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If unsure about motor cases, just look at the oem fische. They will show either a set or individual. I have not seen a motor that splits top and bottom yet that you can buy a single half for, it just cant really happen that way.


It is Ebay that has created the mis matched case problem. Your right you can't buy them separate from the dealer but some Ebayer's think they will make more for those people that just ruined the top of their case when they really have no idea what they are in for when buying mis matched cases.



Good Info.
 
Bump.
This is a good read. Tony, can you or someone else comment on the best bearing choice for the cranks? Referring to 7 mil and 10 mil cub motors so 100-120 hp range. I have read where some say to avoid the TZ due to crank walk. They say to use 10 ball max loads. Others have said the 10 ball max load crank bearings are too rigid and are rated for lower rpm. Also, are straight cuts necessary on these cub motors?
 
"Detonation is pre-ignition"?? Well, that's the first time I've ever seen that assertion, maybe because it's wrong. Bubba, you obviously know a lot, including a lot I don't know, but you should see two pistons I have somewhere in the shop (L-16 Datsun 510) that came out of two engines. One has a hole in it with smooth round edges where the aluminum got so hot it fell away, melted, and one edge of the crown also is melted away; that's pre-ignition. The other piston also has a hole, about in the middle of the crown, with sharp broken edges around it, like you hit it as hard as you could with a ball-peen hammer; that's detonation. Different phenomena, different effects. These two pistons constitute such perfect textbook examples of failure by pre-ignition and by detonation that I have been thinking of giving them to the auto shop at my old high school (in fact I might have already done it; I've given the school some other stuff, and being an old guy I might have forgot about this, LOL).

Pre-ignition can frequently lead to detonation. But you can get detonation without preignition.
 
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