Worked on Motor Today...
11-17-2008, 08:22 PM
#1
Worked on Motor Today... Hi All,
Got my new "micropolished" Comp 918's installed, got my (used) TSP Torquer V2 cam installed, got my new double-row Rollmaster timing set installed, checked my PTV clearance and had 0.200" straight up with 0.240" at 10° either side. Did a cold leakdown with no oil in the cyl's (engine has been sitting on the engine stand for 3 yrs!) amd had 91% front cyls. down to 83% rear cyls. No valves leaking, all rings...
Everything went great until I decided to degree the cam. Admittedly, one major snafu was trying to use the 918's to degree with. I'll get some light check springs tomorrow (the check springs I used to see the PTV are too light).
What I saw using the wrong springs was only 0.360" lift at the retainers and all specs were 30° late with the chain installed straight up. Does that sound right? I'm hoping the light springs will bring all specs into their proper range.
Russ
Got my new "micropolished" Comp 918's installed, got my (used) TSP Torquer V2 cam installed, got my new double-row Rollmaster timing set installed, checked my PTV clearance and had 0.200" straight up with 0.240" at 10° either side. Did a cold leakdown with no oil in the cyl's (engine has been sitting on the engine stand for 3 yrs!) amd had 91% front cyls. down to 83% rear cyls. No valves leaking, all rings...
Everything went great until I decided to degree the cam. Admittedly, one major snafu was trying to use the 918's to degree with. I'll get some light check springs tomorrow (the check springs I used to see the PTV are too light).
What I saw using the wrong springs was only 0.360" lift at the retainers and all specs were 30° late with the chain installed straight up. Does that sound right? I'm hoping the light springs will bring all specs into their proper range.
Russ
11-18-2008, 07:49 PM
#2
Cam won't degree right! Hi again,
OK, I got a light spring installed and (using only #1 intake pushrod) my I.O. is 12° BTDC (instead of the 6° called for). When I rotate the crank until I see 0.050" on closing, my I.C. is 56° ABDC (instead of the 46° called for). Regardless of being 6° advanced, why am I getting 248° duration (instead of 232 called for)?
Before doing anything else, I put the old stock timing set back in and checked it, same results! Next, I retarded the cam 6° and checked it again. Now the I.O. is @ 6° BTDC like the card says, but the I.C. is @ 62° ABDC.
Am I doing this wrong or is my cam mismarked? It's a TSP Torquer V2 which I bought here used (no card). I got with Jason and sent him the serial off the cam and he sent me a card:
________________________________________________
_____________________ __INTAKE_______EXHAUST
Valve Adjustment_________ _HYD___________HYD
Gross Valve Lift__________ _.595___________.598
Duration @ .006 Tappet Lift__281_________ __283
Valve Timing @ .050_______OPEN_________CLOSE
_________________INT:_ _6 BTDC_______46 ABDC
________________EXH:__53 BBDC________1 ATDC
These specs are for cam installed @ 110° intake centerline
_____________________ __INTAKE_______EXHAUST
Duration @ .050___________232___________234
Lobe Lift________________.3500_______ __.3520
Lobe Separation_________ _113°
________________________________________________
Also of note, I'm getting 0.550 lift instead of the 0.595 listed, but that could be some lifter slack...
Any ideas?
Russ
OK, I got a light spring installed and (using only #1 intake pushrod) my I.O. is 12° BTDC (instead of the 6° called for). When I rotate the crank until I see 0.050" on closing, my I.C. is 56° ABDC (instead of the 46° called for). Regardless of being 6° advanced, why am I getting 248° duration (instead of 232 called for)?
Before doing anything else, I put the old stock timing set back in and checked it, same results! Next, I retarded the cam 6° and checked it again. Now the I.O. is @ 6° BTDC like the card says, but the I.C. is @ 62° ABDC.
Am I doing this wrong or is my cam mismarked? It's a TSP Torquer V2 which I bought here used (no card). I got with Jason and sent him the serial off the cam and he sent me a card:
________________________________________________
_____________________ __INTAKE_______EXHAUST
Valve Adjustment_________ _HYD___________HYD
Gross Valve Lift__________ _.595___________.598
Duration @ .006 Tappet Lift__281_________ __283
Valve Timing @ .050_______OPEN_________CLOSE
_________________INT:_ _6 BTDC_______46 ABDC
________________EXH:__53 BBDC________1 ATDC
These specs are for cam installed @ 110° intake centerline
_____________________ __INTAKE_______EXHAUST
Duration @ .050___________232___________234
Lobe Lift________________.3500_______ __.3520
Lobe Separation_________ _113°
________________________________________________
Also of note, I'm getting 0.550 lift instead of the 0.595 listed, but that could be some lifter slack...
Any ideas?
Russ
11-19-2008, 07:07 PM
#3
OK, I'm a dumba$$! I dug out my old Iskendarian "cam handbook" from 1976 and found that I was checking at the valvestem and NOT the pushrod. Everything came out A-OK, motor's back together now. 
BTW, that old book has a pic of an Isky beehive valve spring way back then!
Russ
BTW, that old book has a pic of an Isky beehive valve spring way back then!Russ
