QuestionMr. Surerus,
I appreciate your time and assistance. My friend Joe has a 1967 Mustang fastback, with the 289 hi-po engine. We just received a complete rebuild kit and plan on beginning within the week.
Our question is in regards to honing the cylinder bores. Joe recently ordered a honing tool. It should be here shortly. However, neither of us are absolutely certain how to hone the cylinder walls. Could you help us out with some instructions, or tips?
We would gladly take the block to an engine shop, if not for the logistics involved. We are currently stationed in Japan with the U.S. Air Force. The base has a competent auto shop available, and the car is there now. So far, we have done all of the rebuild ourselves, and I am a competent mechanic. With proper suggestions, or instruction, I am confident that I can perform the work. Any help you could provide will be greatly appreciated.
Respectfully,
John Crawford
AnswerMr. Crawford,
If the cylinders are bored, the cylinders should be bored to 0.0005 to 0.002 in. less than required. the cylinder size and required wall finish should be completed by honing.
If the cylinders are not bored, you can do the honing yourself or have an automotive machine shop do it for you (which as you have stated is rather impossible at the moment due to your current location). The type of ring being used will determine the grit of the honing stone required for the finish. If cast iron or chrome faced rings are being used, the honing grooves for oil retention should be deeper. For the finish honing, a 280 grit stone should be used.
If moly rings are being used, the honing grooves for oil retention should be shallow. For finish honing, a 400 grit stone should be used.
To hone the cylinders, the following is recommended by Haynes Ford Engine Overhaul Manual:
A) Install the main bearing caps and tighten the bolts to the specified torque.
B) Mount the hone in a drill motor, compress the stones (if necessary) and slip it into the first cylinder- BE SURE TO WEAR SAFETY GOGGLES OR A FACE SHIELD!
C) Lubricate the cylinder with equal parts of 20 wgt. oil and kerosene, turn on the drill and move the hone up and down in the cylinder at a pace that will produce a crosshatch pattern on the cylinder walls. Ideally, the crosshatch lines should intersect at approximately a 60 degree angle. Be sure to use plenty of lubricant and don't take off any more than is necessary.
D) Don't withdraw the hone from the cylinder while it is running. Instead, shut off the drill and continue moving the hone up and down until it comes to a complete stop, then compress the stones and withdraw the hone.
E) Wipe the oil out of the cylinder and repeat the procedure for the remaining cylinders.
F) After the honing job is complete, chamfer the top edges of the cylinder bores with a small file so the rings won't catch when the pistons are installed. Be very careful not to nick the cylinder walls from the end of the file.
G) The entire engine block must be washed again very thoroughly with warm soapy water to remove all traces of the abrasive grit produced during the honing operation. NOTE: The bores can be considered clean when a white cloth-dampened with clean engine oil-used to wipe them down doesn't pick up any more honing residue, which will show up as gray areas on the cloth.
H) After rinsing, dry the block and apply a coat of light rust preventive oil to all machined surfaces. Wrap the block in a plastic trash bag to keep it clean and set it aside until reassembly.
I hope that this helps you out. If I can be of further assistance to you, please do not hesitate to contact me. I apologize for the delay but it took me a little time to sort through all my info to find this procedure for you. Good luck and God bless you....let me know how your project comes out!
Ken
