Doing cam timing when engine lock up?
 

Hoping for som e advice here.SmileWavy

I had the left cam tower off in one peice without doing anything to the right side and now on reassembly i came to a stop on 2 things i can`t search for.

I put the cam tower on again with all valves and rockers in place and had to turn the crank a bit with a loose chain. Now i got the cam mark to the top and the crank at TDC and on Z1 mark. I put the the shims sprocketmounted the chain and such on and the chain wheel the tensioner is pressing against. Without the tensioner. I tried to go 720 to check if it where all good but the chain got tighter and sort of jumped a tooth or something. i kept trying until the engine locked up. Is the chain not mounted properly on the crank?

Another part i can`t figure out. Found it somewhere in the chain housing but can`t seem to fint a spot for it. It`s the part all the way to the right. Next to the woodruff key.
http://forums.pelicanparts.com/uploa...1360949688.jpg

Any clues:(

Thanks in advance:)

You can't turn the engine without the tensioner, the cam will get out of timing,
Go back and reset everything....and yes the chain can jump of the crank side gear been there.

That little piece is a mystery. Is it round? Square? There is a pin in the idler arm holding the idler sprocket in place, but I think it is longer than that. Could it be a failed piece from a chain? Unlikely, but were it in my motor I'd be worried also.

When you have the cam out, or move things around without any tension on the chain, it is easy, especially on an engine stand, to have slack pile up down by the intermediate shaft gears. At some point, the slack will jam, and then jam tighter. Putting tension on the chain while rocking the crank will usually allow you to pull the jammed slack chain out. Has worked for me, anyway.

It is a good idea, once you have things back rotating, to use a light and mirror (or a borescope - they are now down in the $100-200 range) to take a look at the IS gears and the chain, to make sure the chain is properly engaged.

Thx for that. I ditt know i had to install the tensioner. Seems logical though:)

That little pin is rund. Fant seem to find out where it gods. I found it or i think it fell out from somewhere when i dissembled the cam sprocket ett. Weird:confused:

Back to timing the cams again:) the guys

Cam Tower oil line plug? #22 on the illustration.

http://forums.pelicanparts.com/uploa...1361023393.jpg

Dose not look like that noe. This pin is just straight and completely round. I'll check though :)

Thx for the tips guys. got it all working now.

Timing the cams and thought i`d check where the right cam was set so this was the procedure.

Set crank at Z1TDC mounted the z block and metric gauge. Turned crank 360 while watching gauge. it turned one round and stopped at 65. that means 1.65mm right? this sound ok? can i adjust the left one at that?

With stock cams, I think I was setting .8mm as spec. What cams are you running?
Bruce

they are stock cams i think. Right side has not been loosened and is set at 1.65 that is why i set it at that. what will this affect?

Also i`m going to struggle to retorque because the cam is completely round and there`s a bolt and shim instead of the big nut so no way to use the crowfoot tool. i need to find another way to lock of that cam to torque it down.

For my '87 3.2 it's 1.25 mm. From what I've read, the correct setting seems to vary from engine to engine. As for the reading, it depends on the gauge you use. On mine I preloaded about 7mm, zeroed the dial. Mine is a 10mm gauge, each rotation of the dial is one mm.

As I turned the crank and approached 360 degrees, the dial indicator spun backward as the valve was depressed by the cam. The dial moved backwards one full rotation (one mm) then stopped at .75, so the full movement was 1.25 mm.

If your dial indicator moved backwards, your .65 may then indicate movement of .35. If the dial spun back a full rotation, then you've got 1.35 of movement.

Fully understanding your dial indicator and finding out the right setting for your engine are necessary to complete this. I'm sure if you posted a pic of the dial indicator you'd get good guidance here.

I hope this makes sense and is helpful.

GK

Sounds like you need the cam holder bar:
Part #: PEL-TOL-P237

Ohe - you have neglected to tell us what engine this is. The SC and 3.2s use the same cam, and over the years Porsche's specifications for where to set the cam ranged from a low of 0.9 to a high of 1.7 mm.

Advancing the cam (higher number) increases torque, and retarding increases horsepower. Bruce Anderson (RIP) asserted that on the 3.2s Porsche went back to a setting about in the middle, and I've heard guys who experimented and used a chassis dynomometer say that is about right. Not a huge difference either way.

1.65mm sounds like it is within range, and since you don't know what cams this motor has, and I guess it ran well before you got to working on it for some ailment on one side, so it makes sense to use 1.65 as a goal.

You have been given the advice you need already: the special tool (alas, you can't just use some kind of regular tool for this the way you could on an earlier type cam), counting full revolutions of your dial indicator, and knowing which way it is turning to interpret the readings.

There is a better dial indicator now available at relatively low cost: the digital indicator. These are switchable from metric to inches if you want, and give absolute readings (no counting revolutions so no getting that wrong). And have a zero button as well. I commend them to all of us who don't do this often - less techinque/things to remember involved, so less chance of a mistake.

Ah sry about that. Engine is 79 3.3 turbo cams are standard. Checked the partnr now. It has some upgrades like the k27 turbo and others i`m not sure of since absolutely no papirs followed the car.

The dial gauge is metric and is dialing the wrong way but it turns one 360 and stops at 35. backwords that will be 65 :)

Thx for the info there. It did run pretty well but had alot of turbo lag and didn`t idle very well.

Dammit. I missed that bar tool when i got a big parts package from pelican last week!! Need to find other ideas to lock that down. Thx :)

I thought that the cams in '79 were still the big nut kind, not the bolt kind. Doesn't mean these are not turbo cams. The '82 US SC motor I bought used surprised me by having the big nut - this after I had purchased the tool for the bolt system (about 15 years later I finally needed it for another motor).

If your cams were timed at 1.65mm, they are way out of spec for stock turbo cams for that motor.

Here are the specs, along with numbers which ought to show up on the end of the cam:



http://forums.pelicanparts.com/uploa...1361152216.jpg

Its marked with 930 143 03

Cou8ld not find that number on the list....?

142 is turbo cam
147 and 148 are SC
Bruce

Oheggem,

Where are you? You could borrow mine for a short time. PM sent with phone number.

Wade

I`m in Ålesund :) Greatly appreciated Wade!!

"142 is turbo cam
147 and 148 are SC"

I found out i think that 930 143 03 is from 930s from 84 if i`m not mistaken. However the only other number that match are those in the link below. I think it`s weird though to change cams to a later model if no modification is done by it. Anyone know if the 84+ has higher lift or something?
http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/423393-racing-cam-part-number-wthe-r.html

A good strategy is usually to track down previous owners and talk to them, they are usually quite chatty about their old cars. :)

The last cam numbers change because the 46mm nut and the 12mm bolt.
All turbo cams have the same values.
Bruce

How does Bruce know a serial number detail like this? Amazing. Though he has worked on a lot of different motors. Unless, like me, he looks things up - the current parts manual for these cars only lists the 03 cam for the 3.3 turbo, showing the bolt attachment. But at least that is solved - the car has a stock turbo cam, and thus can be timed like a stock turbo.

However, the picture in the catalog also shows two small round looking pins which appear to attach to the far end of the left cam. The catalog says they are for the SC model with Sportomatic. I don't know if the Turbo could be ordered with the Sporto (I would doubt it), or if the turbo cams are drilled for these (drive pins for a Sporto pump?), or if they could possibly fit in there without the special end the MFI cams had and the seal, etc. And they are listed as "roll pin 5x24. If they are 24mm long, scratch that off the list of possible sources for the mystery pin which started this discussion.

That pin is shorter than the dowel pin so i don`t think it`s the one you mention. I should`ve maby just removed a cam to see the serialnumber or something. I just hought it was weird to put a cam from 1984+ as the cam number 930 143 03 means without it being something special. Guess we`ll know if i have to rebuild the whole shabang :)

They are timed to about .70 both now so to hell with it ;) Timed and torqued down and covers on. On with the MSD install which i have new questions with.

Thanks so much guys :)

Confusion time!! I should`ve maby made a new thread on this but i`ll see if i get an answer.

When doing the left cam timing i go 360* from Z1TDC and just before Z1 i read from the dial gauge and adjust it from there.
The right is the same procedure?

Ref: http://forums.pelicanparts.com/911-engine-rebuilding-forum/592101-cam-timing-again.html

Saying here that doing the right one should start at Z1 and turn clockwise and just before Z1TDC? Is this correct?

Ref: Porsche Cam Timing

Here it says do the same on both sides. Confused now :(

I suspect my right cam is 180* off now. Do i time the right cam at another point from the left?

That little pin could be a roll pin off the gear end on the distributor used to hold the gear to the dizzy shaft or it could even be the little pin that locks the star wheel inside the dizzy housing to the advance shaft under the rotor.
Both are very tiny pins and could maybe have worked there way into the chain housings and been thrown in there when the dizzy was spinning. Its worth inspecting the dizzy since you have it out of the car for this vlave train work anyway.
It looks too short to be a chain roller pin.

Fred

Ohe - the procedure for timing the right side cam is the same as for timing the left side cam. The cams all turn the same way.

The slightly tricky bit is to make sure they are in the proper phase with each other. When the #1 is at Z1 Firing (both valves closed, spark just went off if running), the #4 should be at the opposite Z1 - the one where both valves are open, with the exhaust almost closed, and the intake just opening - somewhere around a millimeter for stock cams, up to six millimeters (which is hardly just opening, though - that's about half open) for hot race cams on NA motors.

If you find that when #1 has both valves closed, and #4 has both valves closed at the same time, you have your cams 180 degrees out and need to reset one of them. Usually the right side ones, to keep from having to reset your distributor if you have installed it. So there is a sanity check for you.

Walt, if i had two dial gauges mounted one on each side would they be timed at the same Z1 and the dials would move at the same time? I remember that the #1 and #4 pistons where at the same location and that the inlet valves closed at the same time i think.

I think maby my left cam is out because i never touched the right cam. that has been on chain torqued down all the time.

Fred: i have found a small pin other places in parts list like on the crank. Still weird since that has not been loosened.

If it does that, then you have one cam 180 (cam)degrees wrong.

This means that I should`ve set left cam from Z1TDC on #1 cylinder and right cam at Z1TDC on #4 cylinder which is 360* apart from eachother or 180*on the cams. Will this be correct?

Ah the headache ;)

Yes! You got it!

Been there and done this myself setting one cam 180 off... Luckily I discovered it before putting it back into the car.

I know but the fact that the dizzy has not been loosened or removed does not mean that the pin is not from there. Its worth peace of mind to pull the dizzy and check it out in my opinion. Takes about 5 minutes to pull it and inspect it. you can check for shaft end play then as well. I found mine out of spec big time during my last rebuild and needed to shim it under the gear to bring it back in tolerance.
Plus you should lubricate the advance shaft with oil under the felt cap that resides under the rotor anyway. Too often the dizzy never gets lubed and the advance mechanism can seize up.
The fact that you have hard pins like that inside the case worries me though....it could cause tons of damage if it ever went thru the oil pump or through the chain and gear when they meshed.

You might be right fredmeister cause i meant that the crank not has been loosened but the dizzy is out and disassembled. Do you have a good thread on working on the dizzy? I need to mod it for my MSD.

Should`ve just gone with a standalone dizzy free system but don`t have the money now :(

I know there are one or 2 out there just dont have the link right now handy. Try doing a search on ignition and read thru a few of them. One posting had alot of photos on how to lock the distributor and I even posted my own solution to removing the springs and locking the counterwieghts with steel wire in a few pictures. Dont remember which posting it was though....
Basically I ran some steel wire around the counterweight to the post on the mechanical advance plate at their most advanced position to lock them from moving. This way I did not drill any holes or tap screws to lcok them down. Locking them in an advanced position is safe in case they break free of the wire as they can retard timing only at that point.....though centrifical force is going to keep them advanced when running anyway.
MSD is the way to go as you can program your boost retard curve which is all important.
Good luck.