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Thanks for the replies. I tried what I had on hand with no luck. I did not want to damage the bolt head and I plan to reuse. I'll give it another try with the correct socket tonight. Greg
Just want to add that you need to get the correct torque specs off the ARP web site. They typically are not the same as factory bolts. Go to the web site, look up the part number and then you will be able to see the directions.
Very good to get these details and help full hints. Thank you. Hopefully my next question will challenge you guys a little more. I am mounting this flywheel on an engine that was set up for a 4 speed. I know the pressure plate had markings on it for orientation/ balancing. Is this an issue with the new flywheel? It is going on a fresh 455, B heads, .080 over. 10 to 1 comp. figure I would ask before removing it from the old engine. Greg
Very good to get these details and help full hints. Thank you. Hopefully my next question will challenge you guys a little more. I am mounting this flywheel on an engine that was set up for a 4 speed. I know the pressure plate had markings on it for orientation/ balancing. Is this an issue with the new flywheel? It is going on a fresh 455, B heads, .080 over. 10 to 1 comp. figure I would ask before removing it from the old engine. Greg
What flex plate is that ? It looks awful thick. Is it possibly a drive plate for a marine engine ?
Do you still have the flywheel that was on the new engine with the stick shift setup ?
I need to take some fresh pics and get the name off the aftermarket Flywheel. Funny I thought it looked rather thin. Yes I do have the pressure plate that was with the new engine. Also post more details on new engine shortly. Greg
The flywheel in your picture is for an automatic, correct ? They are usually stamped steel and pretty thin. Unless your camera angle is making it look thick.
correct. TH 400. I think its camera angle. More pics... New engine New New New came with this pressure plate? 4 speed. new The flywheel I want to install from old engine
The "flexplate" is not your normal automatic transmission flexplate. That is some type of heavy duty plate. If I didnt know any better I would say it was a marine coupler for a jet drive ? Did you have it in use with the TH400 ? If so it should be ok. You need to get it off and see if there is a weight on the other side. Here is a picture of a stock flexplate. It is about .100" thick.
OK, Yes the Flexplate is about 3/4 " thick or less. (pictured on the engine) It was in use on the old engine/ trany. The Pressure plate. ( For the clutch) has the rug in the back round is much thicker. Note the paint mark, There is one on the crank also. I understand where your coming from and will pull the plate tonight and look for weighting/ drillings.
That's good news. I should have done this last year when I swapped the frame but wanted to see if I could get some miles out of the old motor. I learned a lot in a year, but it has been a long time since i separated an engine from a transmission. Thanks for letting me ask these novice questions. Greg
I don't know about 'yall, but I've not seen one picture of a "flexplate" yet in this thread. What's been shown are flywheels, which are used w/ MTs only. A "pressure plate" is used only with a flywheel to clamp the clutch disk when the clutch pedal is released. If the OP is bolting up to a TH400, he needs a flexplate, not a flywheel/pressure plate. Whatever they are doing, I hope the final solution doesn't throw off the balance of the engine (assuming its been "externally" balanced, meaning the flywheel / flexplate cannot be neutrally balanced). I don't have a feel for how interchangeable flywheels and flexplates are for a "nominally" externally balanced engine.
Last edited by JohnnyBs68S; Dec 5, 2024 at 12:09 PM.
I don't know about 'yall, but I've not seen one picture of a "flexplate" yet in this thread.
The very first picture is certainly a flexplate. If you look at it there are large cutouts where you think the clutch would ride. There is a better picture of it further down in the thread. It is most definitely something heavy duty but it is certainly not a stick shift flywheel. Like I mentioned earlier it almost looks like a coupler plate for a jet boat engine and Oldsmobile engines were very popular in jet boats.
He said he had it in the car and running with a TH400 trans so I am sure it will be fine. My biggest concern is balance.
I will brush up on my terminology. I think I'm confusing you guys. I'll get some better pics tonight after I pull it off the old engine. Balance is my concern also. 442 PM time to go home. Greg
I will brush up on my terminology. I think I'm confusing you guys. I'll get some better pics tonight after I pull it off the old engine. Balance is my concern also. 442 PM time to go home. Greg
I understand exactly what you have Maybe because its what I do all day. Its just that most guys have probably never seen a "flexplate" that thick and sturdy. Actually the correct term is flywheel for both of them but over the years pretty much everyone uses the term "flexplate" for anything that is for an automatic transmission.
[QUOTE=JohnnyBs68S;1605859 I don't have a feel for how interchangeable flywheels and flexplates are for a "nominally" externally balanced engine.[/QUOTE]
They are completely interchangeable as long as they are both factory external balance.
The crank flange looks very corroded. You can check for flywheel runout but will probably want to remove the crank and get the flange surfaced on a lathe.
The crank flange looks very corroded. You can check for flywheel runout but will probably want to remove the crank and get the flange surfaced on a lathe.
Looks like every Mercruiser marine engine in the world It will be fine. OP, make sure the converter snout goes into the back of the crankshaft easily.
Hello all. So this is the Flywheel removed from the old engine. Speedmaster. It has no numbers or weights. I assume this is a neutrally balanced Flywheel.
Please let me know your thoughts on installing . Greg
Greg,
It looks like there is one extra small balancing hole in it at the top in your picture but I dont think that will be enough for the external balance 455.
Do you know the history of the old engine ? It appears that it must have been internally balanced.
All that being said I really think that the easiest thing for you to do is to buy the correct flexplate for the 455. The Pioneer FRA102 I listed above should work fine. If you want something heavier duty go with a well known name like ATI etc. I have seen a couple of "no name" flex plates lately that were nowhere near correct balance.
You could have somebody balance the Speedmaster Flywheel for the 455 but its probably not worth the trouble. Plus if you are going to sell the old engine it would be best to keep the flywheel with it.
The very first picture is certainly a flexplate. If you look at it there are large cutouts where you think the clutch would ride. There is a better picture of it further down in the thread. It is most definitely something heavy duty but it is certainly not a stick shift flywheel. Like I mentioned earlier it almost looks like a coupler plate for a jet boat engine and Oldsmobile engines were very popular in jet boats.
He said he had it in the car and running with a TH400 trans so I am sure it will be fine. My biggest concern is balance.
Yep, I see what you mean now from the outer bolt holes. I've just never seen an aftermarket flexplate that thick where it bolts to the crank. Thanks for the enlightenment.
OK Bill , that's the way I'll go. Makes sense for the money. The old engine was re built by previous owner. I did not hold much hope for it after it was in a wreck, but has proven to be a strong runner. Until it didn't. I have had the rebuilt one hanging around for a couple years and wanted to give it some run time while digging into the old one. Thanks to both of you for the input. Greg
I will brush up on my terminology. I think I'm confusing you guys. I'll get some better pics tonight after I pull it off the old engine. Balance is my concern also. 442 PM time to go home. Greg
