lcvette

Hey guys.. like title says.. I need to find TDC to mark my balancer while the engine is in the car.. my first attempt I used a p[iece of TIG SS welding rod and it got me close, but the balancer is reading around 65* when she is running properly.. I need to dial it in alot closer to be sure my DFI tables are where they need to be and help with the rest of the tuning process.. any help appreciated!

Chris

406shark

The most accurate way is to buy a piston stop tool such as this http://store.summitracing.com/partde...5&autoview=sku

You can get them at Summit, Jegs, etc. You install it in place of #1 sparkplug. Slowly turn the engine over BY HAND clockwise until it stops against the stop. Mark the balancer. Then turn the engine over in a counter-clockwise direction until it stops again. Mark the balancer. TDC is exactly between the two marks you made.

It's easier to do then to explain it.

Good luck,
Jeff

myko

First, I know that this thread is very old but it describes my situation so I figured "why start another?" I want to find TDC with the engine in the car (1980 with crate SBC).

This is all very clear except the BY HAND part. I have tried cranking the flywheel, cranking the balancer from underneath, using a breaker bar on the flywheel nut, even prying between flywheel bolts with a screwdriver (made me nervous so I wasn't very aggressive). I have all of the sparkplugs out. I can bump the engine with the starter and it turns easily. It seems like everyone else can just reach in and spin the motor. Any suggestions?

406shark

BY HAND means not using the starter. Using a piston stop and turning the engine over with the starter WILL damage your engine.

There is a bolt in the center of your balancer... should accept a 5/8" socket. Use a socket on either a breaker bar, or good sized 1/2 ratchet to turn the engine over.

Good luck,
Jeff

myko

I have read about guys breaking this bolt off so I'm not giving it a full pull. Maybe I need to get a shorter 1/2 drive 5/8" socket but it seems like I am really cranking to get it to turn and it stops after a couple of degrees. I don't want to slip off and damage the bolt head. I just wanted to confirm that it takes a pretty good torque to turn the engine. Some guys are talking about literally just turning from the alternator and moving the pistons?

406shark

Do you have a manual transmission? If so, put it in neutral.... you're trying to move the car.

With all the plugs out it shouldn't be really hard to turn over. The guys talking about turning the engine over by spinning the alternator belt either have forearms like the Hulk.... or no compression.

I've used the breaker bar method for over 30 years... never broken or wrecked a balancer bolt. My current engine is a 383 sbc with 12.43-1 compression... I can turn it over to adjust my valves without removing the spark plugs.


Jeff

myko

Nope, AT. I will buy a set of shorter 1/2" sockets to see if it fits a little more solid that the deeper well I tried before. Then I guess I'll man up and give it a spin. Just didn't want to give it hell and end up asking how to fix a broken bolt and hearing about how much of a dumbass I was. I'll let you know. BTW, thanks in advance.

406shark

No problem.

If you're going to buy a new socket... pick up a 6 point socket... better contact than a 12 point... less chance of damaging the head.


Jeff

RealmSteel

I'm not a fan of turning any engine backwards or using piston stops for finding TDC, so I use this roller with my indicator. I just watch the indicator until until it flattens out and starts going back down.
I repeat until I can pinpoint where it changes direction.
Rigging up the indicator might be a pain with the engine still in the car though.

I started doing it this way when building that 2.6L Mitsu engine.
You can't rotate the engine backwards due to the timing chain tensioner.

406shark

I've used a dial indicator as well, but it's not very user friendly with the engine in the car. That's how I do mine when assembling an engine.

I posted up the easiest way for someone to check it in car with everything together.


Jeff

rjs86vette

I'm in the same situation. Can't hand crank it, but starter can. Buddy thinks its timing chain or worse. My deal is that the motor sparks but won't even hint of catching. Found about a gallon of gas in the crank case. I just bought the car from a kid.

mr.beachcomber

This engine definitely needs to be removed from the vehicle and disassembled. If you can't rotate the engine assembly using the harmonic balancer bolt, you have bigger problems than just a broken timing chain (which would just rotate the cam and valvetrain as the crankshaft turned).

If you need a quick look-see before pulling the engine, remove the oil pan, water pump, harmonic balancer, and front timing cover to see what the situation is. (Worse case, a broken crankshaft.)

Good Luck with the engine!

RED99

If you are saying your motor turns by the starter but wont run and you have a gallon of gas in the oil pan, then you have a sever flooding problem. I would first change the oil. Then you may want to squirt or spray some oil into each cylinder because you probably had washed all the oil off the walls and turn it over with a few times to lube them back up. Put in a new set of spark plugs, and fix your flooding problem before trying to start it again.