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#1
12-31-2021, 07:42 PM
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Piston to valve clearance issue
Will post cam card asap....
So Butler cam Bp6014sp Anyway... dialed in at 108 CL... all looks good till I put head on and clay piston. Intake is aMILE away but exhaust is squeezing clay to .040 at valve relief?..... Running 1.65 HS rockers..so .540 lift.... Even rechecked dial in...107-108....ICL Exhaust is @ .050 # 54' BBDC open Close exhaust @ .050 ....2* ATDC THIS is a shelf cam at Butler.... am I missing something m Deck is 0.000 with DSS pistons. I am using an old felpro (.039) basket for nick up |
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#2
12-31-2021, 08:15 PM
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Something doesn't seem right. Are you using a 9 keyway timing set? They can be somewhat confusing. The dot and numbers on the keyway don't correlate to the actual tooth above it. They are splayed apart. One for the keyway, one for the tooth to tooth alignment with the cam dot. Just a thought. Also intake lobe is the second lifter bore in driver's side. Don't mean to insult.
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| The Following User Says Thank You to mgarblik For This Useful Post: | ||
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#3
12-31-2021, 08:23 PM
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The HS rockers are known for ratioing out to 1.7.
I have lived with .060” on two race motors, but ,040” is pushing it too far!
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#4
12-31-2021, 08:43 PM
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Not only would I like to see the cam card but also a flow sheet for your heads. Most time what I have seen is the exhaust does not needed as much lift as the intake.
Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
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#5
12-31-2021, 09:15 PM
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My HS even with stiffer roller springs measure 1.7s.
Sounds like that thing is retarded opening intake late with piston further down bore.
__________________
Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
| The Following User Says Thank You to Skip Fix For This Useful Post: | ||
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#6
12-31-2021, 09:55 PM
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Another option would be to run some Ford Windsor 1.6 rocker arms IF the cam dial-in is 100% accurate.
__________________
 Johnny US Army Retired1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
| The Following User Says Thank You to Johnny406 For This Useful Post: | ||
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#7
12-31-2021, 11:19 PM
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Recheck your camshaft installation again.
Tom V. Happy New Year.
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#8
01-01-2022, 09:07 AM
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gotta be the dial in. I don't see it, but maybe I'm blind to it at the moment having been working on it (and other stuff) too much.
I am using a milidon gear drive. IIRC each cam tooth is 13.5*. (each of the 7 screw holes is worth +/- 1.5* from zero....ISH) Although we already dialed the cam in (which was /is always fun with the gear drive) I marked all 3 gears so reassembly could be made with a simple line up the marks. Will get a fresh start in the NEW YEAR and look for the stupid stuff If dial in IS correct, I guess I will need to get out the borescope and take a look. Currently only in mock up so no rings old head gasket...etc |
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#9
01-01-2022, 09:21 AM
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A good test with light checking valve springs would be to measure how far the exhaust (and intake) valves can drop till they touch the piston when at TDC and also 10 degrees before TDC. With finger pressure, not force. Don't need the rocker or pushrod setup for this.
Measure of the intake and exhaust tappet lift at TDC (overlap cycle) would be great also. Last edited by pastry_chef; 01-01-2022 at 09:40 AM. |
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#10
01-01-2022, 09:46 AM
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was debating that exact thought. Just didn't want to pull off the valve springs......lol spent 3 hrs looking (before finding) 1 little f*cking valve seal spring....that popped off after being seated.....of course!!!...1500 hrs on Friday...New Years EVE....sure every store stocks one of the blue .500 valve seals...and open.... ARGH
Time to remove all my tape marks on degree wheel and do a fresh start. I hate when you do something so MUCH you have the numbers memorized!!! it can make you blind to what you are actually SEEING. |
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#11
01-01-2022, 10:34 AM
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Well found the stupid!.....
So which way does a Pontiac motor turn.....lol So as I'm looking at my degree wheel and tape marks...I watch my son rotate the motor!.... OOPS!...not bad 13 yr old...PISS POOR SUPERVISION!... |
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#12
01-01-2022, 11:32 AM
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I'd call that a win! Easy fix!
__________________
1965 Pontiac GTO 455/469 w/ #48 Heads, '65 Tri-Power 9.25:1 CR Stump Puller Cam Muncie M22W 1st-2.56 2nd-1.75 3rd-1.37 4th-1.00 3.55 Rear Differential Front: 225/60R15 Height: 25.6" Rear: 275/60R15 Height: 28" |
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#13
01-01-2022, 12:25 PM
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Quote:
I'd do pushrod spin and be checking for intake open and exhaust close at overlap TDC. Intake open 29° BTDC overlap and exhaust close 27° ATDC overlap. Got them numbers using Butler cam specs with 108° ICL and one of John Wallace's cam calculators. IO and EC may not be exact. But the 2° more on IO than EC should be really close for the cam installed 4° advanced (108° ICL). Clay |
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#14
01-01-2022, 02:07 PM
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BTW some guys take those little springs off the valve seals for Performance application .
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#15
01-01-2022, 04:14 PM
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If you dial the cam in BACKWARDS...yes things Change..alot...BTDC...BECOMES ...ATDC
So .390" intake clearance.....430" ahaust.... that's more like it with this little cam.... Supervisor has been suspended and on 5 project MAX ..... 
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#16
01-01-2022, 06:51 PM
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Glad you have it all figured out now. I assumed you had a roller chain set-up so my original post is nonsense for your application. BTW, I have lots of those metal jacket blue viton valve seals now. PM me if you need anything and I can send them to you. Good luck.
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#17
01-01-2022, 08:18 PM
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all good....no, using a gear drive...NO MARKINGS....lol.....thats why I took the opportunity to label everything yrs ago.... cam hub has 7 screws which locate the cam gear.....ie TIMING.... 7 screws 52 teeth....
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#18
01-02-2022, 11:43 AM
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#19
01-02-2022, 11:44 AM
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#20
01-02-2022, 11:53 AM
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