Builders......Main clearances checked what to do now.

[m233roller]

Thanks Nick and you are exactly right, I also have seen terrible bearings when set up tight compared to alittle more clearence. As far as STP goes I DON"T think about it , I KNOW from Experience and what has worked for me, it's just that every time someone talks .002 others jump right on with NO-NO you won't have good oil pressure. If you and I'm sure others have good luck with tight settings GOOD go for it.Yes Dave is asking for opinions and I gave him mine in post #4. Also how many guys are just building a drive to the grocery store engine? HELL we ALL run the living daylights out of these poor little engines.

 

[TurboDave]

This thread is still alive so I'll post this here.

The saga continues.

I decided to test fit the old bearings and measure them, both with mic/bore gauges, and compare that to plasti-gage.

Old bearings
mic/bore
#1 .0015
#2 .0020
#3 .0025
#4 .0026


Old bearings
plasti-gage
#1 .0015
#2 .0015
#3 .0010
#4 .0015


New bearings
mic/bore
#1 .0017
#2 .0024
#3 .0020
#4 .0020

New bearings
plasti-gage
#1 .0015
#2 .0015
#3 .0010
#4 .0010


I've done these measurements at least twice with each set of bearings and the readings are what they are.

The only real consistency I seem to be able to achieve is with the plasti-gage, and that with the new bearings.

So on the advice of one of the many experts I put my trust in, I decided to scotch brite the new bearings a little bit, with a little more attention to 3 and 4, clean them up real good to keep any scotch brite from ending up where it doesn't belong, in an effort to loosen them up a slight bit and to get rid of the marks left by the dial bore gauge.

 

[STP]

Let us know how she runs Dave....Should last you another 100k miles. I see you are from Sevierville. Correct me if I'm wrong, but isn't there a fella named Bill Ragland from Sevierville? Is he still into these things? Been years since I talked to him...

 

[LOT]

This thread is still alive so I'll post this here.




I've done these measurements at least twice with each set of bearings and the readings are what they are.

The only real consistency I seem to be able to achieve is with the plasti-gage, and that with the new bearings.


I am a firm believer that if you don't use mics everyday ( for a living) it is very hard for a person like me to get the FEEL of them. Plasti-gage don't lie.
Plasti-gage will repeat time and time again (for me @ least). You need a machinest to measure them--would be interested to see what he gets. (I'm assuming you're not one). Best of luck.---Lee

 

[TurboDave]

I am a firm believer that if you don't use mics everyday ( for a living) it is very hard for a person like me to get the FEEL of them. Plasti-gage don't lie.
Plasti-gage will repeat time and time again (for me @ least). You need a machinest to measure them--would be interested to see what he gets. (I'm assuming you're not one). Best of luck.---Lee

No, not a machinist, just have "most" of the necessary measurement tools. The one thing I don't have is a set of ring gauges to ensure that my bore gauges are set properly. Richard was most gracious in offering to send me any ring gauge I would need, the return shipping is a killer.

When I take the block in to get the cam bearings installed I might just have him measure the mains with bearings installed.
I have absolutely now problem with outside mics. It's the dial bore gauges that I may not be getting set perfectly.

 

[A2000RICH]

No, not a machinist, just have "most" of the necessary measurement tools. The one thing I don't have is a set of ring gauges to ensure that my bore gauges are set properly. Richard was most gracious in offering to send me any ring gauge I would need, the return shipping is a killer.

When I take the block in to get the cam bearings installed I might just have him measure the mains with bearings installed.
I have absolutely now problem with outside mics. It's the dial bore gauges that I may not be getting set perfectly.

actually plastigauge can give you wrong readings----------it is inherently non linear but will do a fair job when used within its range spec--------as long as you get a reasonable reading you can be comfortable with it---------especially if you can double check it with mics----------the readings you have posted should be just fine----------i agree the lower end of the Buick spec is really scary----------.0003 on mains----------a few years ago i carefully took 3 brand new crate engines apart to measure the clearances--------out of 3 engines the tightest bearing i found was .0009 on one main only-----------i did this with a pratt and whitney supermicrometer that cost upwards of 25K so i know its dead on----------while i was at it i did the same engines with a standard mic and bore gauge as well as plastigauge---------results were interesting----------sometime i will look them up but actually i think a couple years ago i posted some of this on the forum already----------one thing is certain if you go below .001 EVERYTHINHG better be perfect-------no taper or out of round and better keep the oil viscosity no higher than 30...............RC

 

[dentmasters01]

Let us know how she runs Dave....Should last you another 100k miles. I see you are from Sevierville. Correct me if I'm wrong, but isn't there a fella named Bill Ragland from Sevierville? Is he still into these things? Been years since I talked to him...

Bill is actually from Shelbyville TN. I was at his house today and he is doing fine. He still has his black car with the staged motor and is still *** deep into these things ! :biggrin:

 

[STP]

Yea that rings a bell now...Good to know he's doing well. I know he kinda got out of it when his racing buddy passed. Back in the early to mid 90's I used to see him down here at some shootouts. Always nice to talk to....Thx for the heads up.

Sorry for the hijack Dave....Back on topic

 

[turbofabricator]

-----------i did this with a pratt and whitney supermicrometer that cost upwards of 25K so i know its dead on----------RC

Are you SURE it wasn't a JC Whitney micrometer?:biggrin:

I have MANY MANY busted knuckles working on BIG Prat's. My favorite was the R2800 radial. Blow a jug (cylinder) off and keep flying. (well for a little while anyway.) Try changing spark plugs on one of those in a day..............uuummmmm........you want it WHEN??? (36 spark plugs)

 

[A2000RICH]

Are you SURE it wasn't a JC Whitney micrometer?:biggrin:

I have MANY MANY busted knuckles working on BIG Prat's. My favorite was the R2800 radial. Blow a jug (cylinder) off and keep flying. (well for a little while anyway.) Try changing spark plugs on one of those in a day..............uuummmmm........you want it WHEN??? (36 spark plugs)

i don't think its the same pratt and whitney as the airplane folks------Pratt and Whitney Measurement Systems appears to be totally different------they make ultra precision measuring devices

 

[GARY HARVEY]

Try this...
Measure the bearings in the block without the crank, same with the rods, then measure the crank (without it being installed) and do the math.

Why.. I don't know, it's just the way I've seen it done for years by two GM Hall of Fame members I spent a great deal of time with back in the 60's and up until their passing and a few other builders
for which I had a great deal of admiration.

Question: Why isn't Howard Gilbert in the GM Hall of Fame?

 

[Mac in SD]

Try this...
Measure the bearings in the block without the crank, same with the rods, then measure the crank (without it being installed) and do the math.

Why.. I don't know, it's just the way I've seen it done for years by two GM Hall of Fame members I spent a great deal of time with back in the 60's and up until their passing and a few other builders
for which I had a great deal of admiration.

Question: Why isn't Howard Gilbert in the GM Hall of Fame?

Hey, maybe you should coat them with a black polymer DuPont Indusrtial non-food grade coating!

 

[GARY HARVEY]

only with a stock crank.

 

[TurboDave]

Try this...
Measure the bearings in the block without the crank, same with the rods, then measure the crank (without it being installed) and do the math.

Why.. I don't know, it's just the way I've seen it done for years by two GM Hall of Fame members I spent a great deal of time with back in the 60's and up until their passing and a few other builders
for which I had a great deal of admiration.

Question: Why isn't Howard Gilbert in the GM Hall of Fame?

That's what I've done. Mics to measure the crank, dial bore gauges to measure the the mains (properly torqued of course), but setting up the dial bore gauge touchy.

 

[GARY HARVEY]

Someone that to size the rods to the same dia.?
(I like a Sunnen).