koleson Posted September 15, 2012 Report Share Posted September 15, 2012 Alright here's the thing I have a 290 cam and have heard to degree it in but don't have a degree wheel and the last time I used one was in school and have long forgotten how to use one. I am wondering if anyone has installed a cam somewhat similar to line and how they did it. Thanks. Quote Link to comment
datzenmike Posted September 15, 2012 Report Share Posted September 15, 2012 There is a dowel on the front of the cam. Put it in the 2nd hole in the cam sprocket when at TDC and test for timing chain stretch. If the chain is OK you're in business. This is the stock cam timing position. You can move the cam one hole forward or back to retard or advance the cam timing 4 degrees. Generally retarding the cam favors high RPM power, advancing it improves low speed torque. Quote Link to comment
koleson Posted September 15, 2012 Author Report Share Posted September 15, 2012 Sweet thanks. Quote Link to comment
koleson Posted September 15, 2012 Author Report Share Posted September 15, 2012 What about breaking in a new cam and also what would I need to set the valve lash? Quote Link to comment
Stupid_fast Posted September 15, 2012 Report Share Posted September 15, 2012 Valve lash is set with feeler gauges, a 17mm and 14mm wrench. 290 lift ? isn't that stock spec for an l20b ? Quote Link to comment
datzenmike Posted September 15, 2012 Report Share Posted September 15, 2012 What about breaking in a new cam and also what would I need to set the valve lash? I've heard of holding revs at 2 K for 20 min or some such... whatever. I seriously doubt Nissan did this when the L20B was new. I would just start it and drive it. (lash set of course) It can 'break in' while driving. If you have an after market cam follow they're instructions for lash. OIL!!!! Be sure to use an oil high in ZDDP. This stuff is being phased out because of roller cams but you should be able to find something. Ask for flat tappet oil that old chevy owners use. Valve lash is set with feeler gauges, a 17mm and 14mm wrench. 290 lift ? isn't that stock spec for an l20b ? 290 is (I think) the cam duration. Stock L20B is 248 duration and 0.413" lift (at the valve) the cam lobe lift would be around 0.275"? If the 290 IS the lobe lift then this would work out to 0.435" valve lift. Some use new rocker arms (sorry, cam followers) so both the contact surfaces are new. You can polish them yourself with fine wet sandpaper and a small sheet of glass. Seen lots of cams changed or rocker arms mixed up and put back in different order and guess what? They ran just fine. Quote Link to comment
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