Another starter thread

Discussion in 'Street/strip 400/430/455' started by Jim Blackwood, Oct 11, 2017.

  1. Jim Blackwood

    Jim Blackwood Well-Known Member

    Specifically gear reduction mini starters. It's become fairly common in the last few years to use a late model small block chevy mini starter on the BB and SB Buicks. The question is this:

    Has anyone had issues with Chevy's change-over to metrics?

    You see, on my son's Chevy 350/383 stroker we discovered that Chevy started with SAE attachment bolts (nach) and sometime in about the 80's switched over to metric bolts. Which by itself would be no big deal except that a metric starter on his older block caused it to make absolutely horrible noises when cranking. The cure was an older starter and it worked fine. Apparently the metric bolts are a bit larger and creates enough slop when used with the 3/8" bolts to make trouble.

    Now what with standardization you'd expect the BBB to use the same starter. Right?
    Then we have the introduction of the OEM mini starter. Don't recall what year. You can bolt one of those up and it works just fine.... until it doesn't.

    Undoubtedly the new mini starter has to use the metric bolts, meaning the same issue with slop on an earlier block. We've been running these for 5-6 years now but reliability has always been an issue. We broke a lot of starter noses, and this latest one is now acting like the bendix is going out.

    I wonder if slop in the mounting bolts could be the problem. What do you guys think?

  2. RoadShark

    RoadShark Well-Known Member

  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I used one of Jamie's mini starters for years, with my first engine. When Jim built my second (current) engine, he used an SFI flexplate, not sure of the brand, but shortly after transferring my mini starter to that engine, it started to make some grinding noises just about every time I started it. I was using the correct bolts that I got from Jamie. Thinking the starter was on it's way out (it had been on the car for 5 years +), I bought a new one from RockAuto. That starter also made noise, and eventually left me stranded. I ordered the Mini Starter that Robb Mc markets. Following the instructions supplied with the unit, I measured the clearance between the pinion gear and the flex plate. The spec from the instructions was 1/16"-3/16". My clearance was less than 1/16", a lot less. The Robb Mc starter is like a Power master starter, it uses a mounting block. You can shim the pinion gear back by using shims between the starter motor and mounting block. Robb supplies one 1/16" shim with his starters. I used that shim, but still had barely 1/16". The starter was grinding, just like the Delco unit. I contacted Robb, and he sent me an additional shim. That gave me the clearance I needed. I also used a 1/32" shim between the mounting block and engine block for gear back lash. The starter works great now, without any noise.

    The Delco starters cannot be shimmed back. Pinion clearance is what it is. I suspect that the Delco starters are fine with a stock flex plate, maybe not with some aftermarket flex plates. Might not be the bolts at all, check the pinion to flex plate clearance. Excessive run out of the flex plate might also cause this.
  4. Schurkey

    Schurkey Silver Level contributor

    It's A problem, it may not be the ONLY problem.

    Yup, you need the step-knurl bolts. ARP bolts have a step-shank that should also work...but I prefer the step-knurl.

    After that, typical shimming process to get the appropriate clearance.

    One hopes that the flywheel is still in good condition, and with no runout.
  5. 65specialconver

    65specialconver kennedy-bell MIA

    You can shim the Delco mini,a couple guys with the JW flexplate had to.Some applications come shimmed from the factory (S-10 comes to mind).But on our cars you shouldn't have to.The metric bolts are 10mm OD on the shank,the stock ones are 3/8 which will cause slop on the metric housing which can give you the milling (grinding) noise.
    ick likes this.
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Jamie, I'm not talking about shimming between the starter and engine block. I'm talking about moving the pinion gear back AWAY (towards the rear of the car) from the flex plate. Again, not adjusting gear backlash. You can't do that with the Delco starter.
  7. Schurkey

    Schurkey Silver Level contributor

    Towards the FRONT of the car?
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    No, the Rob Mc starter uses a mounting block. The starter motor attaches to the face of the mounting block with 4 bolts. You can shim between the starter and mounting block to move the starter motor BACK away from the flex plate, laterally, not radially. I don’t see any way to do that with the Delco starter since it is all one piece. To move the starter back, you would have to egg out the mounting holes, and that is a non starter, no pun intended :)

    Do you guys understand what I am referring to? Shimming between the starter and engine block is common to reduce back lash. That moves the pinion gear radially away from the flex plate. I had to do that as well. The Robb Mc starter looks like some of the Powermaster starters, speparate mounting block.
    Last edited: Oct 12, 2017
  9. 65specialconver

    65specialconver kennedy-bell MIA

    I know what you mean.Never heard of having to do it to a GM though.It can be done by adding a spacer to the armature between the housing & stop collar inside the starter.I've had to do it on tractor units before.
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I'm sure it has something to do with the SFI flex plate that I have. I had your starter on there for many years and it worked flawlessly. As soon as I transferred it to my current engine, it started grinding when I started the engine. I tried a 95 Roadmaster starter and it did the same thing, then the drive failed. The starter would spin without engaging the flex plate. I then went to the Robb Mc starter, and following the instructions, I checked the pinion to flex plate clearance and had almost NONE. It's a good thing I could easily adjust it with this starter.
  11. Schurkey

    Schurkey Silver Level contributor

    I get that you can shim the starter DOWN from the engine block mounting, and with your starter you can move it forward by shimming in a different place.

    My concern is that you say you're moving the starter to the REAR of the car, but wouldn't shims push the starter motor FORWARD? The starter is mounted ahead of the flywheel ring gear. If you want more clearance, the starter (pinion gear) has to go FORWARD by the thickness of the shim...right?

    If you shim the starter motor towards the rear, the pinion gear might never disengage from the ring gear.
  12. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Maybe if I post a picture of the Robb Mc starter motor, it will help.



    Pinion Clearance.JPG


    The shim moves the starter motor and pinion, away from the rear face of the flex plate.
    Last edited: Oct 12, 2017
  13. Schurkey

    Schurkey Silver Level contributor

    Yup, installing a shim to increase the gap between flywheel and pinion will move the starter motor FORWARD, not to the rear.
  14. 12lives

    12lives Engage! - Jean-Luc Picard

    Away (rearward) from the mounting block but forward in the car. :rolleyes: this is fun! I'm in process of mounting my Robbmc, so I see what Larry did.
  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    :)Yes, for some reason, I had it in my head that the starter motor faced the other way. Moving the starter motor away from the mounting block is forward. In any case, that isn’t easily done with the Delco starter. I’m just happy I have a reliable starter.

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