I bought a 1985 Camaro with a 1970s 350 and a T5 transmission. I am having starter grinding problems. From what I was told, the block has been drilled for a straight across starter bolt pattern. The bell housing has been notched where the starter fits to accommodate a larger starter nose cone, I guess. They flywheel has low spots on the teeth where the starter has ground them down. I would like to replace the parts and have trouble free starting.

What is the correct flywheel for a older 70s 350? What starter is correct? Straight bolt or Staggered? What parts should I ask for at the parts store?

Thanks!

 

I have the same combo in my camaro. Use a thirdgen 2pc RMS flywheel(84-86), and i believe I used a starter from the same year as the flywheel, but I can't remember for sure.

 

The 1970s 350 I have has a 2pc RMS, I don't think a 1pc RMS flywheel will work.

 

Anything that will fit in your bellhousing that is for the older 2 pce RMS crankshaft you have in your engine
Don't worry, if you buy the wrong 1 pce RMS flywheel for a late model engine it won't even bolt up

Starter style relates to the size (diameter ) of the flywheel, not the year or block type.

Straight bolt pattern for 153 tooth flywheel
Staggered bolt pattern for the 14" 168 tooth flywheel

Ever considered that hole may not have been drilled perfectly affecting the alignment of the starter to the flywheel teeth?

 

That is what I was also wondering. The hole was drilled by a mechanic who has been in business for 30 years so I hope it is straight.

The ring gear teeth have low spots. What would cause this?

What would a misaligned starter do for damage to the flywheel?

Is there such a starter that uses staggered bolts and fits a 153 tooth flywheel?

 

All sorts of damage if the starter teeth do not correctly mesh with the flywheel teeth.
There are even shims supplied with most starters to achieve the correct spacing
Google SBC starter clearance and measure yours to see if you have the correct clearance between flywheel and starter pinion

Not that I am aware of
There are however ,straight bolt aftermarket starters that do both patterns

 

I know about shimming a starter have tried. I think the flywheel is beyond saving at this point, some of the teeth for spots of a inch or two look pretty worn down. The previous owner said he had problems with grinding, but I am unsure if he put on a new flywheel when he built the car or used a old one, he used lots of old parts.

I meant what would happen to the starter gear and flywheel if the starter bolt hole was drilled ever so slightly off? I can look under the car tomorrow and see if was done right, but I have a old picture of the engine on a hoist and when I zoom the picture in, the starter looks straight in relation to the edge of the block. The block only had the staggered pattern and was drilled for straight across bolts.

I'll get a new flywheel but want to find out what the cause of the original failure was. No point wasting time and money.

 

You're right, I don't know what I was thinking. I know it's a 2pc seal, I was typing that response on my ipad and must have fat-fingered it.

Edit: Went back and corrected my original post.

 

How do these flywheel teeth look? Some are a bit worse (only pic I got). None of the teeth are missing, just worn on the face. Also the tips of the teeth are worn down.

Also I took the starter off today and the nose cone is cracked. The starter was even shimmed. Now I have to figure out if the starter is misaligned and eating the flywheel and wrecking itself, or what the real problem is.

It almost seems like sometimes the starter grinds and spins freely, and other times the starter gear bottoms out in the flywheel and struggles to turn over.

I assume that the grinding is due to the cracked starter nose cone. I will try and look at the bendix gear and see if the wear pattern is even or offset indicating that the starter is not bolted true to the block.

There seems to be only 1 starter in all existence that uses a staggared bolt pattern for a 153 tooth flywheel. Its pricy though: http://www.summitracing.com/parts/cs...make/chevrolet

 

Pretty good
You are always going to get some "damage" on the front of the tooth

 

At what point would you consider replacing a flywheel? There are no missing teeth, but the faces are worn. There even seems to be some low spots on the flywheel teeth. I'm not sure I want to risk another starter if there will continue to be trouble. It is still yet to be determined what is causing the actual grinding/nose cone breaking.

I should also consider engine kickback from excessive timing. Base timing is in the 12-14 degree range. Perhaps that is what I can feel while it turns over sometimes. It feels like the starter turns the crank a revolution then stops and I have to let go of the key and try again, and then it will crank over easy. I thought the teeth were bottoming out and binding, but maybe I've been wrong.

Engine has 10:1 compression and a carb, so there is no timing pulled by a computer when cranking. *Also I do not have the front starter brace, but I will get one.

 

That flywheel looks fine to me.

Flywheel failures aren't the CAUSE of your problem, they're merely one of the SYMPTOMS.

Most likely, your block has The Problem, wherein the starter bolt hole pattern is too far from the crank. If it makes that horrible squealing sort of grinding noise that you can hear from 400 yds away and turns slow no matter what, and gets worse FAST as you add shims, and breaks nosepieces when you hook up a REALLY HOT battery to it, then that's almost certainly what its matter is.

It was caused by (near as I can tell) one of the gang-drilling machines in one of the engine factories, slowly drifting out of kilter, starting around 1971 or 2. AFAIK ALL V8 blocks were affected; big, small, Corvette, truck, full-size, ALL of them. In about 1975, or so, a new starter part # appeared in replacement catalogs, with listing for cars that didn't exist; "1973 Checker Marathon with 454 and Powerglide". Yeah right. But, it located the starter about 1/8" closer to the crank, which solved The Problem by way of an end-around. GM's non-existent toothless gutless lazy incompetent ineffective worthless "quality control" finally discovered what the rest of us had known for years, in about 79 or 80; and blocks after that are OK.

Unfortunately for the matter at hand however, the starter they introduced (the common # is 4347) was for 14" ring gears though, that being the only kind there was during the affected years; so you can't use it with a T-5.

Solution is, a new block; avoiding the 70s ones.

 

A new block isn't the most ideal solution for me at this time. Would using the CSR mini starter that uses an adapter to use the staggered bolt pattern address the problem of the starter bolt position?

If I were to do a new block up, I do have one, it is a 1991 350 roller core, could I use the pretty much new forged pistons and re-sized rods from my 70s 350 on the new one? I know the crank is different. If that is possible I may go that route. Last time I had a block tanked and bored with bearings supplied it was about $500 so not to far off.

 

I still have a good starter that was free I want to try. I want to get the starter brace on and one last try at shimming it to see if that will work. I have never tried the starter brace, I didn't even know it existed. If that doesn't I will have to look at a new block.

 

Rarely is, for anybody; unless they want their car to start.

Those pesky details.

Of course not... how could that relocate the holes in the block?

However, some of those DO hold the starter closer to the crank, thus requiring more shims than the stock one did; so it's not impossible that it might offer some improvement. I'd hate to be blamed for telling you "go out and get one, it'll fix it" though.

 

I took some more detailed pictures of the starter and flywheel. 90% of the flywheel looks good except for about 6 or 7 teeth. I took the solenoid off and manually engaged the bendix gear and there seems to be good engagement. When I tried to get the bendix to mesh with the flywheel it took some effort to get it move into the teeth. It seemed to hit the teeth ridge but when I moved it back and forth multiple times with effort it went it. It took effort to retract it. Would that be due to the flywheel position being out because of the engine being off?

With the bell housing on I can't really tell how much clearance there is between the bendix and flywheel. I am going to drop the transmission and bell housing, to be able to shim and setup the starter one final time before I give up. I will also be replacing the ring gear due to the 6-7 teeth really chewed up.



In this pic you can see that a couple of the teeth are worn out in what seems to be a step pattern.


Some of the teeth are shiny on the tips which would indicate that the starter was bottoming out. Or it might of been from the starter spinning when the housing broke.




The starter bendix gear does not show any signs of the flywheel bottoming out.



Also the drive end bushing in the starter housing is just trashed after only 6 months.

 

The flywheel looks perfectly fine to me. All I see is, the normal wear that happens because the engine tends to stop at one of the same 4 points every time you shut it off (close to TDC on the compression stoke of a cyl), which therefore is where the Bendix always hits it.

Look closely at the top-most pic in the last post, which appears to show the teeth just barely engaging. That is also what I see on the Bendix teeth; their wear extends barely halfway down their depth, meaning that is the deepest they EVER engage at ANY point during the engine's rotation. This is consistent with The Problem as posted above. You can prove this to yourself by adding a 1/8" shim... if that makes the starter quit working completely, you can be sure that THE ROOT CAUSE is, the block was manufactured wrong, and no amount of putzing around with starters and flywheels will move the starter bolt holes to the right place.

 

I think the top picture is a bit deceiving, I wasn't trying to engage the bendix at that point, I was just taking pics as I turned the crank with a socket. I will get a better pic, but when I manually engaged the bendix the gear engagement was almost full depth. I do see what you mean about the wear pattern on the bendix going about halfway down though. I will get a better pic of the gear engagement.

How much of the bendix is supposed to engage towards the flywheel? The wear pattern shows the gear engages half way, but when I manually push it out, it hits the end of the starter nose indicating it is going full throw.

If the holes are out of alignment, is there any hope of getting this to work for a while until I change blocks?

Finally what is causing the starter nose housing to break? The first one broke when I put a new starter in the car because the original one on died. The engine was on a stand for 9 years when I bought the car and I had to put it all back together. I didn't shim that one at all and I know that may have been the cause. Now the other day when the second one broke, it had been working for 6 months, not well, but it was working.

 

I wasn't talking about how far out the Bendix had moved; only, how deeply the teeth are engaged.

Doesn't too much matter how far across the flywheel teeth the ring gear teeth go. THey usually go at least halfway, but not usually all the way. Doesn't make a whole lot of difference once you get past about halfway.

Your starter is too far from the crank. Root cause of your problems.

Not really; unless you can figure out a way to get the starter closer to the crank.

That's fine... shimming it will only make it worse. Unless of course, you know where to buy shims that move things TOGETHER instead of spacing them APART. I used to know a place like that, where you could get all sorts of things like that including drill bits that drill rectangular holes and rear end gear sets that allowed putting a 2 series gear on a 3 series carrier; but they went out of business. Old d00d retired. Went back to the Pleiades or some such where.

The excessive force placed on it by the teeth not meshing properly. When properly meshed, the side of one tooth pushes on the side of its opponent, in a direction radial to (around) the shafts. Most of the force goes into rotation. When unmeshed like yours are, the flat of one tooth pushes against the tip of its mate, and tries to push them apart. Most of the force goes into trying to break something.

 

Well I think I'm near the end of trying to sort through this problem. As stated above the starter doesn't seem to be engaging near enough of the flywheel teeth as seen here:


I think that I have at least 2 strikes now. 1) The starter bolt holes being too far away from the crank. 2) The drilled starter bolt hole being drilled off center causing the bendix gear to drive in at an angle towards the flywheel, as seen here:



As a thought, would milling the starter housing mounting pad down move the bendix gear upwards on the flywheel decreasing the gap between the 2 sets of teeth?

At this point I'm not sure if I even want to try and make this starter work. I have a 350 roller block that I could have bored and honed and would be less headache in the long run.

 

I would give up. the other guy drilled the hole wrong, Looking at the bushing wear opposite the ring gear, the starter is too close to the ring gear. That's what's cracking the starter nose.

 

You say its too close and sofakingdom says its too far away. Either way I think the bendix is engaging on an angle.

 

I installed a CSR mini starter part # CSI-100SBP that uses a adapter plate that bolts to the staggered holes and everything is now working 100%. Pinion gear backlash was measured and came out right in spec not needing any shims.

The original problem was caused by the straight across starter bolt hole being drilled off center causing the starter bendix gear to throw into the ring gear at an angle.

 

bent starter bolts will also cause this to happen- and it's really easy to bend a starter bolt... all you have to do to bend it is to let the weight of the stock starter hang on it while the bolts are loose and it will bend a little bit... been there, done that, broke a few starter noses until i noticed that the starter would wobble when i was turning the mounting bolt... a $5 pack of Dorman starter bolts fixed it right up... i learned this 20 years ago and never, ever let the weight of a stock style starter hang on a loose bolt any more.

 

Good to hear you got it solved!!!!

 

As I noted back in post # 4

 

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