Rear main issues

9,200 RPM isn't going to hurt rear main bearings, but 10,200 will.

RG

 

Exactly
It is amazing what a 1000 extra rpm does
I would not have believed it until we took off the roots and put on a screw and watch in awe at what now becomes the weak links
#5 main saying "well hello there" being the hardest to find the cause

 

Flywheel

Also with the screw John all the power is now at the flywheel. the roots is like a damper on the other end of the crank.

Mark

 

miner motor

Or you could just get a Bob Miner (Fontana) motor and kiss those rear main issues goodbye. It uses a thrust rear like a BBC. nice big bearing where the big load is. No extra oil lines, no sanding your crank, no rub blocks on the clutch, no problems.

 

What i should have said is "Hardest to find the cure",
very nice feeling when you do thou...

 

Clint, do you think these guys will ever believe you. We ran a set of main bearings for three years. The only reason I replaced them this year is because they felt a little loose and I thought ... why not. We bought two blocks from Miner in 1999 and they are still going strong.

OH and BTW ... don't forget that they have NO push rod problems either.

Why anyone would want to put up with all that BS is beyond me. But there are a lot of them out there so I guess they have spare parts in every pit ...

 

Lawren & Clint, do you guys run Chev type mains or 3" in your Miner deals? Where do you source your bearings from?

 

no troubles

They are Chevy size mains and we use Chrysler size rods. Bearings are standard Clevites. Get them from Miner.

Yeah Lawren, no pushrods issues, easy to work on, leave the blower on when pulling the heads, Rocker stands held on by head nuts so no extra fasteners to deal with............
replacable pan rails on the block...........I watched some guys working on a Brad deal at Mission one night. What a pain in the ass, lots of extra work, lots of extra opportunities to make mistakes. I'm with you, I just don't understand why anyone would do all that when there is such a viable alternative that saves time, money and effort. Hmmmm.

 

Here Here,.!!!! Parts attrition is fanominal, easy maintnance motor for you service
guys that tear into the round by round ways of kicking ass. You sometimes forget there are main bearings in a MBR motor, there are just no issues down stairs even with 3, 4, 5 tire shakes. MBR Engines Rock,. 24-27 minute turn arounds,
run the valves,change out rod bearings, service clutch, pack chutes, re fuel and oil.
And if by chance you have to change out a piston and rod lol..flat rate manual says add 8-10 minutes to change it out...

FIRE IN THE HOLE.....

 

miner motor? How many championship and how many 5.40s runs does that bad ass motor have in funny car? when you turn your floater so BLUE it take out the rear main. it is cooking the OIL.

 

I wonder

Yeah, makes me wonder if Frank had one, how fast could he go? 5.35? 270?

 

rear main issue

Funny thing is I ran against monty todd a few times which he ran a screw blower setup and he never could run beside me. He thought he would run off and leave me but in reality screw blowers dont really start making a bunch of power til about 300 feet out and by that time my ass is long gone. Most tracks we run at we have to make all of our power at the time swap feet cuz past 300 feet it turns to shit track.

 

Rear Main Problems

I have always thought a big issue with rear main problems was simply heat. The clutch transfers a ton of heat to the rear of the crankshaft and in turn to the rear main. When I was running KBs we would occasionally check a rear main and find the oil cooked black. Sometimes we caught it in time and could get away with changing a bearing but sometimes it would burn the bearing and hurt the crank and the saddle. The oiling system on those motors and the standard Brad motors oil from the front of the motor to the back unless you run the extra line to the rear of the motor. By the time the oil works it's way from the front to the back it is heated and not cooling much anymore not to mention the pressure loss along the way. The Miner motors oil from the back to the front. So the rear main is oiled first- it gets the cooler oil and full flow and pressure. Why the KB and BAE motors haven't changed over to that style of oiling is beyond me. I love my Miner motor and wouldn't change for anything. Dave Germain