Main Alignment Necessary?

DSMsamurai666 · 11-06-2009, 04:02 PM

I'm rebuilding a 6 bolt block with reconditioned 6 bolt rods and evo 9 pistons. I'm aiming for like 400 horse or so. The block has already been hot tanked and magnafluxed and I'm about to get it bored and decked. I was just wondering if I should get the mains aligned. Looking at them, they look perfectly even and nothing bad ever happened to the motor while it was running. Its 55 dollars to have it checked out and almost 200 to have it aligned. I was just wondering if you guys think I should leave it alone or have it checked. I'm on a really tight budget so it helps to save even 55 dollars, but I want to do whatever it takes to build a reliable motor instead of a timebomb. Thanks.

donniekak · 11-06-2009, 06:21 PM

What did the old main bearings look like when you took it apart?

BogusSVO · 11-09-2009, 10:21 AM

if you go to main studs.. at a min have it checked with the main studs installed and torqued, there is a good chance that you will have to have it aligned honed if you use studs

TOONAH · 11-11-2009, 10:31 PM

My machinist talked me into it. His argument was this: Before he bored out the cylinders to .040" over (with torque plate) he wanted to be certain that the mains bore angle was true to the angle of the cylinders. He claimed this was essential in an engine that was going to have the rotating assembly balanced to
5 milli bob's @10K rpm (Bob is a measurement of balance). Well it impressed me and since I was selling my soul to the devil to build this thing, I went along with him. He had to farm it out to another machine shop and I waited 6 months for that bitch to come back. I paid that man $700 for all the work on the block.
I was very impressed with his work though.

slowgsr · 11-13-2009, 03:57 PM

you dont need to do it. Put it together, make sure the crank turns freely and bearing clearances are good and you will be fine.

When I had my block done, I had the mains line honed, except I used a kiggly gridle and arp main studs. If your not using studs, or gridle, you will be good to go.

95blackGsTurbo · 11-13-2009, 04:07 PM

If you spun a main bearing or the bearings look damaged then I would recommend getting it checked. Otherwise there is no real need for it.

Harriz801 · 11-13-2009, 04:08 PM

It usually all depends on how safe you want to be. Usually most will say if your using stock main bolts that its not necessary.

I would say the least you should do is have them checked. I understand money is tight but 55 bucks is not a ton of money when your talking about building a motor. It will definitely pay off in the end, believe me.

When I built my motor, I had everything checked. I also align honed my mains with a torque plate.

Although, using a torque plate has always been an argument on this forum. I would say using them is a must. I would never align hone main studs without using a torque plate, but some would say different.

I ended up paying right around $700 for my machine work on my block alone.

Building motors the "right" way is not cheap!

4g64fiero · 11-15-2009, 01:48 AM

The deal with using a torque plate is that the torque plate should be aluminum to accurately reproduce the stresses the head will place on the block.

Everything to do with machining the mains is debatable. I installed ARP mains on my 7 bolt and didnt have it align honed and had no issue concerning that. Depends on who you ask. The main thing is to check the journals to make sure they are in spec when the studs are torqued down. If theyre in spec and not out of round, there is no reason to hone or bore.

The proof is in the pudding.