>Hello to tha list,
>
>I have a question regarding the installation of new cam bearing in a buick
>215 engine.
>
>I recently had my block gone through by a local engine/machine shop. They
>cleaned it, bored it .030 over, opened up the oil passages, decked it.020
>and resurfaced the heads and did the valves, etc..
>
>My problem is that they also installed new cam bearings. The shop owner told
>me that the only bearings they could get were the type that came all the
>same size and to properly install them required that they be reamed with a
>special reamer after they have been installed in the engine. The problem is
>that the shop did not have the special reamer and to get the cam to fit the
>bearings they "scraped" them to size (i don't know what they used to do this
>scraping).
>
>I find two things wrong with this procedure. First, I do not think that the
>scrapeing job was done very well. It looks terrible, (worst than the
>200,000 miles plus bearings that were in the engine originally) with scrape
>marks that go completly across the bearing surface. This can't be good for
>oil containment. Second, I am concerned with the various bearing centers
>being out of alignment since each bearing was sized independently of the
>others. This will place a side loading on the cam in the bearings and allow
>oil to escape in the loose side.
>
>Have any of you heard of this being an acceptable procedure?
>
>If not, what is the recommed way to install the bearings?
>
>Does anyone know of a company that manufactures the cam bearings that when
>they are pressed into place are the right size and do not require reaming?
>
>Does anyone know of a shop in the Denver area that can properly install the
>bearings?
>
>I'm readey to build the engine and need to get this corrected soon.
>
>Thanks in advance.
>
>Larry Diede
>Arvada Colorado
**********************************************
5/27/99
Larry,
I presume you saw the comments of the Becketts in reply to the
above. Though I am no bearing expert, I suspect that they are right on, at
least in regard to the relatively slow-moving, low-temperature conditions
encountered in old steam engines. I find such machines totally
fascinating, by the way. Anyhow, scraping was the standard method of
sizing automotive bearings as well, especially when the bearings were
"poured" (cast in place) rather than the replacable inserts we are familiar
with now. Whether scraping still has a valid place in today's engine
building seems questionable to me. There is, in my mind however, an
extreme overemphasis nowadays by most people, on the degree of surface
perfection of bearings & journals. To me the main concerns are trueness of
shape and correct oil clearance. And don't forget that the composition of
bearing alloys is supposed to provide a certain degree of conformability so
that minor irregularities can be tolerated.
All that said, my guess is that most would agree that you deserve
something better than it sounds like you got. As far as I know, there
shouldn't be any problem getting pre-sized bearings for that engine. For
starters, I suggest Dura-Bond part numberB-11. Dura-Bond is located at
3200 Arrowhead Drive/Carson City, Nevada/89706. 800/227-8360. If you
call, you may be able to locate a source near you. I can't imagine why
there should be any problem finding them from any of the other major
suppliers. This just doesn't make any sense to me. The same set fits
Buick 300, 1966-67 Buick 340, and all Buick 350 engines--maybe others? My
suggestion is that you pursue this.
Regards,
David Kernberger
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