down, and inspection typically including correcting parts fit and parts quality.  The cost can be around $500 for the RPMs or the Stealths according to several reputable shops on the FABO forum.  So the aluminum heads will cost close to twice that of rebuilt OEM iron, but with improved performance out of the box.
« Last Edit: March 30, 2014 - 09:04:47 PM by femtnmax »
Phil




Offline Sleepychallenger

  • Sr. Member
  • ****
  • Posts: 1091
Re: 383/432 stroker for the Challenger
« Reply #1 on: March 26, 2013 - 10:22:05 AM »
Good luck. Sounds like a fun build. Keep the pictures and progress coming  :chatting: :useless:

Offline brads70

  • C-C.com Expert
  • ********
  • Posts: 18747
Re: 383/432 stroker for the Challenger
« Reply #2 on: March 26, 2013 - 11:28:16 AM »
Sounds like fun!  :2thumbs:
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

Offline ragtopdodge

  • Resident
  • *****
  • Posts: 4065
Re: 383/432 stroker for the Challenger
« Reply #3 on: March 26, 2013 - 04:55:57 PM »
If you're going with a stroker kit, why not get one w/a 4.150" crank to get 472"?

472 cu. in. (383-400 Main)
Crank: 4.150" Stroke Rod: 6.760" Rod Length
4-383-4150-6760-2374    2-440-6760-2374-990    PREM.
FORGED
(DISH)    4.280    -    -    -    1-48083-1    $2010    1-48083    $2212    1-48083BI    $2336


440 source makes a kit too:

383 >> 496. (4.250" stroke/6.535" rod)  Approximate Bobweight: 2150

Turn that docile factory 383 block into a fire breathing, pavement twisting engine of almost 500 cubic inches, and no one (even the car show judges) will ever be able to tell it's not a 383... until they go for a ride! The time has arrived to dust off those 383 blocks we've been leaving in the back of the garage all those years. Chrysler made 4 times as many 383's as they did 440's, and it's no longer necessary to dig up a 440 block to get almost 500 cubes! The low deck, 4.250" stroke version of our Platinum Series crank used in this kit has the smaller 2.200" (big block Chevy sized) journals, and the counterweights are finished at the smaller "B" engine size, to ensure they will drop right into the block with no counterweight clearancing issues. Depending on the block used, many of customers find this kit drops right in with no modifications whatsoever! We now offer fully chamfered "B" engine main bearings as an available upgrade! We keep all the kits listed below normally on our our shelf and ready to ship, usually within 24 hours!


'70 318-auto Chally 'vert
'71 383-auto 'Cuda 'vert (sold)
06 300c SRT8
04 2500 QCLB 4x4 HO

Offline Sleepychallenger

  • Sr. Member
  • ****
  • Posts: 1091
Re: 383/432 stroker for the Challenger
« Reply #4 on: March 27, 2013 - 09:55:48 AM »
At some point I will be doing the 496 kit....just gotta perfect this process of sh!tting money  :poopoke:

Offline tony 73

  • Jr. Member
  • **
  • Posts: 324
Re: 383/432 stroker for the Challenger
« Reply #5 on: April 04, 2013 - 09:27:59 PM »
I went for the 440 source 383/438 30' kit . Fitted in perfect and goes great. Engine builder said was a great stroker kit. Done 500 miles in it so far, more then enough horsepower of me.

Offline femtnmax

  • Full Member
  • ***
  • Posts: 997
Re: 383/432 stroker for the Challenger
« Reply #6 on: May 17, 2013 - 09:02:05 PM »
Parts include:
Scat forged crank with 3.75 stroke, sized to fit 383 block
OEM Mopar 383 connecting rods with ARP bolts, press fit pins
Diamond forged pistons .03 overbore
OEM Mopar front crankshaft damper
Steel flywheel from Brewers Performance

I chose the 3.75 stroke so the piston pin height would keep the pin away from the oil ring.  Pin height is close to OEM Mopar 360 and Ford 427 if I remember right.  Stroke is Mopar 440/ Ford 427.  Many years ago I had a 440 GTX.  It ran great and had plenty of TQ/HP.  So my build will be similar to the 440 but be lighter weight.
I guess I'm sort of old school.

Next is short block mockup with crankshaft and one rod/piston combo installed at all four corners of the block to determine the deck height, then disasemble and have the block decked for zero deck.  The OEM 906 heads are getting either 1.81 or 1.84 exhaust valves and hard exhaust seats installed.  I'm staying with stock valve spring height or close to it.  Then I'll port the heads and do final valve seat cuts.

For now I'm staying with cylinder heads that have a heat riser passage.  At my elevation, 5200 ft, cold mornings with frost even in the summer months, and drives that take you over 10k ft the heat riser really helps.  A cast iron intake manifold helps too, but I'm going with aluminum manifold.  Will be running iron HP exhaust manifolds for the stock look.

Thanks Tony73 for the words of encouragement:)
I'll get more pics soon.
« Last Edit: July 23, 2013 - 10:38:04 PM by femtnmax »
Phil

Offline femtnmax

  • Full Member
  • ***
  • Posts: 997
Re: 383/432 stroker for the Challenger
« Reply #7 on: July 06, 2013 - 09:43:09 PM »
The Scat forged crank had chamfered oil holes and larger fillet radii.  Sealed Power main bearings #4094 cleared the crank fillets with no bearing scraping required.
Added two small chamfers to the upper half of #3 main bearing to allow oil to flow to the rear facing thrust surface.  I did this to both rear facing edges.
Drilled out all the oil passages to ¼ diameter which is the factory spec, but several of the passages were smaller than this diameter.  Also enlarged the #4 passage to 17/64 to allow more oil to the cylinder heads and not starve the #4 cam bearing.
Had to grind on the block to allow clearance between the block and crank counterweights.   Grinding was located at the rear of cylinders #1,5,7; and front of cyl #2,4,8.   I would grind some at all locations, then clean the block enough to install main bearing upper shells at #1,3, and 5 to support the crank.  Then using a black felt tip add stripes to the ground areas. Then install the crank and rotate one revolution.  Contact would scrape off the felt tip marks and show where to grind next.
« Last Edit: July 12, 2013 - 06:45:24 PM by femtnmax »
Phil

Offline 70RAG383

  • Jr. Member
  • **
  • Posts: 89
  • I'm a llama!
Re: 383/432 stroker for the Challenger
« Reply #8 on: July 12, 2013 - 11:12:01 AM »
That's interesting...you don't hear much about 383 stroker kits.  What kind are the hp and torque increases over a stock 383 magnum 335hp, 425 ft-lbs) ? 

Offline femtnmax

  • Full Member
  • ***
  • Posts: 997
Re: 383/432 stroker for the Challenger
« Reply #9 on: July 12, 2013 - 06:43:59 PM »
What kind are the hp and torque increases over a stock 383 magnum 335hp, 425 ft-lbs) ? 
The 383 stroker with .06 overbore has 438 cubic inches, and has the longer stroke of a 440 and nearly the same bore.  So my guess is the torque and HP would be similar to a 440 depending on how you build it.

Cut a small notch at the lower end of each cylinder wall to clear the rod nuts.  Had to cut the crankshaft counterweights down by .10 inch so the crank would clear the piston pin bosses.  With the pistons at bottom dead center this left .042 clearance between the crank counterweights and the pistons.  Sent the rotating assy off to be balanced.  With the counterweights cut down the clearance cuts in the block to clear the crank may not be necessary or reduced.  I am using 383 connecting rods, if the longer 440 rods are used the counterweights probably don’t need to be cut down at all, but still should be mocked up and checked before balancing the crank etc, and the block would still need to be clearanced to the crank counterweights.
Checked the block deck height at all four corners of the block, cylinders # 1,7,2, and 8.  Pistons were .026 below head gasket deck surface.  So block is being decked .026 for zero deck.  With cylinder heads installed on block, and looking up from crankshaft side of cylinder checked the cylinder head combustion chambers for valve shrouding.   Scribed the cylinder shape on the head gasket surface of each head.  There was very little material that can be removed to unshroud the valves without the combustion chamber reaching over the head gasket surface of each cylinder which makes the unshrouding in this case kind of useless.  Even the 440 cylinder bore only adds a small increase to the cylinder diameter so the photos of huge unshrouding cuts must be to the head gasket outline and are far beyond the cylinder diameter. 
« Last Edit: July 12, 2013 - 06:47:29 PM by femtnmax »
Phil

Offline femtnmax

  • Full Member
  • ***
  • Posts: 997
Re: 383/432 stroker for the Challenger
« Reply #10 on: November 30, 2013 - 08:41:51 PM »
Have been very busy at work, and moved to "new" old house.  Put alot of time into fixing the "old" house to get it ready to sell...The place sold in 2 months, and only dropped the asking price by 1%. 
Put together a 428 Ford FE a couple months ago, but not of interest here.
So finally back to the Mopar engine build.
Had to clearance the block because crank counter weights hit the bottoms of the cylinder skirts.  Were talking Scat 3.75 stroke forged crank in 1969 Mopar 383 block.  Then with crank in the block, the crank counterweights touched the bottom of the piston pin bosses with .040 interference (Diamond forged pistons, Mopar OEM forged rods for 383).  So cut the crank counter weights down by .10 inch then sent the rotating assy out for balancing.   The balance job required several holes drilled deep into the counterweights.  So Scat crank can handle heavy weight rotating assy, such as H-beam rods.  For my street use the factory 383 rods are more than enough with ARP rod bolts/nuts.  Saved $$ too.  I know some will say why didn't I use the longer 440 rods, well because I wanted increased piston pin height for better piston stability.  The final pin height my combo has is very close to OEM Mopar 360/Ford 427.
The Scat crank fit Clevite main bearings no problem.  The rod bearings needed to be chamfered  along the edge facing the crank journal fillet radii.  I did a combination of chamfering the bearing edge along with reducing the width of each bearing shell locating tang so the bearing shells could be moved over within the connecting rod big end bore.  The bearing shellls can be moved "away" from the crank fillet radius and still be within the rod bearing housing bore (not stick out the other side of the rod housing).
The first pic shows the piston/rod on the crank journal with no changes, note the rod does not touch the crank at the side of the rod due to rod bearing riding on the crank fillet.
Second pic shows chamfer of the rod bearing shell.  Third pic shows finished piston/rod.  You can see the large crank fillet on the rod journal.
« Last Edit: November 30, 2013 - 08:51:56 PM by femtnmax »
Phil

Offline femtnmax

  • Full Member
  • ***
  • Posts: 997
Re: 383/432 stroker for the Challenger
« Reply #11 on: December 01, 2013 - 08:48:27 PM »
Took the crank back out of the block and fit the cam to the cam bearings.  My method is to mark the cam journals with a felt tip marker, then install the cam as far as it will fit into the block, then rotate the cam and remove it.  The journals that are too tight will wipe off the felt tip markings, and the corresponding cam bearing will have a bright shinny surface where the excessive contact occurred.   I then scrape the bearing using a bearing knife, remark the cam journal with the felt tip, and redo the procedure.
The cam initially fit about half way into the bearings, with #4 and #5 (the last two) showing contact.  I worked them, each time the cam fit further into place.  Finally #2, #3, and #4 showed contact and I worked them.  When completed all the cam journals touched their bearings to some degree. Cam with cam gear attached turns a little stiff by hand which is the way I leave them ready to run.
Next went to the cylinder heads.  I lightly lapped the valves to the seats to leave a contact pattern on the valve face so the 30 degree back cut on the valve face can be correctly located.  The exhaust seats are only lightly cut, waiting for the porting to be completed then do the final seat cut.

First photo shows the cam in the block with left hand journal felt tip mark showing, and right hand journal the felt tip mark has been wiped off meaning this journal needs the bearing enlarged for more clearance.

Second photo shows the 75 degree cut below the intake valve seats 45&60 cuts.  The 60* cut needs to be kept a minimum of .10 inch wide according to the sources I found., so doing that set the location of the 75* cut.   The 75* cut takes the place of the Mopar template porting saving much time.  This cut will be blended into the bowl down toward the valve guide boss.   The hardened exhaust seat on the right is ready to be blended into the bowl.   Kept the OEM 2.08 intake valve for port throat velocity, and went to a 1.81 exh valve for improved flow so wont need that long exh duration.  I know it wont be the HP king.
I went with OEM cast iron heads for cool summer day drivability.  I know it left HP on the table, that's life in the west.
My location is at 5200 ft elevation.  There can be frost any morning during the summer months.  Having a heat riser passage to heat the intake manifold really helps.  Some drives can take you from 3500 ft to over 10,000 ft all in the same day.  Aluminum heads cool off so quickly if you stop at the store for 30 minutes, and theres no heat riser passage on AL heads.   I had tried an air gap intake manifold on the small block that this BBlock is replacing; the SB engine just never was completely happy, would run great for part of the day..mid day usually, but run rough morning and evening even with a hot air pickup tube.  For the big block the intake manifold is just like an air gap, so I wanted to improve drivability thruout the day.  ON my work truck already had the iron heads, and swapped back to OEM intake with heat riser passage open (but no heat flap).  The truck runs great every day so thats the direction I'm going.  ON the internet some folks run hot water thru the intake manifold cross over passage, I thought about it, just don't want to go that direction at this time.
Here is one of the web sites I'll be following for the head porting:
http://www.moparmusclemagazine.com/howto/mopp_0106_how_to_install_ported_stage_v_heads/
« Last Edit: December 01, 2013 - 09:01:22 PM by femtnmax »
Phil

Offline anlauto

  • Permanent Resident
  • *******
  • Posts: 12328
  • I'm Alan G...I'm a Mopar Addict
    • Alan Gallant Automotive Restoration
Re: 383/432 stroker for the Challenger
« Reply #12 on: December 01, 2013 - 09:28:27 PM »
I'm working on a 71 Challenger right now and the new owner wants to step it up a bit. I just dropped off the 383 at my engine builder on Friday. Plan calls for a 496 stroker kit from 440 source along with their aluminum heads and a few other tricks....



Can't wait... :burnout:
I've taught you everything you know.....but I haven't taught you everything I know !
www.alangallantautomotiverestoration.com

Offline femtnmax

  • Full Member
  • ***
  • Posts: 997
Re: 383/432 stroker for the Challenger
« Reply #13 on: December 03, 2013 - 08:32:07 PM »
Plan calls for a 496 stroker kit from 440 source along with their aluminum heads and a few other tricks....
Yes, the 440 source heads are on my list if I move to a warmer climate:)
Engine block head gasket deck surfaces were cut .029 inch for flat top Diamond piston flush with deck surface when piston is at top dead center.  See deck clearance= 0 on calculator below.
CC'd the 906 head combustion chambers after a .012 inch gasket surface cut on the heads.  Final chamber volume is 86cc, down from 88cc nominal spec.  Using Ferrea valves to eliminate the ski jump off the valve faces so a 30 degree backcut can be added that will flow smoothly off the 45* valve face.
When planning the engine build I had used 88cc.  so now input the actual 86cc into compression ratio calculator.  I use the KB-Silvolite calculator, but there are many to choose from:
https://www.uempistons.com/index.php?main_page=calculators&type=comp&zenid=3b30e4d65b15d922b7d75359887322e6

Data to be entered includes:
Cylinder head volume= 86
Piston volume= 5   (4cc valve relief +1cc top ring below top of piston)
head gasket thickness=.039  (Felpro 1009 head gasket)
head gasket bore= 4.41
cylinder bore= 4.28
deck clearance= 0
stroke= 3.75
rod length= 6.358
Intake closing angle= 60 degrees after bottom dead center
RESULTS:  static compression ratio = 9.8, dynamic ratio= 8.0

Planning for the possible future with 440source heads:
change combustion chamber volume to 74cc (will need to cut the head gasket surfaces to reduce chamber volume).
change the camshaft to have 72 degrees intake closing angle.
RESULTS:  static compression ratio = 11.0, dynamic ratio = 8.2    Then subtract 1 point from the 11.0 for aluminum heat loss which is then 10.0 static ratio...perfect for street use and pump gas.  With this combo note that the quench clearance between piston at TDC and bottom of cylinder head is .039 inch (head gasket thickness).  This is a very acceptable quench clearance.   That is where correct selection of head gasket must be included, not just any head gasket.
 
First photo shows chamber volume checking, photo is missing a thin film of wheel bearing grease on valve seats/valve faces and around combustion chamber/plexiglass plate.  I use blue windex glass cleaner for the liquid to be measured.
Second photo shows aligning degree wheel pointer to "0" with #1 piston at TDC.  Next step is to have dial indicator measure the rise of #1 cylinder intake valve lifter to find camshaft intake lobe centerline.
« Last Edit: December 03, 2013 - 08:36:07 PM by femtnmax »
Phil

Offline brads70

  • C-C.com Expert
  • ********
  • Posts: 18747
Re: 383/432 stroker for the Challenger
« Reply #14 on: December 04, 2013 - 09:08:12 AM »
I'd be spending a few hours with a die grinder under those valve seats..... I just couldn't leave them like that. :grinno:
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0