nwstal
New member
- Joined
- Jan 27, 2011
- Messages
- 6
- Reaction score
- 0
- Points
- 0
- Vehicle Year
- 86
- Vehicle
- Ford
I know there are posts about this already but they seem to break down into Swap in a 4L and never amount to any serious Ideas about actually doing it. They are doing it in Europe a lot however but a $2500 3.5 Kit is too much. Since I already have new world heads, and headers and it is more or less a rebuild I have been looking into it in depth and hers What Ive come up with:
Solving the Fuel system problem with a Mega Squirt ECU you can use your stock wiring harness and cut the wires and put them into the right spots on their plug, and you can do whatever you like as far as and engine upgrades even regrinding a cam beyond the Computer application Specs and seeing what is really possible
Block Deck heights 2.9L 8.084 4L 8.858
Strokes 2.9L 2.8346 4L 3.3071
Rod Piston Pin bore ID 2.9L .9450 4L .9432
Valve size:
2.9 Intake 1.78 Exhaust 1.41
4L Intake 1.71 Exhaust 1.36
Both engines use the same Rods 5.1386-5.1413 and Journal diameter 2.152 (minor Clearance differences The 2.9 generally running tighter tolerances)
World Heads have 58cc Chambers
Use these engine Calculators http://www.kb-silvolite.com/calc.php Ive tried others but these seem the most accurate and Its a lot faster than the scratch paper method because to get to the end result it takes about 15 equations
possible option
Normally Aspirated
Block Bored 0.0405-0.0466 to keep .008 to .0019 wall clearance
4L Crank Offset ground .030 Max bearing you can get is .040 so unless you have a brand new crank you are going to lose .010 Cleaning it up ending with a 3.3671 stroke
Rods either 2.9 or 4L
Mopar 4.7L Pistons
Bore (in) 3.700 in.
Bore (mm) 93.980mm
Piston Style Flat top, with no valve reliefs
Piston Material Hypereutectic aluminum
Compression Distance (in) 1.240 in.
Wrist Pin Style Press-fit
Pin Diameter (in) 0.946 in.
Piston Ring Thickness 1.50mm x 1.50mm x 3.00mm
This puts your deck clearance at -0.02045
using .038 Gasket thickness as an estimate
You end up with roughly 9.688:1 compression
If you deck the block to zero deck you get 10.172:1
If you want to use forced induction which Im not and haven't ran the numbers I would chose the 302 5.09 Rods and a custom Forged piston because there are only Cast options available in the correct bore and Compression Height ranges to consider but there your still going to be way under the price of buying a Kit.
The chilton's manual I got some of this from is wrong the 4.0 has 5.74 Rods
Solving the Fuel system problem with a Mega Squirt ECU you can use your stock wiring harness and cut the wires and put them into the right spots on their plug, and you can do whatever you like as far as and engine upgrades even regrinding a cam beyond the Computer application Specs and seeing what is really possible
Block Deck heights 2.9L 8.084 4L 8.858
Strokes 2.9L 2.8346 4L 3.3071
Rod Piston Pin bore ID 2.9L .9450 4L .9432
Valve size:
2.9 Intake 1.78 Exhaust 1.41
4L Intake 1.71 Exhaust 1.36
Both engines use the same Rods 5.1386-5.1413 and Journal diameter 2.152 (minor Clearance differences The 2.9 generally running tighter tolerances)
World Heads have 58cc Chambers
Use these engine Calculators http://www.kb-silvolite.com/calc.php Ive tried others but these seem the most accurate and Its a lot faster than the scratch paper method because to get to the end result it takes about 15 equations
possible option
Normally Aspirated
Block Bored 0.0405-0.0466 to keep .008 to .0019 wall clearance
4L Crank Offset ground .030 Max bearing you can get is .040 so unless you have a brand new crank you are going to lose .010 Cleaning it up ending with a 3.3671 stroke
Rods either 2.9 or 4L
Mopar 4.7L Pistons
Bore (in) 3.700 in.
Bore (mm) 93.980mm
Piston Style Flat top, with no valve reliefs
Piston Material Hypereutectic aluminum
Compression Distance (in) 1.240 in.
Wrist Pin Style Press-fit
Pin Diameter (in) 0.946 in.
Piston Ring Thickness 1.50mm x 1.50mm x 3.00mm
This puts your deck clearance at -0.02045
using .038 Gasket thickness as an estimate
You end up with roughly 9.688:1 compression
If you deck the block to zero deck you get 10.172:1
If you want to use forced induction which Im not and haven't ran the numbers I would chose the 302 5.09 Rods and a custom Forged piston because there are only Cast options available in the correct bore and Compression Height ranges to consider but there your still going to be way under the price of buying a Kit.
The chilton's manual I got some of this from is wrong the 4.0 has 5.74 Rods
Last edited: