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This is off topic because it is about a Buick engine but the 60° engins have the same flywheel-to-crank setup I beleive.
I'm running a 3.8 SFI Turbo engine, FWD with a 4T65EHD transmission. The 3.8 has the stock FWD chankshaft and driveplate with six 7/16" fine-thread bolts holding the driveplate on.
I have upgraded the bolts to grade 8 (factory had grade 5).
Someone has expressed concern that the flywheel bolts may shear off, since the bolt circle is so small on the FWD crank versus the RWD crank they are used to working with. The late model FWD 3800 has a larger bolt circle at the flywheel. Does the newer 60° engines have a larger golt circle?
I know some of the newer 3500 and 3900's have been turbocharged and are surely putting out at least as much torque as I am. Has anyone had driveplate failures or sheared bolts due to excess torque with the smaller bolts?
Thanks,
David
I'm running a 3.8 SFI Turbo engine, FWD with a 4T65EHD transmission. The 3.8 has the stock FWD chankshaft and driveplate with six 7/16" fine-thread bolts holding the driveplate on.
I have upgraded the bolts to grade 8 (factory had grade 5).
Someone has expressed concern that the flywheel bolts may shear off, since the bolt circle is so small on the FWD crank versus the RWD crank they are used to working with. The late model FWD 3800 has a larger bolt circle at the flywheel. Does the newer 60° engines have a larger golt circle?
I know some of the newer 3500 and 3900's have been turbocharged and are surely putting out at least as much torque as I am. Has anyone had driveplate failures or sheared bolts due to excess torque with the smaller bolts?
Thanks,
David