Technical Sbc help please! Wont turn over with plugs in (figured out, dumb mistake).

I got tired of Jumper cable's from the Auto Stores, so I made
my own I used 200 strand welding Cable with Ends that Napa
sells, the Cables are 12' long with very little Voltage Drop from
one Bat to the other.
The Starter Shims you would Probaly get them at NAPA
and it makes a Big Difference with the Starter!

Just my 3.5 Cents

Live Learn & Die a Fool

 

I have a 200 amp booster on my charger , if the battery is too low , the charger won't start an otherwise good starting engine ...

 

as already suggested have the battery load tested a simple and easy thing.

 

Does it have rocker arms? maybe the valves are all closed.

 

Before you go shimming the starter do this simple test. Remove the solenoid, and then grab the plunger and pull it to manually engage the starter bendix. If it pulls into the flywheel easily there's no issue with starter binding. Then you can reinstall the solenoid and not waste time shimming, and maybe making things worse.
I'm with those saying it needs really good cables. Ground directly to the engine block, and none of those wimpy, cheap cables. At least a #2 awg., and if it's over 36" long make it #1 or #1/0 size cables.

 

Can you explain your adjustment technique? Set to TDC?

 

This... or something like it. No rockers, no pushrods, or no valve ajustment.

 

Wouldn't look at the valve train just yet. There's an issue from the electrical to mechanical conversion in the car. Easiest thing to do, without question, is to take the battery to get tested. There's a reason batteries prices are based on cold-cranking amps. If the jumpers are getting hot there's alot of resistance in the wires due to high amp flow or the wire gauge isn't large enough. Usually the latter of the two.
While its out inspect the battery wires. Thoroughly. If there isn't an engine to ground cable make a temporary one and see if that helps. Also, as many people have said, shim the starter. Youtube will tell you how to do it fairly easily. After these checks, I'd start looking mechanical.
Albert

 

Have you tried installing the spark plugs 1 at a time?

 

1 plug at a time, goes until compression stroke and stops.
No matter what cylinder.
Turns by hand, plugs or not.
Visual inspection with boroscope, no visible indication of plugs or valves hitting pistons.
Compression test goes between 30 to 60lbs per hole. Again motor only does a couple revolutions before it stops.

1970ish lt1, double hump head. Not supposed to be a wild built motor.
I'm at a loss.

 

Ok. Attached large cca battery to starter, bypassed jump cables, cranks like no tomorrow.

Now to figure how to fit larger battery into car.

 

You should have well over 100 lbs. of compression on each cyl. It sounds like you have the cam timing off.

 

I asked earlier, but how did you adjust the valves?

 

Rerun your compression test now that it cranks at the correct speed. Slower crank = lower compression. Even good rings will leak if they're moving too slow.

 

Compression is fine now, prior wasn't enough amps to spin starter. Dumb rookie move...

Dont try to spin motor on jumper cable even if they're large gauge

 

@Bandit Billy tdc for piston. Rocker to 0 lash and 1/2 turn beyond that

 

You can always put the Batt. in the Trunk thats where I have mine

Just mt 3.5 Cents

Live Learn & Die a Fool

 

There’s something else or we would have D8 bus batteries in our trunks. I’ve got a 14-1 engine with 210 cranking compression and one of those cs starters on a medium size Odessy 625 cca that never fails. My battery is in front of the engine and the cable is 30” long 2/0 welding cable.

 

Location issue, t bucket, fuel tank takes most of the trunk, have an odyssey pc680 battery. going to bump up to a 1/0 cable from battery to starter. Then if need be, I can rework a few things and make room for a 2nd pc680 (and move other things) Of course, all this comes after the car is built and painted

 

Work EVERY time.

Ben

 

Wow, I was going to use one of those batteries when I was considering building my T as a "bobber"!

 

The something else is the jumper cables...


Sent from my iPhone using H.A.M.B.

 

@rustydusty im not giving up on the battery just yet. Going to run 1/0 battery cable from trunk to starter, also have a suspicion that my battery was weak coming out of the box, so im going to try warrantying it out (have it on recondition on my charger at the moment.

 

Battery in the back, 0 or 00 welding cable on both leads from battery to engine and solder the ends on the cable.It works every time.