Login  /  Register  
  Home  -  Forum  -  Classifieds  -  Photos  -  Links     

  << Previous Topic | Next Topic >>Return to Index  

Is this what a 390 auto flexplate look like!

October 18 2010 at 6:44 PM

  (Login rudsaki)
Members

My book, shows there should be a metal ring where the bolts go. Also, is this notch on the flange normal? This is a truck block.

http://pics.ww.com/v/ruddy/MyCars/FairWork
Pics are the first 2

forgot to add my reference about the knock and vibration:

http://www.network54.com/Forum/74182/message/1287184137/Knock+and+vibration%2C+part+3


    
This message has been edited by rudsaki on Oct 18, 2010 10:07 PM
This message has been edited by rudsaki on Oct 18, 2010 7:02 PM


 
 Respond to this message   
AuthorReply


(Login tort1325)
Members

My 390 had the ring, can't see

October 18 2010, 7:12 PM 

the notch your refering too.

 
 Respond to this message   


(Login rudsaki)
Members

Re: My 390 had the ring, can't see

October 18 2010, 10:05 PM 

the notching in the flange behind the flexplate......

 
 Respond to this message   

(Login Bullitt406)
Members

Look's like half-moon shape which means 360 n/m

October 18 2010, 7:21 PM 

.

 
 Respond to this message   


(Login hastyb1)
Members

no support ring

October 18 2010, 7:30 PM 

on mid 70s truck engines. I'm not sure what year they dropped them.

 
 Respond to this message   


(Login rudsaki)
Members

Re: no support ring

October 18 2010, 10:04 PM 

ouch, so maybe a 360 truck masqerading as a 390???
I need to find the block numbers I wrote down.

 
 Respond to this message   
Bobby Spears
(Login x4rdtech)
Members

Re: Is this what a 390 auto flexplate look like!

October 18 2010, 9:39 PM 

It looks correct to me but I would get a new one due to several worn or chipped teeth and get a support ring were the bolts attach it to the crank.It helps keep the wheel from flexing and cracking.

[linked image]

 
 Respond to this message   


(Login rudsaki)
Members

why me

October 18 2010, 10:10 PM 

the background is that I have always had this 1800-2000rpm rolling vibration and it stil exists with the transmission removed and just the flexplate on the motor.

 
 Respond to this message   


(Login rudsaki)
Members

it is a little out of round

October 19 2010, 3:10 PM 

when i started the motor and looked at it while it was running.

 
 Respond to this message   

(Login GJCAT427)
Members

If all else fails,,,,,,

October 19 2010, 3:45 AM 

You can have it TIG welded. I`ve done this many times on trannys with no ill effects. As for the vibration what motor is it supposed to be? Did you buy the car complete or put the motor in yourself? Many yrs ago I bought a motor from a Judge`s kid that kept getting into trouble and wanted something else to calm the car down. It was supposed to be a 428 cj which I confirmed buy the local shop who put the motor in for him. Long story short, wrong flex plate, I installed it with my 390 plate and had the 1800-2000 vibration. Changed out the plate for a 428 and no vibe. Is your motor what you think it is? Stranger things have happened.

 
 Respond to this message   

Rod
(Login rudsaki)
Members

I bought it this way

October 19 2010, 9:54 AM 

It was supposed to be a 390. The car is a 390GT clone of sorts, so i knew it was no numbers matching kind of car. Bought it on Ebay couple of states away. At 53 yrs old, I need to stop being so trusting!
The block has the truck reverse 105 on the front. Is there any other numbers on the block to tell me what it is?

 
 Respond to this message   

(Login MikeBasford)
Members

Vibration in "390"

October 19 2010, 10:32 AM 

You should check the stroke with a piece of wire through the sparkplug hole. If it's a 390 with a 428 crank (410 cu ") you need to use the 428 plate, not the 390. Also, there should be a ring between the flex plate and the bolts to spread the load (I think!). I do know that the flax plates can crack from the bolt holes if left off.

 
 Respond to this message   


(Login rudsaki)
Members

inches?

October 19 2010, 11:14 AM 

how many inches with the wire trick, indicate which crank?

 
 Respond to this message   

(Login winr1)
Members

352/360 = 3.5"........390 = 3.78"......410/428 = 3.98"

October 19 2010, 11:24 AM 

Richard.

 
 Respond to this message   


(Login rudsaki)
Members

3.75"

October 19 2010, 1:28 PM 

as close as i can measure; so sounds like a 390 crank

 
 Respond to this message   

(Login winr1)
Members

352/360 = 3.5"........390 = 3.78"......410/428 = 3.98"

October 19 2010, 11:24 AM 

Richard.

 
 Respond to this message   


(Login rudsaki)
Members

Gary: how to know where flexplate wieght goes?

October 19 2010, 7:07 PM 

Now that i read the 390 truck is externally balanced like a 428. How do you line up the weight on the flexplate?

 
 Respond to this message   


(Login TorinoBP88)
Members

its missing the steel ring that goes under the bolts to keep it from cracking. n/m

October 19 2010, 2:58 PM 

m

************************************


1968 GT/CS Mustang. 289/c4 (416/4sp TL going in soon.)

Oh and a Bicycle - daily driver to save gas for the 'F'un 'E'xcursions.

 
 Respond to this message   


(Login rudsaki)
Members

steel ring

October 19 2010, 3:28 PM 

it would be the right thing to get that, but I'm guessing it won't get rid of my vibration.
Are 390's internally balanced? I don't see any weights on my flexplate.

 
 Respond to this message   


(Login TorinoBP88)
Members

check your stroke, make sure its 3.78" not 4.00, 390 interally balanced, 428 not n/m.

October 21 2010, 11:23 AM 

m

************************************


1968 GT/CS Mustang. 289/c4 (416/4sp TL going in soon.)

Oh and a Bicycle - daily driver to save gas for the 'F'un 'E'xcursions.

 
 Respond to this message   


(Login rudsaki)
Members

TE on crank caps

October 19 2010, 3:36 PM 

Truck Engine, right? Were their truck 390's? Or maybe somebody later put a 390 crank in a 360 truck block?
Photo ~673 at http://pics.ww.com/v/ruddy/MyCars/FairWork/

 
 Respond to this message   


(Login rudsaki)
Members

Externally balanced. From a Mustang&Fords tech article

October 19 2010, 4:54 PM 

"The FT is an externally balanced engine, which means it is balanced like the FE 410 and 428ci engines. Keep this in mind during your build."

http://www.mustangandfords.com/techarticles/engine/15999_fe_quick_facts

 
 Respond to this message   

Rod
(Login rudsaki)
Members

just on serious truck motors; series 600, 700, etc

October 20 2010, 4:35 PM 

Just regular FE engines in pickups. Maybe F350s had an orderable FT engine.
Sigh, now I'm back to no good reason for a vibration.
sad.gif

 
 Respond to this message   
Current Topic - Is this what a 390 auto flexplate look like!
  << Previous Topic | Next Topic >>Return to Index