Various 427 Questions, New Member

[RICK LAKE]

Barry R. I am not buying the 40 year rod story. I have a 69 AMX motor in my CJ with steel rods and crank, ARP bolts. The rebuild was done in 75. Motor is raced to 6,500 rpms. The only change to this motor was a supply line to the #5 main bearing for more oil supply and pressure to this bearing and 7 & 8 rods. I know this is not an FE motor. This motor has 40 year old rods and runs fine with 60 psi of oil pressure and 15w-40 oil. Everything I have read and from talking to Pro machinist say about the same thing, If you LIMIT the RPM range and have the CORRECT clearance for the bottom end, there should be no failures. A big part of the problem is the OIL. The rest is machinist using OLD specs for this motor. .003" or rods and mains went out the window 20+ years ago. I just got a stroker kit from you, the motor runs perfect. The balance was dead on. Here's the thing, The rod bearing are under .002" and the mains are at .002" That's a long way from .003" or more. Your a PRO builder. You have put an FE motor in EMC for the last 4-5 years. You motors are not DYNO short term motors. They are very streetable motors for driving. You use the tricks that coat parts, remove weight to the rotating assembly, and work within a set of rules. Low tension rings, controlling oil flow and limiting the top flow to the heads. For your motor you are running a stock oil pump, it uses less HP to drive. Here's the bottom line You are saying that every FE motor with FE rods that are 30-40 years old are going to break from fatigue. I do not agree. I well maintained motor and limit of RPM of under 6,000 should last 1/4 million miles. What causes motors to go bad or break bottom ends? Cheap or no oil changes, Poor machine work, DRY STARTS, you know that metal on metal rubbing before oil pressure is built up. In 80% of the times what rods or mains fail? The last ones to get OIL. #4 & #5 main, # 5,6,7,8, rod bearings. Did the FE rod have a problem, Yes with the ROD bolts. ARP fixed that, we are all running them now. Here the other practice I don't believe in Dynoing a motor with 1-2 hour of run time. IMO this is another possible cause of motor melt downs. In the old days, you built a motor, broke it in for 1/2 hour and spent the next 500-1000 mile driving normal, nothing over 3,500 rpms. Heat cycles to help get everything broken in and living together. Barry, You have been racing in your part of the woods for better than 35 years. Old school still applys today. The design of some parts are better and lighter, but I think the metal the parts are made from today are cheaper with less steel and nickle. I figure my stroker will last 8-10 years of racing it. Limit the RPM's to max of 6,200- 6,500 and I see no problem. This is kind of like the beehive springs, in the proper applications they work and run great. Again have to know the limitations, about 6,600 max. I am hoping to dyno the car in the next 2-3 weeks. I wish I was rich enough to get a 427 or 428 motor, use the 428 cast crank I have and a set of rods C9ZZ-6200A, new in the box with the change of the rod bolts to ARP, with the proper stretch work done, put it on a dyno and make 50 passes. Min HP 500-550 Torque 550-575 ft. The clearance on the mains and rods would be about .002". HPHV oil pump with a min of 60 psi at 2,500 rpms to 80 psi at 6,000+. A good oil, no synthesis. I bet the rods would do just fine. The motor would get a correct breakin with a min of 25 heat cycles. This is no different than the guys running aluminium rods for 10-20 thousand miles in street cars. All you have to do is warm the motor up to get the clearances smaller before driving. Again you and KCR are the PRO's and do this for a living. Me, I live out where the buses don't run but have learn alot in 30 years of wrenching. I make my living turning them today. Hope you and the family are well, baby must be getting big. Looking forward to your next EMC event. Rick Lake