[JSPONT]

My turbo charged street car, this is a SFI flywheel, a 2 piece bolt together PTC converter. The top one is worse but did not get a photo. No the bolts are not loose. I am sure they will be fun to get out.
This ever happen to anyone?

[Scott65]

Are they twisted, or pulling through? Or both? Never had it happen, subscribing to see what the root cause ends up being... Check thrust on the engine yet? Hoping its not worse than what's showing for you.

[Sirrotica]

Closest I've had to that happening is one lug pulled out of the convertor creating a leak that sprayed all over the head pipes causing a fire. This was a T400 with a stock GM convertor on the 67 GTO dirt car in my middle signature picture. Bolts were all tight on that convertor too.

I just went to the sponsor of my car, (Jays Auto Wrecking, on the front fender) in the picture, and he gave me another used T400 to swap into the car, circa 1976.

[GTOGEORGE]

Originally Posted by JSPONT

My turbo charged street car, this is a SFI flywheel, a 2 piece bolt together PTC converter. The top one is worse but did not get a photo. No the bolts are not loose. I am sure they will be fun to get out.
This ever happen to anyone?

Attachment 516069

Attachment 516070

Attachment 516071

Chinese flywheel?


GTO George

[JSPONT]

ATI Flywheel

[Scott Stoneburg]

Never had anything like that happen to me, my only thoughts are that the flexplate is soft.

[johnta1]

The lugs are threaded, not through holes for bolt and nut?

The bolts too long? (bottomed out before tight)

Haven't sen an ATI SFI plate before, but my TCI is a lot thicker than that one looks? (looks like factory one)

[73 TRANSAM]

I think he's right that the bolts might be too long and it bottomed out. This is why I test fit mine when it was out. It looks like ARP bolts to me, so that's a big possibility. GL

[JSPONT]

They were not bottomed out, there is about 4000-5000 miles on it. A few guys with turbo cars I spoke to said I need 6 bolts. They are not hitting anything. I guess when I get it out I can access what happened. Just pissed now. Had a water pump hub break free and send the fan thru the radiator. Saved the $$ for that, took it for a ride, heard a little noise down low, and now this. Loosing the summer with the car sucks.

[GTOGEORGE]

Originally Posted by JSPONT

They were not bottomed out, there is about 4000-5000 miles on it. A few guys with turbo cars I spoke to said I need 6 bolts. They are not hitting anything. I guess when I get it out I can access what happened. Just pissed now. Had a water pump hub break free and send the fan thru the radiator. Saved the $$ for that, took it for a ride, heard a little noise down low, and now this. Loosing the summer with the car sucks.

I have 3 bolts.
I have to admit it sure is weird......sorry.

GTO George

[Scott65]

Were the bolts the same size as the holes? Originally I mean, now they're probably oval shaped. My TCI came with larger holes then the bolts. I guess they make some assumptions on bolt sizing. I had to "load" the converter against the direction of rotation because of this. There was no way to drill out and re-thread my converter holes. I ask this question because the pictures make it look like this kind of rotational, twisting issue could've occurred on yours.

[Sirrotica]

Originally Posted by JSPONT

They were not bottomed out, there is about 4000-5000 miles on it. A few guys with turbo cars I spoke to said I need 6 bolts. They are not hitting anything. I guess when I get it out I can access what happened. Just pissed now. Had a water pump hub break free and send the fan thru the radiator. Saved the $$ for that, took it for a ride, heard a little noise down low, and now this. Loosing the summer with the car sucks.

There may be some truth to that statement as the 4L80E (which is basically a T400 with OD) when used behind the turbo diesels, and in a truck application, used 6 bolt convertors. As GM increased the torque in the Dura Max they upgraded to the Allison transmissions.

Being you have pretty much the same torque in your turbo car as many diesels, it may be that the 6 bolt convertor is necessary for longevity.

[73 TRANSAM]

I converted mine to a 6 bolt 7/16" fine thread. You can only do this if you have six pad mounting surface. I drilled and tapped the converter pad and made sure to tap it straight. Then verify what length of bolts you need. But my car is not running yet.

[GTOGEORGE]

He’s got other issues, 6 bolts is just a bandage!



GTO George

[AG]

Are those ARP bolts and are they through bolts or bolted into the converter?

[JSPONT]

Originally Posted by AG

Are those ARP bolts and are they through bolts or bolted into the converter?

They are arp bolts and bolted into the converter. Ptc billet back with a steel front.

[rod cole]

On my go fast converters they have all been through bolts with 7/16 bolts going into 1/2 plate converter ring. For that to happen I would think the converter pads had to bend also. Which would point to soft or thin converter shell. But like I stated all the go fast converters I have had have a very thick machined plate welded to the cover in multiple places. If the converter pads are still flat that points to loose or soft bolts.

[Scott Roberts]

I didnt have that happen at 2000+ hp... not sure what your hp level is but I had ATI build me a flywheel that was twice as thick...

[JSPONT]

I dropped the tranny, the converter pad is screwed. There are multiple bolt patterns on it so I have to decide what flexplate then I guess drill it to the other pattern, and or helicoil the converter. PTC billet back 1/2 so it is a big flat plate.

[blueghoast]

You probly need to go to the thicker flex plate.
I think your making to much power for the thinner one's. Man you must be making some serious power with that thing. Good luck with it.

GT.