bence13_33

I spent 5 hours (I'm a slow worker) last night checking the clearances and installing the crank. A lot of the time was spent checking the clearances. My clearance was .0030" on caps 1-4 and .0034" on cap number 5. What do you guys think...the clearances are a bit on the "loose" side. I made sure the studs bottomed out but didn't snug them down, they were only hand tight. I then torqued the main caps to 90ft lbs. I did this by starting at 20ft lbs and moving up by 10ft lb incriments. I followed the book "How To Rebuild Your Big Block Chevy" word for word.

After all of my clearances were checked I removed the crank, installed the rear main seal, put some motor oil all over the bearings and the crank journals and layed the crank back in and torqued the main caps back on. With the bearings lubricated I checked the crank to see if it spun freely, it spins nice and smoothly with no hang-ups. What do you guys think? I don't have a feeler guage so I couldn't see exactly how much end play there was with the crank. :cheers:

P.S. I'm gonna have to snap some photos.

*EDIT*
I almost forgot to ask, I was almost certain but not 100% sure of this next question. The studs that I have a for a windage tray. I installed the windage tray studs on caps #3 & #4....did I install them in the correct caps or did I make a boo-boo? :confused:


[Modified by bence13_33, 10:08 AM 2/15/2002]

Neo Fender

When you finally do your final assembly (prior to first startup), I'd suggest some type of assembly lube or moly grease. It's thicker and it will cling to the bearings longer than oil will.


[Modified by Neo Fender, 10:19 AM 2/15/2002]

gkull

You need to beg, borrow, or steal a magnetic base dial indicator. Then you set it on the front of the block and the dial point on the crank and use a pry bar to move the crank fore and aft.

It will make a difference to know that your in correctly. Your bearings last longer and your timing chain is not moving back and forth when your on and off the gas.

It's the little things that count. Because you can't correct it when the motor is in


[Modified by gkull, 11:04 AM 2/15/2002]

Smokehouse69

I don't know if you have an Autozone or O'Reilly's anywhere around your town, but you should be able to borrow one from them. Leave a deposit, get the dail indicator, get your deposit back when you return it.

norvalwilhelm

The clearances are a little loose. You could have gone .001 tighter but it will run fine like this. Invest in a good assembly lube. It stays on longer then oil. Are you going to pre-oil the motor before firing. I have a old modified distributor that I drop in just before firing the first time every spring, preoil the motor then drop in and fire the motor right away.
Get the assembly lube at least for the rods and wrist pins.

bence13_33

I just noticed that I have some Clevite lube that came with my crank (machine shop must have thrown it in). It says it's used for bearing break-in. Should I take the main caps off (again) and coat the bearings with this stuff?

norvalwilhelm

You've already torqued the mains down with the studs . It would be a difficult job removeing each main. Forget it but pre lube the engine before and I mean right before firing it and don't forget the assembly lube on the rest of the parts.

fauxrs

Did you apply any lube to the studs while torquing them? It is the only way you can assure a good reading. I know arp provides different torque settings depending on what lube you use on the threads - I only use moly lube for this as it tends to be the most consistant.

Also did you line hone the mains after installing the studs and torquing the caps on? this is also a recommended step to ensure that the increased clamping forces that the studs allow do not create small distortions in the main caps and webs.

bence13_33

Yes, I used ARP's assembly lube on the studs. No I did not line hone the mains. I don't have the materials to do the line hone. I'm glad to crankshaft installed though. My uncle was right, the hardest part is getting the rotating assembly installed.

I might try to install the pistons, rods and rings this week end. Do you guys have any advice. Thanks!

mountainmotor

Bence,
Did you wash the crank really good after getting it back from the shop? Blow through the journals?We have one of the best machine shops in the US here in town and still I get a little debri out of them.
The mains and rod bearings have a crush built into them .It is OK to remove the crank to put the lube on it.It will need it because the motor will be turned many times on assembly.The crush only leaves after many miles of running.

Also the extra clearance you have is great because you will need a heavier weight oil to keep the cam alive for all it's life.Need the clearance for high RPM as well.

Right now is the time for for 3 additional free oiling mods and a different tip for cam break in .Tips for ring orientation also.Also need to manually set the thrust bearings before rods are installed.Email me if interested.

That block needs align honed.The only way not would have been if it was checked by the shop?Good way to break a crankshaft.





[Modified by mountainmotor, 5:15 PM 2/15/2002]

Steve439

Hey Bence, that's sounds great. Spending five hours means
you care enough to do it right.

Hope I'm not too late, but something that hardly ever comes
up is the fact that ARP recommends torquing and loosening
new fasteners FIVE TIMES before the final assembly.

So if you're going to loosen it you can follow the advice given
here and use the bearing lube.

I'm sending off an e-mail to mountainmotor about those mods -
sounds great...

bence13_33

mountainmotor:
I'm not going to have it aline honed. I've read in numerous books and talked to tons of people who say this is overkill. It's a little late now anyway with the crank in the block. Thanks for the suggestion though.

P.S. I just spent the last two nights (probably about 10hrs worth) assembly my pistons and rods and checking their bearing clearances. These were a little tighter than the main bearings, they checked in around .002". I cut my hand like mother too. I was trying to get the bearing cap off one of the rods and my hand slipped off and hit the sharp skirt on the piston :eek:....cut right through the meat. I guess it comes with the territory though ;)

I'm waiting for my uncle to come over some time this week to help me put the rings on the pistons and get the end gap correct. It's really starting to come together :cheers: .

RatRacer

Bence, With .030" and .034" clearance on the mains you will have about 17psi oil pressure at idle even with straight 50wt oil. I would stop now and go back in and install .001 under main bearings. I can tell you from experience that you will be better off pulling the crank back out now and installing the tighter bearings.

Don't be worried about redoing it at this point, it's a lot easier to do now than when the engine is in the car and you have low oil pressure at idle.

yellow 72

Bence posted .0030 to .0034 not ..030 to .034 :cheers:

RatRacer

just a typo.

ddn

I disagree. Everything I've read says it's a key step in building a serious engine correctly. Just THINK about what it does for a second. IMHO align honing is one of the more important "extras" you can do.

You really need to invest in some Mechanix gloves. It shouldn't come with the territory. Best $20 I ever spent.

Tom454

Align honing is only necessary if you change main caps, or if the saddles are out of "alignment". That is why it is called "align" hone. This step is rarely necessary, and in most cases is overkill. Same as decking the block... only needed if there is a problem... otherwise, overkill (and a nice moneymaker for machine shops). You made the right desision on that one.

The .003 clearances are a little loose...you are pushing the envelope on those. A crank is not like pistons where clearances depend on forged/cast status... a racing engine does not run bearing clearances "loose".

If you had the crank polished, and it is consistently at .003 using a snap gage and micrometer, or an inside mic, then you can get .001 undersize crank bearings. If you used plastigage, then all bets are off. I have been building engines for over 35 years, and I have yet to get a consistent, reproduceable, reliable plastigage reading. I use it only to occasionally ball park bearings when my gages are not available, usually at someone elses garage. I wouldn't go with .001 bearings though unless you are absolutely sure you have >= .003, and that the crank is .003 all the way across the journals. If the plastigage gives you inconsistent readings across the entire width of each journal, then it's time to measure it with mic's.

Signed... "professional engine builder".

mountainmotor

Quote by professional engine builder:
"Align honing is only necessary if you change main caps, or if the saddles are out of "alignment". That is why it is called "align" hone. This step is rarely necessary, and in most cases is overkill. Same as decking the block... only needed if there is a problem... otherwise, overkill (and a nice moneymaker for machine shops). You made the right desision on that one."

If you had not signed that way would have tought you a little about big block Chevy. I gave Bence a rare oppurtunity to call me on the phone to find out why I thought it needed to be at least checked and more that he could do to enhance his project and make certain the motor will live.He has declined and that is fine by me.It his his engine and his money.Can't sat I sat idle and watched as things went bad.

No flames intended but you guys that read books,built a few 400 hp motors and are now the masters of all have spoke/worked with machine shops of the like really don't know as much as you think.

Usually tips or building secrets/tips are kept among the the rightfull owners of the knowledge from experience/money spent or being around the big boys..I have offered freely until now.Really just come here to help those in need not to act like a know it all but doubt you or anyone else on this forum can teach me anything about the big chevy motor.I have seen too many feet in mouths here to think different.

There are a some here that really are in the know of things-deep inside they know who they are.

Anyone that can post about Moraine bearings/history will gain my respect as a knowledgable ""builder"".No replies = your are out of my league.Out of respect,this does not apply to Ganey my friend for years and the select others in the know

Again,no flames intended.This no typer here"me" is tired of being challenged by wannabe's.Tired of trying to help as typing taxes me.Takes me 30 minutes to type what I can relay in 2 minutes.Guess it is because I really do want to help see these guys succeed but tired of defending myself

To my friends here on the forum,keep in touch! I am taking a break from this B/S!

Bob Turner

Mountainmotor,

I can see your frustration. I am having a reputable machine shop put together my BB since I have absolutely NO knowledge of clearances of installing a crank or any of the IMPORTANT things to do when putting together a shortblock.

You were a great help to me though. Regarding those Comp Cams' 924 springs and NOT taking out the inner spring... I reviewed what you said about the small differences in spring rate between the 924 dual spring and the 911 spring. I WILL BE taking your advice and NOT going through all that work of re-installing the inner spring after break-in since the difference is minimal. However, if I had the 930's, I would have to do so. I thank you for the input as you did help. I also asked the machine shop to drill that #20 hole that you mentioned. They have done that in the past and I am grateful for you input on that as well.

Some may take your advice, some may not. Don't give up trying to help some of us!!

Here is the post:
http://forums.corvetteforum.com/zerothread?id=224981

Bob :cheers:

The Dude

Sounds like your work is in parallel to my re-do of Project Problem Child. It took me about 4 hours to get the crank installed. Since Plastigauge is all I have I used it. All me clearances on the main journals were comfortably within spec for the 406:

1. .002" (spec = .002" - .008")
2. .0015" (spec = .001" - .0023")
3. .001" (spec = .001" - .0023")
4. .0015" (spec = .001" - .0023")
5. .003" (spec = .0017" - .0033")

Crank endplay was .0025" on a spec of .002" - .006".

I agree with the earlier poster: Coat the bearing surfaces with assembly lube and not oil. The oil will run off and you'll have some metal-to-metal contact on initial startup even if you prime it.

I got No. 1 cylinder's piston re-ringed last night. I'll check clearances and install this afternoon or tonight.

I will say this about professional engine builders. When they're on their game they're worth the money. When they're not--or when they're hurried--you don't necessarily know what you're getting. My ring end gaps, for example. They're all over the place. I'm rebuilding using the same rings that JE recommends with my pistons and the spec sheet that came with them. According to those numbers and my application, my top ring ought to be gapped at .021" - .023", my second ring at .018" - .021" and my oil rails should be a "minimum of .015".

Disassembly of this particular pro's job has revealed a certain, um...lackadaisical attitude toward ring gaps. My top rings have ranged from .020" to .031", second rings have ranged from .020" to .025" and the oil rails had been opened up to a very loose .040" for some reason when they come right out of the box at .035" inside my 4.155" bores.

This ring-gapping strategy--and the old trick of inadequately sealing the spayed main cap studs that enter the water jacket so coolant leaks into the oil on initial startup--must be some of those tightly kept and mystical "speed secrets" so dear to, and coveted by, The Keepers of Knowledge. There's one thing I've discovered about this hobby over the years, and it's this: Everybody who has ever stepped foot inside a machine shop is an "expert." And all the other "experts" are wrong. :lol:

I'm setting my gaps at .022" top, .020" second and leaving the oil rails at .035" for uniformity's sake. Other folks might have different ideas, but I'm defaulting to manufacturers' spec. range on these.

I think if you (and me) work carefully and slowly we'll get some good results. Good luck to you and keep us posted.



[Modified by The Dude, 12:53 PM 2/17/2002]