Cascade Crew

fiveoformula · Posted: Wed Sep 12, 2012 9:05 pm Post subject: SBC starter tech

So the sound of my '68 pickup turning over can be loud enough to scare young children on the street, were they known for being loud? I figured it was whacking the flex plate to hard and I needed to shim it. I went to the "needa" section at the parts store and bought an assortment of shims. I installed .080" worth thinking that would space it really well, then i t seemed to get louder when I cranked it! Shocked

so I removed them and went with one .040" shim. Still loud. Is there a real science behind picking a shim? Or maybe I have a really worn starter? What you guys think?

iansane · Posted: Wed Sep 12, 2012 9:09 pm Post subject:

Did the shims not come with the measuring stick?

aaron_sK · Posted: Wed Sep 12, 2012 9:13 pm Post subject:

Does the starter gear or flexplate teeth have a wear pattern indicating a distance problem?

Does the starter make a lot of noise when you bench it? Possible that it's a problem only in the starter.

chevymad · Posted: Wed Sep 12, 2012 9:16 pm Post subject:

Starter may allready be too far away and need to be shimmed in tighter. Do this by adding shims to the outer bolt only.

The correct way to do it is to pull the starter gear into the flexplate with a screwdriver(easier with the solenoid removed) then measure the distance between the 2 sets of teeth. A large paper clip is about the right size and should just slip between the top of the tooth and the bottom of the other.

fiveoformula · Posted: Wed Sep 12, 2012 10:23 pm Post subject:

There was no measuring stick with the shims, and I didn't remove the starter completely to test it, just loosened the bolts and added shims. When I checked the ring gear teeth on the flexplate, they looked pretty good, if anything, the worst wear was on the very tips of the teeth. im thinking maybe my noise is just the starter being pretty worn.

aaron_sK · Posted: Thu Sep 13, 2012 5:56 am Post subject:

fiveoformula · Posted: Thu Sep 13, 2012 4:33 pm Post subject:

Good point there.. lol Ill check how they mesh with a screwdriver and let you know. I never thought the clearence might be to far...
Another thing I thought of is that this motor is a 400 smallblock, put in where a 327 was originally, I thought I read somewhere that the 400 needs a different flex plate than any other SBC since it is externally balanced. Is there any chance that it could have the wrong flexplate in, yet still start and run?

Twilightoptics · Posted: Thu Sep 13, 2012 4:37 pm Post subject:

The difference is just counter weights. It's still the same tooth count. 153/168.

fiveoformula · Posted: Thu Sep 13, 2012 4:43 pm Post subject:

So if it has the incorrect flexplate, that wont effect starting at all BUT my engine could be unbalanced...? thats not good I have to check if there are weights on it.

Twilightoptics · Posted: Thu Sep 13, 2012 5:10 pm Post subject:

Some get converted to internally balanced. If the motor doesn't shake like a dog shitting peach pits, I'd run it.

fiveoformula · Posted: Thu Sep 13, 2012 6:18 pm Post subject:

Alright then, I have running pretty smooth now so it must be ok. It still has the funky balancer, that's how I found out it was a 400 after I bought it.

fiveoformula · Posted: Sun Sep 16, 2012 1:53 pm Post subject:

For an update, Brandon was right, it needed to be shimed closer so I added a .060" shim on the outer bolt and its mostly quiet now. Although I noticed that sometimes the gear on the starter would stick when I pulled it out with a screw drive to check the pattern. And ever 5th start or so it does make a nasty noise like its possibly sticking. So it might be new starter time.
And I double checked my flexplate does have a big funky weight on it so I think its correct to the 400.