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Thread: Spark knock

  1. #51

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    I mentioned by ear procedure on timing because marks can be inaccurate. Balancers are marked differently, covers are also, etc. A by ear base and some inspection with a light as it’s revved will tell you how much advance is being ramped in as degrees difference.

    repeat without the advance and you’ll know what the mechanical side itself is doing.

    how much is too much depends upon fuel, compression, and combustion chamber design primarily. Sometimes as little as 30, sometimes as much as 42.

    Id set it by ear with the advance hooked up then plug off the advance. That will drop where you are at immediately and force it to only use mechanical. If the spark knock is still there and mechanical was not crazy it’s not timing related then because it’s as conservative as possible at that point.

  2. #52

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    Quote Originally Posted by erratic50 View Post
    I mentioned by ear procedure on timing because marks can be inaccurate. Balancers are marked differently, covers are also, etc. A by ear base and some inspection with a light as itís revved will tell you how much advance is being ramped in as degrees difference.

    repeat without the advance and youíll know what the mechanical side itself is doing.

    how much is too much depends upon fuel, compression, and combustion chamber design primarily. Sometimes as little as 30, sometimes as much as 42.

    Id set it by ear with the advance hooked up then plug off the advance. That will drop where you are at immediately and force it to only use mechanical. If the spark knock is still there and mechanical was not crazy itís not timing related then because itís as conservative as possible at that point.
    For ****s I can wire the mechanical advance so it does not add any. That would be one of the tests.
    Going to check rocker stuff etc. When I get home one of these nights.

  3. #53

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    Good luck with getting it figured out.

  4. #54

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    Quote Originally Posted by erratic50 View Post
    Good luck with getting it figured out.
    Thanks!!
    Btw I like your car with the 4 headlight system.. I never did understand why guy convert them to the plastic lense 2 eyed..
    Last edited by 78futura; 06-02-2018 at 04:41 PM.

  5. #55

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    Thanks! I completely agree! And so many of the four eyed cars were converted in the late 80ís and 90ís in the name of newer looks and cheaper repair parts and availability of parts, etc.

    The only modification Iíll probably ever make to the front of any of my cars in the light department is swapping over to an 85-86 LX style bumper cover with no fog lamp holes. After seeing the GT style bumper on my Silver Saleen project car it was a necessary.

    Iím having an 85 GT restored then finishing out the Racecraft/Saleen conversion on that was started on it in the mid 80ís. It has had everything under it and several pieces of the visual package including the wing and the ground effects but it hasnít had the Saleen facia or rear spats before.

    To me the three piece front facias found on the three 84 Saleen prototypes and the early production 85ís are the bomb but that facia looks terrible on the GT style bumpers, thus the switch to LX.

    Im going to finish the Saleen built on LX type swap by going over to an LX style instrument cluster bezel and an actual four eyed Saleen gauge cluster with a 170 MPH speedometer in it. I might switch the head over to the new BBK 170 speedometer I have NOS with zero miles too. Itís a ground up build replacing everything possible with either brand new or completely remanufactured and rebuilt or restored everywhere else. It will be about as close to a new 1985 any of us have seen in a long time, and the only four eyed car wearing Saleen gear in silver with grey stripes in existence. The parts list and cost and effort in the build have been considerable. When itís done it will look the part with only clues like being numbered 1985-006 giving any major hints. The parts combo should stop from 60 in about 1/2 the distance of the cars made then and have double the horsepower of the Saleen cars built in 85. So basically a super car hidden behind the skin of an 85 Mustang wearing a made of unobtanium Saleen body kit.

    The three four eyed cars in the stable... one 85 and two 86ís. All GTs. Two hatchbacks and one rag top.
    Attached Images Attached Images   
    Last edited by erratic50; 06-02-2018 at 06:26 PM.

  6. #56

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    Quote Originally Posted by erratic50 View Post
    Thanks! I completely agree! And so many of the four eyed cars were converted in the late 80ís and 90ís in the name of newer looks and cheaper repair parts and availability of parts, etc.

    The only modification Iíll probably ever make to the front of any of my cars in the light department is swapping over to an 85-86 LX style bumper cover with no fog lamp holes. After seeing the GT style bumper on my Silver Saleen project car it was a necessary.

    Iím having an 85 GT restored then finishing out the Racecraft/Saleen conversion on that was started on it in the mid 80ís. It has had everything under it and several pieces of the visual package including the wing and the ground effects but it hasnít had the Saleen facia or rear spats before.

    To me the three piece front facias found on the three 84 Saleen prototypes and the early production 85ís are the bomb but that facia looks terrible on the GT style bumpers, thus the switch to LX.

    Im going to finish the Saleen built on LX type swap by going over to an LX style instrument cluster bezel and an actual four eyed Saleen gauge cluster with a 170 MPH speedometer in it. I might switch the head over to the new BBK 170 speedometer I have NOS with zero miles too. Itís a ground up build replacing everything possible with either brand new or completely remanufactured and rebuilt or restored everywhere else. It will be about as close to a new 1985 any of us have seen in a long time, and the only four eyed car wearing Saleen gear in silver with grey stripes in existence. The parts list and cost and effort in the build have been considerable. When itís done it will look the part with only clues like being numbered 1985-006 giving any major hints. The parts combo should stop from 60 in about 1/2 the distance of the cars made then and have double the horsepower of the Saleen cars built in 85. So basically a super car hidden behind the skin of an 85 Mustang wearing a made of unobtanium Saleen body kit.

    The three four eyed cars in the stable... one 85 and two 86ís. All GTs. Two hatchbacks and one rag top.
    Nice!!!
    Mine is a 78 futura all original 302 maybe 375hp-400 (who knows who cares built for myself) c4 hood ornament and original 14" caps. Anything else would be wrong.

  7. #57

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    I love the futura’s. They make a great sleeper!
    -- James

    "Trigger" - 86 Mustang GT - Black with red interior. 5.0 T5 built as Z. Original motor ~1/2 million miles. 18 yr daily, 7 a toy
    "Silver" - 85 Mustang Saleen 1985-0006? (Lol) Rare 1E silver / charcoal interior. Mystery. Current project roller, tons of Saleen pedigree

    Also in the stable - 1986 Mustang GT Convertible. Black/Black/Black conversion. 93 leather. VM1 ECU. T5Z

    past foxes -
    1989 Mustang LX Sport 5.0 AOD white/tan black top.
    Wife also had a 1987 Thunderbird Turbo Coupe in the 90's.

    I'm a four eyed pride supporter, are you? Become one today!

  8. #58

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    Does anyone have experience ith scorpion roller rockers? Are they any good or junk? What is the correct preload for a comp cam flat tappet hydralic?? Currently with the pushrod all the way down I can grab my thumb and slightly turn the roller.. and rock the rocker in its pivot perhaps this is the sound. That was with 1/2 turn preload..when it is revved sounds like a wrench taps the valve at 3k.. i have about 2 hours to try something then it is next weekend... any ideas??

  9. #59

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    I have sent scorpion several emails to see if they know anything about this.. maybe have to trailer to the engine shop 35 miles and see if he can figure it out in the driveway for big money..

  10. #60

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    I hope I can help, but keep in mind I'm not a professional mechanic. I'm not sure if I follow you. Are you saying that can move the rocker arm when the lifter is on the base circle of the cam? If this is actually happening, it will destroy the lifer and can cause a catastrophic engine failure. Do not run the engine in this condition.

    As far as setting preload, you are correct at 1/2 turn past not being able to turn the push rod with your fingers. I've never used Scorpion roller rockers, but it seems to me that the push rod length is incorrect.

  11. #61

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    Quote Originally Posted by AJ1398 View Post
    I hope I can help, but keep in mind I'm not a professional mechanic. I'm not sure if I follow you. Are you saying that can move the rocker arm when the lifter is on the base circle of the cam? If this is actually happening, it will destroy the lifer and can cause a catastrophic engine failure. Do not run the engine in this condition.

    As far as setting preload, you are correct at 1/2 turn past not being able to turn the push rod with your fingers. I've never used Scorpion roller rockers, but it seems to me that the push rod length is incorrect.
    The push rod length was set by the engine builder. It runs in the middle of the valve stem.
    This is the second time I set them as once with a single valve spring and once with 2. I have set before on my brothers factory 5 cobra with 20000miles from when I set them and not screwed up yet..

  12. #62

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    Ok... I found at the rear of the valve cover there is a baffle. And I checked many times and it may be contacting the set screw on the rocker arm. The adjusting nut is higher than the rockers like 1/4" and it is impossible for the rocker arms to contact first.
    Perhaps under load it is making noise? I will try 2 gaskets and see if it helps. I spent 8 hours grinding the surface of the valve covers to get them to stop leaking. They are fabricated aluminum. May as well threw them out as they look cool but are absolute ****.

    Anyone know of a valve cover that has over 2 3/4" of clearance at the baffe?? I bought these to replace my factory because any idiot would know they would not fit...
    Maybe make some??

  13. #63

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    Could always use double gaskets with a set of spacers

  14. #64

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    Quote Originally Posted by erratic50 View Post
    Could always use double gaskets with a set of spacers
    Going to put 3 gaskets on and see it the noise stops if it does will get 1/4 or 1/2" spacers.
    I can not believe the chinesium level on my valve covers..

  15. #65

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    Quote Originally Posted by 78futura View Post
    Going to put 3 gaskets on and see it the noise stops if it does will get 1/4 or 1/2" spacers.
    I can not believe the chinesium level on my valve covers..
    Ok that didnt work no change.. calling engine shop tomorrow to see if he has any ideas...

  16. #66

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    It is really sad cause it sounds great otherwise and should be out driving around. Been years of work...I know I think we covered all our bases here.. just need to tell someone.. my wife is ready to murder me over how much money I dumped into that ugly piece of crap as she calls it.

  17. #67

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    When my crank bearings got destroyed I had a 2.5k knock... sounded like this... https://youtu.be/CF-qZ7sKkfY

  18. #68

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    One more base to cover... and, no offense meant if you already know the procedure (lifters for the cylinder being checked/set being on the base circle, zero lift of the camshaft, and then adjusting rockers, and... procedure below) for checking/setting hydraulic lifter pre-load that's going to be pasted below that I've pasted into a few other threads, because I suspect that from your later words within this thread that the rockers may not be set properly...

    This: "... Currently with the pushrod all the way down I can grab my thumb and slightly turn the roller.. and rock the rocker in its pivot perhaps this is the sound. That was with 1/2 turn preload..." shouldn't be possible with pre-load (the opposite of clearance (your ability to rock the rocker in it's pivot), like the clearance/lash that's set with a solid lifter camshaft) set right everywhere at all 16 rocker arms. FWIW, I've always adjusted for 1/4 turn hydraulic lifter pre-load, which has always done away with the possibility of lifter "pump up", eliminating the necessity of buying more expensive "anti-pump up" hydraulic lifters, and there was never any clatter or ticking and the engines would rev about as high as you cared to spin 'em.


    Real good procedure for checking/setting hydraulic lifter pre-load, most especially when you have adjustable rocker arms:

    Pull the valve covers and spark plugs, rotate the crankshaft to #1 TDC compression stroke (indicated by the balancer/pointer, and the distributor rotor pointing at #1 plug wire terminal), mark the balancer or crank pulley at TDC, put another mark 180-degrees from that, and marks halfway between both those at the 90-degree spots, so you've essentially (because your balancer's TDC mark won't be straight up) got marks at 12 (TDC), 3, 6, & 9 o'clock (the cylinders fire every 90-degrees), then while still at 12 o'clock, #1 TDC compression, check #1 cylinder's (front passenger side) rockers/valves for any slack between rocker and valve stem tip, and if none, just for good measure, or for when purposely setting all the pre-loads, loosen those two rocker nuts until there's some clearance at pushrod/rocker, grab each push rod with finger and thumb, and slowly tighten the rocker nut just until there's no up/down clearance, or slight drag to rotating the pushrod, and then tighten the nut the additional 1/4 or 1/2 turn for pre-load... then rotate the crankshaft clockwise 90-degrees to your 3 o'clock position and check the next cylinder in the firing order (the firing order of the camshaft, and therefore the ignition plug wire routing, is known and has been checked/verified, yes?)... continuing the same for each cylinder in the firing order, rotating the crankshaft 90-degrees between each cylinder checking/setting with your 12 & 3 & 6 & 9 o'clock marks, until all 8 cylinders have been checked/set.
    Last edited by Walking-Tall; 06-06-2018 at 08:16 AM.
    Mike
    1986 Mustang convertible 3.8L ---> BUILD THREAD
    1983 Mercury Cougar 3.8L LS
    1986 Ford Thunderbird 5.0L ELAN
    1966 Ford Fairlane sedan 200-6
    1966 Ford Fairlane GT (390ci 4spd)
    1981 Mercury Marquis Brougham
    1980 Capri RS Turbo
    1971 Mustang Fastback
    1974 Pontiac Luxury LeMans

  19. #69

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    Quote Originally Posted by Walking-Tall View Post
    One more base to cover... and, no offense meant if you already know the procedure (lifters for the cylinder being checked/set being on the base circle, zero lift of the camshaft, and then adjusting rockers, and... procedure below) for checking/setting hydraulic lifter pre-load that's going to be pasted below that I've pasted into a few other threads, because I suspect that from your later words within this thread that the rockers may not be set properly...

    This: "... Currently with the pushrod all the way down I can grab my thumb and slightly turn the roller.. and rock the rocker in its pivot perhaps this is the sound. That was with 1/2 turn preload..." shouldn't be possible with pre-load (the opposite of clearance (your ability to rock the rocker in it's pivot), like the clearance/lash that's set with a solid lifter camshaft) set right everywhere at all 16 rocker arms. FWIW, I've always adjusted for 1/4 turn hydraulic lifter pre-load, which has always done away with the possibility of lifter "pump up", eliminating the necessity of buying more expensive "anti-pump up" hydraulic lifters, and there was never any clatter or ticking and the engines would rev about as high as you cared to spin 'em.


    Real good procedure for checking/setting hydraulic lifter pre-load, most especially when you have adjustable rocker arms:

    Pull the valve covers and spark plugs, rotate the crankshaft to #1 TDC compression stroke (indicated by the balancer/pointer, and the distributor rotor pointing at #1 plug wire terminal), mark the balancer or crank pulley at TDC, put another mark 180-degrees from that, and marks halfway between both those at the 90-degree spots, so you've essentially (because your balancer's TDC mark won't be straight up) got marks at 12 (TDC), 3, 6, & 9 o'clock (the cylinders fire every 90-degrees), then while still at 12 o'clock, #1 TDC compression, check #1 cylinder's (front passenger side) rockers/valves for any slack between rocker and valve stem tip, and if none, just for good measure, or for when purposely setting all the pre-loads, loosen those two rocker nuts until there's some clearance at pushrod/rocker, grab each push rod with finger and thumb, and slowly tighten the rocker nut just until there's no up/down clearance, or slight drag to rotating the pushrod, and then tighten the nut the additional 1/4 or 1/2 turn for pre-load... then rotate the crankshaft clockwise 90-degrees to your 3 o'clock position and check the next cylinder in the firing order (the firing order of the camshaft, and therefore the ignition plug wire routing, is known and has been checked/verified, yes?)... continuing the same for each cylinder in the firing order, rotating the crankshaft 90-degrees between each cylinder checking/setting with your 12 & 3 & 6 & 9 o'clock marks, until all 8 cylinders have been checked/set.
    Found the problem!!! #6 intake lifter failure!! Comp cams sucks donkey dick.. madd in china crap.
    On that cylinder can push the rocker in and out easily can not do that with any other.
    I followed scorpions procedure for setting the rockers.
    When exhuast pushrod starts to go up set intake when intake rocker is open and just starts to close set the exhaust..
    Thanks for the responses and ideas to throw around. No offense taken. I am a truck tech(Foreman now) for 23 years. But when it comes to mechanics there is always another way to go about things so I listen to everything everyone has to say. These funny sound problems can be tricky sometimes!!
    Last edited by 78futura; 06-06-2018 at 09:53 PM.

  20. #70

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    Quote Originally Posted by emerygt350 View Post
    When my crank bearings got destroyed I had a 2.5k knock... sounded like this... https://youtu.be/CF-qZ7sKkfY
    This was a snap at 3k. Now I know that was the roller on the rocker tappong the valve stem.. happy it didnt knock out my valve keepers and drop the valves or some horsecrap like that. Would have been really great..

  21. #71

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    Well it’s found! That can be 95% of the job sometimes. The rest is blow apart and go back together. Way faster by comparison!

  22. #72

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    Quote Originally Posted by erratic50 View Post
    Well itís found! That can be 95% of the job sometimes. The rest is blow apart and go back together. Way faster by comparison!
    I need to order parts today. Hopefully will get them by friday so I can repair and have going for next weekend.

  23. #73

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    Update.. all but 4 lifters are collapsed...
    I got intake gaskets and the one lifter but after checking them all they push in easily. Only 2 hold pressure..
    Am I checking this **** right? Going to buy another set..
    The fn cam kit gives you a single cam sproket set up yet.. what horsecrap.. hi performance comp cams?? My ass they are... never again.. warning comp cams are crap cost you time and money. Save the hassle and buy a better brand not mass produced ****.

  24. #74

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    crazy, I would be worried there was something about my valve springs/cam/oil passages that would lead to a run of bad luck like that.

  25. #75

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    Quote Originally Posted by emerygt350 View Post
    crazy, I would be worried there was something about my valve springs/cam/oil passages that would lead to a run of bad luck like that.
    I know I am feeling sick about it.. my valve springs are not binding and dont see any metal in oil. They are high energy lifters. The cam is extreme energy. See what comp does iz sell mismatched parts in the kits. They do have 4 different lifters I probably needed the best ones with the higher lift fast ramp rate cam. So now I am wondering wtf to do.. go to parts store and get 16 melling lifters? How to know what is compatible with the cam? Could be the oil band not the correct height. Never thought lifters were such a big deal to figure out.

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