449 stroker

[Sand hauler]

Performance Summary:
      Cubic Inches:   449            Dyno brand: Super Flow
      Power Adder:        you too       Where dynoed: Carlsbad NM, Stoney's Speed Shop
      Peak Horsepower:666.5 @7000 where we stopped the pull
      Peak Torque:635.5 @4500

Horsepower and Torque Curves:


Engine Specifications:
   Block brand, material, finished bore size, other notes:
      390 ribbed block, 4.10 bore
   Crankshaft brand, cast or forged, stroke, journal size:
      Scat 4.25 cast
   Connecting Rods brand, material, center to center distance, end sizes, bolts:
Molinar 6.7
   Piston brand, material (caster, hypereutectic or forged), dish/dome volume, static CR:
Mahle dish, 10.75 cr +/-
   Main Bearings, Rod Bearings, Cam Bearings brand and size:

   Piston rings brand, size, other notes:
Stoker kit from Survival Motor Sports
   Oil Pump, pickup, and drive:
Precision blue printed hv, FT pick up, 1/4 in ARP drive
   Oil pan, windage tray, oil filter adapter:
F/T pan with added trap door baffles, Canton windage tray,stock truck adapter
   Camshaft brand, type (hyd/solid, flat tappet or roller), lift and duration (adv and @.050")
Mike Jones hyd roller,254/261@.050 ,.390 lift at lobe, tight lashed .015 hot.
   Lifters brand, type: Crower solid roller with pressure oiling

   Timing chain and timing cover:POP double Roller, FT  cast iron cover

   Cylinder heads brand, material, port and chamber information: BBM , CNC'D port's by Blair Patrick,

   Cylinder head flow in cfm at inches of lift (28" H2O pressure drop):
      Intake               Exhaust
      .100               .100
      .200               .200
      .300               .300
      .400               .400
      .500               .500
      .600               .600
      .700               .700
      .800               .800

   Flow bench used, location:

   Intake valve brand, head size, stem size:
2.20 Ferrera,11/16 stem
   Exhaust valve brand, head size, stem size:
   1.68 Ferrera,11/16
   Valve springs brand, part number, specs:
PAC
   Retainers and locks brand, part number, specs:
PAA
   Rocker arm brand, type (adjustable or non-adj), material, ratio
T&D race,1.76,1.80
   Rocker shafts and stands, brand, material:

   Pushrods brand, type, length:
Comp cam, 3/8
   Valve covers, brand, type:
Holley M/T
   Distributor brand, advance curve information:
Pertronix Billet
   Harmonic balancer brand:
Power Bond sfi
   Water pump brand, type (mechanical or electric):
Stewart hv
   Intake manifold brand, material, porting information:TFS track heat, unported

   Carburetor(s) brand, type
Quick Fuel 1250 dominator
   Exhaust manifolds or headers brand, type:
2" primary home assembly from a bbf Speed way motors kit and flanges from Hells Gate Hotrods.

     

[fryedaddy]

thats the kind of dyno i like to see.great power for a 390 stroker.nice to see the good power coming from those bbm heads.now i know for sure i need to take my heads to Blairs for cnc

[1968galaxie]

Fantastic build.
Thank you for posting.
I was wondering about the BBM heads used with a smaller bore engine.
I see 2.20" and 1.68 valve size used. Were valve sizes changed(reduced)?
BBM CNC heads advertised 2.25" and 1.71" valve sizes as standard.
Did Blair modify intake? (sleeve push rod holes and move them apart?)

Very good results with reasonably low compression, and a smallish cam!
The cylinder heads and intake are working well.

[Sand hauler]

Blair did all the head work. Sent him bare castings. His combo on them . The intake we did here , but could have had him it. Had to mill it .045 to fit the heads  and yes had to massage some of the pushrod hole a little bit on the bottom and the top. Blair cut the heads .120 if I remember correctly, to bring up the compression with the dish pistons. Worked out nicely with .020 valve clearance . Lift at valve was .686& . 703 I believe +/. -

[blykins]

What were the spring pressures?  You may have had some pretty significant valve float going on.

Starting at around 6100, the horsepower was not linear but jumping all over the place and your BSFC went inefficient at that rpm.   

[jayb]

You may have had some pretty significant valve float going on.

MAY have??  That engine is really, really unstable at the top end.  The power numbers are slamming back and forth 40+ HP up there, and that inertia affects the accuracy of the dyno's torque link.  Obvious valvetrain problems at the higher engine speeds.  Nice build, but from 6000 RPM up those numbers are not accurate.

[Sand hauler]

A little over 550 over the nose as I recall. The distributor started having a intermittent miss after 6. Is a plug and play pertronix Billet flame thrower 2 . That we have determined was the cause of it. I'm going swap distributor to either a MSD or a OEM . Wand a cd box. Called pertronix and they think it's the module since it's over 2 yrs old.

[Sand hauler]

Plan on re running it after a dist. Change

[blykins]

I'm really starting to think you don't have enough spring.  Not leaning towards distributor miss.  What you were probably hearing was valve float.

Seat pressure is most important but open plays a big role.  What was seat pressure?  Open pressure should have been 650-700 lbs. 

[Sand hauler]

Don't remember offhand. Although is it possible that push rod wall thickness would caus that as well? It's .080 wall on them.

[blykins]

Don't remember offhand. Although is it possible that push rod wall thickness would caus that as well? It's .080 wall on them.

Probably not to the effect that you were seeing. 

If you didn't have at least 250 lbs seat pressure, you were too light. 

A floating exhaust valve is a ticking time bomb.  I would double check your spring pressures before you put it on the dyno again.

[Sand hauler]

I'm really starting to think you don't have enough spring.  Not leaning towards distributor miss.  What you were probably hearing was valve float.

Seat pressure is most important but open plays a big role.  What was seat pressure?  Open pressure should have been 650-700 lbs.

Will double check

[Stangman]

alittle lean up top also no. I thought low to mid 13s is about were it should be. Not saying thats why its jumping around but maybe alittle tuning in there might help although 667 HP is nothing to sneeze at.

[1968galaxie]

I would double check what valve springs were used and what the open and closed pressures are.
Mike Jones knows more about camshafts and valve spring pressures required than anyone on the planet. (period)
I would be asking Mike and possibly Blair Patric. I am not sure which person spec'd the spring for the hydro-roller cam profile
with solid rolled springs. Using solid roller lifters usually requires a little more spring pressure - open and closed.

Ask the person(s) who put the combination together - they will know the answer.

[Sand hauler]

Absolutely