What do you run for bearing clearance?? According to what displacement and oil???

This is a 496, kinda cool I think in that it is being designed - assembled with the capability to run either hydraulic roller lifters or solid roller lifters on a 8620 billet cam core with a hydraulic roller profile. 10w 40 oil for either or 15w- 50 oil using solid lifters / tight lash.

PAC valve springs are 155 on the seat and 460 on the nose.

I've got a set of Crower solid roller lifters it's starting out with.

It's going in either a rotisseri 70 Nova or a 69 Camaro, both factory condition muscle cars. I've got a relative in Vegas who wants it and a long time friend who used to race with us at Sunshine, with the other engine for one of the two already in the works.

496 cid Aluminum Pro Comp 305's (oval port) assembled in Tennessee.

Main bearing clearance .0035 rear main .0030 fronts.

Rods .0024 .0026 vertical .003 .0033 lateral

Clay Smith hydraulic roller profile. Joy ride, choppy rough idle.

What is your approach on this? What displacement? Oil?

.0027”-.0032” was always the range I shoot for and the higher end on the mains.

I generally use 20-50 oil and I could care less what others use or recommend

That’s in BB engines generally with 80 lbs of oil pressure cold

A small block with less power and maybe a Stocker type engine I’m using 10-30 or 5-30 but usually would shoot for the lower end of bearing clearance.

Mobil 1 5-30 worked well in some engines I built and raced as in Stock eliminator cars.

Real good parts will look fine with less clearance I believe

Good cranks, good rods and blocks. Less flex, cap walk and clearance can be tighter with lighter oil and makes more power BUT !

Looser is safer and if your clearances are too loose nobody will know but if their too tight everybody will know !!!

An old saying but true.

Callie’s once upon a time packed an info sheet with their cranks and it said tighter was better and explained their reasoning for why. Leaning closer to .0020”

My co worker at the time built dirt track engines at home separate from our shop that built engines. He tightened his buddies engines clearance up after reading the Callies info sheet

That engine spun a bearing very shortly in its life

Loose is good tight is not ! Lol

quote:

Originally posted by SCDIV1:
.0027”-.0032” was always the range I shoot for and the higher end on the mains.

I generally use 20-50 oil and I could care less what others use or recommend

That’s in BB engines generally with 80 lbs of oil pressure cold

A small block with less power and maybe a Stocker type engine I’m using 10-30 or 5-30 but usually would shoot for the lower end of bearing clearance.

Mobil 1 5-30 worked well in some engines I built and raced as in Stock eliminator cars.

Real good parts will look fine with less clearance I believe

Good cranks, good rods and blocks. Less flex, cap walk and clearance can be tighter with lighter oil and makes more power BUT !

Looser is safer and if your clearances are too loose nobody will know but if their too tight everybody will know !!!

An old saying but true.

Callie’s once upon a time packed an info sheet with their cranks and it said tighter was better and explained their reasoning for why. Leaning closer to .0020”

My co worker at the time built dirt track engines at home separate from our shop that built engines. He tightened his buddies engines clearance up after reading the Callies info sheet

That engine spun a bearing very shortly in its life

Loose is good tight is not ! Lol

My approach is like yours, the wild card on this is hydraulic roller lifters are very reliable using 30 or 40w oil, not so much 50w oil.

Being these engines are gonna be able to use either, tolerances on what I can allow as far as loose, are limited.

I had to edit the original post from 468, I actually forgot which I was working on. This is a 496, it's getting a Crower "Beast" hydraulic roller profile on 8620 billet cam core.

The Crower won't have a iron gear staked on the billet core, so it'll need a melonized distributor gear.

We'll use a EverWear distributor gear with the Clay Smith cams.

The mains ended up a hair tight, but Amazon just showed with the xtra's, so the crank will be in it here shortly.

It’s fine to mix bearing 1/2’s to adjust clearance and I’ve done it all the time

I don’t mix brands though, always the same brand and usually Clevitte now Mahle I believe

King makes some nice bearings too. Coated

My own engine rebuild 2 winters ago I went thru about 4 sets of mains trying to get the clearance right. Tried coated, not coated, Clevittes, Kings

Was a major league PITA and cost time and money.....

Callie’s did not do me any favors on that one!

quote:

Originally posted by SCDIV1:
It’s fine to mix bearing 1/2’s to adjust clearance and I’ve done it all the time

I don’t mix brands though, always the same brand and usually Clevitte now Mahle I believe

King makes some nice bearings too. Coated

My own engine rebuild 2 winters ago I went thru about 4 sets of mains trying to get the clearance right. Tried coated, not coated, Clevittes, Kings

Was a major league PITA and cost time and money.....

Callie’s did not do me any favors on that one!

Worthwhile when it see's the track though! We had a Callies like that, runs good now though.

The Eagle cranks were horrible like that back in their early days.

I sold lots Lunati's cranks showing people they'd need lots of bearings, using Eagle back then.

Something has changed though, these china cranks come bad to the bone tolerance wise these days.

You can't discuss bearing clearance without exploring topics like oil viscosity, block material,bearing diameter etc.

Spinning a bearing is as easily caused by a dozen other issues as it is clearance. You should never change bearing clearance without understanding the affects on oil flow. Heat buildup with small clearances and heavy weight oil goes though the roof.

Small clearances are ran everyday....

Eagle cranks were so bad size wise, it was common to buy one and it was already ground .010 .010 under to save you the hassle of dealing with bad finish sizing and taper !

I bought one from Shafiroff like that. Brand new 010 010

Crank made many runs and was never a problem in a 460 BB and went in the 7’s with injection in my old dragster.

The Callie’s I had trouble with was just too small on the mains. Consistent size wise but mains were under minimum spec and it was brand new and a $2 grand+ magnum

I bought a rotator direct from Callie’s

I Was not happy but made it work and was told they grind them small

Small means small not UNDER min spec.

I waited 2+ months for that balanced rotator and was not gonna send it back !

quote:

Originally posted by NortonRacing:
You can't discuss bearing clearance without exploring topics like oil viscosity, block material,bearing diameter etc.

Spinning a bearing is as easily caused by a dozen other issues as it is clearance. You should never change bearing clearance without understanding the affects on oil flow. Heat buildup with small clearances and heavy weight oil goes though the roof.

Small clearances are ran everyday....

All true and I agree but we’re talking about basic race or street strip engines and you go with what works.

My V-10 Ford motorhome gets 5-20 oil and sees lots of rpm pulling hills with a trailer behind it

Ford built the engine and that’s what’s spec’d for it so that’s what I’ve used with zero problems

quote:

Originally posted by SCDIV1:
Eagle cranks were so bad size wise, it was common to buy one and it was already ground .010 .010 under to save you the hassle of dealing with bad finish sizing and taper !

I bought one from Shafiroff like that. Brand new 010 010

Crank made many runs and was never a problem in a 460 BB and went in the 7’s with injection in my old dragster.

The Callie’s I had trouble with was just too small on the mains. Consistent size wise but mains were under minimum spec and it was brand new and a $2 grand+ magnum

I bought a rotator direct from Callie’s

I Was not happy but made it work and was told they grind them small

Small means small not UNDER min spec.

I waited 2+ months for that balanced rotator and was not gonna send it back !

Yeah, I used these points to sell a few Lunati cranks, and GM back in the day.

I just picked up a Big Block Chevrolet 4.00 stroke GM steel crank a local crankshaft shop cut 10/10, this man did a beautiful job on it.

Excellent work.

Jewelry

Every engine shop in my area and for miles around sent cranks to one shop in NY State. Star crankshaft. One man did all the performance crank work. Fred Tobas and he was very experienced and had worked in California for Hank the Crank I believe. You could send him a crank and have him grind a half a thou to three quarters off it and he’d do it. We were a drop off spot for other shops and they had cranks done there. He did make a mistake or two over the years but generally did great work. They picked up and delivered once a week and I had them stop at my home when I was doing engines there. Drove there a few times and it was at least an hour ride so pickup and delivery was a big plus.

He offset ground a SS BB Chevy crank + .013 stroke and it was over that limit and was caught in tear down at Indy
The engine builder was a very famous NJ shop and the racer was one of his best longtime customers and friends.

A lot of unhappy people over a few thousandths of stroke !

The phone lines were burning up over that one !

I live in East Texas and have raced for many years at all the Dallas, Texas area tracks. Dallas is also the long-time home of R & M race engines, even back to the early days of Lee Shepherd, with the R & M Team being a solid force in Pro-stock. Many Dallas area racers have machine work, head work, and engines built at R & M. The knowledge and stories from that shop are often the topics of race day conversations.

The story goes that the team was in the last-minute rush to finish a Pro Stock engine and be off the event. So with a late Thursday night, dyno test and Lee said, "hmmm, the power is excellent, but something does not feel right, some vibration I do not normally feel" They cut open, the oil filter looked fine, no metal. They ran the vales, all OK, nothing had changed. So they install the engine, load up and drive to Houston for a Friday morning qualifying run.

At the races, the car ran well, qualified well, and they won the race. But, with each run, Lee would say, "I feel that vibration. It has never done that, and something is not right."

Monday back at the shop, they tore the engine down and discovered the crank was .010 under on the mains with standard bearings. David said the bearings looked new.

Even before that story, I always believed "loose is fast"

Anything is possible but that story is pretty hard to believe to be honest especially coming from one of the most experienced and famous teams of all time.

They still have a very good reputation and I’ve bought parts from them.

Bad to the bone rear main bearing clearance.

.0035 rear

.003 fronts

quote:

Originally posted by SCDIV1:
Anything is possible but that story is pretty hard to believe to be honest especially coming from one of the most experienced and famous teams of all time.

They still have a very good reputation and I’ve bought parts from them.

Ahhhh yeah, I'd say.

Looks like ARP has redesigned their BBC main stud. We had an old windage tray kit I planned on using the four for the tray. I think I'll machine these to look like the new ARP design at the bottom, before screwing them in the block.

As is now the threads are into the main cap when installed.

quote:

Originally posted by SCDIV1:
Every engine shop in my area and for miles around sent cranks to one shop in NY State. Star crankshaft. One man did all the performance crank work. Fred Tobas and he was very experienced and had worked in California for Hank the Crank I believe. You could send him a crank and have him grind a half a thou to three quarters off it and he’d do it. We were a drop off spot for other shops and they had cranks done there. He did make a mistake or two over the years but generally did great work. They picked up and delivered once a week and I had them stop at my home when I was doing engines there. Drove there a few times and it was at least an hour ride so pickup and delivery was a big plus.

He offset ground a SS BB Chevy crank + .013 stroke and it was over that limit and was caught in tear down at Indy
The engine builder was a very famous NJ shop and the racer was one of his best longtime customers and friends.

A lot of unhappy people over a few thousandths of stroke !

The phone lines were burning up over that one !

Wow! I can imagine!

Powermaster 9540 with 153 tooth sbc 350 Chevrolet flexplate, this thing oughta spin over like it has no spark plugs in it.

8 counter internal balance, why not. Speedway sent this billet flexplate, looks alright.

quote:

Originally posted by SCDIV1:
Every engine shop in my area and for miles around sent cranks to one shop in NY State. Star crankshaft. One man did all the performance crank work. Fred Tobas and he was very experienced and had worked in California for Hank the Crank I believe. You could send him a crank and have him grind a half a thou to three quarters off it and he’d do it. We were a drop off spot for other shops and they had cranks done there. He did make a mistake or two over the years but generally did great work. They picked up and delivered once a week and I had them stop at my home when I was doing engines there. Drove there a few times and it was at least an hour ride so pickup and delivery was a big plus.

He offset ground a SS BB Chevy crank + .013 stroke and it was over that limit and was caught in tear down at Indy
The engine builder was a very famous NJ shop and the racer was one of his best longtime customers and friends.

A lot of unhappy people over a few thousandths of stroke !

The phone lines were burning up over that one !

I remember Fred ! He did a couple of cranks for me and did a great job !

Both my rods and mains are at .0035" cold. Not sure how they ended up the same, but they did. Zero issues, billet crank and aluminum rods. Going to steel rods though, more expensive, but less worry about life cycles, etc...

quote:

Originally posted by Coloradoracer:
Both my rods and mains are at .0035" cold. Not sure how they ended up the same, but they did. Zero issues, billet crank and aluminum rods. Going to steel rods though, more expensive, but less worry about life cycles, etc...

I've run em like that works fine 50w oil. This engine is being built to run either solid or hyraulic roller lifters. I'm assembling with clearances in mind for 30, 40 or 50 w oil.

Hydraulic roller lifters perform better, last longer along with light weight oil.

I've actually got four engines I'm building currently, I'm doing this way.

Hydraulic roller profile on 8620 billet cam cores.

This message has been edited. Last edited by: Mike Rietow,