strotter Posted December 9, 2001 Share Posted December 9, 2001 OK, my '66 or so 327 ("old" style everything) is gradually coming together, money's flowing like wine and everything's cake. Then last night I come upon a reference to "new style cranks require new style flywheel" somewhere on the net. Huh? I'd assumed I could use the flywheel from my donor '89 Firebird, along with its' T5. The motor is on a stand and I can't get to the back end to measure it, but have I found a *new* problem? If so, is there anything *else* I should know? Pilot bearings? Pressure plates? Bellhousing dimensions? HMMMM? Has anybody on the board put an old motor onto a new clutch/tranny? Quote Link to comment Share on other sites More sharing options...
denny411 Posted December 9, 2001 Share Posted December 9, 2001 Yes,you have a problem.the flywheel you have from the 89 sbc is counter weighted to compensate for the one piece rear main seal.I am not sure whatflywheel will work for you,but if you know someone adventureous at a machine shop you might be able to pursuade them to mill the counterwieght off.just make sure they can balance it afterwerds.I have done this with flex plates for early to late model ford and chevys DENNY Quote Link to comment Share on other sites More sharing options...
John Scott Posted December 9, 2001 Share Posted December 9, 2001 Earlier '55- 85 cranks have the 3.58 crank flange bolt pattern. 86 and up have the 3", so removing the weight won't work. Make sure you get the small diam flywheel (153 tooth). 10.4 diam 26 spline clutch. Chevy has a hd pilot bushing with needle bearings, #14061685. JS Quote Link to comment Share on other sites More sharing options...
dsommer Posted December 10, 2001 Share Posted December 10, 2001 Scott, I checked out my OLD style 2 piece crank against the T-5 flywheel w/153 tooth flywheel (92 model) and all the bolts lined up with the crank. It matches up so well I can use the out line of the old crank that used to be bolted to the tranny. Now as far as the balance is concerned I thought all 350 SBC's were internaly balanced and the flywheel didn't have a balance issue unless you were going to stoke it (383 or other configuration) Anybody want to comment on the balance issue here? (Fast Frog are you running an old style block ie pre 86 with your T-5?) As far as what Denny said that the flywheels were counter weighted for the one piece rear main seal I dunno but would like to hear more. Denny, can you give us more info on this one piece vs. two piece flywheel issue concerning Chevy's only I know nothing about Ford balancing. Jonn Scott good info thanks. David Quote Link to comment Share on other sites More sharing options...
Mike C Posted December 10, 2001 Share Posted December 10, 2001 When GM switched to the one-piece rear seal in 1986, they had to change the counterwighted rear flange on the crank to round in order for the one piece seal to slip over the crank end, so the counterweight had to move to the flywheel. At this point, the 305 and 350 use a different flywheel post '86. They also revised the bolt pattern at the same time. Quote Link to comment Share on other sites More sharing options...
strotter Posted December 11, 2001 Author Share Posted December 11, 2001 OK then, what are my options? I have three: 1. Find a 158 tooth flywheel from a pre-86; make sure the appropriate plates and whatnot fit. Plenty of wrecking yards around here. Q: what vehicles used such a flywheel? Will an '89 clutch assembly fit an older wheel? Are the other critical dimensions (I'm thinking plate thickness) similar? 2. Machine the existing flywheel. It's not in perfect shape to start with, and would need to be refaced as well as have the counterweight removed, and the bolt holes punched. Probably not wise, but an option? 3. Obtain and install an "old" style flywheel (larger diameter) and fit a larger bellhousing to the T5. Q: are larger bellhousings available for the T5, from a yard, and can I adapt the hydraulic clutch assembly to it? Will a larger housing fit a Z and allow good positioning of the engine? Would a larger housing interfere, such as with the exhaust? 4. Something else? I'm beginning to understand why the JTR book is so strident about getting a complete assembly, and then using it intact! These kinds of details can drive you nuts. Quote Link to comment Share on other sites More sharing options...
strotter Posted December 11, 2001 Author Share Posted December 11, 2001 OK, one more option: Summit has a Hays steel flywheel, 152 tooth for '83 to '85 Chev, internally balanced (HAY-10-330), "drilled with both Borg and Beck and long style clutch pattern". Ouch, $229.95 and prolly add a bunch o' shipping. Their tech support says it'll fit, both the bellhousing and the '89 clutch mechanism. Quote Link to comment Share on other sites More sharing options...
Mike C Posted December 11, 2001 Share Posted December 11, 2001 I would not hesitate to buy the steel flywheel. Without shelling out the big bucks for an explosion proof bellhousing, the steel flywheel makes good sense, although it won't contain a clutch explosion, the bellhousing probably will. The bellhousing WILL NOT contain a cast iron flywheel explosion... Quote Link to comment Share on other sites More sharing options...
Ray Posted December 11, 2001 Share Posted December 11, 2001 Hey scott didn't you mention that the guy you got the trans from has it in a 85 TA.. It was probibly a 2 peice block and so you should have th right flywheel.... As John pointed out the bolt patern and the pilot dia are different...Looks like you got lucky.... Quote Link to comment Share on other sites More sharing options...
Guest Thurem Posted December 11, 2001 Share Posted December 11, 2001 What are the pro's and cons of cast nodular lightweight flywheels versus billet steel ones, that weigh about the same. Flatlanderracing.com has both types for reasonable cost. Thure Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.