2000StreetRod
Moderator Emeritus
- Joined
- May 26, 2009
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- 10,597
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- City, State
- Greenville, SC
- Year, Model & Trim Level
- 00 Sport FI, 03 Ltd V8
I'm seeking information on what is required mechanically to stroke an Explorer 5.0L V8 engine. The purpose of stroking the engine will be to slightly increase low speed torque.
Rotating assembly balance: I've read that the stock engine is designed for an external balance of 50 ounce-inch that is provided by the crankshaft harmonic balancer. Apparently most stroker kits are targeted for Mustang engines with a designed external balance of 28 ounce-inch. For the Mustangs I've seen references to flywheel external balance and harmonic balancer external balance. It seems there are two methods of achieving rotating external balance for a stroker kit. One is to fabricate/assemble a new 28 ounce-inch harmonic balancer of the correct diameter fitted with an Explorer trigger wheel. The other is to retain the stock 50 ounce-inch harmonic balancer and remove an appropriate amount of metal from the crankshaft counterweights.
I'm looking for comments on cost, reliability, complexity, etc. comparing one method to the other.
Additionally, I'm aware that for the 3.4 inch stroke the bottom of the cylinder bores will have to be notched for rod bolt clearance and the ledge next to the oil pump support pad must be cut back slightly for crank counterweight clearance. Are both block modifications required for the 3.235 inch stroke?
Are any other mechanical modifications required? Please do not side track this thread with discussion about heads, cams, headers, blowers, ect. unless they pertain to actual required modifications. I suspect a custom tune is essential but that is not a mechanical modification.
Rotating assembly balance: I've read that the stock engine is designed for an external balance of 50 ounce-inch that is provided by the crankshaft harmonic balancer. Apparently most stroker kits are targeted for Mustang engines with a designed external balance of 28 ounce-inch. For the Mustangs I've seen references to flywheel external balance and harmonic balancer external balance. It seems there are two methods of achieving rotating external balance for a stroker kit. One is to fabricate/assemble a new 28 ounce-inch harmonic balancer of the correct diameter fitted with an Explorer trigger wheel. The other is to retain the stock 50 ounce-inch harmonic balancer and remove an appropriate amount of metal from the crankshaft counterweights.
I'm looking for comments on cost, reliability, complexity, etc. comparing one method to the other.
Additionally, I'm aware that for the 3.4 inch stroke the bottom of the cylinder bores will have to be notched for rod bolt clearance and the ledge next to the oil pump support pad must be cut back slightly for crank counterweight clearance. Are both block modifications required for the 3.235 inch stroke?
Are any other mechanical modifications required? Please do not side track this thread with discussion about heads, cams, headers, blowers, ect. unless they pertain to actual required modifications. I suspect a custom tune is essential but that is not a mechanical modification.