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  • Camshafts

    Cam options for the 3.4 DOHC are few and far between. You could possibly have Crower or some other company make a solid billet cam set custom for your motor, but thats going to cost anywhere from $1000-2000. The alternative is to have the stock cams reground for a better profile. Lunati will NOT do them, same goes for Crane. A company in California will do them however for around $500. You can contact them on thier website, Cadillac Hotrod Fabricators.

    UPDATE 6-8-05
    I haven't verified this but a member on the forum has noted that Crower will do the regrinds for 400.

    UPDATE: 6-29-07
    Fieromadman has found another source for cam regrinds. Has done three sets of DOHC cams that worked excellent. Looking at around 100 a cam.

    Steve Long Racing Cams INC. 951-273-0816

    (Read a recent thread about cam regrinds)

    Cam Timing

    Because the cam gears are not keyed, the options for cam timing are nearly infinite. While this can cause a problem for the novice trying to set the cam timing, it also allows great flexibility for those with more experience. First, I must add that any painted timing marks are to be ignored. To learn more about how to set the cam timing, go here.

    It has been over a year now that the 13 degree exhaust retard spread across the internet as an easy way to get power out of this motor. It seems that another person has experimented with the timing on a ported engine mated to the automatic trans. It retains the 13 degree aspect but advances the intake cam as well to lower the powerband from what we had already tried. I hope this is right, 7 degrees advanced on the intake, 6 degrees retarded o­n the exhaust. As of now I do not know where this lines up the timing mark for 91-93, so you are o­n your own for figuring it out. I do however have a better picture to show the timing mark for the 10 and 13 degree timing. Basically, 10 degrees is what I thought 13 was originally. I am now running 13 on my car but the idle is a hair rougher than with 10.

    Stock Timing



    10 Degree Retard



    13 Degree Retard



    Update: 6-8-05 I have now tried 6 advance intake / 6 retard exhaust on a 94 cutlass and my 91 grand prix. The cutlass is an automatic, and was timed to stock from the belt stretch timing of -8/-8 rear bank, -4/-2 front bank. This obviously made the car idle and run better than before. The 6/6 timing was then applied. Wow...simply amazing for an automatic. The powerband starts lower, idle is smoother than stock timing, and low end is increased a nice amount. Top end was helped out as well over stock though with the auto, stock shift points don't go as high as you can with the manual. The owner also noted an increase in gas milage though I also tuned the chip with this timing done. I am testing the gas milage in my car now.

    6/6 timing on a manual car is a different animal, because instead of shifting at 6200, I usually went to 6600 or so (power dropped after 6600 with 13 degree retard on my motor). My car now only likes to make power to 6200 or so and then drops off noticably. The low end is a hell of a lot nicer and the exhaust note when I cruise around at 1500 is smoother. It no longer feels like its working hard below 2500 I am going to try some more settings out later after I tune my car how it sits and compare gas milage.

    If you are wondering how I am able to accurately set the cam timing to 6/6, check out this product on our store. DOHC Timing Tool. I highly recommend this tool as it has made my life easier on all the cam settings I want to try out.
    Ben
    60DegreeV6.com
    WOT-Tech.com

  • #2
    Cam timing

    I haven't scanned in the dyno sheet - I will if I get the chance - but for road racing I have been running the specs developed by Dave Deerson of T&Z Auto Service out of South River, NJ - 7 degrees retarded intake, 13 degrees retarded exhaust. Seems radical, but works, really cranks nicely at track speeds. Dyno shows 228 whp with a modified intake (Camaro V8 throttle body, modified manifold), 2.5" custom tuned equal length headers (open dual exhaust), power pulley. Otherwise bone stock. Amazing what you can do with proper "feeding".

    Anyway - other cam timing considerations:

    First off: The 95 and up motors had the infinite adjustability by just loosening the bolts on the cam sprocket & giving it a tap. In pre '95 motors you needed to swap out the sprockets & keepers for the later models to achieve this. As far as I know there were no pre 95 motors with the easily adjustable cam sprockets.

    Next: On the pre - 95 motors it is possible to time the cams 180 degrees out (learned this the hard way). This is because the computer takes the cam sense signal from the "dummy" INTERNAL cam - which really serves no other purpose on this motor other than as a drive pulley for the cam belt. In the 95+ motors there was a cam sensor on the intake cam for the #4 bank that did this, so there was no possibility of timing 180 degrees out - it read the actual position of the overhead cams, not the internal "dummy". In the pre 95' motors the paint marks on the "internal cam pulley" must be UP when the motor is at TDC to time the #1 bank. If it's DOWN then start by timing the #4 bank first. The motor doesn't really time to the #4 bank (as has been stated on a couple of threads), unless the internal cam is in the "180 out" position. You have to remember that this internal cam only rotates once for every TWO rotations of the crank - and since it feeds the computer - yes, kids, there IS a "180 degrees out" setting (been there, done that).

    Anyway - just thought I would pass that hard-earned knowledge along.....

    Dana.

    Comment


    • #3
      Got any pictures? probably best for a different thread but I would love to see your custom intake and headers

      94-97 have the easy to adjust cams. 91-93 use a press fit setup which means a puller is needed. All are fully adjustable though (non keyed).

      Your cam timing has to be mod specific, as retarding both cams on a stock intake/exhaust motor doesn't work too well at all. It does show that the motor is setup to easily adjust to other mods though.

      As far as being 180 out, that is not true. The dummy cam has no sensor. 91-93 is batch fire so it doesn't need to know which bank is which. THe only 180 out timing is if you set both banks with the cam flats up, leaving you with a dual inline 3 cylinder basically. Both banks will be on the compression stroke at the same time. The original manual failed to express the need to time 1 bank, then turn the crank 360 degrees to time the other bank.
      Ben
      60DegreeV6.com
      WOT-Tech.com

      Comment


      • #4
        cam timing

        OK, now I'm totally confused. I picked up a '92 3.4 (Lumina Z34) with 8k original miles (crate motor out of a wreck) to replace a rather more tired motor with over 90k on it. I wanted to swap the cam sprockets with the later (non keyed) version to increase cam timing flexibility, so I pulled the belt, swapped the sprockets, rotated all 4 cams until the flats were "up", locked both banks in place using the GM tool, replaced the belt. I then rotated the crank to TDC, locked down the sprocket bolts for the #1 bank, release the cams (removed the GM tool), rotated the crank one revolution, repeated for the #4 bank. The car would not run. Out of sheer frustration I swapped the plug wires between 1 & 4, 2 & 5, 3 & 6 - guess what - it started. That says 180 degrees out to me. I pulled the motor (only takes ~ an hour on this car to remove the cradle) - it's sitting at TDC right now, #4 cyl. is in firing position (both valves closed), #1 cyl. exhaust is closing, intake is opening. Perfect, rotate 360 degrees, #1 is now ready to fire, etc.

        SO ...... how does the motor know when to fire #1 vs. #4. Several folks have said via the crank sensor ..... except the crank is going to be in the same position when #1 fires as when #4 fires (just one crank rotation later).

        That's what's making me crazy. How does the car know when to fire #1 vs. #4. It can't be firing both at once, otherwise it would have run before I swapped the wires.....

        Confusion reins, my head hurts.....

        Dana.

        Comment


        • #5
          You have 1 coil for 1 and 4. how would swapping the wires between 1 and 4 matter when they both fire at the same time? The cam timing itself is what dictates which bank is compression, and the other is exhaust. it fires the spark plug on the exhaust stroke too, making this a waste spark setup. Even 94-97 are like this but they are sequential fuel injection, so they must know which bank is compression and which is exhaust for the fuel injectors. Ignition doesn't care.
          Ben
          60DegreeV6.com
          WOT-Tech.com

          Comment


          • #6
            i too have verified this same thing ben, when i have run beyond rich, i get an extra fireball down the primary that i couldnt figure out. then i discovered what waste spark meant and how/why it happened. after some testing, it was verified again. so ill back ya up here...not that u need it...just trying to help out
            3500, 1280 cam and PR, ls6 valve springs, port and polished heads, ported lim, ported uim, 4.3 70mm tb, ported trueleo headers and y pipe ALL FOR SALE (minus the car)
            96 LT4 6spd corvette. 355, AI 215cc LT4 Comp CNC Heads, Prope SRS pistons, Ported intake, ARH long tubes, Corsa Indy Pace 4:10 gears
            2012 Chevy Sonic Turbo 6spd
            1970 M35A2 Deuce and a Half, Spin on filters, Turned up IP, HIDs, Flat Black, 11.00x20 singles.

            Comment


            • #7
              Never did complete this thread. I learned a lot about the 3.4l dohc from this.

              1. When I timed the cams I DID get one intake a bit out - about 4 degrees retarded from where I wanted it (I actually timed the cams to some custom numbers, not "stock" settings).

              2. Discovered that the majority of the problem was due to a BRAND NEW set of ACCEL 8 mm wires. The reason moving the wires made a difference was simply because I disconnected / reconnected the wires. I found rubber "flaps" inside some of the boots that were preventing good contact on the distributor ends. Tested the wires, resistance was all over the charts wire to wire.

              3. Retimed the cams, corrected the 4 degree error I had made on the one cam, installed Taylor Made wires, car started, ran like a banshee.

              Took 2nd in an EMRA TT at the new Lightning Raceway at New Jersey Motorsports Park (ST3). Car was easily capable of taking first (I wasn't that day, unfortunately - missed it by 0.1). In the closing laps of practice I snapped yet another BRAND NEW part - a Timken rear hub assembly. Happened to have a stock bearing / hub assembly backup, swapped out the assembly, but I was a bit hesitant after losing the left rear wheel just a few laps earlier (according to my hot lap timer I slowed by over 2 seconds a lap).

              Anyway - thanks for all the help when I was trying to determine what the heck I did wrong. I felt much better when I discovered the real culprit was parts more than anything I did wrong. Well, both the bad parts AND lack of knowledge have been taken care of now......

              Thanks, all. On to Pocono Raceway (East Course) on August 12 (EMRA again), Then CART (Connecticut Autocross and Rally Team) on August 29th (Pocono North), EMRA August 31 (Pocono North again!).

              If anyone is interested in running any time trials in the Northeast let me know - I'll can give you the details for any given course / event. September 29th - CART is running at Pocono - ALL 3 COURSES AT ONCE ALL DAY, 75 car MAX (max of 25 cars per race course). Two time trials, unlimited track time (no "run groups") across 3 different circuits (this one is almost full - $240 for the day).

              Dana.

              Comment


              • #8
                cam tool

                hi do you sell the cam timing tool?
                thanks.

                Comment


                • #9
                  No one makes them anymore.
                  Ben
                  60DegreeV6.com
                  WOT-Tech.com

                  Comment


                  • #10
                    damit gonna have to do some searching around then

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