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Forum Home > General Discussion > Step TWO - Details

Clyde
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Posts: 32

Before we start with rebuilding the engine, I just want to make sure you did all your adjustments on the alignment was with the proper  air pressure at all times. The engine must be done with attention to detail. It is not hard but it is very detail oriented. Disassembling the engine is just as important as reassembling it. Removing the head is done by starting with loosening the head bolts from the outter one and cris-crossing the middle one. Putting the head back on is done by starting from the middle and cris-crossing to the outter plus tightening in steps; step one is all to 35 pounds of torque then all to 70 ibs. When you take anything apart that is matched to another metal part it MUST go back to that same mated surface, if you do not do this then those parts must rematch to each other which causes slight seating that results in some metal grindings. Once the crankshaft is removed it MUST get magged (checked for cracks) as long as it is not cracked use it again because cast metal gets stronger with age! Yes, your older crank is stronger then a new one. Be sure to make the main bearing caps marked, the number one cap is easily marked the center as well as the rear are all marked from the factory but  number 2 and 4 are not and while they will fit the are not where the belong. The same is true with the rod caps, they must go back with the rods they are matched to. Mark all push rods and the lifters they are matched to as well as to the rocker that makes them move. An electric scribe tool is a good way to always have the part numbered to where it belongs. Look on the backside of the bearings to find out the size of the replacement bearings unless when you had the crank magged they re-cut due to scoring and then the crank grinder will etheir get the bearings for you or at least tell you the new size, I do not go past .030 for racing. The piston rings need to have a gap for the rings to expand without hitting the ends, I increase the recommended gap by 5 thousands due to the heat we get during racing and waiting on the darned false grid. Re-doing the valves is another case of putting them back where they belong due to matting with the rockers. Lapping the valves is not a problem unless you have bent or burnt problem then replacement is the answer. A bent valve will probably ruin the valve guide and you will need to visit a machine shop at this point have them set-up the spring pressure to 70 lbs exhaust and 60 lbs intake. I will bet your bent valve was an exhaust, if they do not close fast enough (Float) they hit the piston so be sure the matching piston is not damaged as well. Hopefully, you have an oil temp gauge to be sure you are running the oil above 212 degrees to boil out the condensation that happens due to heating and cooling. If you are running points, be sure to run the heavy duty option and do not take any time between ignition and start-up, then the points last a long reliable time. The timing chain should be replaced if when headled with both hands level, it has more then 1/2 inch of droop. If it has less then keep it as a new one will stretch and change the valve timing; 110 to 1l11 is good but this is a complicated thing to do. If you where happy with the RPM and power before the rebuild and the chain is in good condition you are done but if not then get help with this step. Finally, I want you to understand the crankcase pressure situation; Many formula ford engine builders were plugging up the crankcase breather system that the factory installed when the engine was new. Understand the factory never spends money unless it has to; so when they put in the crank breather system they had to; when the engine builder plugs that system up it is wrong! The drag racing world even allows crankcase vaccum systems. FRCCA does not allow for the expensive pumps but you can allow the crankcases to breath. The Ferrari engines I worked on had breathers that measured 1 1/4 inches just to allow the crankcase to breath out the pressure. Think about this "what is better pushing the piston against pressure or allowing it to be drawn into a vaccum?" In closing, I must tell you I think the Kent Ford engine is a great engine and most of the blow-ups are caused by not cleaning the engine outside parts (cooler,Oil lines, reserve tank or not removing the oil pan welded splash guard to clean below) another problem is over-revving, the engine is great to 6,400 RPM's but some guys think going to 7,000 is ok - NOPE. If that is what you want then you need to spend much more money and I believe that money should be spent on track time.

 

February 10, 2018 at 5:17 PM Flag Quote & Reply

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