Timing the engine

Cacti_Ken · Post by **Cacti_Ken** » Wed Dec 21, 2005 4:25 pm

Well I thought this was going to be easy....
L 134 engine.

I have rebuilt engines before, but I didn't rebuild this one, so I don't know if it is timed correctly.

Senario, My engine is sitting on the floor with head bolted on.
No spark plugs in. No flywheel, bell housing or starter mounted. Only crankshaft pulley is mounted.

I am trying to make sure that the oil pump/ distributor rotor versus the crankshaft time-ing marks are in the correct place before I install the power plant onto the frame.

I cannot determine when No. 1 piston is at TDC since I can't see no. 1 piston. About all I can see is the exhaust valve through the spark plug hole.

Will I have to put the flywheel, bellhousing and starter on so that I can spin the engine over so that I can determine when no 1 piston is at the compression stroke by pluging the spark plug hole with my finger to determine pressure is established when piston is up and valves are closed, and distributor rotor is at No. 1 position.

Also.... I am not sure where No. 1 position is on the distributor. I am not sure if the picture on page 177 in TM 9-8012 is what I should be going by.

Ken

OKCM38CDN · Post by **OKCM38CDN** » Wed Dec 21, 2005 5:05 pm

Ken,

Do you have a compression gauge? Also are the timing marks on the pulley and cover?

I ask this because if the answers are yes, then here is the method I used to time my engine was this...

Align the timing marks for TDC, then using the hose on your compression guage try to blow into the #1 piston, if there is no resistance you are 180 degrees out; spin the pulley one full turn and try again. If there is resistance you are on 5 degrees before TDC. Now insert the oil pump looking for this indication down the distributor hole...

Now insert the distributor and #1 should be in the lower left position. I have found that if you have the waterproof distributor the center screw on the cap aligns with the rotor and timing is pretty much on...

Hope this helps...

Cacti_Ken · Post by **Cacti_Ken** » Wed Dec 21, 2005 5:27 pm

I have a compression gauge. Timing marks are on the pully, but not distintive on the cover. There is a raised area about a 1/4" wide and 1" long just about the 10 or 11 o'clock position on the cover. I am assuming that is the mark.

I am using the water proof 24 volt distributor.

How many revolutions does the crankshaft turn from when No.1 Firing position and then back to it's firing position again?

And I was thinking that no 1. position was as you have discribed in the distributor.

I'll wait for a reply before I try anything.

Ken

OKCM38CDN · Post by **OKCM38CDN** » Wed Dec 21, 2005 5:39 pm

Ken,

It takes two revolutions to go from firing position to firing position...

If you have MS Messenger or AIM I am on both look for my email address

Cacti_Ken · Post by **Cacti_Ken** » Wed Dec 21, 2005 6:08 pm

I don't have MSN messinger installed. I have a hotmail account though, and I will install messinger I have a dialup connection so It will take about 30 minutes. I put the test hose in the spark plug hole. I noticed that when the piston was starting to come up at the beginning of the compression stroke ( I could tell this by the air starting to come out of the test hose), the rotor in the distributor was at no. 1 firing position and the timing marks on the pully were at 7 o'clock. When the piston got to the top, the pully mark was at the timing mark on the cover, and the rotor was between no 3 and no 4 in the distributor. Don't look good to me.

OKCM38CDN · Post by **OKCM38CDN** » Wed Dec 21, 2005 6:21 pm

With what you are saying, the oil pump is off, easy enough to fix. Just pull the 3 bolts and rotate it CCW (I think). You will also have to redo the distributor... Remember the oil pump will spin as it reseats...

Sounds like your timing marks are correct for the crank and valves...

Ken, if you want send me an email and I can give you my phone number...

Cacti_Ken · Post by **Cacti_Ken** » Wed Dec 21, 2005 8:48 pm

Ok that wasn't too bad. Pull the three bolts. and slid the pump out. rotated the gear one way, installed it... checked rotor position, oops wrong way, pulled pump turned gear the other way slightly... installed it, checked rotor position again, going the right direction now. a couple more like that and it's good.

Thank you for the instructions Hal

Ken