Silverbullet82

Hello All, I need some help figuring out how to diagnose the cause of cam lobe wear. I rebuilt my engine about 8 months ago. I recently noticed poor performance at low rpms. Mainly as stumbling and backfiring, once rpms are around 3000 the this smooths out and the powers is back and runs good also runs good as boost builds. I checked for vacuum leaks with propane could not find any. I checked timing and it was where I had set it previously. Pulled spark plugs all looked great except for #1, it was fouled with wet black goo. I pulled the valve cover and checked valve adjustment. All where OK except for both intake an exhaust on cylinder #1. They where both too big. I re-adjusted them to warm spec. That is when I noticed the cam lobe wear. I am wondering how to verify if the cam oiling is working correctly. Any ideas on how to diagnose this. I was thinking of starting the car with the valve cover off but I think that might make a big mess.



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PredatorZ

When you rebuilt your engine, did you keep all the valve train parts together in sets, i.e. not mixing them altogether and putting back together with a random mix. Because they wear to each other and need to be kept organized and reassembled exactly as they came out, or replace them all.

Silverbullet82

I had the head re-worked about a year ago. When I rebuilt the bottom end I just clean the head up good and re-installed the head so the valve train was not taken apart.

Silverbullet82

Wondering if anyone has experience with this COMP cam 84-123-6.
COMP Cams: Nissan 6 Cyl High Energy Camshaft

Silverbullet82

Also wondering what people's experiences are with Delta Cams. Because they could regrind my stock oem cam and resurface the rocker arms for significatly less money than buying another cam and rocker arms. Does anyone have a forumla for the optimal custom gring for L28et, 14psi boost, street car.

Silverbullet82

Found some interesting information on Hybridz there is a thread there titled "Swapping Nissan L6 Cams?" Sounds like this is what I need. "Specs are .420" Cam Lift, .462" Valve Lift (1.1 Rockers) 274 degrees of advertised duration, and 242 degrees of duration at .050", on a 108 Lobe Center." posted by Tony D . I am going to call Delta Cams and see if they can re-gring my oem cam for .460"valve lift, 242 duration. Then I will get new springs, new thicker lashpads and put it back together.

ricksilvia

hey bud, i went with delta cams and so far so good 50 miles lol.. cam specs are: 270/280 duration and lift is .460 i had the rockers resurfaced as well. if you want to verify oil flow there are a few ways. (1) pull valve cover and start it yes a mess but you can quickly see what isnt oiling, (2) pull valve cover and remove coil wire and spark plugs and start the engine as it turns over you should see oil coming from the lobes amusing you have an internally oiled cam this will make a considerably smaller mess (3) remove valve cover and oil pump and distributer and oil pump/distributer drive shaft and fab up a metal dowel with a notched end that will fit the oil pump drive slot re-install the oil pump and slide the dowel down the distributer hole on the timing cover toward the oil pump and fit your slotted end into the oil pump and attach the other end to a power drill and oil should flow.

Silverbullet82

Thanks i will go for option #2. I will see if I can bump it at the battery while watching cam oiling.

ricksilvia

it make take a few rotations to see it burble out of the lobes

GNRick

Buick Grand National owners have been using ZDDPlus to reduce cam wear for at least 5 years....ZDDPlus | Maintain proper ZDDP levels in your engine