Technical Starter Help Buick Straight 8

Ok, so I have a 1940 model buick straight 8 engine I bought as a spare. Motor is complete. I have two separate starters. I am trying eitjier starter with 12 volts, no other vehicle electronics hooked up. From what I read the starter can handle the 12 no issues. When I try these starters outside of the vehicle (testing with jumper cables) they function flawlessly. When on the car both starters will barley crank the engine when the bendix is engaged. I thought maybe the engine may be tight or trying to lock up, but the engine has no belts currently and can be turned by hand fairly easily. Thanks!

 

You have the same problem with both starters, so I doubt that they're the problem.
Did you paint the mating surface between the starter and the bellhousing? Possibly affecting getting a good ground?

 

Quite possibly I thought about that, it's probably not getting a very good connection regardless using jumper cables.

 

Jumper cables won't work for that, you need battery cables. And heavy ones...

 

Aha...

 

Thanks guys makes since I'm young and never had anyone really show me how to work on anything so it's trial and error.

 

Maybe check to make sure you have a good ground - maybe run one to the frame to the motor and of course to the motor - I've missed that myself.

 

@1941g506 Where are you in East Tennessee? I spent some time out there in the 1970's. Nice country.

 

Near Johnson city, Kingsport area. Thanks guys

 

You may want to pull the valve cover and check how quickly the valves close. Turning the engine over by hand allows time for valves sticking in the guides to slowly close. There might be one or two sticking enough to cause slight interference when cranking with the starter. I do agree with Squirrel, use heavy cables.

 

There were also different starters, (atleast with additional windings) for the differently sized straight 8s, and where a starter for a Special, might be slow to turn over a bigger engined Century or Roadmaster. But, like Squirrel said, thick battery and ground cables and a battery should yield some results

 

Larger cables, as 0000, if possible. They will be as large as your thumb or larger. Local parts store probably does not have them.
If using 12V, parts store cables will probably work. They are probably 2GA, the jumpers are probably 6 or smaller.

Ben

 

2 gauge would probably work fine. 00 definitely is big enough.

 

Thanks guys! She fired right up when using the heavy cables.

 

Yay

 

Bet those jumper cables were getting hot as hell