IP timing after the valve job.... - Page 4 - PeachParts Mercedes-Benz Forum

nhdoc · #46 08-29-2007, 12:27 PM

Quote:

Originally Posted by tangofox007

What is the point of turning the crank when you have the IP in your hand?

Duh, good point...

symbolic95 · #47 08-29-2007, 01:45 PM

OK ,so i removed pump yesterday ,marks were align perfectly so conclussion chain never skipped, problem is the cam ... by the way you cant just turn ip 180 degrees when turning it has 4 stages , similar to the camshaft with valves; so after each one it jumps ,theres no smooth movement.
What i did i just align marks -crank was at 24 ,i rotated engine 360 so crank again 24 and cam lobes now pointing up...reinstalled pump....result-0
Engine doesn't start .
This morning went back and rotated camshaft 180 degrees , by removing cam towers for #1,#2 cylinder (time 1hr install /reinstall ,compare to 4hrs on IP) ,
result engine started right away but performance worsened,
tried to time IP no luck ,again fuel flows only on exhaust stroke ,at compression stroke 0 , but this time fuel flows when pumping primer pump,no dripping ,now im really confused , im back to were i started with worst results,all suggestions are appreciated.

GVB · #48 08-29-2007, 02:51 PM

Quote:

Originally Posted by tangofox007

If the camshaft was 180 degrees off, there would be no problem whatsoever with the valve timing. (The crankshaft being 180 degrees off would be different.)

To illustrate, let's say the the #1 piston is at TDC on the compression stroke. The head is removed, the camshaft is rotated 180 degrees, then the head is reinstalled. The #1 piston is now at TDC on the exhaust stroke. Valve timing is correct. The injection timing is 180 degrees retarded.

Sure about that?

Go put an intrusion engine on tdc, and set the cam 180 off, then crank it, you tell me what will happen

And yeah, I am sure about that, seeing as though I have been specializing in Benz for the last 15 years

GVB · #49 08-29-2007, 03:03 PM

Quote:

Originally Posted by GVB

If the cam was installed 180 off, you would not be turning the engine. The vales would hit.

If you did a valve job, and for some reason, why I don't know, turned the engine over while the head was off, the pump is off. It is going to be much less work to just set the engine to TDC, remove the IP, align the marks on the IP, replace the IP gasket and grease both sides so it does not tear when timing the IP. Reinstall the IP and use the low pressure (drip) method to retime the IP. Remember to do two things when timing:
1) Remove all vacuum lines to IP, and make sure the IP is at FULL THROTTLE (and of coarse the cam lobes are "up")
2) Set the IP at 24-23.5 if you have not replaced the chain. If you have replaced the chain, set the pump at 25. When the chain stretches, it retards the timing, i.e., when you loose much power due to IP pump off timing, time to put a chain in .

Ooops, I guess my thoughts where faster than my fingers.

Set to TDC to make sure timing marks are correct, but when installing IP set to 23.5-25 BTDC, depending on how old the chain is.

GVB · #50 08-29-2007, 03:11 PM

Quote:

Originally Posted by symbolic95

OK ,so i removed pump yesterday ,marks were align perfectly so conclussion chain never skipped, problem is the cam ... by the way you cant just turn ip 180 degrees when turning it has 4 stages , similar to the camshaft with valves; so after each one it jumps ,theres no smooth movement.
What i did i just align marks -crank was at 24 ,i rotated engine 360 so crank again 24 and cam lobes now pointing up...reinstalled pump....result-0
Engine doesn't start .
This morning went back and rotated camshaft 180 degrees , by removing cam towers for #1,#2 cylinder (time 1hr install /reinstall ,compare to 4hrs on IP) ,
result engine started right away but performance worsened,
tried to time IP no luck ,again fuel flows only on exhaust stroke ,at compression stroke 0 , but this time fuel flows when pumping primer pump,no dripping ,now im really confused , im back to were i started with worst results,all suggestions are appreciated.

It is pretty basic, I think you are "making it harder" that it actually is.

Start over

Set to TDC, check the timing marks. Crank on 0, cam marks line up, and lobes are up. Now set engine to your 24 degrees BTDC, remove the IP, reset the IP with the mark on the input shaft, and the mark on the pump itself. Reinstall the pump. Set to full throttle by tying the IP with a string or what-not, and use the hand pump with the drip method, and time by 1 sec drips to the 24. You really don't need to keep rotating the engine, just move the IP and synch to the desired drip time.

symbolic95 · #51 08-29-2007, 05:36 PM

Ok i guess brake was necessary ,i went back and everything started to work, fuel started dripping at compression stroke (it drips even on exhaust stroke

), i set it 24BTDC at 1dpc,she started right up . Why i had a problem i still dont know , but i don't regret 2 days of work as we have saying in Russian " century live....century learn.."
Thanks everyone for their input.

Brian Carlton · #52 08-29-2007, 05:50 PM

Quote:

Originally Posted by GVB

Go put an intrusion engine on tdc, and set the cam 180 off, then crank it, you tell me what will happen

TF is correct.

There will be no interference with the valves if the camshaft is set 180 degrees off the "correct" position. The valves will open and close on the compression/power strokes instead of the exhaust/intake strokes.

The only thing that defines the strokes is the injection event. Without injection, the camshaft can operate the valves in either of two positions..............0 degrees and 180 degrees.

symbolic95 · #53 08-29-2007, 06:01 PM

You correct theres no interference ,but to turn camshaft you have to remove cam tower just 1st one , on the camshaft rotate spacer with mark 180 degrees and then rotate camshaft -- till align with mark,about 10 minutes of work.Without taking cam towers off impossible to turn camshaft,valves will hit piston.

Brian Carlton · #54 08-30-2007, 06:11 PM

Quote:

Originally Posted by symbolic95

Without taking cam towers off impossible to turn camshaft,valves will hit piston.

Agreed.

tangofox007 · #55 08-30-2007, 07:17 PM

Quote:

Originally Posted by GVB

Go put an intrusion engine on tdc, and set the cam 180 off, then crank it, you tell me what will happen

And yeah, I am sure about that, seeing as though I have been specializing in Benz for the last 15 years

I believe the appropriate term is "interference engine."

Did you say 15 years?