I have a 400 in my '76 T&C that I am rebuilding. I was checking the bearings and noticed something on the rod caps I am not familiar with. It looks like the caps have been drilled to relieve oil from the bearings. It has been a while since I have had 400 apart and I dont remember seeing this before. Is it correct?
Question RE rod caps
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Landyacht
Active Member
I have a set of rods from a 73 400 and they look the same. That should be correct
Yes, that is correct. The oil from the holes sprays the camshaft.
C Body Bob
Old Man with a Hat
This is why I'm not a fan of a windage tray on a pure street car
Please explain Bob ... Thx in advance
C Body Bob
Old Man with a Hat
Bryan most cars didn't come from the factory with a windage tray. Simply because it was not needed. With nationwide speed limits being reduce downward & power levels dropping along with rear gear ratios. Most normal passenger cars cruised along at 2500 to 3000 rpm. Even performance models rarely came equipped with a windage tray. As rpm increases the oil will wrap around the crankshaft & create drag on the counterweights of the crank an this prevents the oils return to the sump. As RPM increases obviously the engine is working harder & demands more oil. At low RPM there is a bit of windage, but there is also as much or more of a sloshing effect. Or splashing of the oil all under the crank & even on the bottom of the intake. This is I believe what you want to increase duribality. Having oil everywhere splashing around. The engine at this low RPM can easily over come the oil demand & drag on the counter weights. At high RPM on let's say a serious performance or race engine it actually helps performance & durability to control windage. As these engines often have chamfered oil passages , oil galley block offs & screen & even oil feed tubes. Basically control of windage when windage begins to be a problem.
Yes
moper
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The relief is not for the camshaft, but for the opposing cylinder wall. If you notice any aftermarket rods now, and many rod bearings do not include this passage anymore. That's because it was found to encourage oil burning by flooding the scraper rings and contaminating the combustion chamber. Oil splashing around is good in a lawnmower. Controlled oil delivery is good for an engine with a pressurized oil system. Windage trays only help oil from getting pulled up from the sump by the rotating assembly. They are beneficial in any engine that runs hard. That's why they were on all performance V8s, and police cars.
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