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Showing results for tags 'camshaft'.
Found 6 results
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I'm trying to diagnose a few things on my 75 280z 2+2, and I'm wondering if they might be related. Any help would be appreciated. Also, does anyone know why the section of my camshaft above cylinder #2 is red? Video. In summary, I can't seem to get power out of my engine. It used to run "great", but now I can barely get the car over 30mph. I ran a compression test, fearing a blown head gasket, but though the readings aren't great, I would have expected to get over 30mph with them (1: 170, 2: 156, 3: 167, 4: 169, 5: 160, 6: 165). That #2 cylinder seemed especially low, so I ran it with a tsp of oil in the cylinder, and no change - still 156. My vacuum is measuring low at about 13 in of Hg. I replaced all the old vacuum tubing, but it's still running low, even with most subsystems' vacuum lines blocked off. Fuel is spraying well out of all injectors. Fuel pressure is at 38 psi with the fuel pump on, but engine off, then drops down to ~30 psi when idling. Using a timing light, I adjusted the distributor til the engine was at exactly 10 degrees by the timing mark. I lashed the valves back in the day at cold, but I definitely hear a clicking from the engine that I don't love. Based on that and everything above, I imagined that I must have just screwed up the lash, so I opened the valve cover and checked, but no, the lash was exactly where I left it. So I don't know. Any pointers, ideas, or other debug steps would be appreciated. And yeah, if anyone knows why that section is red on the camshaft, I'd love to know! Thanks everyone. Valves in action
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I while back I took my car, (280z) to a dyno the result, (discussed in separate thread,http://forums.hybridz.org/topic/127636-thoughts-on-my-dyno-result-280z-triple-webers/?hl=%2Bdyno+%2Bresult I contined the investigation regarding the strange figures. I surely have jetting isusue, I however also discovered that my cam was way to retarded. After several measurements with degree wheel and indicator clock I decided to move the cam one notch forward. After this the measurements look quit ok, would probably be a even better with adjustable cam sprocket After advancing the cam these are the figures i got. Max lift intake lobe at 105 degres, approx 12,3 mm, defined max lift according to cam card 12,57 mm at 104 degreess Max lift Exhaust at 111 degrees, approx 12,3 mm, defined max lift according to cam card 12,57 mm at 108 degreess Intake lift at overlap 4,5mm Exhaust lift at overlap 3,5mm Below are figures I measured when camshaft mounted in engine. At 0,05 inch. Exhaust opens 65 degree BBDC Exhaust closes 17 degree ATDC. Intake opens 27 degree BTDC Intake closes 51 degree ABDC Overlap 44 degrees Overlap according to cam card 32 degrees The Duration I get with measured figures Intake 258 degrees Exhaust 262 degrees. Figures according to the cam card. Exhaust opens 50 degrees BBDC Exhaust closes 14 degrees ATDC Intake opens 18 degrees BTDC Intake closes 46 degrees ABDC Duration according to cam card. Intake 244 Exhaust 244 What I don´t understand is the differences in Duration and overlap when comparing to the cam card, this is very strange to me. I´m measuring this with valve play at 0,08 inch as stated in cam card and at the valve retainer. There are certainly some degrees here and there that are incorrect, but as whole I think this is correct. The big picture is showing a quit a big difference in Duration and overlap. I´m I missing something when measuring? The feedback I get from supplier are more aiming towards that the Max lift should be at the correct timing, and not focus on Duration and Overlap. For me this is a bit strange, I would like to know the actual Duration and overlap of the cam in the car. Grateful for any help. /Henrik
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I´m right now on the final stage of my complete engine rebuild. Before engine start I´m double checking the timing alignment. I however seem to miss the V shape mark on the sprocket(aftermarket OSK) which makes me a bit hesitant. Below pictures show the alignment as i sits right now, can anyone please feedback whether it´s aligned or not. Car is a 280z -75. Chain, cam and sprocket are new and the the marking down at the crank is aligned.
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I am looking for a complete set of of rocker arms for my N42 head that I can send in to be resurfaced. Mine are too pitted to be cleaned up.
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Hi guys. I just picked up a rebuilt 1997 mark vi vortec 454 .030. The engine was done to stock specs. The guy I got it from started a project and abandoned it so I got the complete long block for a great price. Everything was rebuilt/replaced on the engine. These run about 9:1 stock compression and I'm assuming that it's going to be right around there give or take .3. I have a question. I'm going to be upgrading the cam before I get further into the project. What is the largest cam that the vortec heads can handle without machining the valve guides for seal to retainer clearance? I don't feel like taking the heads off and totally disassembling them. I need a quick cam change. I will upgrade the valve springs if necessary. I'd also prefer to stay with the nonadjustable valvetrain vs. spending more money. It's already going to cost an additional $1200 or so in parts for me to get this to work. Engine will be a carb engine with an edelbrock performer RPM intake. Hei distributor. Vehicle it's going in is my truck. 1992 Chevy k3500 mason dump 4x4, nv4500 5 speed with 4.56's front and rear. Truck is heavy but I need this engine to have some power. I don't tow, but do get loads stone (6000lbs on average) and the 350 that was in it required downshifts on hills even unloaded. I'd like this to pull above 5k and not die out like the TBI 350 did at 3800. Truck weighs 7540 with me in it. Any advice? Thanks.
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Apparently my engine has a bit hotter of a cam, and there's a little bit of valve ticking, but I just adjusted the valves and the sound prevails even when at factory recommendation. Would a hotter cam alter the required amount of valve clearance? If so, is there a trial and error method of adjusting the valves until the ticking is gone, and therefore a proper seat is found? Or am I just doing the adjustment wrong?
