That's what your old cam was correct? What will your spings handle? Will they take more than .521 without binding? That's what I need to know. Thanks Mark
The springs I have on the cars specs are Seat load:95@1.850 Open load:300@1.350 Coil Bind:1.280 415 Lbs/inch Does that help?
Yes, thank you. The cam I had in mind won't work, too much lift. Time for plan B. Just a suggestion, next time go with more seat pressure (125-130#) and less overall spring tension maybe 330 open at .550 lift, 415lb/in is a bit much, means you need to be light on the seat just like you are. Plus even with just .521 lift you're getting close to bind if they were installed where they should have been. Maybe a reason for wiping out some lobes? Just a thought.
Maybe I know marty was useing the Ta duals on his engine when he wiped one lobe.CASON! what springs were you using when you wiped a lobe??
Russ; yes I run the T/A Super Duals. @1.730 installed height, they have 125lbs. seat pressure, and with .584 lift should have about 360 lbs open. Coil bind is at .990 which is great for high lift cams. Guide bosses are cut down on height for retainer to seal clearance & o.d's for teflon seals. I like the springs!:Brow:
So should have posted this earlier I wrote down my oil pressure readings. 60Psi cold start and during warm up 45 psi at 190 degrees cruising at 40mph about 40-42 psi doing 70mph on the freeway at 2800 rpm When I hop off the freeway its about 10-15 it jumps around at idle I think because i havent tuned the carb yet witht the 268 back in. Now that is with 10w-30 royal purple with a fram filter (I have read they suck on this board ) and with 6kish on the engine since rebuild I will have to look when the sun comes up to give approximate mileage. Do those numbers seem bad??Could that have attributed to the lobe failure or just never putting in an additive and relying on royal purp.Take Care lets keep this thread a rollin!Russ:beer :beer
wiping the cam is not caused by the springs, unless you got something really f'ed up. This problem with wiping cams did not happen until the mid 2000's when oil manufactures pulled the zinc (which lubricates the valvetrain) outta the motor oils. If your cam was already nice and broken in, it was not an issue....if you were using a new cam and flat tappet lifters it was suicide for the cam. The camshaft "break in" oils did not exist at this point and were invented for this fact. Ever since then, I have heard about wiped cams daily....has anything else changed? Is the cam blank being manufactured in China??? Has the composite material changed in the camshafts??? I'm puzzled unless it is the lack of proper break in of a camshaft causing these failures. Step 1) Add engine break in oil from Comp, Crane..... and or use Rotella T as it has a high level of zinc to start with. Step 2) Start engine for the first time after a nice pre-lube of the oil pump. Step 3) upon firing, look for leaks, top off water and get the timing "close" while holding the engine RPM to 2500 for the duration of 10 minutes. Step 4) idle engine, set timing properly, adjust carb with vac gauge, top water (if needed). I have followed this simple start up procedure since the 80's and have not had a problem..... please let me know if something else has changed in camshaft breakin procedures.
Did the exact same stuff in break in with Rotella T and comp break in oil took the in spring or damper or whatever its called of the springs Lubed the piss out of the cam bearings lifters distributor drive gear broke her in for 20 minutes drained oil put in the royal purple drive it around for 50 miles then did another oil change and filter:TU: .
Damn the PTSD I cant sleep tonight Im thinking of going all out here when I get my new cam like finally and for real.What I mean is spending money on good quality head porting and getting marks roller conversion and new springs if needed.Now my question is what roller rockers links to the part would be prefered.
When I talked to someone at Erson cams last year he thought that the cam problem was less of an oil problem and more of a crappy lifter problem. Also talked about a new type of roller cam that would allow them to make roller setups for Cadillac, Buick and others at a reasonable price. Have not heard anymore about that. Rotella is not what it used to be. The stuff with the rainbows on it do not have the same amount of ZDDP etc. I was using Amsoil products that have the correct ZDDP percentages. But I now have a 9 qt oil system and going with Valvoline VR-1 racing oil. http://www.valvoline.com/faqs/motor-oil/racing-oil/76
I personally witnessed a loss of 7hp on a dyno using Royal Purple, apples to apples. I checked with Erson. About 6-7 years ago is about right for the influx of Chinese stuff. That's when Johnson lifter made the change then went out of business. A new cam and lifters and the right oil combo should work well, after you get all the old stuff out.
