alright ive got a problem. i got my whole motor put back together and thought my lifters were fukd after sending the head off to chicks off s.cobb to get decked. the guy removed all the shims and guides which really screwed us. we took off the valve cover, checked timing, put it back on and let the car idle for 30 minutes hoping the loud ticking would go away after oil circulated through good. it semmed to be getting better we revd it up and it started misfiring. took the valve cover off and noticed one of the rockers slid off and 2 rocker guides broke.
so what do i do from here. do i have to buy all new guides and get the tool to measure every single guide
ROCKER SHIMS and Guides
Re: ROCKER SHIMS and Guides (WHYTEBO1)
so i think i figured this out. i read 2.7 rocker guides go on the exhaust side and 2.7's go on the intake side according to tomei
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Hijacker
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- Joined: Wed Aug 13, 2003 4:57 am
- Car: '92 240sx Convertible
'94 F-150 - Location: Fredericksburg, VA
The way it's supposed to work is that you have to measure the rocker guide (notched shim) with a special dial gauge. The gauge is on a stand that fits into the lifter hole. Then you measure the top of the valve that is paired to the one with the guide. You then subtract the numbers to get your shim thickness, which you would then order from nissan.
The idea is that you want the surfaces between the top of the shim and top of the guide to be as level as possible. However, it's not uncommon for people to simply measure the guide's thickness inside the notch and then slap a matching shim in there. It's not the proper way to do it, but it's also not going to lead to a catastrophic failure.
What happened to your head sounds like you had some stressed parts and they just simply broke. If they bit the dust during an idling session, I would have to assume they were pre-stressed (over-revving usually does that). Just buy some fresh OE parts and go on from there.
If you want to do it properly, you can order the tool. Do a search for "valve shim tool" and there should be a thread or two of people who custom make it. I think I linked one of those threads in my motor rebuild DIY.
And to get rid of the ticking, you need to prime the lifters. They do not prime themselves, and you will have to bleed the air out of them manually. This usually occurs when the lifters are not stood upright. The oil leaks out and air gets in. You'll have to put them in oil, take a thin rod and pump the checkball inside them a few times to get the air out.
The idea is that you want the surfaces between the top of the shim and top of the guide to be as level as possible. However, it's not uncommon for people to simply measure the guide's thickness inside the notch and then slap a matching shim in there. It's not the proper way to do it, but it's also not going to lead to a catastrophic failure.
What happened to your head sounds like you had some stressed parts and they just simply broke. If they bit the dust during an idling session, I would have to assume they were pre-stressed (over-revving usually does that). Just buy some fresh OE parts and go on from there.
If you want to do it properly, you can order the tool. Do a search for "valve shim tool" and there should be a thread or two of people who custom make it. I think I linked one of those threads in my motor rebuild DIY.
And to get rid of the ticking, you need to prime the lifters. They do not prime themselves, and you will have to bleed the air out of them manually. This usually occurs when the lifters are not stood upright. The oil leaks out and air gets in. You'll have to put them in oil, take a thin rod and pump the checkball inside them a few times to get the air out.
Re: (Hijacker)
Same thing just happened to me, got my swap running and the first time i revved it over 4k it had a backfired and i had alot of ticking at idle accompanied with a misfire, pulled the valve cover and had two broken rockers and bent valves. The cams pushed the rocker arm pieces into the springs and bent the valves. So this weekend ill be installing new rockers, valves, and BC springs and retainers and re-shimming everything.
PS, i stole the special tool from the local Nissan dealer (its never been used).
Maybe ill rent it out
PS, i stole the special tool from the local Nissan dealer (its never been used).
Maybe ill rent it out