What mods would you do to the crankshaft?

[396_WAYS_TO_SPIT]

Just curios to see what you guys are doing to the cranks that you run. I was going to post this question in the other thread but didnt want to hijack the thread.
I have heard of crossdrilling and putting a radious on the journals. anything else? What about the main bearrings? 3/4 or full groove? Lets talk about a new steel crank.....

[WannabeRacing]

Any good aftermarket Chevy style crank should have a .125 radius from the factory. That is really the standard. Standard h series bearings bolt right up, etc. You can go further, but from the machining, the odd bearings, and not matching stuff up in the future, you really have to say; "is more than a .125 worth it?"
Taking a stock crank and cutting it to a .125 is possible, and common in the talks around here. Actually makes them stronger than they were before cutting. But when you get a good crank, most just keep the .125 when they cut it down again.
You can profile the counterweights to cure some of the blunt nature of the leading edge of the crank. But most cranks are set-up 'as is' for balancing. Cutting too much off the leading edge makes for a balancing nightmare. You can feather it a touch without too much trouble, or try to scare the thing with heavy metal after really cutting on the couterweights. Usually, if it has knife edged stuff from the factory, it is designed for it, and if it does not, just do very little, or leave it entirely.
If you are making a total racing deal, you can coat different parts of the crank with different coatings. The most common is the counterweights with oil shedding properties to keep oil from sticking and adding weight, and trying to keep down on windage friction. For these applications, it is a total waste of money.

[Fiat48]

What we were referring to about radius is the stock chevy cranks have a poor radius and are prone to cracking in that area. Many guys would have a GOOD crank grinder (not all crank grinders are good) grind brand new chevy cranks with a radius before they would even run them. Stock chevy cranks are famous for being bent when you get them.
The aftermarket cranks are better than the chevy. I think most out there have pretty good radius cut in them. Straightness is much better although not all are straight. I am talking Eagle, Scat etc.
Although some cranks are still crossdrilled and we used to think it was the way to go (old school) Cola cranks insisted (and even Hank the Crank agreed) that crossdrilling the crank weakened it.
I think the general feeling today is that with the use of a 3/4 groove bearing (which most performance bearings are) that crossdrilling is not required. Still some old guys just will not build without a cross drilled crank.
I think the general feeling out there quality wise is Sonny Bryant crank is the piece to have. If you can afford it. Crower is another one. Lunati, Callies...etc.
Best cranks I have run (could afford to run) are Lunati. I have run Eagle and Scat also. I would not run another stock chevy crank and go through what is needed to get the thing useable.
Rigidity and material get to be especially a big deal when you put a blower on it. N/A you can get away with lesser cranks.
Full groove bearings due to the loss of load capacity have been considered a no-no for a long time. But like most things I have done it in a pinch.

[Moneypitt]

The aftermarket units are not crossdrilled anymore, but, they have moved the oil holes a few degrees,(priority oiling???) to assist the rod bearing's supply of oil. If you're gonna use a GM crank, crossdrill it!! The 396/427 cranks were the same, except the factory choose to crossdrill the 427 hipo cranks, not the 396. I doubt GM went to the extra expense for the hell of it, they found out something when the added power of the 427 caused some failures......I even crossdrilled a 340 Mopar crank and abused it for years.......I've never seen a crank break at the crossdrilled hole in the center of the main journal............MP
Also, remove any and all flash, burrs, sharp edges, and check the chamfer on oil holes and radii after grinding. Rifle brush all passages 3 times minumin, chase threads on BOTH ends before cleaning. For storage, hang from rear flange, or stand on rear flange. (in Cal secure from falling in an earthquake).......

[DEL51]

are the new 572 engines from chevy any better in the crankshaft department?

[396_WAYS_TO_SPIT]

are the new 572 engines from chevy any better in the crankshaft department?
Ya beat me to the punch. That was my next question.
So the eagle/scat cranks would be fine in a 540(800-900hp) range?
Ive also heard that people are running .004 on the mains:eek: Does this effect the oil pressure? Ive been taught to run .0025-.003 on the mains and .002-.0025 on the rods..... assuming that the motor will see under 6500r's

[WannabeRacing]

Finishing a crank on the low is an old race deal. Especially in the days before the really low viscosity oils. A few tenthousanths to a thou between the crank and the bearings. Got rid of a few tidbits of less resistance, and made it possible for more oil volume without the higher pressures. There are also 1thou under bearings that can do the same thing without cutting the crank. Really you have to ask yourself what the engine does, what oil you are going to run, and make sure you have VERY accurate readings on your crank, etc. There is not room for error here.
For your engine and your application, a little on the low would be fine if you are going to run a decent thickness of oil Something like a Valvoline 20-50 VR1 racing oil. But if you are going to try thinner oils, or thin synthetics, there is no reason to finish on the low.
For engines that need to see at least 100000 miles, there is no room for the extra room. But for race stuff, and quick lake stuff- it is O.K. because we really don't see that many hours.
Again, like everything else- there is no magic answer. It is all a package deal that fits together like a puzzle. You have to plan before you start buying and building.

[396_WAYS_TO_SPIT]

I guess ill just stick with whats been working for me;)
I ran a olds with .003mains/.0025rods and it had 80lbs of pressure. She never skipped a beat until I sold her. They wonder how it blew up:eek: I asked them if they drained the gas tanks and the reply was"NO". I then said that you can run that long with water in the tanks:eek: The caps leaked but they didnt listen to me......

[Moneypitt]

They wonder how it blew up:eek: I asked them if they drained the gas tanks and the reply was"NO". I then said that you can run that long with water in the tanks:eek: The caps leaked but they didnt listen to me......
OK, water in the gas, "you CAN run that long"?.....But how did that contribute to "blowing it up"?? Please explain what failed because of water in the gas tanks.........MP

[Moneypitt]

As said to me by Rick Hubbard, (retired crankshaft master and balancer), "look at all the real nice factory pieces, Mercedes, Jag, Feriere, (sp), Lotus; Those engines are fine tuned watches and their clearances are always at a minimum.........extra clearance is a crutch for non precision pieces and will never work as well as a truly matched assembly".....
I have to agree with him. Those precision high dollar engines, like Indy stuff, rev almost twice as high as any BBC, and like it!!!!! Of course the high dollar BBC parts can be just as precision as those others and should be tightened up inside accordingly............MP

[396_WAYS_TO_SPIT]

OK, water in the gas, "you CAN run that long"?.....But how did that contribute to "blowing it up"?? Please explain what failed because of water in the gas tanks.........MP
Lean condition Im assuming. When the motor is detonating it will live forever:D I never had any issues with that motor and it ran very well. Then again they had the t-ram polished and couldnt seem to put it back on properly:rolleyes:

[GofastRacer]

The aftermarket units are not crossdrilled anymore
Hey Ray, just FYI Eagle 4340's are available crossed drilled, I didn't get one for this motor though!..

[Roaddogg 4040]

Ray... I love your Earthquake comment... Just one more reason why I don't live in California any more...:D
Steve

[GofastRacer]

Ya beat me to the punch. That was my next question.
So the eagle/scat cranks would be fine in a 540(800-900hp) range?
Ive also heard that people are running .004 on the mains:eek: Does this effect the oil pressure? Ive been taught to run .0025-.003 on the mains and .002-.0025 on the rods..... assuming that the motor will see under 6500r's
On my POS I'm running .0035 on the mains and .0028 on the rods, 7500r's no problem, the K motor I'm building will have min .004 on the mains and .003 on the rods!..

[GofastRacer]

Ray... I love your Earthquake comment... Just one more reason why I don't live in California any more...:D
Steve
A 15 second shaker is way better than a 12 hour Hurricane!..:D

[JAY4SPEED]

A 15 second shaker is way better than a 12 hour Hurricane!..:D
I wish hurricanes only lasted 12 hours....:squiggle:
So what is the optimal Blown BBC bearing clearance for rods and mains on a marine setup, "fast" lake use, forged Lunati blower crank?
I read in that article (http://www.hotrod.com/howto/113_0206_chevy_big_block_build/) posted up a while back on cs19's DNE engine build where Lunati had cut down the counterweights according to bob weight. I understand why they do this as to keep the rotating mass as close to the center of rotation as possible, but can someone explain the bob weight thing to me? Is that the total weight of the 2 rods and pistons on one crankpin?
Jay

[Fiat48]

What block? What stroke?
I should not have said bobweight. I was referring to heavier and lighter rotating assemblies. The basic 454 steel rod..forged piston deal is about 2500 bobweight....which is considered heavy. That is what I meant.
This will explain bobweight better.
http://www.automotiverebuilder.com/ar/eb40634.htm

[JAY4SPEED]

In keeping with the thread, I was just mentioning how grinding the counterweights (making them shorter) instead of drilling the crank counterweights was a cool way to go about balancing it, that it was an interesting crank mod.
What block? What stroke?
I should not have said bobweight. I was referring to heavier and lighter rotating assemblies. The basic 454 steel rod..forged piston deal is about 2500 bobweight....which is considered heavy. That is what I meant.
Dart tall deck dart block p/n 31263454, 4.5 bore, 4.25 stroke. Not sure what H-beam rods yet. This is the combo I'm trying to setup in the near future.
More to the point of the question I was trying to ask was, what is bobweight and how do you arrive at a specific bobweight number?
Edit: thanks you edited with the link before I posted....
Jay

[Fiat48]

Big end weight of 2 rods (rotating)
weight of 2 rod bearings (rotating)
Oil allowance (rotating)
weight of 1 piston, pin and locks. (recip)
weight of 1 set of rings (recip)
weight of one rod small end (recip)
I would do .0035 on the mains. 003 on the rods. Being that Lunati is a good stiff crank...you might get away with .003 on the mains. But you will probably find that as you receive the crank from Lunati it will come put at .0035 with standard bearings.

[JAY4SPEED]

Big end weight of 2 rods (rotating)
weight of 2 rod bearings (rotating)
Oil allowance (rotating)
weight of 1 piston, pin and locks. (recip)
weight of 1 set of rings (recip)
weight of one rod small end (recip)
I would do .0035 on the mains. 003 on the rods. Being that Lunati is a good stiff crank...you might get away with .003 on the mains. But you will probably find that as you receive the crank from Lunati it will come put at .0035 with standard bearings.
This will explain bobweight better.
http://www.automotiverebuilder.com/ar/eb40634.htm
This answered my question exactly! Thanks!
Jay

[Warp Speed]

On my POS I'm running .0035 on the mains and .0028 on the rods, 7500r's no problem, the K motor I'm building will have min .004 on the mains and .003 on the rods!..
Just curiouse, why are you going that wide (.004/.003) on clearances?!?:2purples:

[GofastRacer]

Just curiouse, why are you going that wide (.004/.003) on clearances?!?:2purples:
Well this may be a dumb theory, but it seems to me that the oil acts like a shock absorber so with a little more clearance you have that much more oil=more cushioning, especially with a blown motor which this one is going to be!. I have noticed that with the same amount of running time, I see less wear on the bearings with a little more clearance!. Now daily driver street stuff I'll stick to the tighter clearances!..

[Blown to the Bone]

http://i132.photobucket.com/albums/q8/blowntothebone/XMASLUNATI014.jpg

[Fiat48]

I think it is more of "room to move" than oil cushion effect. The whole idea of looser clearances is to prevent that crankshaft from ever touching a main bearing. The slightest touch and the main bearing shrinks and wraps itself around the main journal. When that happens you get the spun bearing blues.
In theory, as long as you have the oil wedge between the crank and the bearing this cannot happen.
Yet spun bearings do happen and I have seen it when there was no oiling problem. Fought these issues for years on the blown stuff. I don't have all the answers but here are the things I found at the cost of a lot of spun bearings and hurt blocks:
#1. The drag cars are harder on the main bearings than the boats. I attribute this more to burnouts and the high load the crank sees at the starting line with a pair of planted slicks.
#2. The shorter the stroke the better the bearings look. I attribute this to leverage.
#3. The stiffer the crank (Lunati, Cola, Callies, Crower, etc) the better the main bearings look. I attribute this to crank rigidity.
#4. Main bearing caps move. Regardless of studs or bolts. Mating surfaces are etched with metal transfer iand caps no longer fight tight in their locaters is the proof. If things are moving...what happens to your clearance?
Maybe the splayed cap stuff is better. I sure hope so. And maybe the dowel pin merlins are better. I have no proof of that yet.
#5. Internal balancing helps main bearing life.
#6. Chevy cranks are the worst flexers. The older(pre 80's) cranks flexed less the newer cranks. An example of that is I fit one at .003 on the mains. Spun a main bearing. Caught early I turned the crank and saved it. Went .0035.
Spun that in about 4 runs. Turned the crank again. Now .004. The crank lived 2 years in blown alcohol.
Another "test" was a very rigid block (P&S cast iron) and a Cola 4340 crank in the Fiat. Mains fit at .003. 5 runs at 190+ mph and took it apart. 2 main bearings had touched and one had actually shrunk. One more run and she would be gone.
Current test is the motor in the flat. Dart splayed cap block, Lunati 4 inch crank. Fit at .0035. At 10 runs in the flat (8000 rpm or so) the main bearings were as good as I have seen. So it has been together for 3 seasons now. It comes apart this year to see what is going on.
Bear in mind that I have my own machines so there are no machinest variables, rod bearings always looked so good you could get a refund on them so these motors were not pounding themselves to death and these were blown alcohol motors at pretty good rpm's. So I think the many tests done over years is pretty accurate.
Perhaps you will see why I think loose is better than tight. I don't like the excess oil flying around either but it is better than a spun main bearing.
And if you were ever wondering.....the nostalgia nitro guys that run the BBC...they told me they run .005 on the mains. Only way they could keep them together.

[wsuwrhr]

Right click/save as. Good info to know.
and....
Damn at .005 you might even be able to hear the crank slopping around when you rotate the motor on the stand.
Scary
Brian
And if you were ever wondering.....the nostalgia nitro guys that run the BBC...they told me they run .005 on the mains. Only way they could keep them together.

[058]

One thing that hasn't been addressed is expansion rates of cranks/blocks. Clearances are checked with parts at room temp. What happens when the parts get to operating temp of 200-250 deg? Do the blocks [iron for this excersize] expand at the same rate as the cranks? Do different materials, say a SAE 1060 steel expand the same as a 4340 steel? If, for example, a .003" main clearance is used checked at 70 deg. what would that oil clearance be at a block, crank temp be at 230 deg. or more? We all know that aluminum blocks have to be set up looser than a iron block to compensate for the much greater rate of expansion of aluminum but little has been said for iron/steel or iron/iron.

[WannabeRacing]

One item that may be worth touching is the volume of oil flowed. The larger volume of oil flowed through the bearings, the cooler the oil when finishing it's engine cycle and hitting the reserve in the pan, then back through the entire thing again. When you run an oil cooler, there are definite pros to running larger volumes of oil due to wider clearances. The oil flows faster through the system. It does not heat up as much in the engine and does not cool down as much in the oil cooler. The oil temp leaving and incoming are more even and consistant. Problems have been seen with really hot oil leaving and cold oil incoming. Hard on the bearings when the oil coming in is too cold. Spoke to one SuperStock boat builder that said he wanted oil coolers off his engines because he saw this too many times.
But then note that crappy oil filters cannot handle the increased capacity of an .004 clearance. Time to step it up boys. No more $1.99 Checker auto paper specials. Time for an inline, or a System1 style spin on.
And 058 is dead on with the swell rates, etc. Billet caps do not grow the same as iron caps. Bill Mitchell stated that he prefers iron caps to billet caps. The growth is the same. Titanium caps are not growing much at all. What block are you running? How strong is the block and how can it stay true? If you block tends to flex more, you may need more clearance. . .etc. Not to mention thrust.

[Moneypitt]

In keeping with the thread, I was just mentioning how grinding the counterweights (making them shorter) instead of drilling the crank counterweights was a cool way to go about balancing it, that it was an interesting crank mod. Jay
You could remove some material from the entire surface of the counterweight, but the holes and heavy metal additions are placed at a specific point in the counterweight. Kinda like balancing a tire, the weight must go at a specific point on the wheel to counterbalance a heavy spot 180* away. (yeah, I know about triangulation). With a super light assembly I guess you could remove some of the entire weight, but you'll still have to isolate removal and addition spots.............MP

[WannabeRacing]

Grinding the counterweight to make it shorter is the super trick way to balance. When you get a huge dollar crank from Bryant or Winberg balanced to your bob weight, that is how they will balance. But this deal is not grinding, it is a specialty machine that leaves a perfect finish on the outside of the counterweight. Not a machine that you will see around town.
I have only seen this done successfully by a few companies. Two are listed above. I don't know that I would trust the corner machinist to try this one. Certain things should be left to the professionals, in my opinion.
I have a few of these cranks laying around if you would like to some by and see what I mean.

[Moneypitt]

Grinding the counterweight to make it shorter is the super trick way to balance. When you get a huge dollar crank from Bryant or Winberg balanced to your bob weight, that is how they will balance. But this deal is not grinding, it is a specialty machine that leaves a perfect finish on the outside of the counterweight. Not a machine that you will see around town.
I have only seen this done successfully by a few companies. Two are listed above. I don't know that I would trust the corner machinist to try this one. Certain things should be left to the professionals, in my opinion.
I have a few of these cranks laying around if you would like to some by and see what I mean.
I have no doubt those guys do it all the time, but to trying it on a 7414 GM forging could lead to lots of headaches........Garbage in, garbage out....MP

[Fiat48]

Yes..all the variables and expansion rates. Wondered many times. Actually I always wondered why not a 3 inch main in a BBC...aka like Ford.
Course we are all kinda abusing an original design truck motor in the first place.
I left something out in that last post. I always wanted to try a fully center counterweighted crank as I am sure that would mean a lot but there is no lottery to win in Nevada.
On turning counterweights...The Cola crank would not clear the P&S block at all. I actually cut the counterweights down and profiled them on a lathe......very slowly. Once I got it to clear I put it on the balancer...read it....then chucked her back in and cut some more. Pain...but no heavy metal in that deal at all.

[LakesOnly]

On a few notes above (I read this page only):
Yes, oil has to be warm to do it's job properly and effectively. Not just a lubricant, oil is also a cooling agent, a cleaning agent, an anti-corrosion inhibitor, acts as a seal, often serves as a hydraulic fluid (pressure-backed chain tensioners, hyd lifters, etc.), and even aids in cold starting (multi-viscosity knows when to be thin).
While technically cross drilling may indeed weaken a crank, wouldn't y'all agree that the amount of weakening is insignificant in most applications (relative to the crank's strength prior to cross-drilling)? That aside, there is certainly more than one way to skin a cat and get the same results w/o cross-drilling, such as using a main bearing with more groove around the shell's circumference...(same end result of increased oiling via cross-drilling).
3-inch main like a Ford? :D I haven't actually called Velasco to ask who all is doing this these days, but about 15 years ago a lot of the Top Fuel guys moved up to 3-inch mains because they were pounding the hell out of the smaller main bearings that they were running. The increased surface area of the larger main bearings provide improved support and bearing life.*
LO
p.s.: *By the way, don't no chebby guys give me crap about the Ford's 3-inch main bearings having a greater "bearing speed" than the chebby's. Bearings remain at a stand-still in the block and are proteced by a film of oil...a bearing's oil clearance can be adjusted for journal size and resulting effects. Oh, and if it's frictional losses you telling me that you are actually alluding to, then you may be surprised to learn that the 3-inch Ford mains have 8 square inches LESS swept area than the 2.75-inch BBC's.* :D
p.p.s.: * Sorry, I can't help my poor self...:redface:

[wsuwrhr]

No wonder why big chebby valve covers are so wide.
Damn Ford cranks.
Brian
Oh, and if it's frictional losses you telling me that you are actually alluding to, then you may be surprised to learn that the 3-inch Ford mains have 8 square inches LESS swept area than the 2.75-inch BBC's. :D

[Moneypitt]

On a few notes above (I read this page only):
[list]
p.s.: *By the way, don't no chebby guys give me crap about the Ford's 3-inch main bearings having a greater "bearing speed" than the chebby's. Bearings remain at a stand-still in the block and are proteced by a film of oil...
p.p.s.: * Sorry, I can't help my poor self...:redface:
The refered to speed relates to surface speed, larger circumference, greater surface speed. Not nesessarily a bad thing when all factors are considered..MP

[Fiat48]

I knew that would open into a Ford commercial but I really did expect Brian to say Chrysler don't have main bearing problems because they are designed better with more support around the mains and side bolts to support the caps. Plus I think the Mopar is 2.375 main journals.
LOL. Perhaps he will.

[LakesOnly]

By the way, don't no chebby guys give me crap about the Ford's 3-inch main bearings having a greater "bearing speed" than the chebby's. Bearings remain at a stand-still in the block and are proteced by a film of oil...The referred to speed relates to surface speed, larger circumference, greater surface speed. Not nesessarily a bad thing when all factors are considered..MPYeah, I know...just pointing out the misnomer(chuckle)...the point about frictional losses and improved support remains the same, though. ;)
LO

[wsuwrhr]

I was hoping noone took me serious.
I was just funnin with you guys. But since you want me to nut-swing on Dodge some more...
You guys have to know by now that Chrysler is the best anyway. I don't need to beat it into you.
The Y block design(probably stolen from Ford 312) makes for a strong bottom end. It adds a 100lbs of shit to the motor though.
I am not sure about your number, sounds small, I don't have to get into the bottem end of my RB's too often.
See Y block, above.... I'll check for you though.
Merry Christmas peeps
Since you were looking for facts....
Brian
I knew that would open into a Ford commercial but I really did expect Brian to say Chrysler don't have main bearing problems because they are designed better with more support around the mains and side bolts to support the caps. Plus I think the Mopar is 2.375 main journals.
LOL. Perhaps he will.

[LakesOnly]

I knew that would open into a Ford commercial .... I think the Mopar is 2.375 main journals.Bob, what can I say...I already apologized. :cool:
LO
p.s. Mopar rods are 2.375"

[wsuwrhr]

Does Olds 455's have bigger mains than Ford?
Just curious.
I seem to remember thinking they looked pretty big when I tore the Olds down when it spun a bearing, surprise, surprise.
Brian

[Fiat48]

Yeah I blew that crank size big time! I see 2.750 is the main size. Seems to me Olds was quite large and I think I remember the Arias deals used Oldsmobile journal sizes. Correct me if I am wrong.

[058]

Does Olds 455's have bigger mains than Ford?
Just curious.
I seem to remember thinking they looked pretty big when I tore the Olds down when it spun a bearing, surprise, surprise.
BrianOlds mains are 3", same as a BBF....Pontiac 455 mains are 3.250"

[058]

Yeah I blew that crank size big time! I see 2.750 is the main size. Seems to me Olds was quite large and I think I remember the Arias deals used Oldsmobile journal sizes. Correct me if I am wrong.Bob, another useless bit of trivia is the 460 Ford rear main seal will replace the old rope seal used on most Olds 455s.
Just another bit of info to file away under "useless sh*t" :D

[steelcomp]

http://i132.photobucket.com/albums/q8/blowntothebone/XMASLUNATI014.jpgI wonder what type of oil this is based on? Several Cup engine builders have said that you really need to adjust your clearances to the type and temp. of oil you're using. If you know that you run high oil temps, you need to set your clearances a little tighter. If you're running thin oil, like a lot of the new synthetics, you need to tighten up your clearances, and the opposite is true for either. Thicker oil, more clearnace, and low oil temp, the same. I also dissagree with the 10psi for every 1000 rpm. RPM is not the biggest factor for bearing load, it's HP. A better rule is 10psi for every 100 hp. Now mind you, this is all based on NA motors, and circle track motors at that. Add a blower on alky, and things change real quick.

[steelcomp]

One thing that hasn't been addressed is expansion rates of cranks/blocks. Clearances are checked with parts at room temp. What happens when the parts get to operating temp of 200-250 deg? Do the blocks [iron for this excersize] expand at the same rate as the cranks? Do different materials, say a SAE 1060 steel expand the same as a 4340 steel? If, for example, a .003" main clearance is used checked at 70 deg. what would that oil clearance be at a block, crank temp be at 230 deg. or more? We all know that aluminum blocks have to be set up looser than a iron block to compensate for the much greater rate of expansion of aluminum but little has been said for iron/steel or iron/iron.Coeffecient of expansion of steels and cast irons are very close, including stainless. Malleable iron has a CE of 7.5, Grey cast is 5.8, A 536 ductile irons are all in the 5.9-6.2 range, and cast steel is 7.0. Commercially pure Ti is at 5.1, Ti-5A1-2.5sn is 5.3, and Ti-8Mn is 6.0. Stainless from 3000 series to 5000 series is between 5.8 and 9.6 You can see these are all very close, and the expansion differences are in the 1-3 (a little more in stainless) millionths range. BTW...those numbers are millionths of an inch per inch per degree of change in temp.
A value of 6.2 = .0000062"/per inch per degree farenheit. In sum, they all grow at a very similar rate.

[Warp Speed]

p.s.: *By the way, don't no chebby guys give me crap about the Ford's 3-inch main bearings having a greater "bearing speed" than the chebby's. Bearings remain at a stand-still in the block and are proteced by a film of oil...a bearing's oil clearance can be adjusted for journal size and resulting effects. Oh, and if it's frictional losses you telling me that you are actually alluding to, then you may be surprised to learn that the 3-inch Ford mains have 8 square inches LESS swept area than the 2.75-inch BBC's.* :D
p.p.s.: * Sorry, I can't help my poor self...:redface:
If that Ferd 3 inch main was the way to go, that Big Block Ford would be the most popular race engine, not the stuff with smaller sizes ( aka Chevy, spelled with a V!).
And by the way, it isn't bearing surface area that matters in frictional losses, it is actual surface speed, in which case the larger stuff is worse!;)
Other than maybe some top fuel guy's, the rest of the racing world is going in the other direction, smaller and tighter!:jawdrop:
End of Ford commercial !!:crossx::D LMAO

[Warp Speed]

Coeffecient of expansion of steels and cast irons are very close, including stainless. Malleable iron has a CE of 7.5, Grey cast is 5.8, A 536 ductile irons are all in the 5.9-6.2 range, and cast steel is 7.0. Commercially pure Ti is at 5.1, Ti-5A1-2.5sn is 5.3, and Ti-8Mn is 6.0. Stainless from 3000 series to 5000 series is between 5.8 and 9.6 You can see these are all very close, and the expansion differences are in the 1-3 (a little more in stainless) millionths range. BTW...those numbers are millionths of an inch per inch per degree of change in temp.
A value of 6.2 = .0000062"/per inch per degree farenheit. In sum, they all grow at a very similar rate.
Nice info!!
Unfortunatly, we learned alot about different expansion rates this year, the hard way!!
50* engine block and internals meets lots of 375* oil, couple that with a little slippin' the clutch heat, and you can guess what happened to the rear main!!:mad:
Above mentioned materials grow at a similar rate, unless total mass varies and they are heated at greatly different rates!!:(
Then, things can stack up in a hurry!!

[steelcomp]

If that Ferd 3 inch main was the way to go, that Big Block Ford would be the most popular race engine, not the stuff with smaller sizes ( aka Chevy, spelled with a V!).
And by the way, it isn't bearing surface area that matters in frictional losses, it is actual surface speed, in which case the larger stuff is worse!;)
Other than maybe some top fuel guy's, the rest of the racing world is going in the other direction, smaller and tighter!:jawdrop:
End of Ford commercial !!:crossx::D LMAOLOL...you need to tell us what you really think.:D
Don't be too hard on Lakes...he really can't help himself. :)
If that Ferd 3 inch main was the way to go, that Big Block Ford would be the most popular race engine, not the stuff with smaller sizes ( aka Chevy, spelled with a V!).
Now you've done it. :notam:.

[Warp Speed]

LOL...you need to tell us what you really think.:D
Don't be too hard on Lakes...he really can't help himself. :)
If that Ferd 3 inch main was the way to go, that Big Block Ford would be the most popular race engine, not the stuff with smaller sizes ( aka Chevy, spelled with a V!).
Now you've done it. :notam:.
I was just kiddin' :redface: , I know Ford is spelt with an O !! :D :D :D :D:2purples:

[steelcomp]

One item that may be worth touching is the volume of oil flowed. The larger volume of oil flowed through the bearings, the cooler the oil when finishing it's engine cycle and hitting the reserve in the pan, then back through the entire thing again. When you run an oil cooler, there are definite pros to running larger volumes of oil due to wider clearances. The oil flows faster through the system. It does not heat up as much in the engine and does not cool down as much in the oil cooler. The oil temp leaving and incoming are more even and consistant. Problems have been seen with really hot oil leaving and cold oil incoming. Hard on the bearings when the oil coming in is too cold. Spoke to one SuperStock boat builder that said he wanted oil coolers off his engines because he saw this too many times.
But then note that crappy oil filters cannot handle the increased capacity of an .004 clearance. Time to step it up boys. No more $1.99 Checker auto paper specials. Time for an inline, or a System1 style spin on.
And 058 is dead on with the swell rates, etc. Billet caps do not grow the same as iron caps. Bill Mitchell stated that he prefers iron caps to billet caps. The growth is the same. Titanium caps are not growing much at all. What block are you running? How strong is the block and how can it stay true? If you block tends to flex more, you may need more clearance. . .etc. Not to mention thrust.I always wondered what came first...bigger clearances, or bigger oil pumps? As HP increased, and we added bearing clearance, I'm guessing oil pressure dropped. Increasing the pressure really didn't increase the volume, so that wasn't the answer, thus the Hi Vol. pump. If clearances are kept to a minimum, then the volume of oil needeed to do it's job, is less. Less volume, less pump requirement, less HP lost. I never used anything but a stock Ford pump on any of my engines as a kid, and I honestly don't remember ever having a bearing failure. (First bearing I ever spun was my 67 396 Chevelle.)

[LakesOnly]

If that Ferd 3 inch main was the way to go, that Big Block Ford would be the most popular race engine, not the stuff with smaller sizes ( aka Chevy, spelled with a V!). :crossx::D LMAOWarp Speed,
Main bearing journal size alone does not determine what engine is most suitable for a given race application.
429/460's are effectively eliminated in many forms of racing due to rules that prevent them from being entered in the first place, some rules which may be specifically intended (whether admittedly or not) to prevent the 460-based motor from being entered in the first place. (example: NHRA 4.84" max bore spacing)
Where they do run, the are often spanking the crap out of the chebby's http://www.fordforums.com/images/smilies/nutkick.gif
LO
But enough already! This is a crankshaft thread. :D Reply if you want, WS...I'll let it hang there; if you want to carry on with this sidebar and be enlightnened, then PM me.

[Fiat48]

Lakes...will I get to see the u know what boat run in 2007? Just asking.

[LakesOnly]

One way or the other, YES. All stops being pulled in favor of completion.
PM sent.
LO

[Warp Speed]

Warp Speed,
Main bearing journal size alone does not determine what engine is most suitable for a given race application.
429/460's are effectively eliminated in many forms of racing due to rules that prevent them from being entered in the first place, some rules which may be specifically intended (whether admittedly or not) to prevent the 460-based motor from being entered in the first place. (example: NHRA 4.84" max bore spacing)
Where they do run, the are often spanking the crap out of the chebby's http://www.fordforums.com/images/smilies/nutkick.gif
LO
But enough already! This is a crankshaft thread. :D Reply if you want, WS...I'll let it hang there; if you want to carry on with this sidebar and be enlightnened, then PM me.
Ok, I'll humor ya! "Enlighten" us on the ways of the world, and race engine technology. Sticking with the topic at hand, teach us about cranks and oiling systems. You might want to scroll forward a couple of chapters in your book, this is 2006, not 1986!:eat:
I'm all ears!!

[Taylorman]

I think it is more of "room to move" than oil cushion effect. The whole idea of looser clearances is to prevent that crankshaft from ever touching a main bearing. The slightest touch and the main bearing shrinks and wraps itself around the main journal. When that happens you get the spun bearing blues.
In theory, as long as you have the oil wedge between the crank and the bearing this cannot happen.
Yet spun bearings do happen and I have seen it when there was no oiling problem. Fought these issues for years on the blown stuff. I don't have all the answers but here are the things I found at the cost of a lot of spun bearings and hurt blocks:
#1. The drag cars are harder on the main bearings than the boats. I attribute this more to burnouts and the high load the crank sees at the starting line with a pair of planted slicks.
#2. The shorter the stroke the better the bearings look. I attribute this to leverage.
#3. The stiffer the crank (Lunati, Cola, Callies, Crower, etc) the better the main bearings look. I attribute this to crank rigidity.
#4. Main bearing caps move. Regardless of studs or bolts. Mating surfaces are etched with metal transfer iand caps no longer fight tight in their locaters is the proof. If things are moving...what happens to your clearance?
Maybe the splayed cap stuff is better. I sure hope so. And maybe the dowel pin merlins are better. I have no proof of that yet.
#5. Internal balancing helps main bearing life.
#6. Chevy cranks are the worst flexers. The older(pre 80's) cranks flexed less the newer cranks. An example of that is I fit one at .003 on the mains. Spun a main bearing. Caught early I turned the crank and saved it. Went .0035.
Spun that in about 4 runs. Turned the crank again. Now .004. The crank lived 2 years in blown alcohol.
Another "test" was a very rigid block (P&S cast iron) and a Cola 4340 crank in the Fiat. Mains fit at .003. 5 runs at 190+ mph and took it apart. 2 main bearings had touched and one had actually shrunk. One more run and she would be gone.
Current test is the motor in the flat. Dart splayed cap block, Lunati 4 inch crank. Fit at .0035. At 10 runs in the flat (8000 rpm or so) the main bearings were as good as I have seen. So it has been together for 3 seasons now. It comes apart this year to see what is going on.
Bear in mind that I have my own machines so there are no machinest variables, rod bearings always looked so good you could get a refund on them so these motors were not pounding themselves to death and these were blown alcohol motors at pretty good rpm's. So I think the many tests done over years is pretty accurate.
Perhaps you will see why I think loose is better than tight. I don't like the excess oil flying around either but it is better than a spun main bearing.
And if you were ever wondering.....the nostalgia nitro guys that run the BBC...they told me they run .005 on the mains. Only way they could keep them together.
So what are you running your rods at?

[Fiat48]

Rod bearings are not a problem area in a BBC. Desired .003. Have run at .0025 and .0035. Unless you are pounding them or metal goes through them...they will look like new on inspection.

[058]

Bob, Do you do your own cranks or do you have a local shop do them?

[Fiat48]

No I don't have a grinder nor the finese to do that operation. For years I had a good crank grind guy local who did a great job. Anymore I just buy the crank brand new or send it back to the manufacturer for repair.
I quit racing so I only build a few motors a year since then. Kinda retired. :)
PS: Got to thinking....the guy who did my cranks name was Armando. He moved to bay area about 5 years back and has his own place. When he was here he just worked for someone in a machine shop and traveled up here just to grind their cranks. You might ask around your area....maybe somebody knows him and where his shop is.

[LakesOnly]

Guys, I think he's in Redwood City; need to double check my notes when I get home...see if my memory is correct on the name.
058, I was led to a crank guy in RC named Armando when I was looking for a 429 truck crank. Armando pointed me to Mike at Ashland. ;)
LO

[Taylorman]

Why do the clearances have to be looser on the #5 main than on 1-4 mains?

[058]

No I don't have a grinder nor the finese to do that operation. For years I had a good crank grind guy local who did a great job. Anymore I just buy the crank brand new or send it back to the manufacturer for repair.
I quit racing so I only build a few motors a year since then. Kinda retired. :)
PS: Got to thinking....the guy who did my cranks name was Armando. He moved to bay area about 5 years back and has his own place. When he was here he just worked for someone in a machine shop and traveled up here just to grind their cranks. You might ask around your area....maybe somebody knows him and where his shop is.
Armando sounds familar or am I thinking of the pan guy? Could he be at East Bay Crankshafts In Hayward? I've never done business with E.B.C. as I have George Santos [S&S] do most of my work or Mike at Ashland if George is too busy. Lakes, Did Mike have any 429 cores? With all the cores he has I'm sure he had to have at least one in among that forest of cranks in his shop:D .

[Oldsquirt]

In the late 80's-early 90's, Armando worked for Al Leist Machine shop(across the street from where I worked at the time) in Burlingame before moving down the Peninsula to work at Elgin's in Redwood City, I believe. Wondered if he was still there. Fiat, did you say he was up your way for a while? Nice guy, a little "eccentric" back then. Did a bunch of my spare Healey cranks before leaving AL Leist.

[Fiat48]

He never lived here but came into town about every 2 weeks and would grind the cranks for Motor Machine (old machine shop here in Reno) on weekends. I knew he lived in the Bay area but not sure where. Lakes may be right that it was in Redwood city. Anyway I know he opened a shop and it may have been in Redwood city. When he repaired or even welded a crank with a bad journal you would paly hell ever telling he did it. The guy was just flat good at crankshafts and knew what he was doing.

[LakesOnly]

Still looking for the name.
Fiat, does the business name "CCR" ring a bell? Complete Crankshaft Repair, or Custom Crankshaft Repair? This is the name of the shop that I think is Armando's shop in Deadwood City. (Ask the guys at Motor Machine, they should know.)
LO