157 or 164 tooth flexplate?

[lalojamesliz 56]

How is this figured out?  I'm trying to figure out what flexplate I need but I don't know if I need the 157 or 164. 

I have a 4r70w for my 351w stroker and it needs to be neutral balanced. I've seen recommendations for a 157 and some for a 164 flexplate.......Thanks guys.

[det0326 179]

as far as I know the c4 aod and 4r all use the 164 tooth flex plate. The weight imbalance would depended on the engine application, if your engine is internally balanced then I don't see why u couldn't cut the weight off the stock one that was on the 4r. Now there is a long and short starter snout, there again tho if you have the starter that came with the 4r it should be correct. If u go with a used flex plate be sure it is for the c4 aod or 4r. there are some out there for eod or c6 that just looking at them seem to be the same but has a slight different offset and won't work it will damage the pump.

[lalojamesliz 56]

My engine is 0 balance so I'll look for one. I just read a post of a guy that ran one that looked fine but the flexplate was too thick or something and it was pushing against the torque converter then ruined his trans.... 

I need to look into that to make sure I don't do the same

[det0326 179]

I know some people had trouble with the after market stoker crank where the snout of the converter mates. I would check that ID and depth on all the steps to make sure that yours is same as a stock crank. Other than that when u mate the trans with the engine and u can slide the converter forward and back 3/16 to 1/4 inch u are golden.

[lalojamesliz 56]

2 hours ago, det0326 said:

I know some people had trouble with the after market stoker crank where the snout of the converter mates. I would check that ID and depth on all the steps to make sure that yours is same as a stock crank. Other than that when u mate the trans with the engine and u can slide the converter forward and back 3/16 to 1/4 inch u are golden.

The converter I have now came with my trans and was used with it.  It even came with a flexplate but I think it's 28oz so I can't use it since I need a neutral weighted one.

Once I find a flexplate I'll try assembling it and check for move like you said.  Thank you

[lalojamesliz 56]

I'm seeing I need a 164 tooth version.  The pioneer fra-205 should work BUT it's not neutral balanced. Crappers

[det0326 179]

Just a quick look on the web and found this one. They are out there but because of covid a lot of places are out of stock, I would make sure they have in stock ready to ship. I would not have a problem cutting the weight off the old one that came with the 4r, it is only welded in a few spots in most cases. 

 

https://blueprintengines.com/products/ford-flexplate-164-tooth-steel-external-50oz-imbalance-bppf50164

[lalojamesliz 56]

So by cutting the weights off they become neutral/0? I thought those also would balance the flywheel like how tires use weights to fix any fitment issues

The flywheel that was on my c4 trans (I-6 250 original engine) has no weights. It's neutral balance?

[det0326 179]

what kinda rpm's u planning on running this beast?  If u cut the weight off and not remove any material from flexplate it would have to be as neutral as it could be. That weight is only put on there to counter balance the crank throws. If u are afraid of it tho I would get a 0 balanced one but in the after market world that's no guarantee either. Another solution is cut the weight off and get it balanced by whoever balanced your engine. More money more money never ends does it.  I sure know that feeling. Good luck with your engine.

[lalojamesliz 56]

My trans is buried in my garage now but later when it could down I'll dig it out and look up the flywheel it has again. 

on a different topic, I never put stickers on my cars. Period.  I have a window sticker that has a wrench and it says built not bought.  That will probably end up on one of my windows when I'm done. At least for a short while ha ha ha

[RPM 1,190]

Did not the guy who balanced your motor have the flex plate when he did the balancing? I've never heard of your issue. 

[lalojamesliz 56]

No, I just had the bare block and took that over to the guys at JGM. They ordered the rotating assembly and I took them the cam. They just built the shortblock.

While searching for this online recently I saw someone say the trans is what determines the flywheel besides the weight requirement..... I keep seeing different answers and that's what confuses me. 

[lalojamesliz 56]

I dug it out and I did another bone head move some time ago. I must have tossed away the flexplate.  I'm sure it's because it wasn't a neutral balanced flexplate and that's what I need.  

It does have a 10" ptc aode converter though.  I need to call ptc and find out what I can. Maybe they can suggest a flexplate 

[GypsyR 32]

Sounds like you want to look at a 1998 or so Mustang 3.8 164 tooth flexplate if you want a stocker but it seems to me with what you have going on you might be better off with an aftermarket and custom SFI approved flexplate.

[lalojamesliz 56]

36 minutes ago, GypsyR said:

Sounds like you want to look at a 1998 or so Mustang 3.8 164 tooth flexplate if you want a stocker but it seems to me with what you have going on you might be better off with an aftermarket and custom SFI approved flexplate.

I just want to get whatever will work and won't give me fitment issues and not push my converter to far in and destroy my trans.

Should a flexplate from that mustang work? Do you think it can cause any other issues?

Would the converter I have change what flexplate I need?

To be honest,  if I didn't already have a 4r70w and new fpa headers for it I would just go with a manual trans to avoid this headache and just teach my family on how to drive a manual trans. 

My wife told me to stop stressing and just get a manual trans and that she doesn't have to drive it. Then I told her that a new trans will be 5k+ for everything. She stood quite ha ha ha

[det0326 179]

22 hours ago, lalojamesliz said:

I just want to get whatever will work and won't give me fitment issues and not push my converter to far in and destroy my trans.

Should a flexplate from that mustang work? Do you think it can cause any other issues?

Would the converter I have change what flexplate I need?

To be honest,  if I didn't already have a 4r70w and new fpa headers for it I would just go with a manual trans to avoid this headache and just teach my family on how to drive a manual trans. 

My wife told me to stop stressing and just get a manual trans and that she doesn't have to drive it. Then I told her that a new trans will be 5k+ for everything. She stood quite ha ha ha

U are making way to much out of this. Buy the neutral balanced 164 tooth  flex plate that  is advertised for the C4 Aod 4R and when u marry the transmission to the engine check the clearance as I posted above and u have no worries.  

[lalojamesliz 56]

I ordered the PAX30210 from summit racing.  It's not in stock until October but I have plenty to keep me busy for now.  I didn't order it from somewhere else because I love summit's return policy.  

So if it doesn't fit I'm good

[GypsyR 32]

The PAX looks to be your best choice. At least they SAY it fits. All I know is the 3.8 flexplate I mentioned is zero balance from the factory, is the right diameter with the correct number of teeth, and I think has the correct offset. But the only one I actually have on hand is a flywheel for a 3.8, not a flexplate. Though I do have a 157 tooth 5.0 flywheel handy I'm not at all sure the comparison between those two would translate usually into pertinent info for what you need. 

I've personally compared the offsets between an AOD/e/4R70W flexplate and one for a C6/E4OD and found the difference surprising small. You about have to use a micrometer to tell them apart. But that tiny difference very much matters. Trying to say though I can do my best to compare two apples I can't say that what I find will the same for two oranges. In fact I doubt it would.

 

By the way, I had to go to Summit and search up what you bought. When I look it says it would be backordered until mid-October. Link:

https://www.summitracing.com/parts/pma-pax30210

[lalojamesliz 56]

34 minutes ago, GypsyR said:

The PAX looks to be your best choice. At least they SAY it fits. All I know is the 3.8 flexplate I mentioned is zero balance from the factory, is the right diameter with the correct number of teeth, and I think has the correct offset. But the only one I actually have on hand is a flywheel for a 3.8, not a flexplate. Though I do have a 157 tooth 5.0 flywheel handy I'm not at all sure the comparison between those two would translate usually into pertinent info for what you need. 

I've personally compared the offsets between an AOD/e/4R70W flexplate and one for a C6/E4OD and found the difference surprising small. You about have to use a micrometer to tell them apart. But that tiny difference very much matters. Trying to say though I can do my best to compare two apples I can't say that what I find will the same for two oranges. In fact I doubt it would.

 

By the way, I had to go to Summit and search up what you bought. When I look it says it would be backordered until mid-October. Link:

https://www.summitracing.com/parts/pma-pax30210

I saw others but they aren't neutral balanced. What do you think of getting one of those and removing the weight and welds carefully. Do you think it will work?

People have good luck with aod transmissions with this one but it's not neutral.  https://www.summitracing.com/parts/pma-pa26467/make/ford#overview 

it has a 2.5mm thick center plate. The other I was looking at also has a 2.5mm center but people were complaining about it cracking.  

the one I ordered has a 4mm I think.  That might be a bad thing since I need all the space I can get but I'll just have to find out

[det0326 179]

On 7/24/2021 at 12:52 PM, GypsyR said:

Sounds like you want to look at a 1998 or so Mustang 3.8 164 tooth flexplate if you want a stocker but it seems to me with what you have going on you might be better off with an aftermarket and custom SFI approved flexplate.

GypsyR check your message box please

[GypsyR 32]

On it. 

If it were me and I didn't want to try a 3.8 flexplate I'd knock a weight off. Then I'd find a ball bearing that fit in the middle of the flexplate (maybe with some temporary glue) and set it up like I was hand balancing a motorcycle or bicycle wheel. That way I could grind off a tad bit more steel if I weren't happy with how neutral it turned out to be.

 

Kind of curious how you ended up with a custom balance engine but it wasn't dynamically balanced before you got your hands on it. My local guy won't balance a crank unless you have all the involved rotating parts there for him.

[RPM 1,190]

On 7/24/2021 at 10:21 AM, lalojamesliz said:

I just want to get whatever will work and won't give me fitment issues and not push my converter to far in and destroy my trans.

You need to measure if you ever swap flex plates. I believe the gap should be 1/16 to 3/16", but you'll need to confirm the measurement. 

[lalojamesliz 56]

8 hours ago, GypsyR said:

On it. 

If it were me and I didn't want to try a 3.8 flexplate I'd knock a weight off. Then I'd find a ball bearing that fit in the middle of the flexplate (maybe with some temporary glue) and set it up like I was hand balancing a motorcycle or bicycle wheel. That way I could grind off a tad bit more steel if I weren't happy with how neutral it turned out to be.

 

Kind of curious how you ended up with a custom balance engine but it wasn't dynamically balanced before you got your hands on it. My local guy won't balance a crank unless you have all the involved rotating parts there for him.

 

So I dropped off the bare block and they ordered the rotating assembly that worked for the 9.48 block and it ended up being neutral balance. I can't remember for sure but they probably asked if I wanted neutral.  I had the (and still have) I'll choose whatever is better way to choose things.  The bad thing i learned about that is it requires deeper pockets!

What were they supposed to do for me? I'm a bit lost on that. 

On a different subject,  the flexplate I ordered will be here in the 5th!  I guess they had one in stock. I really didn't want to wait till October 

[lalojamesliz 56]

6 hours ago, RPM said:

You need to measure if you ever swap flex plates. I believe the gap should be 1/16 to 3/16", but you'll need to confirm the measurement. 

I'll check that when I receive the flexplate.  Thanks Bob 

[GypsyR 32]

When you have an engine dynamically balanced they need the crank, rods with the bolts, pistons, rings, wrist pins, balancer, and the flywheel/flexplate you are going to use. 

When balancing they don't actually spin balance all your parts, they just want them so they can weigh them. So the pistons, rings, and wrist pins don't need to be assembled.

Some builders will only dynamically balance the crankshaft with the flywheel/flexplate and the harmonic balancer and just weight match the other parts.  Apparently you can get good results with either method.