Need hi torque starter recommendations for my fresh 440hp 468, 9.7:1. Bought a standard rebuilt Olds V8 starter at O'Reillys. Was like $60, thought Id try it. Cant really turn the motor over. Thinking it was a bad rebuild, they swapped it out, same thing. Checked cables (trunk mount battery), voltage drops, grounds, and had battery load tested. Sometimes it can (barely) turn it over where engine starts and runs great, but most of the time it cant really turn motor over. Starter engages flexplate perfectly (shimmed too to eliminate any bind issues), but it cant really turn over the motor. Even jumped car to add more CCA, made no difference. I just put engine together and its a pretty tight motor with a healthy Lunati Voodoo cam, strong springs, .0015 piston to wall, mains at .0015, rods btw .0015 and .002. When running it sounds phenomenal. When I turn the key off, the engine stops pretty darn immediately...lol. Engine sounds mean. Is it time for a high torque starter? If so, which one?

 

I would try moving the battery back in the engine compartment and try it there. You might experiencing voltage drop due to the long cables?

 

https://www.ebay.com/itm/Powermaster...-/223500598418

 

What gauge battery cables? Do a voltage drop test, I bet you would be surprised at how much curre t is lost in heating up the cable, instead of spinning the starter.

 

Did you get a high torque starter for an application such as an early 455 engine, or a later model low torque starter?

 

Its a "hi-torque" GM starter with the long bolt, and is allegedly for a 1970 Olds Cutlass 455. The battery is in the trunk and has a meaty 2 gauge, 18ft cable for positive (under 1.5 ohms for 18ft) and the negative is probably a 4 gauge of about 2 feet to the decklid hinge frame (under 1.5 ohm from this trunk attaching pointt to engine block). When I jump it with my other car, Ive got 14+ at the solenoid terminal (as you would expect). Ive been doing reading on these hi-torque starters, and they sure seem to be the cure for this situation. Lots of guys with this situation and the gear reduction starters easily remedied it. Its a tight 468 motor (all tolerances are min, with 1.5 piston to wall (Sealed Power states .001 min for their forged Speed Pros). When running, she sounds awesome. When you shut off the key, it stops instantly (no coast down from 1000 as im more used to).

 

 

Don’t know what others have used for trunk mounted setups but I always used 00 or 000 welding cable (+ & -) back in the day. Don’t know where your problem lies but just figured I would put that out there.

How about bypassing the trunk wiring by jacking up car & just run a short power cable from battery under car to the lug & see if things act differently? That might provide some insight but only one way to find out. If it turns out that cable is the culprit you should upgrade ground(s) as well. IMO battery ground should go direct to frame rail then frame rail to block up front.

Don't know where it lies but start with basics - load test fully charged battery again & have them check starter draw on the bare unit @ the store if they are capable.

 

IMO, you're losing voltage along the length of your ground strap - albeit; you don't have enough voltage to the starter. Just a quick/rapid test. Move your unmounted battery to the front of the car, hook up your 18' 2 gauge wire to the positive terminal of the battery. Take the negative wire which would have originally run from your block to the negative battery terminal and hook up that block ground wire to your battery negative terminal. BAM! That starter should fire off in a millisecond. You can get more elaborate and measure the voltage drop along the length of your ground wire (the one you said runs from the deck lid to the engine block) but IMO, your issue is a large voltage drop along the length of that ground strap. There are numerous ways to address this (more ground straps, larger wire from trunk deck lid to starter, large properly sized ground wire running directly to the block, etc.). You should be getting about 0.004 ohms along the entire length of your ground strap - being under 1.5 ohms might be a good 'ball park' for lighting wiring, accessories, etc. For a high torque starter you should be closer to less than 0.05 ohms. End of day - you need a massive ground strap from block to battery to fire off your starter. Electrons flow from the negative terminal to the positive terminal - they never flow in the opposite direction (unless you hook something up backwards). So, in a nutshell - you don't have enough electrons flowing into your positive terminal as a result of having far too much resistance in the ground (negative terminal). You'd be able to achieve this just fine by jumping - but jumping you're using the other cars ground and not your own. Using your own ground you're just not getting the job done.

 

I agree with the above, too much voltage drop through the wiring.


Well that doesn't sound right at all. From all I have read over the years, those pistons need a lot more clearance than that.

 

A 24 gauge wire will show 1.5 ohms of resistance over 18 feet, but wouldn’t carry enough current to power the ignition. Two gauge is what GM used on the big engines with the battery under the hood. As I stated earlier, I’m betting your losing a lot of current as heat.

Take your positive meter probe, put it on the positive terminal of the battery. Take the negative probe and put it on stater stud (where the positive cable connects to the starter). Disable the ignition, crank the engine. You shouldn’t see more than about .5 on the meter. If it’s more than that, you need a bigger cable. Do the same thing on the negative cable. Put the negotiable meter probe on the negative battery post, the positive on where the negitive cable bolts to the engine. Crank it again, ideally about .5 volts.

 

This is called "new technology". It started a firestorm on another thread in the last year.

 

My 2 cents:I assuming your using the stock ignition switch right? Install a relay, that took care of my issue with heat soak and voltage drop anyway.. That took all about 10 minutes to do. Lots of articles on it too.

 

This isn't rocket science.

The OEM negative/ground strap from battery to block is a 2 gauge wire. A 2 gauge wire running 2' produces 0 (ZERO) resistance. That's as in no (negligible) resistance - which is optimal.

Let's be clear. The negative battery terminal runs to the engine block. The starter is mounted to the engine. The starter gains its ground from the engine. The starter is not mounted to the body/chassis, nor does the starter gain its ground source from the body/chassis - which is exactly where you are hooking your ground strap at the trunk deck hinge. Then, you're expecting to gain free-flow electrons through the entire body/chassis to the ground terminal on your battery from the trunk deck hinge? Add to this, as soon as you turn your IGN SW to the ON position (before you even attempt to hit START) - every single wire on the ENTIRE vehicle which requires a ground is now increasing the resistance you're getting at the trunk deck hinge bracket because nearly every single ground wire is connected to the body/chassis. Why not pass the ground wire through the entire city of Chicago with all the lights in the city turned on? That is completely wrong.

You want one dedicated wire from the negative terminal of the battery to the engine block. You should NOT be using any portion of the body/chassis as a ground for the negative terminal of the battery.

A 10.0' run of 2 Gauge (AWG) wire yields 0.002 ohms.
A 10.0' run of 1 Gauge (AWG) wire yields 0.001 ohms.
A 10.0' run of 24 Gauge (AWG) wire yields 0.257 ohms.

You realize the difference between 0.257 ohms & 0.002 ohms is nearly 100 times more resistance. The difference between 1.5 ohms and and 0.002 ohms is nearly 750 times more resistance. That's just in wire size alone - add up all of the other ground wires total resistance when you turn the IGN SW to ON and you'll be surprised how much resistance you have at the hinge bracket. I'm not clear why we're referring to a 24 gauge wire, but as a comparison (from above) I used it. End of day - you want a dedicated ground strap and a dedicated power cable. You could maybe add a dozen ground straps somewhere along the frame. But, why would you do this? You're talking about turning over the starter, which turns over the flywheel of the car - this requires MEAT. Why even consider compromising this scenario? You require a dedicated ground.

 

Doubt that the relay will solve the issue. I would do a test with a temporary hookup with a short run of wire as bccan suggested and see if it will crank to rule out your wiring and battery location.

 

To put this into perspective based on the resistances you originally posted:

The formula for a voltage drop is:
Voltage = resistance X current

So assuming you have 1.5 Ohms resistance (half of what you measured), and you attempt to run 10 Amps current through the cable (this is just an easy number to work with, the starter likely draws 100 Amps or more), the equation is this:

Voltage = 1.5 X 10

The voltage drop across your cable would be 15 Volts. That is a problem as the battery can supply only 12.6 Volts.
You gotta reduce the resistance in the starter wiring.

 

The voltage drop along a dedicated 10' 2 Gauge (AWG) ground strap w/ a starter drawing 100 amps = 0.2V

1.5 ohms along a 12V battery ground strap is enormous resistance; you'd be lucky to spin the starter once and then the battery would be dead.

EDIT: BTW, a cold cranking starter would probably draw ~200amps. Therefore, 0.4V

 

 

Sincere thanks to all of you for the great input and making me think. The thoughts about the ground circuit going through the body being flawed does make alot of sense. Time to rethink this! I did buy a beast of a starter today from Jegs, the Powermaster Ultra (3.4hp, 2.5kW, 4.4:1) but I do think this ground circuit through the body is flawed. As for the .0015 piston to wall, Sealed Power states .001 (1 thousandth) as minimum piston to wall with their forged pistons now. Clearly these new high silica pistons dont expand (plus the block itself expands with heat. Anyway, huge thanks for all the in-depth replies, you have made me think (not easy to do)! CMM.

 

Been there... Done this !
Better get back on track with your wire/cable issues before you smell something funny. 🔥

 

Every time someone crams a battery in the trunk, and then has starter trouble, I know in advance that the wiring to the starter is sub-standard. It's like clockwork.

For the record, steel is a crappy conductor. So if you're using the frame--or worse, a unibody--as part of the ground path, good luck. You'll need it.


2-gauge is laughable. Meaty--Ha! 1.5 ohms cannot be correct, should be a fraction of that. And by the way, ohm-testing a battery cable cannot prove that it's good. It might prove that it's bad--but not likely.

If this was me--and it isn't--I'd be using 0 or 00 COPPER cable on both + and - sides. Don't get me started on Copper-Clad Aluminum (CCA) cable. Cheap ****.


This is probably the biggest problem. The ground is just as important as the positive cable, but guys always cheap-out on the ground side by trying to use steel as a conductor. Again, an ohm reading means nothing.

WHAT ARE YOUR VOLTAGE DROP RESULTS?

This has already been said as text, but maybe a diagram will help. Your meter test leads won't be long enough, so you'll need to extend one of them with some 12, 14, or 16-gauge primary wire.

 

I just finished a trunk battery install in my 53. Used 00 welding cable to Ford-type solenoid in trunk, same size cable from solenoid to starter (Powermaster), same from negative battery post to frame at rear, then made two separate ground cables from the same 00 welding cable to connect the frame to the engine, one on each side of the block.

Put in a relay to operate the solenoid to insure instant lack of juice to the trunk solenoid when releasing the key from start.

No issues at all, fires instantly. Used kit from MAD Electric.

 

Nice!

 

Welding cable from the + side to the starter and the - side to the frame. The frame was cleaned were the - cable attached to the frame.
We also ran a jumper from the frame to the engine block. Never had a issue using a factory starter.
Today I think the trunk mounted battery for anything other than a true all out race car is counter productive.
When the cable was removed during restoration , I could not help but think we slowed the car down by adding 40 lbs of cable weight to the car.
Reason for moving the battery weight transfer and loading the right rear tire with existing weight.
I agree with everyone that most likely the issue is voltage drop do to install and wire sizing.
Good luck with the fix.

 

Great thoughts, Im learning alot. Thr car was a serious drag car with a blown big block, nitrous, etc and thats where he had battery with master shutoff, and fuel pump relay (all trunk). There may have been more cables i didnt get. My 440hp 468 is very tame by comparison obviously. Think i will move it back up front. I do always try and consider all performance aspects to maximize, so on many levels I loved the weight transfer. But of course, big cables add weight too. Ive learned alot here from all of you. I can build a nice engine, but starter circuits clearly arent my strength. Sincere thanks to all of you, this has been excellent!

 

Today you can buy light weight cable that can handle the current load.
The trunk mounted battery is also cool looking and works with your HP Build.
When mounting the battery in the truck you just have to design a system that works and is safe.
1. Rubber grommets were the cable goes through the floor to prevent shorting.
2.The battery has to be mounter securely
3. Correct cable sizing
4. Terminations/cable ends should be secure and protected to prevent shorting.
5 Cable should be mounted securely and away from hazards
6.Battery box that vents outside the trunk is a good idea.
Battery shut off is always a good idea.
Take your time and build a clean well thought out system.
I'm sure I missed some key points so do your homework.

 

Cabling. Not only do you need to make sure you have large enough "good" cable to avoid voltage drop. Make sure you run both a positive and negative from the battery to the starter. You don't know the route the ground is taking to the starter unless you run a dedicated ground cable.

 

00 or bigger cable. Use welding cables. Ground strap from engine block to frame, and neg side of battery bolted to frame. Use internal star washers. This has always worked for me. Even on engines with 13 to 1 compression. Also a good idea to use the long field starter.

 

Olds diesel starter time? Seriously, Check your remanned starters for absolutely tight bushings, nose cone, overrunning clutch sliding on armature, and less important, back side by brushes. If the ORC or nose cone bushings have any perceived slop or rocking on the shaft, it contributes greatly to grunting caused by frictional losses. Parts house starters even NAPA rarely are tight in this critical point. Only Delco new or remans from Andersen Indiana check good this way. Local boutique rebuilders get it right (usually). I have always ran a second heavy ground cable from starter attachment bolt to trunk mount battery to remove all doubt of circuit integrity.

But still no point in discussing voltage drop during cranking which might factor in here, you’re engine is tight and you said so. Tight piston skirt clearance seldom opens up in the short term, even with just knurled skirts. You’re lucky it turns at all when at operating temp. Even a 22:1 Olds diesel rolls over with a bar. Maybe a ign kill button to crank when hot then cut in ignition, but my bet is regardless starter ring gear life will be short, wearing out at the usual starting mesh position. One of the best hi-T mini starters will lower the current draw but still might roll over slow.

My opinion has been Olds should have redesigned the starter with the potential for high compression after 1949, but since the inventor of the electric starter was also the Olds V-8 head of design, was prob no chance of that. The less efficient design remained to the end of V-8 production.

Best of luck, I hope you don’t have to tear the engine down.

 

If you have cast pistons .0015” is not too tight. Neither are your bearings. Are you saying you can’t turn the engine over with a breaker bar or the starter can’t turn it over? If you put old style 5/64” rings in, the motor is going to take a lot of torque to turn it over even by hand. I would buy one of the lightweight gear reduction starters, that will spin it. Once you put a few hundred miles on it will loosen up.

 

https://www.robbmcperformance.com/pr...s_starter.html


I put a Robb Mc starter in my car. Worked great