Flex Plate

[grant schaffer]

So, here is what I found on the crank, I had to remove the pan and the oil as well as the crank as it needed to get balanced with the late model off
hole location flexplate. reason for some reason in my 1972 455 block there is installed a 1968 -1969 odd ball nodular iron crankshaft that was only
made for two years. Isn't that just my luck. so odd ball crack in a 1972 455 block, and now balanced with a flex plate with two hole drilled oversized
as the only flex plate available for this crank is a sfi racing flexplate that is $350.00

1" wide.
397363 455 '68 - '70 Nodular iron. 'N' on front weight

so word to the wise not everything is what is should be and yes for some reason there are some engines out there that have mis matched parts.
so another $400.00 added to the engine build as it has to balance between the flexplate crank and balancer. $10,000 and climbing and no end to the
bleeding. one of these days ill be able to drive my coach again.
--
1974 GMC Sequoia 26'

 

[Matt Colie]

> So, here is what I found on the crank, I had to remove the pan and the oil as well as the crank as it needed to get balanced with the late model
> off hole location flexplate. reason for some reason in my 1972 455 block there is installed a 1968 -1969 odd ball nodular iron crankshaft that was
> only made for two years. Isn't that just my luck. so odd ball crack in a 1972 455 block, and now balanced with a flex plate with two hole drilled
> oversized as the only flex plate available for this crank is a sfi racing flexplate that is $350.00
>
> 1" wide.
> 397363 455 '68 - '70 Nodular iron. 'N' on front weight
>
> so word to the wise not everything is what is should be and yes for some reason there are some engines out there that have mis matched parts.
> so another $400.00 added to the engine build as it has to balance between the flexplate crank and balancer. $10,000 and climbing and no end to the
> bleeding. one of these days ill be able to drive my coach again.

An issue like this in my early engine building is why I always keep a damper/crank/flywheel as a set.

There is a local guy that took an engine from me for evaluation. He brought it back and I gave him back his deposit, then I noticed that the
flexplate was missing. He has refused to return that or the lube oil pump. He is on my Shix list.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[johnny]

Matt, is this asshole a GMC Person or just a local turd?

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell

 

[Matt Colie]

> Matt, is this asshole a GMC Person or just a local turd?
>
> --johnny

Just a local guy. If I heard he was looking for a coach, I would do my best to discourage him.
Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[johnny]

Well, whyncha go get your stuff back?

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell

 

[Matt Colie]

> Well, whyncha go get your stuff back?
>
> --johnny

Because I don't know where he actually lives and that flex plate was on a bad cast crank and I have more important things to do.
But a good ask.
Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[grant schaffer]

I certainly hope you are not talking about me! Quite frankly I would have no use for a crank and a flexplate by them selves as our coaches are too
valuable and BTW i have ownerd my coach for 7 years now so certainly wouldnt be part of your "asshole" discussion.

Also, after taking the pan off due to my builder having to rebalance the crank assembly there are some 455's out there that have 68 and 69 cranks
installed which has a different flexplate.
--
1974 GMC Sequoia 26'

 

[dave king]

A question to Matt C and the other engine GURUs. With a V8 engines, I® understand that the
weights of the rods and pistons are part of the balancing equation. Does this mean that
An engine that might not have been balanced or parts of the assembly that goes together
In the to be balanced assembly are missing that the whole process of weighing all the rods, piston pins, pistons, bearings must all be done completely
from scratch again?
--
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada

 

[hal stclair]

Not necessarily, If you need to replace a component, flex plate, balancer they can be spun separately, a piston or rod can be balanced but you'll have
to know the weights so the motor will need to be disassembled to check unless someone made and kept all the weights which I don't think I've ever
witnessed. Kind of an unusual circumstance to replace an individual internal piece though.
Just my thoughts, Hal
--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1975 Eleganza II, 101230,

1974 Eagle Bus 45',w/slideout,

Rio Rancho, NM

 

[Jim Hupy]

Hmmmm? Engine Balancing. Inline 4 cyl are one thing, V-4 another. Inline
6, quite another. V-6 dang near impossible. Straight 8, different deal as
well. V-8, which we are dealing with, is kinda like 2ea 4 cylinders hooked
onto the same crank.
Some basic rules do apply across the board. Pistons need to be the
same weight, as do upper ends of the rods, lower ends of the rods. Rings,
pins, crankshaft counterweights, all reciprocating mass, all rotating mass,
etc. You can balance for static (stationary) mass, reciprocating mass, and
on and on. Yes, one piston can be replaced, with an exact duplicate of what
is replaced. Flywheels can only be mounted a certain way, same with front
compensating pulleys. Too technical to go into specifics here. Lots of info
out there on the internet. Enough to keep you reading for weeks. Confused
yet? Just wait until everyone jumps in here.
Jim Hupy
Salem, Oregon

On Sat, May 9, 2020, 8:17 PM Hal StClair via Gmclist <

> Not necessarily, If you need to replace a component, flex plate, balancer
> they can be spun separately, a piston or rod can be balanced but you'll have
> to know the weights so the motor will need to be disassembled to check
> unless someone made and kept all the weights which I don't think I've ever
> witnessed. Kind of an unusual circumstance to replace an individual
> internal piece though.
> Just my thoughts, Hal
> --
> 1977 Royale 101348,
>
> 1977 Royale 101586, Diesel powered,
>
> 1975 Eleganza II, 101230,
>
> 1974 Eagle Bus 45',w/slideout,
>
> Rio Rancho, NM
>
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