Engine building problems...HELP!!

joeboisselle · #1 03-06-2007, 10:21 PM

Ok, I've been gathering parts together to build an o-360-a1a, for the last several months, and I think I've got everything. Crank was overhauled, ground .003, renitrided, cad plated etc. So I bought oversized bearings and attached the connecting rods last night and everything worked fine. Tonight I closed up the case with cam, crank and tappets inside. As I started to tighten up the bolts on the top and bottom of the case, I noticed the crank would no longer move. My first thought was perhaps the crank wasn't ground .003 and the oversize bearings were the cause. But why would the case bearings be tight and the rod bearings be fine if both were .003 over???

Next, I see small holes inside the case, pointing out twards each cylinder. I assume these are supposed to be for piston cooling oil jets. The only -360 model I can find with these jets is the vo-360-b1a. Should I find and install the jets, or can I just plug them off?

Thanks in advance for any help.

Radomir · #2 03-06-2007, 10:56 PM

Here's a pic of piston cooling nozzles.. if you're talking about same location you can either plug them or install nozzles.

http://www.vitez.net/rv7/engine/asse...s/IMG_1502.htm

c177tx · #3 03-06-2007, 11:06 PM

did you use the proper size silk thread?

joeboisselle · #4 03-06-2007, 11:07 PM

That's what I'm seein'! I'm always up for good lubrication inside an engine and more is better in my opinion... where'd you find your nozzles at?
I don't recall what diameter the thread was, but it was fairly thin. Hard to imagine that, or even .003 oversize bearings would seize it up as tight as it was.

Radomir · #5 03-06-2007, 11:15 PM

Ordered them from Mattituck. Part number is: 73772 -- and they're about 18 bucks a piece..

PS. Did you check if your main front bearing moved during assembly? Was it lined up properly and engaged dowel pins?

c177tx · #6 03-06-2007, 11:35 PM

who did your case, was it lined bored? Is the cam tight? If your mains are binding, and the mains and bearing measure out then could it be your deck height?

joeboisselle · #7 03-06-2007, 11:40 PM

Thanks for the number. And it looks like everything is set in place, the bearing didn't appear to be sitting on top of the dowel pins.

joeboisselle · #8 03-06-2007, 11:44 PM

Quote:

Originally Posted by c177tx

who did your case, was it lined bored? Is the cam tight? If your mains are binding, and the mains and bearing measure out then could it be your deck height?

Aircraft Specialties did the case, crank and cam according to Dana Overall, whom I bought it from. I don't recall the case being lined bored, the cam isn't tight. I'm not sure about deck height, I havn't anything to measure it with.

mahlon_r · #9 03-07-2007, 06:03 AM

Make sure you have torqued all thru bolts and all case backbone bolts properly and to spec. That includes all on the thru bolts on the cylinder decks. If it is still tight, then try to turn the case around the crank or the crank in the engine, whichever your build up stand will allow. If a bearing is tight it may leave a signature on the effected bearing surface. I assume you physically checked all journal dimensions and also did the math to confirm bearing clearance or used plastigauge to find clearance..right? Also assume you checked end play and thrust clearance during assembly? If this turns up nothing, disassemble and check all bearing bores especially the nose bore for size at several locations and planes and check with dial gauge for straightness vertically and horizontally. Double check, that there was nothing behind any of the bearing shells.
If that turns up nothing, try a different crankcase for starters it may be deformed when torqued and if that doesn't work try a different shaft it may have some whip to it.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

Allen Barrett · #10 03-07-2007, 06:19 AM

Also, verify that the dowel pins in the bottom of the main bearing bores are set deep enough. They need to be a finished driven depth .070-.090. If they are too high they will hold the bearing off the case, making it tight when assembling. Deck height is not a factor, yet. Practice proper torque procedure. Verify that no burrs exist on the thrust suffaces (Mahlon mentioned the correct thrust clearance), and slinger clearance. Check bearing size. The bearing size is marked on the back side of the bearing. Wouldn't be the first time bearings have been packaged wrong.

AND, once again verify that the front bearings were not pinched on the pins. This is critical. Ask me how I know..

Allen
BPE, Inc