"A" Camshaft on P90a solid lifter Problem

[ArchetypeDatsun]

I have a P90a hydraulic lifter head that I converted over to a solid lifter with the lash pads from Timesert this head was taken to a machine shop to only get it cleaned. Me and a friend of mine are working on it at the moment he's doing most of the work when I'm working during the days. The lifters are off of a P79 head and I also wanted to use the "A" Camshaft but as putting the "A" Camshaft onto the P90a it sat on there perfect but for some reason the rocker arms didn't align with the Camshaft. The rocker arms would fit half way on the cam sockets and lifters were a little off on the camshaft lobes.

 

Is there something that needs to be changed? Can I change the rocker arms from the P90a Camshaft onto the "A" Camshaft? From what it looks like everything is more spread out on the P90a than the P79 head. My worry is can the stock P90a camshaft I believe "M" Camshaft would work with solid lifters, or could I use a P90 camshaft that I have as a spare work better? At the moment my buddy put everything back together for the start up as he tried to also put in that "A" camshaft before.

 

Hope this was clear if not please correct me.

Edited May 25, 2012 by 280zx@541

[SleeperZ]

I'm not sure if I understand exactly what the issue is, but the cam towers and valves are all in the same position across the entire line of L6 engines, so if your rockers don't line up with the cam lobe and the valve, maybe you put the cam in backwards?

[rossman]

I don't understand either. A picture or two would help.

[ArchetypeDatsun]

I'm not sure if I understand exactly what the issue is, but the cam towers and valves are all in the same position across the entire line of L6 engines, so if your rockers don't line up with the cam lobe and the valve, maybe you put the cam in backwards?

 

Sorry for the confusion, i totally forgot to add my the head is going on a 83 L28ET (stupid of me) I found the problem one of the rocker arms that goes on the front was in the back I don't know how that happened so I will try again see what happens. I'll try to get some pics up soon If I haven't figured out the problems thanks for looking guys sorry for the confusion.

 

I had a quick question would a "F" Cam work as good as a "A" cam for a L28ET my engine is pretty much stock exception of a Z31 ECU MAF set up and AiResearch T3/TO4E Turbo. I read the specs on both camshafts look almost similar but I see the A cam would probably have the better advantage for a street build. I'm not looking for big HP numbers just trying to use what I got in hand.

[Tony D]

By "lifters" do you mean "adjustable pivots" or "rocker arms"?

 

 

"Cam Sockets"?

 

"Lash Pads from Timesert?"

 

I'm with Sleeper Z---the lobe spacing is identical.

 

You have an ADJUSTABLE PIVOT, ROCKER ARM, and LASH PAD in the mix.

 

Adjust the pivot up to see where contact occurs on the WIPING PATTERN where the CAM LOBE meets the ROCKER ARM and where the ROCKER ARM meets the LASH PAD on the VALVE STEM.

 

If these WIPING PATTERNs aren't centered on the wearing areas of the respective components, it's possible the valves are 'too short' and to compensate for this you will have to use thicker LASH PADS to get proper VALVE TRAIN GEOMETRY.

 

Use of the proper terminology will help everyone understand what you are talking about, as well as give you a PLETHORA of SEARCH HITS which should explain this setup in detail (FAQ section will also help.)

Edited May 25, 2012 by Tony D

[ArchetypeDatsun]

By "lifters" do you mean "adjustable pivots" or "rocker arms"?

 

 

"Cam Sockets"?

 

"Lash Pads from Timesert?"

 

I'm with Sleeper Z---the lobe spacing is identical.

 

You have an ADJUSTABLE PIVOT, ROCKER ARM, and LASH PAD in the mix.

 

Adjust the pivot up to see where contact occurs on the WIPING PATTERN where the CAM LOBE meets the ROCKER ARM and where the ROCKER ARM meets the LASH PAD on the VALVE STEM.

 

If these WIPING PATTERNs aren't centered on the wearing areas of the respective components, it's possible the valves are 'too short' and to compensate for this you will have to use thicker LASH PADS to get proper VALVE TRAIN GEOMETRY.

 

Use of the proper terminology will help everyone understand what you are talking about, as well as give you a PLETHORA of SEARCH HITS which should explain this setup in detail (FAQ section will also help.)

 

My bad Tony by "Cam Sockets" i meant to say Cam Towers.

 

Yes the measuring tappets that go on the solid lifter to convert the P90a Hydraulic lifter head to a solid lifter head.

 

I figured that out once i saw that the cam towers were in the wrong order, they must have got mixed up by accident.

 

Thanks Tony for clearing it up for me sorry it was a mess and hard to understand i was using my phone i was typing like a maniac and didn't re-read what i was writing as the result nothing was really clear for you guys. It seems everything is going to work the way you explained it should have it fired up tonight if not tomorrow.

 

I know this is off topic and i also searched this but found nothing on this but i just found this out, the A cam i thought i had resulted in really being a F cam. So my question now is will this F Cam be as good as the A cam for the P90a with solid lifters in the L28ET. I'm not looking for a huge power increase I just had read on here that the A cam which i thought i had should give the car an extra 500 rpm. I searched on xenons130.com and was looking that the A cam is slightly different than F cam but not by too much.

Edited May 26, 2012 by 280zx@541

[Tony D]

little changes make big differences.

 

Try this for s&g:

 

Change your valve lash 0.002" tighter, and looser than specification.

 

Do a valve timing event chart (cam card) and see what changes occur.

[ArchetypeDatsun]

little changes make big differences.

 

Try this for s&g:

 

Change your valve lash 0.002" tighter, and looser than specification.

 

Do a valve timing event chart (cam card) and see what changes occur.

 

I'll try that thanks Tony!