383 / 432 Mopar stroker short block cost & build

[femtnmax]

Slowly building a "B" engine 432 stroker. I am doing as much of the work myself as possible. Here is the short block costs:

Complete engine, 1969 383 oil pan to intake manifold $250
Stroker crank, Scat forged crank, 3.75 stroke, Flatlander Racing $886
#4-383-3750-6760-2374
Forged flat top pistons, Diamond #51910 $640
Moly piston rings w/ napier 2nd ring, Mahle #315-0035.035 $120
Connecting rod bolts&nuts, ARP #145-6002 $67
9 keyway timing chain, Cloyes #9-3504X9 $96
Crankshaft main bearings, Sealed Power #4094M $70
Crank rod bearings, Sealed Power 8-2320CP $68
Cam bearings, Durabond #PDP-17 $27
Engine gasket set, Felpro #KS2110 $46
Head gaskets .039 thick, Felpro #1009 $76
Intake manifold valley pan gasket, Felpro #MS96007 $13
Valve stem seals, positive PFT, Sealed Power #ST-2004 $48
Oil pump, Melling #M63 $80
Camshaft, Crower #32241 $157
Lifters, Crower #66031-16 $87
Engine block freeze plugs, Sealed Power #381-8011 $13
PARTS TOTAL: $2744


Bore & hone block $200
Cut block head gasket surfaces for zero deck $185
R&R cam bearings $55
Resize OEM 383 connecting rod big ends w/ ARP bolts $120
Heat connecting rods, install pistons/pins onto rods $48
Cut .10 inch off crankshaft counterweights $85
Balance rotating assy $250
LABOR TOTAL: $943

Short Block Total: $3687

 

[txstang84]

Good info-that was about the same direction I'd thought of going...and still may. That is a pretty mild grind-what heads do you plan to use?

 

[Old Man Mopar]

I will be watching as I just bought a complete salvage 400 from Hemimark
and will be S L O W L Y assembling a rollerized 470 Stroker.

Thanks.

 

[femtnmax]

That is a pretty mild grind-what heads do you plan to use?

The mild cam is a Crower 267/271, 220/223 @ .05. I'm hoping it will work well in a 4000 lb Challenger with 3.23 axle gears, and 5200 ft altitude. So everything points toward the need for low rpm torque, so I was going that direction. If the cam proves too mild I can always change it out. I would not mind going a solid lifter flat tappet.

Firefighter Ron had suggested the Crower cam one step up from the one I picked, but I was concerned of loss of low rpm torque, and they say to pick the smaller cam if your on the fence.

I thought of going with a 400 block, but this 383 was sitting there, and still turned over smoothly, so that made the deal right there.

The 383 engine had only 80k miles on it. I will reuse the OEM stamped rocker arms, rocker shafts and pushrods. I checked all 16 rocker arms for correct ratio; each of them was off ratio by less than ONE percent. So much for the talk of real low rocker ratios on OEM stamped rocker arms. Maybe I was lucky. If I end up needing a little more mid-top HP I have a set of 1.6 Crane iron rocker arms that I may try, which with the mild cam will up the .05 duration to 223/226, and push the valve lift to over .500.

For cylinder heads, I need to keep the cost down. I've dumped too much money in this car. Plan to use the OEM 906 heads with home porting job based on several internet articles including one about the stage 5 heads. The Diamond flat top pistons will allow for aluminum heads in the future without having to redo the short block. My Ford work truck has a 428 FE engine, and runs real well at my cold climate with iron heads and iron intake manifold, so I was going to go that route for now.

I'm not sure if I should post my compression ratio study for iron vs alum heads. It's not too long but not sure if it is of interest.

 

[txstang84]

I think the cam will be fine for your purposes-it ought to run pretty damn strong. I would also agree you're lucky with the rockers, everything I've read points to stock ones being a little off. The 906 heads will also work well with your project-can't wait to see more!

 

[femtnmax]

Planned the engine build using KB Silvolite compression ratio calculator.
https://www.uempistons.com/index.ph...e=comp&zenid=3b30e4d65b15d922b7d75359887322e6

Data to be entered includes:
Cylinder head volume= 86 (906 heads milled .012 inch)
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 (piston flat top flush with top of block gasket surface)
stroke= 3.75
rod length= 6.358 (383 rod length)
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 aluminum heads:
Reduce 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.

So the short block can handle iron or aluminum heads with the correct cam choice. I think this is good for future changes. You never know what new ideas come around.

 

[femtnmax]

The Scat forged crank counterweights hit the engine block cylinder bottoms, and they hit the piston pin bosses also (when using the shorter 383 rods). Cutting .10 inch off all the counterweights fixed the interference issues, and still left plenty of material on the crank for balancing the rotating assembly when using OEM forged connecting rods, either 383 or 440 rods. Should be ok also when using the heavy H-beam rods, as the photos I’ve seen with H-beam rods required only one or two holes drilled in each counterweight.
The rotating assembly was internally balanced.

As the crank was rotated, the connecting rod nuts bumped the bottom of each engine block cylinder. Grinding a small notch at each contact location fixed the problem.

The crank main bearings did not need chamfering to clear the Scat crankshaft main journal fillet radii. All the connecting rod bearings required chamfered and offset locating to clear the crank rod journal fillet radii. I believe 440Source sells chamfered rod bearings, and I would buy those next time around to save hassle and time.

The 1969 OEM crankshaft harmonic balancer fit the Scat forged crank, and only required two small nips with the end of a drill to neutral balance.

 

[Challenger340]

Slowly building a "B" engine 432 stroker. I am doing as much of the work myself as possible. Here is the short block costs:

Complete engine, 1969 383 oil pan to intake manifold $250
Stroker crank, Scat forged crank, 3.75 stroke, Flatlander Racing $886
#4-383-3750-6760-2374
Forged flat top pistons, Diamond #51910 $640
Moly piston rings w/ napier 2nd ring, Mahle #315-0035.035 $120
Connecting rod bolts&nuts, ARP #145-6002 $67
9 keyway timing chain, Cloyes #9-3504X9 $96
Crankshaft main bearings, Sealed Power #4094M $70
Crank rod bearings, Sealed Power 8-2320CP $68
Cam bearings, Durabond #PDP-17 $27
Engine gasket set, Felpro #KS2110 $46
Head gaskets .039 thick, Felpro #1009 $76
Intake manifold valley pan gasket, Felpro #MS96007 $13
Valve stem seals, positive PFT, Sealed Power #ST-2004 $48
Oil pump, Melling #M63 $80
Camshaft, Crower #32241 $157
Lifters, Crower #66031-16 $87
Engine block freeze plugs, Sealed Power #381-8011 $13
PARTS TOTAL: $2744


Bore & hone block $200
Cut block head gasket surfaces for zero deck $185
R&R cam bearings $55
Resize OEM 383 connecting rod big ends w/ ARP bolts $120
Press pistons/pins onto rods $48
Cut .10 inch off crankshaft counterweights $85
Balance rotating assy $250
LABOR TOTAL: $943

Short Block Total: $3687

* are those Pistons for the 1.094" Mopar Pin on your Stock Rods... just checking ?
* Pin-Fitting.... get Panetta at Diamond to do it there on the Pistons, Where are you getting the Rod small ends done ? Even running "pressed pins" should be set to .001" interference only... so as NOT to distort the Pin.
They are installed "thermally" by Heating...NOT Pressing.

Cut Counterweights .100" ?? Is this not a lowdeck B Crank ? or an RB Crank ?
Try Sealed Power O/H gasket set 260-1009, cheaper than the FelPro, same gaskets.
* New Dizzy / Oil Pump Drive Shaft & Tower Bushing ?

 

[femtnmax]

* are those Pistons for the 1.094" Mopar Pin on your Stock Rods... just checking ?
* Pin-Fitting.... get Panetta at Diamond to do it there on the Pistons, Where are you getting the Rod small ends done ? Even running "pressed pins" should be set to .001" interference only... so as NOT to distort the Pin.
They are installed "thermally" by Heating...NOT Pressing.

Cut Counterweights .100" ?? Is this not a lowdeck B Crank ? or an RB Crank ?
Try Sealed Power O/H gasket set 260-1009, cheaper than the FelPro, same gaskets.
* New Dizzy / Oil Pump Drive Shaft & Tower Bushing ?

Yes, the Diamond pistons have 1.094 pin that can be installed on stock rods by heating the rod small end. Yes, using OEM 383 connecting rods. Should not have said "pressed". My error. I will correct the earlier post.
Diamond makes a piston #51950 to fit 440 rods.
http://www.flatlanderracing.com/diamond-chrysler03.html

The Scat crank is low deck crank with smaller main bearing journals. I first 'relieved' the block where the crank counterweights were touching. Then with crank installed found the counterweights hit the piston pin bosses...because the crank is specced for 440 rod length, I knew this when I bought it, just didn't realize the crank would hit the pistons. Measured interference was .04 inch. I wanted to use the shorter rods, and found out the hard way that the crank OD needed turned down. To avoid hassle maybe use the 440 rods next time. I'm a little old/old fashioned and like pistons with "pin height".
So if using 440 rods, would not need to turn the crank c-weights down, only need a little clearance grinding on the engine block. I'll post a photo.

First photo is crank c-weight clearance notch, second pic is rod nut clearance.

Thanks for the Sealed power gasket info. I will write that down.
I am installing a new electronic ign dizzy & tower bushing. Need to look over the drive shaft, but so far everything off this low mile engine is in very good condition.
thanks for the questions...keeps me on target and paying attention.

Good info you provided on your engine builds you listed on MRL street 470. Thank you!
Phil

 

[Challenger340]

Oh OK... sorry Phil... wasn't trying to confuse LOL !
NOW I get it... I missed that in your posts about the lowdeck length 383 rods ?
and I have to agree with the longer skirt Piston over long term useage.... and quieter than the 438/451.... 1.34" Compression Distance.

yep also...to "either end" of the Block at the bottom of the Cylinder Banks being the larger clearance area for the counterweight.... other than that..... just the small "ridges" from the center main webs are good to check,
Gonna be a dandy mill !:headbang:

Bob

 

[femtnmax]

Had to replace distributor oil pump drive shaft and bushing.
Bushing: Dura-Bond AD-584, cost $1.97
oil pump drive: Melling IS-63, cost $55.97

So total parts cost is now $2802.

Had to relieve the block to clear the crankshaft at 6 locations, not just the two ends. The Scat forged crank journals were all at the small end of the spec range, so fitted the main caps/housing bores to the small end of their spec and ended up with .002 inch main bearing clearance. The crank rotates in the oiled main bearings with 1 inch pound of torque to start it rotating.
File fitted all the piston rings to the cylinder they will go into, with .017 gap top ring, and .021 gap 2nd ring.
Checked the Crane 1.6 iron rocker arms for correct ratio. Ended up with 1.63/1.64 final ratio. That is great. Looks like will have to cut the guides down about .05 inch to avoid the spring retainers hitting the guides. I will be trying out valve stem lash caps to move the rocker/valve stem contact pattern a little closer to the intake side of the stem; then determine final pushrod length.

 

[femtnmax]

Well the long block is together, ready to go in the car. Here are some of the details that stood out.

Looks like if you use an OEM 440 crank and turn down the main bearing journals, the crank counterweights also need to be turned down 0.125 inch radius so they clear the engine block. On the Scat forged crank I used, apparently they are taking a 440 crank and turning the main bearing journals just like oem, because the crank counterweights had to be turned down. I took 0.100 inch off the radius. For consistency I would say take the same off the counterweights on the Scat crank as the oem 440 crank. That is 0.125 inch.
I used the oem 383 rods which are said to have the same beam cross section as the longer 440 rods. I used them because they came with the 383 engine, and Diamond has pistons to fit them and press fit or floating wrist pins. The oem rod small ends could be bushed for full floating pins if you want. A side note: I went with the pressed pins because on the 340 duster I had years ago, it had full floating wrist pins. When I rebuilt the engine with 130k miles on it, some of the pins were turning in the rod bushings, some turning in the piston pin boss, and maybe one or two were free to turn in both the rod and piston. It did not seem to matter to the engine, it ran fine on the street without much ‘full floating’ going on.
The Scat crank main and rod journals (out of the box) were all cut to the small side of the bearing journal spec. I had to fit all the bearing bores to the small side of their specs to come up with bearing clearances under .003 inch. Lots of opinions on bearing clearances, but I prefer to stay in the middle of oem specs for my street use, rather than the loose end (.003).
The Scat crank thrust bearing width was on the minimum side of the spec...good. The main bearings fit the cranks large fillet radii with no issues. The rod bearings needed to be scalloped to clear the cranks large fillet radii.

Other details: There are more connecting rod choices if you go with the longer 440 rods.
I had initially cut clearance notches in the block to clear the crank counterweights, but after turning the counterweights down, the block work was not necessary.
It was easy to internally balance the Scat forged crank with oem rods and forged pistons. Had to drill alot of deep holes in the counterweights. Looks like Scat left plenty of material on the crank so you could internal balance with heavy H-beam rods.
I had no issues with any parts that mated to the Scat forged crank. Everything fit with no issues, from the oem vibration damper to the Mcleod steel flywheel & pilot bushing for the 4 speed. The Diamond forged pistons were nicely machined, no problems there.
The short block went together with no problems.
Decked the block .026 inch for zero deck, and cut 0.02 off the heads; the intake manifold still fit on correctly (just barely) with no extra machining of the intake surfaces on the heads.
I chose to rebuild the oem iron 906 heads, cost was about 1k with all new parts. This was half the cost of aftermarket alum heads when you include tear down inspection, touching up valve seats and guides, and replacing the ‘weak’ parts.

For my build, the next part of the puzzle is did I choose the right camshaft duration to match a street driven heavy Ebody, 3.23 axle ratio, and 5200 foot elevation. I went conservative with 220/223 duration at .05 lift. I know your all gasping at that “tiny” cam. The OEM 440 HP cam had 214/220ish duration at .05 lift, so I’m a step up from that. I prefer acceleration right out of the hole, not waiting for the engine to build rpms. I'll bet my cam choice is close based on past engine builds at my location, if not swapping cams is no big deal to me.

 

[txstang84]

Sounds like it'll be a strong running combo with completely docile street manners-let us all know how it turned out!

 

[moper]

Looks good.
FYI - The 440 Source 3.75 crank is the only one I know of that doesn't need the counterweights cut down for the B wedge block. I've used a couple of them. It's about $100 cheaper but the tolerances will be more variable than the Scat.

 

[femtnmax]

I have been over busy at work all summer. Finally have the new 432 dialed in. So here it is.

This big block pulls an Ebody around with no problem. A mild big block with iron exhaust has much stronger torque everywhere than a built 360 with headers. So the extra cubes really help. Moly rings sealed right away…had slight suction on the PCV intake hose by the time the cam/lifters were seated in.
Fuel system from the gas tank has in-line filter, then Mallory electric pump ahead of rear axle, 3/8 fuel line feeding Carter street mechanical pump, then vapor separator and on to carb. With the electric pump ‘off’, the mechanical pump feeds with no issues to 3500 rpm…75 mph hwy cruise. But at the stop light you can only pull thru 1st & 2nd gear before the float bowls empty….need the electric pump for clean pulls. I may switch to a higher volume/pressure mechanical pump but would need a pressure regulator and still feed thru the OEM vapor separator…or give up the mechanical pump all together…I like the extra reliability of two pumps for long distance cruises.
Had 14 inches vacuum at 750 rpm smooth idle, with 267/271 cam, 220/223 duration at .05 lift and 112 LSA for iron manifolds. Even at my altitude 5200 feet could have gone for more cam, but would loose the healthy bottom end torque the engine has now for pulling 3900 lb around. I have a set of 1.7 adjustable rocker arms, probably try them at some point…this will increase .05 duration by about 6 degrees; then see how the engine likes it. Maybe switch to a mechanical cam then.

Some engine tune details:
Fuel line was too close to heater hoses/ engine block. These big blocks have issues with the mechanical fuel pump getting hot. I had a fuel pressure regulator, but it did not remove the hot vapors, so replaced it with a big block OEM style vapor separator. The mechanical fuel pump still heats up. Why doesn’t the aftermarket add a ceramic isolator spacer and lengthen the fuel pump lever…like some other vehicles have from the factory….this would go a long way toward keeping the mechanical pump cool.
Need to add a heat shield along side the vapor separator to reflect heat from the iron exhaust manifolds.
Ignition timing with iron heads and Mancini Racing Mopar electronic ignition package. Ended up at 16* btc idle and 38*total. I tried 18* but this caused hard starting when the engine was hot. I want to try a little softer advance spring, to bring more mechanical advance in earlier. I had to disconnect the vacuum advance...caused stumble/surge at low speeds....dont know why but much better with just mechanical advance.
Air fuel ratio is 13 idle, 14-15 at highway cruise, and 12.75 at wide open.
Blocked off the intake manifold heat cross-over. This helped keep the intake manifold and ignition coil cooler. I considered moving the ignition coil to the inner fender, but still need room for a fuel pressure regulator.
The one inch thick carburetor spacer “ribs” did not line up very well with the minimal flange width on the Edelbrock DP4B intake manifold. A slight leaking was found at the mid span of each side of the spacer/gasket. RTV silicone sealed the problem.
Engine temp is 175-185 degF with Milodon high flow water pump and matching Tstat, and small block sized radiator.

Carburetor jetting….Edelbrock AVS 800 cfm for 5200 foot elevation, no heat Xover.
Primary jet .107, second jet .104, meter rod 7342 with pink rod springs, secondary air door 1 ¼ turn on the tension spring. Accelerator pump nozzle .038. 7/16 float setting with 1 1/8 float drop, idle mix screws out ¾ turn. A square and ½ of the transfer slot showing with throttle plates closed to idle setting.
Widened the idle circuit transfer slots from the out-of-box .029 inch width to .031 inch. Hand cut with drill bit in pin vise… it cuts quickly so doesn’t take much effort to work up/down the slot.

Kept the small block radiator, so switched the water pump inlet to 'motorhome' style. Still using the small block upr lwr radiator hoses.

 

[Abodybomber]

Looks great.Have the pistons already, in discussion for the rest of the short block. Thanks for posting.

 

[dkbug]

What converter are you using? Also what rear end ratio? Tire size? You going with a holley red/blue pump?

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[femtnmax]

Looks great.Have the pistons already, in discussion for the rest of the short block. Thanks for posting.

IF you can, find a machine shop that can torque plate hone the cylinders. I had no one like that to go to...always a hassle to get the oil rings to seat in.

 

[femtnmax]

What converter are you using? Also what rear end ratio? Tire size? You going with a holley red/blue pump?

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I am 4speed. Rear ratio is 3.23, car is heavy 3900 lb, so need lots of TQ to move it.
Tires are 24 inch tall mickey thompson street tires.
Electric pump is Mallory...said to run quieter than Holley elec pumps. I had a Carter electric pump, but it would not let the mechanical pump pull thru it beyond 60ish mph, so happier with the mallory pump.

 

[femtnmax]

So, I weighed the car (me and an Ebody) with the new 383/432 engine....4000 lbs.
Thats with iron heads, iron exhaust manifolds, alum intake manifold along with alum water pump and pump housing.
This compares to the small block 360 with iron heads, headers, and alum intake/water pump/pump housing at 3920 lbs.
So only 80 lb difference....sure enough...put alum heads and headers on a low deck big block and have very close to the same weight as a small block.

The weight difference has been mentioned before; just letting you know my back to back weight results at the same certified scale.

 

[Abodybomber]

Good info, appreciated...

 

[femtnmax]

Crane Gold roller rocker arms
I checked cam lobe lift vs valve lift with checking spring, measuring lift at the valve spring retainer with a Blue Point magnetic dial indicator.
The 1.5 Gold rocker ratio came out to 1.59, and the 1.6 Gold rocker ratio was 1.69.

The Gold rockers fit correctly on OEM replacement rocker shafts (Sealed Power) with slight deburring of the rocker shaft drilled holes, both oil and bolt holes. With the shafts held upside down I used a large drill bit to add a slight chamfer to the holes. Cylinder heads are Mopar 906 iron with 8.1 inch long ball cup oil thru pushrods from Smith Brothers; With this length there were 2 threads showing on the rocker arm adjuster between the adjuster ball and rocker arm body, and the hydraulic lifter piston was depressed .05 inch (1/2 turn on the rocker arm adjuster).
Valve springs are Comp 911-16 with 120 lb seat pressure at 1.90 installed height, and 323 lb at .540 lift. Coil bind clearance is .16 at .540 lift so no issue there.

I'm going to install the 1.6 ratio on the intake and 1.5 ratio on the exhaust. The lift at the valves will be .540 int/.508 exh. The valve spring retainer to the intake valve positive oil seal clearance is .538, so I'll pull the heads and trim the intake guides shorter by another .04 inch max so the spring retainers wont contact the oil seals. I had previously trimmed the guides 0.10 inch shorter, so just trim a little more.
The Crower cam is low rpm friendly with 267/271 seat duration and 220/223 duration at .05 lift, that with the added rocker ratio will be 226/226 at .05 lift; and .540/.508 lift at the valves. The extra valve lift is said to be good for 20+ HP on a big block. The ported heads should be able to make good use of the extra valve lift. The valve spring rate fits in the middle of Crowers mild vs race specs for .540 lift BBC cams.
If the valve action is too fast for the hydraulic lifters then I'll switch over to a solid lifter cam.
I'm not saying this is the ultimate answer, Its just an experiment...my old Ford work truck has a 428, and the RV cam thats in it has .520 lift with only 256 degrees seat duration. Its been working fine with no issues for years. Big block chevys and Fords came with 1.7/1.76 rocker arm ratios from the factory, so why not try it.

 

[Abodybomber]

Good luck.

 

[fratzog lover]

What year is your car?