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Degreeing my cams and my left intake is late 12*

Discussion in 'Engine/Tuning' started by Happster, Aug 31, 2019.

  1. Happster

    Happster New Member Established Member

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    Had a eureka moment at 3 am, dreaming about possibly snapping my first driveshaft once I get her breathing. Ok, a pipe dream. ;-) Quick Strike is 100% right, the numbers don't rise and fall in unison on both the exhaust and intake cams, because your center lines are on opposite sides of TDC. So as you advance and the ICL (which is BTDC) the intake gets closer to TDC and the numbers fall, the ECL, being ATDC, gets further away and the numbers rise. And vice versa. Thanks Quick Strike, that was the exact piece of info I was missing.
     
  2. Quick Strike

    Quick Strike Active Member Established Member

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    Glad to have helped! An important practical application of all this is that as the cams are advanced the piston to valve clearance at TDC is decreased for the intake and increased for the exhaust. When retarding the cams, the piston to valve clearance at TDC is increased for the intake and reduced for the exhaust. This makes it very important to check the piston to valve clearance of aftermarket cams when advancing or retarding the cams when not using the exact specifications on the card. Even when installing the cams as directed, is a good idea to check clearance for peace of mind. The necessity of checking the piston to valve clearance becomes greater as duration and lift are increased.
     
    Last edited: Sep 2, 2019
  3. Happster

    Happster New Member Established Member

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    More great info. I'm going right with the specifications even if I have to grind the keys. I went with the most aggressive Cam that is recommended for these engines, with a .475 intake lift, so I don't want to get cute with the clearances.
     
  4. Quick Strike

    Quick Strike Active Member Established Member

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    Your cams are within a few degrees of my custom cams. I have more lift on the intake, less dish then stock pistons and 1mm oversized valves. All that adds up to much less piston to valve clearance at my 115* intake CL then you will have at 114*. I had almost .090" on the intake and well over .130" on the exhaust. You should be just fine with the cam card specs.
     
  5. Happster

    Happster New Member Established Member

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    Was hoping to get lucky, but dialed the left ICL to 114.25* using 4.5* of advance on the adjustable cam sprocket and ECL came in at 123*. :-( Going to have to do the grind-the-key thing, at least on the left, likely on the right too. Got the left ECL at 118.25* with 3* advance on the sprocket, now waiting on the ARP bolts to grind the cam gear key off to set the ICL to 114*. Bummer no one has engineered an adjustable secondary for these things. Royal pain in the arse having them handcuffed to one another. Stripped one of the allen bolts for the sprocket too...wrench wasn't all the way in. :mad: Hope they sell replacements, although I suppose I can match it up.
     
  6. badcobra

    badcobra It's Fast Established Member

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    I wish I would have done this. I did bullet cams late 2017 and never checked. When I pulled the engine out this year, I found two front exhaust cam journals wiped out. I sent the head and cam to BES for cam bearing repair. They polished the cam and ensured fitment in the head with the bearings, but never checked runout. My cylinder head guy put it in a fixture and found it out by .012". Fortunately we caught this before I put it back together. I had the cam straightened by a local guy who beat it back to within .002 and it spins nicely now. Definitely worth checking runout on those shiny new cams. Any machine shop should be able to do this easily.
     
  7. Happster

    Happster New Member Established Member

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    Looks like Cloyes sold adjustable secondaries at one point:
    Cloyes Timing Camshaft Sprockets S790HP9

    although no longer. Must be a reason for that. Lol. Shouldn't have to file much, I read .006" per degree at the crank. Will pull readings and get to work with the diamond hand file from Harbor Freight.
     
  8. 4sdvenom

    4sdvenom Never Enough! Established Member

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    They quit making them do to pressure from Ford to kill the mod motors so the Coyotes didn’t get upstaged by them. Same reason Ford killed all of their mod motor support.
     
  9. Happster

    Happster New Member Established Member

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    Got 3 of 4 cams dialed in nicely. Left side CIL 114.25 and ECL 117.5. Whoever said you grind the key .006 for every degree that you need at the crank was spot on. Right ECL spot on at 118 and the intake was also 118 pregrind. Need to advance that 4 degrees by taking off .024 from the key. Struggled with the dial indicator and finally broke down and bought the $10 extension set and the $8 tip set. If you're doing it in the car, this is a must. Setting aside the nightmarish set up times, I was getting inconsistent readings and losing 0 at peak. A couple more tips to readers for the modular Ford DOHC degreeing...never turn counterclockwise, even a little. The slag in the chains and the tensioner creates false/inconsistent readings. Also, after you adjust the primary gear, turn it over a couple of times. I found it takes time for the chains to settle before the adjustment shows up. And finally, make sure your degreeing wheel isn't slipping off TDC. .the washers that came with my Summit were not machined very well...the wheel could spin with the crank bolt torqued down. Learned that the hard way too, after thinking I had my left cams good to go.
     
  10. Quick Strike

    Quick Strike Active Member Established Member

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    I used welding clamps on the tensioners to keep the primary chains tight and also only went clockwise when checking CLs. I can't imagine doing this in the car. It took a weekend on the stand and I thought it was miserable. Using the stock gears only added to the misery, but by the end i was very fast at tearing it down and reassembling it as needed for gear filing.
     
  11. Happster

    Happster New Member Established Member

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    Yeah, had I known what I was in for, I'd have pulled the motor in a heartbeat, or at least left the cam rollers out of all but 1 and 6. Such a pain in the arse to get them in and out in the car that I laid as many in as possible before installing the cams. Good workout turning that f'er over 1000 times though! Good idea with the welding clamps. I put hose clamps around the piston of the fully extended tensioners for a while, but did not notice enough of an upside to put them back on after a few times. Staying true to clockwise motion was the key it seemed, but then, I'm 60 hours deep with a cam to go, so WTF do I know? Lol
     
  12. Happster

    Happster New Member Established Member

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    Ok she's dialed in. So here's what I got... 98 GT Convertible with a aluminum 2001 Cobra block, JC Racing dished pistons, forged crank balanced, forged H-beam rods, Cleveland bearings, ARP studs up and down, custom stud girdle, high volume oil pump with the forged drive gear. Was running 99 Navi heads but just rebuilt a set of Cobra DB (3rd gen of 4) heads with comp cams (4.75 intake lift), MAC long tubes, beehive springs, heads and plenum ported and polished and ported my Eaton blower. Comp stage 2 clutch, Tremac T45 tranny, still running the solid rear axle and rear end from the GT. Was getting 425 to rear wheels with the Navi heads and unported blower. Looking for advice on a throttle body and MAF. Would hate to give her new big lungs and choke her out with a little mouth. Will post stats after re-tune and dyno.
     
  13. Quick Strike

    Quick Strike Active Member Established Member

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    I would recommend the BBK twin 65 MM TB and a SCT BA-2600 TB if you were going to stay where you are at with this engine. Your build, however, seems to be crying out for a bigger blower. It would be nice to have parts you can grow into if you can no longer resist the cries. So, an Acufab single blade TB and a Granatelli BA-2800 would still be very tunable for your current set up, but also handle a 2.8L or so SC if you go that route one day. You might as well step up to larger injectors during the retune as well (60s 0r 80s). You should be able to find a deal on all of these in classified section if you keep after it.
     
    Last edited: Sep 14, 2019
  14. slo984now

    slo984now AKA 01yellerCobra Established Member

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    FWIW, I ran a BA3000 on an upper only eaton. It worked pretty well. I only took it off because I was dealing with smog.
     
  15. Happster

    Happster New Member Established Member

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    OK, she's breathing, but struggling. Engine racing pretty bad...up then cuts out, then back up. Given all the air I've added between the larger cams, opening up the supercharger and porting the heads is that expected and will the re-tune take care of that? Not sure I can even drive it to the tune, which is about 60 miles away. My fuel pumps sounded awful the first few times I turned the key, then they were quieter. I'm wondering if that could be an issue? I'll get a fuel gauge and see how those are doing. Full disclosure, this whole rebuild started when the engine just died while I was laying a patch for a couple hundred feet. Was only getting 60 lbs of pressure in #8, 120 lbs in the rest, but the valves in 8 looked fine besides the exhaust valves being caked with carbon. Thought I whacked a valve but no sign of that once I got into it. They probably just were not seating with all the carbon. But it should have still ran. I should probably just upgrade the pumps and the injections too, take those out of the equation. Running the stock '04 dual pumps with a direct wire to keep the voltage up.
     
  16. gt347mustang

    gt347mustang Well-Known Member Established Member

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    Fuel pumps always sound different when priming the system and purging air.

    I'm hoping you leaked down the engine before installing it? That's the first thing you need to do after degreeing cams.
     
  17. Quick Strike

    Quick Strike Active Member Established Member

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    How is your compression now? It kind of sounds like a vacuum leak. Have you had a vacuum gauge on it? You will be leaner with the new amount of air going into the engine. I would call your tuner and see what is suggested. Maybe they can put a rich tune in your handheld tuner to get you to the dyno. That is what my tuner did. I had a no boost break in tune based on my new mods sent to get me through break in and down to the tuner. This would allow you to add injectors, TB, MAF, pulleys (if desired) and whatever other changes you want before going to the dyno.
     
  18. Happster

    Happster New Member Established Member

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    It was the fuel pressure sensor...took the vacuum line off and fuel came out. Lol. Failed in a big way. Vacuum source is the booster port and I also pumped a pint of fuel out of the supercharger plenum. Got a new one and it runs great. Need a booster bypass actuator valve too...that was full of fuel. To answer your question, compression 120 across the board. Didn't do a leak down yet...sat too long and cylinders were dry, but I put air to each cylinder on the flat of the cam and got no air coming out of the valves. They're fine.
     
  19. Quick Strike

    Quick Strike Active Member Established Member

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    I would bet you know to check your crankcase oil for contamination when the FRPS fails. It almost always results in an oil and filter change.
     
  20. Happster

    Happster New Member Established Member

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    Yes, I did the appropriate cam break in procedure and then changed it and the filter right away. And you're right, brand new oil looked like it was well overdue for a change and smelled like fuel. I was going to wait until 500 miles for the next change, but I think I'll change it again right away with another shot of zinc additive. Scary that a FRPS can wreak so much havoc without tripping a code. Thankful I checked the vacuum line, SC and boost actuator for fuel too.
     

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