FAQ |
Members List |
Social Groups |
Calendar |
Search |
Today's Posts |
#21
|
||||
|
||||
Quote:
As for the pump, there is a place in MI not real far from me that will rebuild my pump for $138 with a 2 yr warranty and 7 day turnaround so I may go that route unless I find a cast impeller option cheaper.
__________________
1977 Trans Am 400/4speed (swap) Brian |
#22
|
||||
|
||||
On to a few more questions. And I’m not even into the engine yet.
Last time I had the engine out I pulled the trans to be “rebuilt” by a local shop. Should’ve done it myself. They cause me all kinds of hassles and I ended up bringing the whole car to them at one point to make the trans right. Probably a mistake as they must have gotten the clutch assembly or flywheel hot because it chattered after. I’ve dealt with it and it improved some but now is a good time to fix it. Question: should I replace this flywheel based on its condition and if so point me in the right direction for a replacement. It’s already been resurfaced by me once back when I did the 4 speed swap probably 6-8 years ago or so. Question 2 is whether or not you think I the chatter is from the flywheel or pressure plate but as it turns out I forgot to take any pictures of the PP so that will have to wait a bit.
__________________
1977 Trans Am 400/4speed (swap) Brian |
#23
|
||||
|
||||
I see discoloring from hot spots.
These areas are now a different hardness then the non discolored areas and as such when heated expand at a different rate then the surrounding metal , and there’s your chatter, IE irrattic contact! I would replace the flywheel while the job is easy, otherwise you will be giving yourself yet another self Ass kicking. You lucked out with the motor dropping I bet, but don’t push it with this!
__________________
I do stuff for reasons. |
#24
|
||||
|
||||
I also see that the previous cut that was made to clean it up was by far too course.
The flywheel lost a good amount of contact area just due to that ! The finish needs to look like a brand new brake rotor. Also while your at the Ass end of the motor with the flywheel off take a close look at the freeze out plugs and if you have any doubt about them replace them now with Brass ones. This is another hard learned lesson myself and others have gone thru!
__________________
I do stuff for reasons. |
#25
|
||||
|
||||
Quote:
__________________
Will Rivera '69 Firebird 400/461, 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears ‘66 Lemans, 455, KRE D-Ports, TH350, 12 bolt 3.90 gears '69 LeMans Vert, 350, #47 heads: work in progress |
#26
|
||||
|
||||
Thanks for the comments and tips. I’ll look at that pump too since it’s about the same price as rebuilding. Rebuilt price included shipping shipping be way.
Here’s a pic of the pressure plate. Looks like hot spots again yea? I’m guessing it should also be replaced? As for the flywheel, aren’t some balanced and some unbalanced or am I off with that? I feel like when I looked years ago I found differences.
__________________
1977 Trans Am 400/4speed (swap) Brian |
#27
|
||||
|
||||
Question about that flow looker pump too. Can I reuse my divider plate with that pump or does it require a slightly different design?
__________________
1977 Trans Am 400/4speed (swap) Brian |
#28
|
||||
|
||||
It’s uses the plate and the two sealing rings.
You should still check and or set if need be the plate to impeller clearance so as to have max flow.
__________________
I do stuff for reasons. |
#29
|
||||
|
||||
So my current divider plate should work? Flow kooler too obviously. Dumb phone.
__________________
1977 Trans Am 400/4speed (swap) Brian |
#30
|
|||
|
|||
Quote:
i use a aluminum PRW water pump, works great on a stroked 467, the impeller is cast but the fins have been CNC'd, it fits nice to the divider plate to. https://butlerperformance.com/i-3164...tegory:1234740 |
#31
|
||||
|
||||
Quote:
__________________
1977 Trans Am 400/4speed (swap) Brian |
#32
|
|||
|
|||
Quote:
According to Hendrickson and Osterstock there is about a 6 inch-ounce unbalance it stock Pontiac flywheels. |
#33
|
|||
|
|||
Your correct Sherman, Within production tolerances the mainstream 326 350 389 400 421 428 455 Pontiac flywheel has a 6 inch ounce imbalance built in just look at a pic of a stock flexplate and observe the holes, the front dampener is neutral,
|
#34
|
|||
|
|||
Quote:
pontiac engines were internally balanced by adding/removing weight from the crank counter weight as far as im aware, as opposed to 301 or sbc etc. pontiac flexplate/flywheels can only bolt on one way to the crank so those parts arent usually used to balance the engine. heres 2 examples of flexplates & each one calls them internal/neutral balance. i used the PRW on one of my engines from butler & it just bolts on & was not needed for balancing the engine. & another example of a flywheel i used on manual trans pontiac, also called internal/neutral balance. https://butlerperformance.com/i-2617...tegory:1234750 https://butlerperformance.com/i-2445...tegory:1234750 https://butlerperformance.com/i-2445...tegory:1234750 |
#35
|
|||
|
|||
Quote:
SBCs are internally balanced from the factory except for the 400. That is the flywheels and dampers are neutral balanced and all compensation for the reciprocation and rotating mass is handled internal to the crankcase. In other words by the crankshaft alone. |
#36
|
|||
|
|||
Quote:
when i bought the flexplate & flywheel i asked what was needed for a pontiac that is internally balanced & was told by butler that the neutral/internal balanced flexplate/flywheel were the correct ones to use.. machine shop confirmed that too & didnt ask for the flexplate or flywheel when balancing the egines. |
#37
|
||||
|
||||
I hope a machinist on this site who does balancing will correct me if I am wrong , but 6 inch once’s does not tell you crap but for how far the imbalance is from the crank centerline.
What’s not stated in that I much quoted info from HO racing is how many gram’s of imbalance there is in that factory balance job at 6 inches out from the centerline. A small imbalance of even a few grams out that far from the centerline is a lot!! Most common machine shops balance at 3 inches, and with the needed high end balance machine set up the top race shops balance to 1 inch. One once of imbalance at 6 inches is 6 times more distructive then at 1 inch.
__________________
I do stuff for reasons. Last edited by 25stevem; 05-01-2022 at 02:50 PM. |
#38
|
||||
|
||||
This is what I’ve picked out to replace my flywheel. Middle of the road price wise, looks most similar to the current one I have compared to others I’ve found. There are probably some cheaper options but I noticed some listings didn’t specify the crank size nor the balance and I don’t want to deal with sending stuff back to find the right part so I think and hope this will suffice
https://www.firebirdcentral.com/Prod...D2880&CartID=1
__________________
1977 Trans Am 400/4speed (swap) Brian |
#39
|
|||
|
|||
Quote:
|
#40
|
|||
|
|||
Quote:
|
Reply |
Thread Tools | |
Display Modes | |
|
|