Yank 6-lug converter + TCI Flexplate?
10-11-2005, 06:41 PM
#1
Yank 6-lug converter + TCI Flexplate? I have a PYE 3600 here and a tci flexplate. Only 3 of the holes on the flexplate line up with the lugs on the converter. The other 3 are off center. Do I just use 3 of them? I would like to make the other holes work, but the mounting spots on the flexplate are countersunk and that would make it really difficult....
10-12-2005, 09:37 AM
#3
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Yes, (3) bolts are what is on the stock verter/flexplate - but Yank offers (6) for a reason. Personally I would want to use all (6) especially with a stall in the hi range (I used all six for my PY3600E).
I had no problem with the ATI flexplate and my Yank in the one T/A, but had the same problems with my second Yank and the TCI flexplate for the other T/A. I eventually did get the bolts to all go in on the bench - but don't know how easy it would be to do while installing? Another item, which has been brought up in other threads, is that the bolt holes in the TCI unit are for 7/16 bolts - hence they are oversized for the stock metric verter bolts that the LS1 uses. I didn't like the slop in the holes either, and just think how hard it would be to have the bolts line up if the hole clearance was tighter!?
I talked with TCI and they state that their flexplates are all done on highly accurate CNC machines (of course! I'm sure all the flexplates are) and that there should be no problem with the bolt hole pattern.
So at this point I don't know if it's the pattern on the flexplate that is off, or on the verter lugs themselves? I tend to go with the flexplate being off since the very same verter fit fine with a different mfg. flexplate.
One thing I do know, I WOULD feel more comfortable if Yank would go with the larger 7/16 bolt threads on their units in addition to the increased number of lugs. But I guess that would mean that everyone that buys their verters would also have to buy a new flexplate with the larger hole size (not that that is a bad thing since the stock flexplates suck for performance apps.)
BTW, I ended up selling the TCI and buying from different mfg. I'm not trying to bash any one company here - just stating the facts concerning my experience.
Just my .02 worth...
I had no problem with the ATI flexplate and my Yank in the one T/A, but had the same problems with my second Yank and the TCI flexplate for the other T/A. I eventually did get the bolts to all go in on the bench - but don't know how easy it would be to do while installing? Another item, which has been brought up in other threads, is that the bolt holes in the TCI unit are for 7/16 bolts - hence they are oversized for the stock metric verter bolts that the LS1 uses. I didn't like the slop in the holes either, and just think how hard it would be to have the bolts line up if the hole clearance was tighter!?
I talked with TCI and they state that their flexplates are all done on highly accurate CNC machines (of course! I'm sure all the flexplates are) and that there should be no problem with the bolt hole pattern.
So at this point I don't know if it's the pattern on the flexplate that is off, or on the verter lugs themselves? I tend to go with the flexplate being off since the very same verter fit fine with a different mfg. flexplate.
One thing I do know, I WOULD feel more comfortable if Yank would go with the larger 7/16 bolt threads on their units in addition to the increased number of lugs. But I guess that would mean that everyone that buys their verters would also have to buy a new flexplate with the larger hole size (not that that is a bad thing since the stock flexplates suck for performance apps.)
BTW, I ended up selling the TCI and buying from different mfg. I'm not trying to bash any one company here - just stating the facts concerning my experience.
Just my .02 worth...
10-12-2005, 10:21 AM
#4
as to the bolt size we have at least 3 off road race teams that are supported by GM that run 3 of the stock type metric bolts in the flexplate with 800 to 875 H.P. with a weight of over 5000 lbs with off the ground 4X4 action for over 10 years and I have not seen a bolt fail!
But the flexplate holes are close clearance to the size and we do not like the 7/16 clearance hole that are closer to 1/2 in the outside flexplates
they would be better off to leave the holes smaller so you can drill them out if wanted.
6 bolts are better than 3 as it will hold the flexplate flatter and not prone to cracking and vibrations that is why you HD trucks all use 6 bolts
some onfo the early or ones orderd for a 98 to99 LS-1 PY converters have 6 bolts on the LS-1 pattern for the early style flexplates and the latter ones have 3 on the LS-1 and 3 on
the LT-1 (350) style the fit aftermarket units
But the flexplate holes are close clearance to the size and we do not like the 7/16 clearance hole that are closer to 1/2 in the outside flexplates
they would be better off to leave the holes smaller so you can drill them out if wanted.
6 bolts are better than 3 as it will hold the flexplate flatter and not prone to cracking and vibrations that is why you HD trucks all use 6 bolts
some onfo the early or ones orderd for a 98 to99 LS-1 PY converters have 6 bolts on the LS-1 pattern for the early style flexplates and the latter ones have 3 on the LS-1 and 3 on
the LT-1 (350) style the fit aftermarket units
