Dyno day, the good and the bad....

It's my understanding that only the vertical (90 deg from parting line) measurement matters, "A" in your sheet. The parting line dimension depends on the rod housing which is usually not perfect at that point. And bearings will have eccentricity anyway so will be thinner at that point. I've been told not to even consider those numbers.

 

That's what I had hoped, thanks.

I found another thing tonight...
I took the three inner main bearings out leaving the #1 & #5 bearings in place and installed the crank, cap and torqued. I put a dial indicator on the #3 main to check straightness. I do not know what kind of run-out is acceptable, but I've got 0.002" variation (high to low).

I keep going back to how hard it was to turn the motor over at the dyno, though it was noticed mostly after we ran it some a couple of times.

I also had only 0.010 side clearance between #1 & #2 rods and about 0.012 side clearance between #7 & #8. Contributing factor??

 

I'm no expert in crank straightnes but 0.002" runout is a red flag to me. I would get the opinion of an expert on that issue.

 

Red flag here, too. Unfortunately I've not heard of successfully straightening a cast crankshaft, either.

Devon

 

Anybody else on crank straightness? I don't think the mains need to be turned, but turning them would likely reduce this run-out. I doubt polishing will do anything for straightness.

I've heard that Clevite bearings are somewhat inconsistant in thickness, and tend to run on the fat side (this is what I used). I also heard that Federal Mogal bearings are more consistant but run towards the thin side and ACL's were most consistant running between the two.

Do any of you guys measure and mix and match like bearings to optimize sizing? Maybe this is more race related but I've go the tools to check them next time so I will.

 

Here are the main caps, I've included the measured clearances of the used bearings shown. The bearings that look more worn have the larger clearances. Stacked left to right #5 to #1.

 

A good crank man could take that .002 runnout out of it in a few seconds. Straightening iron cranks is an everyday process, and part of good crankshaft servicing.

As to your bearing measurements.. you cannot measure the hole, and then measure the bearing thicknesses, and do the math.. This does not work with acceptable accuracy. Install the bearings, torque to spec, and measure with a dial bore gauge.

This is the only correct way to set bearing clearances.

JW

 

That's good to hear, I'll ask my crank man to see if he can do that.
Jim, do they bend the crank or what to do this?

Thanks for making that clear, I was only asking about the bearing thickness to see how much mine had wore down. For the clearances listed, I used the old bearings, torque of course (just out of curiosity). Using the old bearings to get my clearance measurments indicate the mains were close to desired. The least wore is #5 has close to desired clearance and the most worn bearings, #1 & #4 have more/too much clearance.

 

Craig,

It's a process called Peening.

Crank shops have sets of special rounded face punches and the correct one for the particular crank is used on the fillet of the journal.. just a couple taps in the high spot is used to straighten it.. And for a small straighten like this, you don't have to re-grind.

No kidding, I called my crank guy this afternoon, who is certainly one of the best in the business, and he explained the procedure to me. I knew you could straighten the crank, because he does it all the time for me, and I have come across ones like yours in the past, in repair jobs typically.

I called to ask Roger, how much it could be straightened, when I said you measured a .002 runout. His exact words were "Piece of cake, I could fix that in about 10 seconds". He went on to say that he can straighten iron cranks, up to about .010-.015", but these often have to be re-ground.


10-4 on the bearings.

Got that dial bore gauge yet?

You need the 2-6" dial bore gauge set, as well as a 2" and 3" mic that reads in 10 thousands.

To help you, and others looking in here, I will list the tools I use in the shop here..

Dial bore gauge

I pulled these off this site http://www.industrialboys.com/index.aspx?session_id=222634379

0511166 MITUTOYO Range: 2.0-6.0", Graduation: 0001", Probe Depth: 6", Inch Size $342.00


Micrometers

0068013 STARRETT USA T436.1XRL-3, Range: 2-3" $153.90

0068019 STARRETT USA T436.1XRL-4, Range: 3-4" $168.30



Record and share your measurements with us when you get them done.

Most important right now is main housing size, and out of round.

JW

 

Good info, I really like the part about "don't have to re-grind". I just hope my crank guy can do the same.

Here are some of the tools I'm using...Fowler dial bore gage, micrometers, calipers.... and at 46 don't forget the reading glasses.

This little set-up for the dial bore gage makes it easy and repeatable to double checking measurments.

I use the smallest micrometers with different tip to check bearing thickness.

 

Here are the cam bearings I took out today. #1 and #3 have the most ware, the others look good. The top side looks great here are shots of the bottom side. Ignore the marks I made while measuring the diameter before taking them out. The cam rotatated nicely. My block under the first cam bearing is grooved from 4:30 position counter clockwise to the 3 o'clock position (previous owner). Would you re-use these bearings, or complete 360 degree 1/8" wide groove?

Oh, my crank guy does not have the tools for peening the crank to take the 0.002" run-out out. He said they put pressure on it then turn it.

Bearing #1 was posted twice and #5 is in the following post.....

 

Oop's, here's #5.

 

My trip to both Auto Zone and Advance came up dry. I told them I was torquing up some main studs on an engine block and wanted to use moly as a lubricant on the threads. I did find some Lucas assembly lube (semi-synthetic), is this the same as moly or do you have to get it from ARP?

On the bottle it says it "Contains Zinc, Moly and other high pressure additives for maximum protection during engine break-in."

 

The Murray's near me carries moly lube in the grease section.

Devon

 

With Moly lube you wont torque to 130# due to the change in friction.
The more I read about this thread the more I think there were several issues and I completely agree with Jim.
3 1/4 main needs a PERFECT main bore to have that tight of a clearance. There again, a little more oil clearance is cheap insurance.
.002 if that is really the case for journal run out>(as a crank grinder myself) that's obscene and SO unprofessionally done!
I'm sure Jim and some others can attest, FIND a good machine shop! Engines will live just fine if the parts are all straight and round.
We don't use any special type of ZDDP additives on break in here. Just 18-2200 and NOT for 10 minutes. PLEASE, PLEASE, PLEASE GUYS! Make your cam companies and machine shop happy. They suggest a 20 minute break in, do 30! Similar to painting a car. 7 minute flash recommended, do 9!
Good numbers though! I think once you get it back together, you wont have any more issues. I would guesstimate that there is a little more power there as well. It should be a real 'ground pounder' and I look forward to hearing about your results.

Mike
If you need moly lube, I have a couple extra tubes laying around.

 

I finally got out to the garage today for more inspections.

Time to measure the mains without bearings. I began by installing the #1 main cap. I noticed after getting the cap seated I was still able to move each side of the cap by tapping it with a hammer. Knowing this would change the alignment of the mating surfaces I used a straight edge to check it. I placed the straight edge just below the parting line and held it flush against the surface letting the straight edge extend out the front of the block. I pulled a chair over to where it just touched the end of the straight edge (the straight edge was 24" long). I did the same for the cap surface just above the parting line. To my surprise there was about 3/16" difference, granted this was 24" away. I checked both sides and aligned the cap for best case. It seems a better situation would be either the shoulders were closer or the cap was wider. We are talking a minuscule amount here, but if not assembled in the same position as when align honed then you could have less than ideal alignment for final assembly.

Anyways, my goals were to measure the mains to see diameters at different points and to try using different torque to see if there was any variations.

I took these diameter measurements with a calibrated dial bore gage and I used 30W oil for lubrication.

Here are the average dimensions on #1 main without bearings:
Torque -------->80 ------ 95 ------ 110
Vertical ------ 3.4388 --- 3.4385 -- 3.4381
45 deg ------- 3.4383 --- 3.4380 -- 3.4376
Parting line --- 3.4385 --- 3.4384 -- 3.4386

These numbers confirm that indeed torque has a direct effect on the final clearance and could be used to tweek clearances.

Back to the cap position findings, since it is not held as tightly as it could be, maybe I should stay towards the upper torque range to minimize movement? Is there something else that can be done to support the cap better where it fits into the block (short of a girdle)?

Oh, Mike thanks for the moly offer, but I'll have some tomorrow.

 

Sounds like you have a main cap "register" problem, which should have been taken care of before the line hone was done. Hopefully JW can chime in and give his $0.02.

Devon

 

Block, crank and other parts delivered to the shop today. Hoping to get it back for an after Christmas assembly .... then another dyno day. This is my "Project 11s", and you know what that means.

 

Well, you just found another problem... that's adding to the woes of a tweaked crankshaft..

5 tenths out of round from vertical to the 45 is too much.

Imagine how far undersize it was with 130# of torque with moly lube. I'm amazed you didn't break the block.

That block needs to be align honed. And have the machinist check the register of the caps. They can tighten them up a touch.

Then check it again, and if it's not round, +/- .0002 from the vertical to the 45* measurement.. find a new machine shop.

Torque it up with the bearing shells in place.. and measure again. I recommend not fooling around here, just go to the next undersize and get a fresh turn on the mains and rods of the crank... remember, never enough money to do it right.. always enough to do it over.

Have the crank turned to give .002-.0025 on the mains, and .0025-.003 on the rods. Shoot right for the middle of that range. It will vary, trust me.

Anyone that tells me they have .002 on the mains and rods, just told me they don't know how, or have the tools, to measure it properly. There is always a little variation, and that's ok, just stay in the desired range. As the HP level of the motors go up, I get more picky, but only the 750HP+ stuff gets an individually size journal ground crankshaft.

Make sure they check the crank for straigtness. If you can't find a good crank shop, send it to me, and I will have it done for you.


That .4381 on the 110 number is the bottom of the spec, and explains why your main clearance was so tight (that and the torque and lube).. The spec for the main bore is 3.4380-.4390. Have it done to the middle of the spec (3.4385.)

 

Nope, mean exacty what I said.

JW