Cam timing Pics

[imtb]

I am trying to figure out if my cam timing is correct. Here is a couple of pics. I thought the number two should be on top. Anybody see anything out of wack.

 

I also am trying to figure out the cam, i used a mirror to see on the rear of it and its got number 101l, t4.12, 288, 412. These make any sense.

 

Please help. If just doenst seem like I am getting the power for 2.0 with 10 to 1 compression, cam headers, dual carbs.

 

HOW CAN I POST MY PICS?

 

thanks,

mike

[datzenmike]

288 probably the duration and 412 the lift. For comparison the stock L20B is 248 and 413.

 

Go o Photobucket and join, don't worry, it's free. Then just follow the directions to load your pictures from your computer. They will host them and you can go there and transfer them here. I worked it the first try it was that simple.

[imtb]

doesnt really seem like a proformance cam to much. I check the v on the cam gear and it pretty close halfway in the notch.

 

It seems to run better when the timing is at zero or five to 6 degrees advance and it goes up to 28 total. Does this seem out of line or strange?

[datzenmike]

If that is the lift (412) then you won't have to change the lash pads the stock ones and springs should be close. If that is the duration then it will move the peak hp and torque about 2,000 RPMs higher. (assuming bigger carb maybe a header)

 

Stock timing is 12 and total just over 30 ish. What head are you running? Do you know the compression or pistons used? A much higher compression would lower the timing.

[imtb]

Thanks for the response. Being a newbie trying sort out what I have. Compression is 10 to 1 with U67 milled head with header, Dual DCOE 40's. I did a compression test and have 210psi. I am also have MSD box and pointless dist. I guess i'll leave the timming around zero advance and recheck the total advance, if you thinki it now big deal.

 

Running 140 main jets with 32 chokes, it kinda gargles around 3000 rmps when I put my foot to the floor, I think maybe the 225 air corrector are to big and going to try 180 or 200, see if that helps. I am installing a O2 sensore to get a better reading on the jets.

 

Straight exhaust to the muffler, I am going to add Resonater and Flowmaster muffler, hopefully this would get rid of the fart can sound and give me a little more low end torque.

[datzenmike]

Generally, retarding the cam slightly improves low end idle and torque while advancing takes that away and adds to top end. Timing falls where ever it runs best.

[imtb]

Which way would the dash be in the v notch to be retarded or advanced.

 

thanks

mike

[datzenmike]

Vee to the right of horizontal etch mark on cam thrust plate is advance, the the left is retard. The etch mark is about 4 degrees wide. Each of the holes marked 1, 2, or 3 is a 4 degree adjustment or just under 1/2 tooth.

 

http://i138.photobucket.com/albums/q251/datzenmike/L%20Z%20Heads%20and%20Motors/motorLcamtiming.jpg[/img]"]

Edited December 24, 2008 by datzenmike

[imtb]

Mine seems to be closet to number 3 dowell pin and slot . The numbers are not stamped right under the holes like your pic. So would that mean mine is advanced 12Degree's or 4 ? and would that be why it seems to run better with the timing arouond 0-5 degrees. The intake and exhaust look right 10-2.

 

I also check TDC on the piston and my mark on the crank pulley and it almost seems like the number 4 piston is almost higher than number one.

 

Can you PM pictures?

[datzenmike]

This picture is probably a tight new chain. There are two more holes to allow 2, 4 degree advancements for chain stretch. The L20B and all Z series motors come from the factory set on the #2 position, L16 and 18 are on #1. Nothing says you can't try the other holes to try and gain something. It may run better advanced.

 

If you are on the #3 hole to get the Vee on or just to the right, maybe your chain is stretched or slightly or worn.

 

You can P/M pictures.

Edited December 24, 2008 by datzenmike

[ggzilla]

It seems to run better when the timing is at zero or five to 6 degrees advance and it goes up to 28 total.

If you mean the spark timing, this seems right on:

* initial (idle) timing is always advanced (for any make and model of car engine), usually between 5-10 degrees BTDC

* Total timing of 28 degrees is pretty typical for Datsun engines. however, that's the average. You'll make more power at about 32 degrees which is the higher end of the spec. I'm looking at my Datsun A12 engine spec, the L20B will be similar.

The above is not about cam timing, but is spark timing.