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Author Topic:   voltage drain
racer17j
Member
posted July 19, 2003 01:01 AM
hey guys can't seem to get my engine to fire do to a lack of voltage. i have 16 volts to the hei when i hit the starter it drops to under 8 volts instantly. i'm wondering if my cables are bad or maybe a spun bearing but if i had a spun bearing i wouldn't have any oil pressure right? right now while i turn it over it will get up to around 25-30# of oil pressure. i know my battery is pretty much shot so i've just been tring to get it to fire hooked up to the booster charger the last nite i ran started to run hot i believe do to lack of voltage to get a good spark and keep her cool i pulled in at 235 and it had been turning over real hard and not starting ever since. think a new battery, alternator and cables will help me out or do you guys think i have internal problems


BayouGent
Member
posted July 19, 2003 03:22 AM
Before I'd go after the engine I'd check that starter. A bad starter can draw far more power than needed to start an engine. Testing the battery wouldn't hurt, since you are assuming it's shot and remember, you can have a battery check OK for voltage but fail miserably under a load. If you are running a starter button check the wires that you have run to and from the starter posts and make sure that one didn't weld itself to a header or something else with the extra heat. If it did when you hit the starter button you are grounding your positive against the engine and ultimately battery ground, which will cause a power drop as well. If you are concerned in any way that you may have spun a bearing you can always change oil, examine the oil for shavings, and cut the oil filter open and look for shavings in there as well. If you spun a bearing I can almost guarantee that you will see shavings in the filter. Just some things to try first. No need to pull the engine yet. Hope this helps and good luck!!


Pickles
Member
posted July 19, 2003 10:53 AM
Start with the starter! No pun intended.


racer17j
Member
posted July 19, 2003 04:28 PM
thanks gent filter has alot of shavings looks like i'm done for the year


BayouGent
Member
posted July 20, 2003 11:26 PM
Sorry to hear that. I was leaning more to the starter problem. I did discover something a couple of weeks ago that probably caused one of our engines to blow, and could be a contributing factor to yours. I was running one of the cheaper "claimer" oval track pans and the pickup that is sold with it to match. A mistake I made was assuming that the matched set would have the proper oil pump pickup to oil pan clearance. What prompted me to check it is when I built the new engine we decided to use a 1/4 oil pressure line going to the gauge instead of the 1/8 inch to get better response to the actual engine oil pressure. What I discovered was when the car was coming out of 2 different turns on the track was that the pressure would drop for about a second or two and then pick right back up. Doesn't sound like alot of time but one second at 3000 rpms is equal to about 5 crank revolutions and so on. To avoid blowing another engine we pulled the motor and dropped the pan to see if what I suspected was right. Using clay I checked clearance from pickup to pan and found 5/8 of an inch. That would probably be ok driving down the road but in this pan calculating area volume it was probably leaving about a quart of oil untouched in the bottom of the pan and when the oil sloshed to the side the pump would catch air for that second or two and cause the drop. I had never seen that drop before with the 1/8 inch oil pressure gauge line. Needless to say, the oil pan was scraped for a 8 quart champ oval track pan with pickup. Did the clearance test and had precisely 3/8 of an inch, which is pretty much the recommended amount. Raced on both a banked track and flat track this past weekend and had no more problems with oil pressure, but finding the problem now won't help one very good 355 chevy that threw the # 6 rod and had other failed bearings. Just thought I'd share that info with you and everyone because I'd bet that I'm not the only one that assumes that when you buy an oilpan and pickup combo that the clearance is correct. Hopefully you are lucky and bearings didn't spin in your motor. A good engine cleaning and a crankshaft and bearing kit could get you rolling again. Good luck!!


racer17j
Member
posted July 21, 2003 05:26 PM
mine got hot thats how i think it happened do to my battery being run down so not enough juice to keep it cool i'm hoping it's just like you said on a rod bearing and not a main i have another crank and re ring kit but if she needs line bored i'n done for because i don't have anymore blocks that are ready to go


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