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flywheel problems sbc400

YZEATER

YZEATER

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does anyone know where to look up chevy flywheel casting numbers or know what numbers go with what engines. i have a pile of flywheels and need to compare an aftermarket one with a chevy one. at one time i bought 2 sbc400 flywheels. i didn't mark them.

i have numbers 3988795 and has 'nodular' stamped on it. i have 2 of these.

4091599- 1 of these.
973468n- 1 of these.

i have 2 others, and have pics. i have one i have no idea what it was off of.

i need to find out which is a 400 sbc to match up to a aftermarket sbc400 my buddy has. he has had starter grinding problems since he put in this engine i got for him from another friend. more on that later. he pulled the transmission out to get this problem sorted out. i don't know how many starters he has ruined. he just finished off a vortec $150 starter.
 
The 454 flywheel and 400 would look similar just cuz they are both externally balanced. I'll take a picture on one I have for a 400 and check numbers
 
hmm, i don't have any that look like that. i remember i had a 454 that kinda looked like that. i'll take pics of all the ones i have tonight.

i totally lost track of what i have.
 
I don't have a way to look em up, but many times I have good luck with casting numbers just by googling the number, along with "casting" or "flywheel" or whatever it is, or maybe both words if the search is too big. Many times you will find what it is. Good luck getting it sorted out.
 
i have these.
IMG_20110730_184829.jpg


IMG_20110730_184836.jpg


IMG_20110730_184843.jpg

IMG_20110730_184849.jpg


IMG_20110730_184904.jpg

this is what my buddy is current;y using, it's a summit brand, for a sbc 406.


IMG_20110730_184911.jpg
 
the #1 has a pad that is very slghtly raised, only about 1/16 if that.


look at #5 on the left side SPIDER.
 
Are you sure if the engine is an original 400 crank or an aftermarket built piece with an internally balanced crank and longer rods? It looks to me like there was some balancing done to "Toms" flywheel that may have been done custom?

Was the engine running fine/smooth other than the starter issue? You may need to have a machine shop balance the new flywheel to match the old one if it was a custom balance job when it was built. I am sure you'll figure it out.

#5 looks junk, a lot of the teeth are missing or flattened.
 
it's a 400 block. built to a 406. a friend of my BIL had it built. he ran it for a bit, i bought it for a spare and then sold it to my buddy for his buggy. it came with an summit brand flywheel for a sbc 400 ( part #'s match up correct). he had the flywheel resurfaced, and a new ring gear put on. he's had starter problems ever since. it's like the starter gear does not engage far enough onto the ring gear and eventually strips out after 6 times starting. he tried standard starters and then bought a vortec starter because i said to and that's what works for my engine.

when he had the flywheel resurfaced he got a small shim to put between the crank and flywheel to make up the difference,(.025? i think, he is using a hydraulic clutch).

i need to know if i have any 400 sbc flywheels to dimensionally compare them to the summit flywheel.

i also think he needs to change his wiring around to have the ignition on a separate switch to be able to get the engine turning over first, then hit the the ignition. i have my wired that way and works better (knock on wood.)
 
i don't know if we do or not yet. he was thinking of taking the bushing out of the end of the starter to get some more travel on it.

i'm at a loss on this, and it's costing him money every time he trashes a starter. he's hardly got to use this engine.

i did some searching around and i found some info about there being a older , different starter for 400's? having a cast iron nose. some of our other friends have had problems like this too with 400's.
 
Have you seen one that was stripped out?
What did the damage look like?
In other words, was it on the front edge of the teeth, outer edge of them, all the teeth?
The wear pattern should tell you why they are stripping out and maybe what to do to fix it.
 
on the leading edge of the teeth, not the tips of the teeth. it doesn't seem to engage far enough. the solenoid doesn't push the gear towards the transmission far enough.
 
Ok, if we are on the same page, the bad starters should have the ends of the teeth worn off but some good untouched teeth material on the back side towards the starter.

That shim would tend to aggravate that condition, but if its .025 I would not think that it enough to cause that.

Of course, a cracked bell housing might be the problem, but the cause I think might be it is so obvious I would assume he would have seen it.
Is the new ring gear on all the way?

Plus, and more likely, is it the right ring gear? I have never compared them, but there are a ton of vehicles out there, and I would doubt that all the different starters have the exact same pitch and tooth count.

Plus, some of the old Fords had two different starters. They were sold as stick vs automatic, but you could find them on opposite cars. One was 3/8 inch longer than the other, and if you swapped the flywheel you could wind up with a wrong starter.

Since it seems to have started when the ring gear was replaced, I would start there.
If he has one of the old starters left, I would pull the Bendix out and manually slide it into the ring gear's teeth to see if it fits.

The wrong pitch might let it only go it a short way.
 
yep, the ends of the teeth are chewed off. the ring gear is flush with the edge of the flywheel. the shim would only set it further away, but only by .025, i think that was the thickness, whatever the removed during resurfacing. now that he has the trans out, i can go up and look at it myself and try to figure this out.
 
Cool, if the tranny is out, it should be simple to at least see what is wrong.
You can disconnect the short jumper from the solenoid to the starter motor, and then you can fire the solenoid back and forth to see what is going on without the starter turning.
If you can get a light and maybe a mirror in there, make sure that the Bendix is actually hitting the inside end of the starter housing when it fires.
A bind might make it look like the starter is too short even when it isn't.
 
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