A story about Chevy small block starters and flywheels

Hello everyone,

I really enjoy the enormous amounts of information I find on the HAMB, but I always feel guilty after I learn so much and don't contribute anything in return. Well, I'm not sure how helpful this will be to the general reader, but maybe someday somebody will find this worthwhile.

My El Camino has a bad engine. My good buddy Dan offered me use of his "spare" 327 (he's that kind of guy, and on the HAMB-- go figure), so I'm in the process of a transplant. Today I thought I could get the new motor in place and put the hood back on, as we are expecting rain tomorrow-- but I ran into some problems mounting the starter.

Do my neighbors tell me this is unacceptable? No. Would I blame them if they did? No.​

With automatics, Chevy starters bolt up with two bolts into the block (on some older manual trannys the starter bolts to the bellhousing). This 327 (mid 60's) has three tapped holes for starter bolts (I don't know if all chevy small blocks are this way, because this is something I've never really paid attention to). Anyway, one of the bolt holes had been screwed pretty good. In the picture you can see it's the one that's all shiny-- that's from a Helicoil attempt that failed the other night (another story, but one I'd rather not admit to). Of course, as my luck would have it, the starter I want to use from my dead motor relies on bolting up to this bad hole. However, I'm not discouraged, because I (like many of you) happen to have a milk crate full of starters on the shelf that I can now justify having held on to.

Bad Hole.​

I get down my spare starters, and am happy to see that it appears that I have three that will bolt up to the block with the two good holes. "Great, I'm back in business." In fact, I even digress from the motor transplant to clean two of them up and test them with some jumper cables, and mark them as "good" with a paint pen, just to know for sure their condition in the future (which only leaves three filthy starters in the milk crate on the shelf! That's progress). I go to the assortment of starter bolts I've collected over the years and get ones that are the right length. The starter bolts up, and it's time to get the motor off the stand so I can put on the flexplate.

Starters. Left to right: the one I was using on my bad motor that won't mount, one that will mount, starter from a cadillac big block that appears inter-changable with chevy small block, starter that looks like it will mount (but it won't).​

Well, it was no surprise when the flexplate didn't fit. I sort of remember from a few years ago (when I was trying to learn about flywheels for a NV4500 install in my C30) that they come in different diameters. Luckily, I had just seen that data page upstairs among catalogs and magazines that I need to put away sometime soon... My flexplate is of the 14 inch variety, and I figure that the starter I was trying to use is cast to work with 12 3/4 type.



"Fine... one of the other starters will work." I was not defeated (at least I thought not at the time) because I noticed one of the spare starters was cast with three mounting holes (I figured it was engineered redundancy, so that this one starter could be used in several applications). I put it side by side with the starter that I knew would work with this flywheel (but wouldn't mount), and it appeared to have the same "relative drive position" in reference to the starter bolts, and I was home free.

Not quite. Of the three holes in the starter, the two bolt holes I needed to use would not match up with the holes in the block. Aaaargh! Even though this starter was cast with three holes, only two of them would match up with the two in the block... and on this 327, one of those two holes is bad! Yeah!

This prompted me to figure out what da heck. After I thought I understood what da heck, I decided to share it with HAMBland. I think it breaks down like this:

For all Chevy small blocks (both pre '86, two piece rear main seal, and post '86, one piece rear main seal) there are big diameter flexplates (14"), and small diameter flexplates (12.75"). The appropriate corresponding starter has to be used for either.

Old style small blocks have a 3.58" diameter crank flange bolt pattern (and a two piece rear main seal). New style small blocks have a 3" diameter crank flange bolt pattern (and a one piece rear main seal). You can't use a flexplate from a pre '86 engine on a post '86 engine, or vice versa.

On pre '86 engines (possibly also with post '86 engines-- but I never mess with such new technology, so I can only imagine), starters that are compatible with the large diameter flexplates mount to the block with the bolt holes that are 1. furthest from the oilpan, and 2. closest to the motor mount. Starters that are made to work with the small diameter flexplate mount to the block with the holes that are 1. furthest from the oilpan, and 2. not closest to the motor mount (I fought the temptation to talk about these in terms of sides a, b, and c of the right triangle formed by the bolt holes... but I fear I'd get lots of strange looks).



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Yep, that's what I learned today, the hard way. I doubt this is comprehensive for all variety of chevy small block, but it is probably a good rule of thumb for the older motors. Has it been a waste for me to have stored those starters for this long? I don't think so... I will be able to use on of my spares on this project. One of the ones on my shelf works just fine and bolts to the good holes on this motor. I just need to get the smaller diameter flexplate (don't have one of those on the shelf... at least I don't think I do).

It was a little over $40 at Napa, and I'll be able to try again tomorrow (or Saturday... I guess I should go to work tomorrow).

Thanks HAMBsters, for reading this. It's long, I know.

acosta

 

it would be nice if you could somehow post that info sheet so we could read everything on it or make our own copy. thanks for the info.

 

Thanks for posting

 

I went thru the same thing basically what it comes down to is 85 and older sbc takes the 168 tooth flyweel, with the angled bolt starter, and the 86 and newer sbc take the 153 tooth flywheel, with the staright across starter!! basically the same thing you said!

 

but all the sbc stuff interchanges with one another....

at least that's what all the Chevy guys tell me.

I'm learning too in case I mess with one in the future though.

 

no , actually there were many pre `86 SBC's that had 153 tooth flywheels

 

It all depends on the application.

The good thing with all the spare starters is that you can pretty well mix and match. . The Chev end frames will fit right on the Cad starter field housing and armature so the combinations there are pretty well endless. Makes it easier to come up with a heavy duty starter without going out and buying one too. And brushes and bushings are Cheap.

 

Thanks for the info and sharing your experience.

Mike

 

I made an info sheet for everyone. If you see a mistake let me know.

 

Hi guys--

It's really flattering to have this episode well received.

Hi Brady--
I couldn't find the same table I printed off a few years ago, but I did find the same information online. I harvested it and am attaching it to this reply.

Hi Carlos--
I wish it was that simple. If it was, I wouldn't have encountered this problem, but instead would still be stymied by the bad bolt hole (grrrr). I think 36-3window's reply is more correct. Each of the starters in my pile are all pre 86 taken from cars and trucks I've had in the past, and they are of both sorts. You did, though, nicely summarize how to identify which starters go with which flywheel: 168 tooth="angled bolt" starter; 159 tooth= "straight across" starter. I think the thing to watch for, though, is that pre-86 flywheels will not bolt to post-86 cranks, since the bolt pattern circles are of different diameters. Thanks!

 

ahhhh! You beat me to it, Mark! I think that is the same table I found online a few years ago. Say, where is Parker relative to Denver? I'm in Louisville, we might be neighbors.

 

There was an article in the late 80's in street rodder that when over this toppic I wish I still had it.

Parker is south east of Denver just north of Castlerock.

 

I guess iam wrong then, thats what i was told. but it still sucks because that slowed me down on my process but i got the right flywheel already!

 

Good stuff guys, mod should save this in Tech articles if hasnt been done so already. I saved it in my comp. but by the time I need that info this thing will be outdated and long gone.

 

Acosta, thanks for taking the time to post your findings. Chevy flywheels and starters have always been a challenge for me and I used to work in the parts department at a Chevy dealer.
BTW, I am GLAD you are NOT my neighbor. ..., I probably wouldn't get any work done on my own car, hanging out with the neighbors Chevy and all

Thanks,
Dale K
Cleveland OH

 

168 or 153 teeth...stagger bolts for 168 teeth (# 3510 starter ) straight bolts for 153 teeth (# 3664 starter )
Or you can use a generic mini starter. They have 2 set of mounting bolt holes, one set for either size flywheel.
Dave
BTW , the caddy starter is a high torque unit that will work for the 153 tooth flywheel.

 

heres another one for you..
I have a 57 corvette 283 in my 1927 T bucket, it was coupled up to a 1947 ford 3 speed tranny and i am switching to a 700r4 and narrowed 9 inch rear end. The block has all three holes for the starter, and the inner one for the the straight across starter application is smaller. I matched up the new flex plate with the the old flywheel and both are the bigger size, 168 tooth i believe. I bought a new high torque starter advertized to work with the large flexplate and the small block chevy. Now, I received my cool new gloss red high torque starter in the mail, and went to bolt it up. Come to find out, none of the holes are tapped! the starter has 4 holes in a straight across pattern for either engine application, and the outside hole and the smaller inner hole match up. the starter gear is meant to always be in position on the flexplate as far as i can tell.

Any suggestions for me moving forward with drilling the smaller hole out bigger and tapping the two required holes??

 

RCD makes a nice blower starter.

 

Typically, the first gen SBC's were designed to work with the old style starter that bolted the the front of the bellhousing with three bolts instead of the underside of the block.
My 1959 block is drilled and tapped for both small and large flywheel starters FWIW. It is a truck engine with the staggered valve cover bolts.

 

Don't forget the small bracket that mounts to the other end of the starter to the block.... More imporant than you think

 

good to know and thanks for posting....I'm sure to be knee deep in this soon....
​

 

Other Bracket?

 

other bracket?

 

he is probably talking about the small bracket that bolts to the front of the starter and the block. it helps support the starter. i lot of guys leave it off , but i always use it

 

Yeah, heard that lotsa times too.

 

First,,thanks for posting the info sheets.
I have a flywheel that is numbered 3973456--and what appears to be an "N".
Also has GM2 and A303 on it.
168 tooth(for sure)
Takes an 11" clutch
Crank flange,,I measured center to center across the 6 bolts & its 'about' 3.580.
With ring gear,it measures 14-1/4 across the teeth and 13-1/4,flywheel only.

So my question is,,what does the 3973456 number leave me with,and how do you tell if the flywheel is for a 400?(I dont 'think' it is),and what starter do I need?
This is a 350 block using a 350 crank.I'm setting it up as a blown & injected Fueler to run on a stand,so I wont be using a balancer,just a crank hub & blower pulley.
BTW,,the orange starter housing is a "tool" I made about 30 yrs ago.
It works great for installing/pressing on CV boots & collars on early Toronados & Eldos.
Thanks again for posting the info!
Troy Cagle

 

Anybody?

 

Great info thanx for sharing.

Not to hijack, but I'm looking to mate a 67 283 to a TH 200R4.

What starter should I be using/looking for?

Rat

 

Ok to mess with you guys, i have a 82 block, i run a 92 firebird 700r4, not sure of the flywheel, and ive been useing late 90's ministarters one i got from a camaro the other i think off a shelf or out of a box. These mini starters work great and are cheep. stagered bolt pattern and all.

 

Acosta, I can't thank you enough for your article. I purchased my 39 ford when I was 15 yrs old and due to lack of time and money was not able to work on it. It is now thirty some years later and my 16 year old son got motor running and installed disc brakes.

Motor is 69 327, bellhousing is 56 chevy so the starter is attached to the bell housing. Flywheel has 168 teeth.

I purchased high performance 153 tooth flywheel from chevrolet back in 1980.

Several months ago, I could not understand why I could not use 153 tooth flywheel with the 56 bellhousing, until today after reading your article. Now I know that I can purchase new starter (made for my 153 tooth flywheel) and new bellhousing (as the 56 housing cracked today) made for new starter bolted onto block.

I saw pic of three bolt holes and went out with son and we removed starter and there they were...

I can see the light! Again THANK YOU.

Best Regards,
DJC