Difference between ta crank and tr crank?
- Thread starter TurboKen
- Start date
Ok than lets clarify "crossdrilled". Does that mean theres a hole that is drilled from the main bearing journal through to a rod bearing journal? I just purchased a crank and it has this kind of drilling. And does that mean a turbo regal does not have this kind of drilling? If not, what kind of drilling does a tr have? Just trying to learn, thanks
Ken
Ken
A cross drilled crank has a hole drill straight across the main journal....from one side to the other. This hole also intersects with the hole drilled from the main journal to the rod journal. This way the oil is always fed to the rod journal. This is because the upper half of the main bearing has a grove in it that supplies oil to the crank, to supply to the rod. But it can only get this oil when the crank is turned so that the drilled hole is in the upper half of the main bearing where the grove is. Now if you cross drill the crank, one of the holes is always in the uper half of the main bearing. So you see without a cross drilled crank, you are only suppling pressureized oil to the rod bearing one half of every rotation of the crank. Don't worry to much, most cars on the road don't have crossed drilled cranks. But you could crossdrill your TR crank I guess.
Will I don't see why you couldn't. Some of the other post on this subject state that they have cross drilled TTA cranks, and I don't think there is any real difference in the way the cranks are made. I have cross drilled several cranks, but I have not done a GN crank. But I have never had a GN motor apart either. Look at the bearings you are going to use and see if just the upper half is groved. If both upper and lower are groved you won't need to cross drill the crank. Most people like for the bottom half of the bearing not to have a grove in it because it takes away some of the load carrying ability of the bearing, i.e. more surface area equals more load carrying ability with the solid bearing. With a boosted motor like the GN, if you are going to run much boost you probably want all the load carrying alility you can get.
