robslow Posted June 11, 2008 Report Share Posted June 11, 2008 I was trying to put a 4speed off an l16 I got and I think its from a truck and put it on a running L16 that had an auto, it came from a 510 but the flywheel is not the same bolt patern as the auto, the crank on the auto engine is bigger than the manual engine, I dont want an auto............ Quote Link to comment
pl521sss Posted June 11, 2008 Report Share Posted June 11, 2008 the flywheel is not the same bolt patern as the auto, the crank on the auto engine is bigger than the manual engine, I dont want an auto............ there's no flywheel on automatic. Behind the crankshaft is the flexplate and torque converter. What do you mean bigger? The auto crankshaft end is taller and has a spacer. But still the same 5 bolt crank from L16 auto or manual. Quote Link to comment
robslow Posted June 11, 2008 Author Report Share Posted June 11, 2008 yes the flywheel dosnt fit the crank end because it is taller, can I machine the flywheel so it fits over the auto crank Quote Link to comment
banzai510(hainz) Posted June 11, 2008 Report Share Posted June 11, 2008 Dude No oblo? a auto L16/18 and manual L16/18 cranks are the same. 5bolt crank. Look CLOSELY ,get a screw driver and pry on it . There is a plate that should come off. It looks like the back of the crank but is really 2 pcs. i thought the same thing when I was new to L motors Quote Link to comment
robslow Posted June 11, 2008 Author Report Share Posted June 11, 2008 cool Ill try that when I get home. Quote Link to comment
datzenmike Posted June 11, 2008 Report Share Posted June 11, 2008 The auto tranny flex plate will look like this, with a spacer between the bolts and the flrxplate: http://i138.photobucket.com/albums/q251/datzenmike/transautodriveplate88D-21Z24i.jpg[/img]"] There will be another spacer between the flexplate and the crank, like a sandwich. The spacers look like these. Several kinds were used, yours may be like the top right one which wraps around the end of the crank and has to be 'popped' off. http://i138.photobucket.com/albums/q51/datzenmike/transautodriveplatespacer.jpg[/img]"] These are from a variety of L20B and Z engines and are 6 bolt. Yours must have 5 bolt for it to work. You did say the bolt pattern was different?? Quote Link to comment
pl521sss Posted June 11, 2008 Report Share Posted June 11, 2008 I think even with the spacerplate removed, it's still slightly taller than the manual crankshaft. Once the flywheel is on, sticks out further. Don't remember doing anything else cause the starter was still able to reach and mesh with the gear. 6 bolt flywheel doesn't work on L16L18, correct? Or is there a 6 bolt flywheel for L16L18 Quote Link to comment
datzenmike Posted June 11, 2008 Report Share Posted June 11, 2008 All 4 cyl. engines, L18 and lower, have the 5 bolt crank with 2.1631" main bearings. All L20B and all Z20/22/24 series engines have the 6 bolt cranks with 2.3599" main bearings. Other than the number of bolt holes, they should be the same size shape and number of ring gear teeth. Pretty sure the torque converter bolt spacing pattern is the same too. Quote Link to comment
datzenmike Posted June 11, 2008 Report Share Posted June 11, 2008 Well, to lay it to rest who has the bigger crank, I whipped out my part and measured it: http://i138.photobucket.com/albums/q251/datzenmike/autostdflywheel.jpg[/img]"] Surprisingly they are not the same. The automatic flex plate starter gear is further from the end of the crank shaft than the standard flywheel by 0.060" or sixty thou. Having said that... This +- 0.060" could be taken up, when the tranny is tightened against the block. The torque converter is 'squashed' against the tranny to seat and seal it to the hydraulic oil pump and would slightly bend the 'flex' plate forward. Could this be why it is called a FLEX plate??? Quote Link to comment
datsunaholic Posted June 11, 2008 Report Share Posted June 11, 2008 Mike, that flexplate looks nothing like my '81 Z20 flexplate (which is identical to a L20B flexplate). The ones I have are practically flat. The spacers I've had ('78 L20B, '81 Z20S) were like the top right one you have. pl521sss, the Manual and Automatic cranks are 100% identical. Not a smidgen of difference. I've swapped them both ways (A/T to manual, manual to A/T). Just different hardware on the end. There is no such thing as a 6-bolt L16 or L18 crank or flywheel. L13, L14, L16, L18 used 5-bolt, and used the same flywheel design (with varying weight and clutch size). Flexplates depended on if they were used with a Borg-Warner or JATCO Automatic. All 6-cyl (L20, L24, L26, L28) and L20B, Z20, Z22, Z24 all used 6-bolt, also with varying weight and clutch size. The flexplates were the same except possibly the ones with lockup Torque Converters. Quote Link to comment
datzenmike Posted June 11, 2008 Report Share Posted June 11, 2008 Like this one: http://i138.photobucket.com/albums/q251/datzenmike/autostdflywheel001.jpg[/img]"] So the flat one is for an L20B or any 3N71B auto. Yes, (got so much 'stuff') the one in the pic is from an '88 Z24 so it would have the L3N71B. The good news is that the ring gear to crank distances are identical so they will interchange one way only. To further prove that (and more) I gave away one just like the '88 one to a guy in Co. for his 620. I mistakenly thought it was off an L20B but it was actually off an L4N71B. He was very happy with the fit so it's safe to say that the L3N71B and L4N71B flex plates are the same shape to fit the larger torque converter, and will work on an L20B. Quote Link to comment
robslow Posted June 12, 2008 Author Report Share Posted June 12, 2008 thanks for the responses. That spacer on the end of the crank came right off and the flywheel fit perfictly.. Thanks again Quote Link to comment
racerx Posted June 12, 2008 Report Share Posted June 12, 2008 Well, to lay it to rest who has the bigger crank, I whipped out my part and measured it: http://i138.photobucket.com/albums/q251/datzenmike/autostdflywheel.jpg[/img]"] Surprisingly they are not the same. The automatic flex plate starter gear is further from the end of the crank shaft than the standard flywheel by 0.060" or sixty thou. Having said that... This +- 0.060" could be taken up, when the tranny is tightened against the block. The torque converter is 'squashed' against the tranny to seat and seal it to the hydraulic oil pump and would slightly bend the 'flex' plate forward. Could this be why it is called a FLEX plate??? Actually my Crank is bigger:D just kidding, I just had to Quote Link to comment
datzenmike Posted June 12, 2008 Report Share Posted June 12, 2008 Chick's dig the longer rod stroke. Quote Link to comment
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