I am in the process of trying to startup an 8BA flathead that has been converted to 12V for the first time and am running into difficulties with the starter motor that probably has a simple explanation but since this is my first time I am obviously overlooking something. I have bench tested the starter which is a brand new 12V unit so I know that it is functional and after mounting it on the engine I am attempting to have it turn over directly from battery to jumper cables to the starter to eliminate any other potential issues. When I power up the starter it might engage the gear but beyond that does nothing. I can crank the engine with a socket wrench and also had removed the plugs to eliminate compression. I don’t have experience to know if the crank is harder than normal. To me it seems that it should need less torque but it also seems easier to crank then my Model A engine that I am replacing. One thing that I did notice was the screw on the starter drive head wasn’t fully down on the spring and I am thinking it may protrude into the housing thus interfering with the shaft turning. Should this screw be fully down on the spring? I tried to tighten it but may have stripped the screw as it won’t screw down beyond a certain point now.
Being 12 volts, it has to be aftermarket. Aftermarket parts have reputation lately of being bad out of the box. Do yo you still have the original starter from the engine, or can you borrow one? If so, I'd install it and try again.
This is the only starter I have as I had purchased the engine without one. This starter does crank well when I test it on the bench separately.
What’s the cca of the battery you are using? Do you have it - to ground + to starter? Is the starter spinning in the correct direction? Is the starter too close to the flywheel?
I’ve tested it with two different batteries to make sure that wasn’t the issue. Both are over 600 CCA and are fully charged up. + to starter motor and - to ground (bolt on bell housing). Spins in correct direction when I bench test it. Starter is mounted on truck bell housing with matching starter plate. Using jumper cables to eliminate any other wiring circuit issues for now and measuring over 600A going through when connected.
You may have the wrong starter plate. There are two kinds. In appearance, they both look and install the same. There is a big difference, however. One has the starter mounting pad parallel to the flywheel and the other one has the starter mounting pad slanted slightly toward the engine. Pretty hard to see while it's assembled. The one with the slanted pad will not work with your situation. The flywheel and starter will bind and it will not turn. Take the starter off and both will test good. The screws on the Bendix drive need to be tight and the lock tabs bent tightly against the bolts. Trying to force it can destroy your Bendix drive and/or bend the starter shaft, rendering your new starter useless. Check your starter plate.
Good theory from Glenn, ^^^, I also would like to see that bolt down closer to the spring, they have a shoulder on them so it won't go tight, but should be closer, and also, on the corner of the hex head looks like a witness mark from the bolt crashing into something.
Here's a few photos of my Bendix starter that has been converted to 12V Neg ground on a 1953 8BA engine in a 1940 Ford. I am using a matching 1949-50 Merc pressed steel bellhousing and starter plate. You said you are using the truck bellhousing. Is it the cast bellhousing for the 11 truck clutch. As was mentioned earlier, the biggest problem is not using the correct matching bellhousing and starter plate. You must first identify the starter plate and bellhousing you are using so you know you are on the right track. Can you post photos of what you are using? Perhaps they will help. NOTE" When I installed my 8BA in my 40 Ford I used a 1950 Mercury flywheel, pressure plate, and cutch Here's very good info. on converting your 6V starter to 12 V. Good for future reference. How To Convert 6V Starter to 12V - The Ford Barn Go to this thread and read everything with the word starter and bellhousing in it. The Ford Barn - Search Results Here's the Merc starter plate and bellhousing. Notice it is smooth. Ford and Mercury Trans Adapters (vanpeltsales.com) and Mercury Flathead V8 Stamped Steel Bell Housing 1949-1951 8CM-6392 | eBay This starter plate WILL NOT work. ORIGINAL 1949-53 FORD V-8 FLATHEAD & 1949-51 MERCURY V-8 FLATHEAD STARTER PLATE | eBay Read this: Difference between pre 1949 flywheel and 49-51 flywheel - The Ford Barn This starter plate WILL NOT work. 1949 - 1951 Ford Passenger All Models Starter Plate 8 Cylinders Used | eBay
I have the non-angled starter plate to match the bell housing so that shouldn’t be the issue. I will be looking for a new Bendix assembly because I think the problem lies with the now stripped spring screw on the end. There seems to be some tight clearance issues inside the can on the bell housing where the Bendix spring resides and the can on my bell housing had a lot of hammering and weld fixes on it that makes a tight fit even tighter.
Socal66: Are you installing the starter support bracket at the rear of the starter? It attaches to the oil pan bolt and supports the weight of the starter preventing misalignment. Photo below. Read and see it here: Open and scroll all the way down. Starter motor support strap - The Ford Barn Also, can you inspect the flywheel? Flywheel inspection possible? - The Ford Barn Not installing this bracket can cause your problem.
Yes I am using the starter support bracket as well. I am thinking that my issue may be related to the end spring screw not fully setting in and my somewhat banged up cup on the bell housing. I got a replacement end drive head and screw for the Bendix assembly today and will replace those items on my starter unit tomorrow and recheck for clearance in the cup as well. Hopefully that fixes it or at least will then rule that out as being the problem.
Socal66: In the first photo posted in your Post # 10 it appears that the starter plate is not installed. I don't see the edge of the starter plate between the engine block and the bellhousing. This causes a slight tilt in your starter as shown in the second photo of Post #10. That might be your problem. Below is my set up. You can see the edge of the starter plate between block and bellhousing. Are you sure you are using the correct starter plate?
You also need to check for a good, solid, clean ground for the starter case. Run a ground strap from the engine block to the frame and another from the firewall to the engine. Clean ground connections. No paint. I may have missed something here but here's a common problem not many folks check for: if your car uses a one wire starter button be sure it's grounded properly. It grounds to the dash via the button case and clips. Must be a clean contact to the dash, otherwise.......... nothing. Are you using a 12 volt starter relay with two small posts between the big posts? You may have the wires switched (?).
“One thing that I did notice was the screw on the starter drive head wasn’t fully down on the spring and I am thinking it may protrude into the housing thus interfering with the shaft turning.” I wonder if you’ve done something and now the screws that hold the Bendix on aren’t seated in their holes? What happens when you try and move the pinion up and down the shaft?
To crank that starter over with jumper cables your connections must be really good as others have mentioned. Your jumper cables need to be heavy 1/0 or 2/0 minimum and they will still get hot cranking. don't even try using them cheap 4 gauge jumper cables.
Ok I got a new retaining bolt for the Bendix assembly and it now fastens the spring firmly snug. Unfortunately that still doesn’t do the trick. I doubled checked the clearances between the shaft and the bell housing cup and everything looks ok. The starter gear will engage the flywheel but just stops. I removed the plugs to reduce compression and I cranked the drive pulley with a torque wrench and it takes around 30 lbs of torque to rotate the crank. With no prior V8 flathead experience I am not certain if the crank should move with less torque but I am thinking that this is an ok figure. Checking the starter plate orientation and the flywheel they both look parallel. When I run the starter motor on the bench it seems to spin quite forcefully. At this point assuming the crank torque is ok I am looking at either getting away from the jumper cables and using the appropriate gauge wiring or getting another starter motor and trying that. Does anyone see any other options? I don’t think my use of jumper cables is the issue as they are hefty for what they are and I have read over 600A going to the starter when I use them but it may be worthwhile to just switch the wiring to rule that out.
What happens to the voltage at the battery when the starter stops? That will point you to a problem with the starter or a problem with your jumper cables. If the voltage goes way down, below say 9 volts, when the starter stops, you have a problem with the starter. If the voltage stays relatively high, above 11.0, your connections or cables themselves are the problem.
Could be a bad starter. I have a fresh reman starter here for a sbf that spins like a top on bench test but wont turn over a 289 with the plugs out
The last thing I can think of and then I'll shut up. What clutch do you have in it? Have you been able to turn the engine manually through one complete clockwise revolution with everything assembled? No indication of anything hitting an obstruction? I ask this because certain tranny cases will not accept a large clutch because of clearance problems between the pressure plate spring pockets the casting under the 2 little screws that hold the small inspection plate in front of the floor shift lever if you have one. The cases in question have a heavier casting under the inspection plate, where the screws hold it on. these cases will not work with a large diameter clutch. The first spring pocket on the pressure plate will hit the casting at this point and the engine will not turn past it. Occasionally I have run across cases where the hit was hard enough to jam the spring pocket under the casting point and lock it up so bad it wouldn't turn either direction. Starter rotation and lateral force: since the starter is essentially putting upward force on the flywheel as it turns it, any amount of play in the rotating assembly will be taken up by this upward (lifting) force. Though very small, this can help make this situation worse. To fix one of these, the transmission will need to be removed and the inside area around the inspection plate hole ground down almost level with the rest of the casting. ( tranny bell, not flywheel bell housing). 30 pounds of torque is fine. Easy for the starter to tun. Best of luck to you. I'm now out of ideas.
Jumper cables are a bad idea. Getting solid contact is questionable at best. Any wire will roll it over on the bench but may not carry enough current to turn the engine over. The starter should have a 0 to 2 gauge cable and bolted to the starter and larger if the battery is far away like in the trunk. Good connections may not be your problem but they are vital. Just a thought…
In your last picture of the spring, the bolt that goes in the end of the spring does not look like it's all the way in, and may not pin the spring to the shaft.? Maybe not lined up to the hole in the armature.
Next week I’ll start off with dumping the jumper cables and use the correct wiring. If that fails I will get another starter and try that. Right now it’s on an engine stand with no transmission so no worries about that being in gear.
Try this, disconnect the battery on your daily, hook the jumper cables to the battery cables from your FH battery. See if you can start it. I don’t think you’ll be able to, but then you’ll know one way or the other.
My 6V starter running on 12V recently stopped working. Works great on the bench powered by a battery charger. Put it back in and still didn't work. Put a greasy old used one in & it works as it should. No idea why it doesn't work in the car but does on the bench. It's worked for several years until it didn't.
get rid of the old style Bendix. Snyders Antique and others sell a 'modern' bendix that will not drop those bolts into your bell housing
Looks like you are in so cal Mabee you could borrow or buy a good used starter that’s known to work I’ve always just ran my Flathead starter on 12 volts They’ll run for years, although it can eventually break the bendix spring
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