225 Push rod length.
Now hang on now. That sounds like a FIGURED valve lift and not MEASURED. Is that right? I ask because slant 6 rockers are never ever 1.5. Some are even as low as 1.4. They're pretty inconsistent. I'm terrible with descriptions. I need pictures. If you can maybe post a couple of good ones when you can that would help.
Rocker ratio 1.5
Discussion Starter ·
#1 ·
8 mo ago (Edited by Moderator)
An Insane Number of Mopar Slant Six Engine Specifications
Journal Number
1980 3.7-Liter
(225 CID) Slant Six
1 2.75' x 0.877"
2 2.75" x 0.877"
3 2.75" x 1.107"
4 2.75" x 0.877"
The engine had four replaceable steel-backed (aluminum alloy on steel) babbitt crankshaft main bearings. Oil grooves were in the upper half of the bearings, and in the lower half of the #1 bearing. The connecting rod bearings were aluminum on steel.
In most years, closed-circuit crankcase ventilation was used; crankcase vapors were routed to the combustion chambers through a PCV valve located in the valve cover. Vapors were burned before being expelled into the air through the exhaust system.
Oil pressure ranged from 35-65 p.s.i. @ 2.000 rp.m. Crankcase oil capacity was four quarts (one more when changing the filter).
1968 detailed specifications
Engines
170 cubic inch 225 cubic inch
Carburetor
Single barrel Single barrel
Bore and Stroke (nominal)
3.4 x 3.125 3.4 x 4.125
Bore spacing (CL to CL)
3.98 (1-2, 3-4, 5-6);
4.0 (2-3, 4-5) 3.98 (1-2, 3-4, 5-6);
4.0 (2-3, 4-5)
Firing Order
1-5-3-6-2-4 1-5-3-6-2-4
Compres. Ratio (nominal)
8.5 8.4
Cylinder Head Material
Cast iron Cast iron
Cylinder Block Material
Cast iron Cast iron
Cylinder Sleeve
None None
Number of mtg. points (Front)
Two Two
Number of mtg. points (Rear)
One One
Engine Installation Angle
Lateral 0°, Up 3° Lateral 0°, Up 3°
Taxable Horsepower
27.7 27.7
Publishing max. bhp* @eng. RPM
[email protected] [email protected]
Publishing max. torque * (lb. ft.
@RPM)
[email protected] [email protected]
Weight (piston only ) oz.
16.4 16.4
Clearance (limits) Top land
.024 min. .024 min.
Clearance (limits) Skirt Top
.0005 - .0015 .0005 - .0015
Clearance (limits) Skirt Bottom
-.0005 - +.0005 -.0005 - +.0005
Ring groove depth No. 1 and No. 2 ring
.179 .179
Ring groove depth No. 3 ring
.181 .181
Compression Rings Twist and taper, tin-plated Twist and taper, tin-plated
Oil Rings Cast iron, steel expanders 3-piece abutment-type, stainless steel spacer-expander with chrome-plated segments
Piston Pins 170 cubic inches 225 cubic inches
Length
2.965 2.965
Diameter
.9008 .9008
Type (Locked in rod, in piston, floating, etc.)
Press-fit in rod Press-fit in rod
Type (Bushing, in rod or piston)
None None
Type (Bushing, material)
- -
Clearance (In piston)
.00045 to .00075 .00045 to .00075
Clearance (In rod)
.0007 to .00014 interference .0007 to .00014 interference
Direction & amount offset in piston
Right .06 Right .06
Connecting Rods 170 cubic inches 225 cubic inches
Weight (oz.)
25.7 26.8
Length (center to center)
5.707 6.699
Bearing (material & type)
Lead-based babbitt on steel Lead-based babbitt on steel
Bearing (overall length)
.985 .985
Bearing (clearance [limits])
.0002 to .0022 .0002 to .0022
Bearing (end play)
.006 - .012 .006 - .012
Carburetors (Valiant)
170 225
Idle speed - Manual*
750 650
Idle speed- Automatic*
750 650
Idle air-fuel mixture*
14.0 - 14.4 14.0 - 14.4
Transmission
Manual, Automatic Manual, Automatic
Carburetors (Make)
Ball and Ball** Holley
Carburetors (Model)
BBS-4414 S (Manual), BBS-4415 S (Automatic) R-3919 A (Manual), R-3920 A (Automatic)
No. used and type
1, 1-bbl 1, 1-bbl
Barrel Size
1.56 (Manual), 1.69 (Automatic) 1.69
Suspension details (Valiant) 170 225
Front spring height by diameter 35.8 x 0.83 35.8 x 0.83
Spring - Rate at wheel (lb. per in.) 85 85
Number of leaves in rear springs 4 5
1968 Slant Six crankshafts
Material
Drop-forged steel
Vibration Damper Type
Non-adhesive, rubber, dynamic
End thrust taken by bearing (No.)
Three
Crankshaft end play
.002 - .007
Main bearing (material & type)
Lead-base babbitt on steel, removable, precision
Main bearing (clearance)
.0002 - .0022 specified,
.0005 - .0015 desired
Main bearing (Journal dia. and bearing overall length) No. 1
2.75 x 1.034
Main bearing (Journal dia. and bearing overall length) No. 2
2.75 x 1.034
Main bearing (Journal dia. and bearing overall length) No. 3
2.75 x 1.254
Main bearing (Journal dia. and bearing overall length) No. 4
2.75 x 1.034
Crankpin journal diameter
2.187
1968 slant six camshafts were hardened cast iron, with the oil pump and distributor drive gears cast integrally; bearings were lead-based babbitts on steel. There were four bearings. The crank sprocket was made of malleable cast iron or sintered iron (Super Oilite). The cam sprocket was cast iron.
1968 slant six valves
Model
Slant Six
Lifters
Mechanical
Valve Rotator, type (intake, exhaust)
Low-friction lock on exhaust
Rocker ratio
1.5
Operating tappet clearance (Intake)
.010 hot
Operating tappet clearance (Exhaust)
.020 hot
Timing (Intake - opens [°BTC])
10
Timing (Intake - closes [°ABC])
50
Timing (Intake - duration -deg.)
240
Timing (Exhaust - opens [°BBC])
50
Timing (Exhaust - closes [°ATC])
6
Timing (Exhaust - duration -deg.)
236
Timing (Valve opening overlap)
16
Intake (Overall length)
4.77
Intake (Actual overall head dia.)
1.62
Intake (Angle of seat & face, deg)
