• If you log in, the ads disappear in the forum and gallery. If you need help logging in or getting registered, send request to: webmaster@southernairboat.com

Flywheel question??

AirRanger

AirRanger

Well-known member
This weekend I attempted to bolt my gear reduction to my 4.3L. I've always been told that this engine was identical to a sbc minus two cylinders. The bell housing seems to be the same but I found that the six hole bolt pattern at the crankshaft and the flywheel did not align to the gear reduction. Because I can not add extra adapters between the flywheel and the reduction due to spacing issues I am hoping that some one has seen this or can offer any solutions. Or am I simply SOL.
 
your fly wheel should just bolt to the crank shaft and then the gear box should bolt to the holes in the fly wheel where the trans torque converter use to be.
 
Should the flywheel have a separate set of holes that line up with the holes on the gear reducer? The flywheel bolts up to the crank perfectly. The best way I can describe my problem is kind of like having two wheels each with a six lug pattern but say one is spread out a little more than the other.
 
It`s the flywheel basically.A standard uses a flywheel and automatics use a flex plate,which is whats used for airboat gear drives.If you flex plate don`t line up with your crank,you have the wrong one.
 
In your first post you said the 6 hole pattern at the crankshaft did not line up,are you talking about the six holes on the drive plate for the gear box don`t line up with the flex plate?
 
Sorry Joe, I just re-read my post. It was a bit confusing. I edited it. Please re-read it again. Thanks
 
OK :D sorry this is from classic airboats site,they all so make flex plates with different patterns,hope this clears things up for you8)
Place rotator on engine dowel pins and hand tighten securing bolts.
2. Rotate rotator dampner bolt holes to match bolt holes on automatic clutch plate.
3. Secure rotator attaching bolt to engine block using lock tight.
4. Insert spacer washer between automotive and roator flex plates.
5. Insert large flange bolt through rotator flex plate, through spacer washer, and through automatic flex plate. Secure large flange nut and hand tighten.
6. Rotate flex plates to next bolt hole and repeat Step 5.
7. Any automatic flex plate bolt holes that do not align with rotator flex plate bolt holes must be drilled. Use rotator flex plate bolt holes as pilots to drill finish holes in automotive flex plate.
8. Six flex plate nuts and bolts should be done in sequence. Bring torque gradually up to maximum of 35 ft. lbs. Use lock tight.

CAUTION: Do not "grunt down" and fully torque each bolt as it comes around. You need to bring up torque in sequence.

REMINDER: Use lock tight on all rotator hardware except prop bolts
8)
 
I guess I'll be doing some hardcore drilling. I just hope there is enough clearance around the original six bolt heads for the adapter plate to sit flush.
 
#4 You use spacer washers to take up the extra space between the two plates, And remember you can get a flex plate with different patterns.On my Buick i only had to drill 3 holes that didn`t line up.Or call classic or one of the many other manufactures and they can probably send you one ready to go
 
Is your motor flywheel the staggered and the gearbox are all the same. This is most common. You can buy gearbox's with the staggered or the straight and there are even to straights a large bolt patern and a small bolt patern. I prefer the staggered because 90% of the time they line up. Hey Stan I made a jig and buy new flywheels because you can buy the G.M.s with only three holes then when I see what flywheel the gearbox has I transfer the correct holes from my jig and Drill them!
 
WT, I have a small hole pattern on the crank and flywheel and a large hole pattern on my gear drive. How would you attach those together?
 
You don't want to hear this but change the flywheel or change the gearbox flywheel. Are all 6 of your flywheel bolt's in the same Dia. If so I can get you another gearbox flywheel.
 
They are all the same diameter. I think the real bad news is when I tell you that the gear reduction is an aircraft planetary. Am I SOL ? I can take. I may be searching for a 350 but would really like to get this set up to work.
 
You must log in or register to reply here.
Back
Top