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L28ET Cam Swap


Zguy91

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  • 3 weeks later...

So is there a definitive answer on this? I've lined up an L28ET from an '81 and found a C cam locally. I'm just going to be running the motor fairly stock - just an intercooler and maybe 12psi. Firstly, will it work on my motor (I don't know what lifters I have) and will it be worth it?

 

Thanks,

Dave

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  • 1 month later...

I am installing an E31 "A" Cam, rockers, and matching external oil towers with spray bar into my L28ET/P90A solid "lifter" (rocker post) engine. The full engine rebuild will start today and proceed for the next couple of weeks. Based on the info here, I should have a nice gain in top end with some possible mid range torque gains. Will report my butt dyno results, of course. Any word from the OP and the "C" cam?

Edited by cygnusx1
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I have the P90A head so without modification I cant use the cam. Let me know how converting your head to be able to use the cam works. I might want to do the same

 

Converting the head to solid is fairly easy with thread adapters for the solid rocker posts. Then just install the new cam, and check the wipe pattern. My P90A head happens to be factory solid. I didn't convert this one.

 

 

 

 

I always reference this chart for cam info. The early A is not drilled for oil, I am not sure about the later A cams.

 

http://www.atlanticz.ca/zclub/techtips/cam/index.htm

 

 

Edited by cygnusx1
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Yep, I have THREE P90A's in my shed... NOT ONE is "Hydraulic"--you can not go by casting number, you have to look.

 

The fourth P90A I have is in a relatively unmolested 83 ZXT 2+2, and it's got the hydraulics in it. Externally it's identical to two of the ones I have in storage, and the other one simply doesn't have the oil cooler on it.

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Converting the head to solid is fairly easy with thread adapters for the solid rocker posts. Then just install the new cam, and check the wipe pattern. My P90A head happens to be factory solid. I didn't convert this one.

 

 

 

 

I always reference this chart for cam info. The early A is not drilled for oil, I am not sure about the later A cams.

 

http://www.atlanticz.ca/zclub/techtips/cam/index.htm

 

Is there an advantage to this rather than going with a non-hydraulic lifter head?

 

This tompic has peaked my interest, but I have a p90a Hydraulic head.

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Mines an 83 so its hydraulic

:rolleyes:

 

OMFG...

 

TWO of the THREE I got in the shed came from 83's. The year, the casting... MEANS NOTHING--you can say you have Hydraulic when you have LOOKED and CONFIRMED it.

 

How hard is this? :huh:

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  • 4 weeks later...

Let me translate my own post. A P90A/H with a solid kit installed, including a correct cam, is equivalent (performance-wise) to a P90 that came with solid posts.

 

I don't know if they varied the coolant chamber design between the two heads.

 

 

Edited by cygnusx1
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  • 2 weeks later...
  • 6 months later...

I am bumping this thread as it is relevant to what I intend to do to get my S30 turbo back on the track this spring with Megasquirt. Some of you know I wiped a lobe on my Schneider cam earlier this year, so I want to swap another cam in to get the motor working without a cam break-in to worry about while tuning the MS.

 

I pulled an E31 head from a scrapyard engine, and the cam looks good. There is some bearing surface wear, but I'm hoping that doesn't create an immediate issue -- the lobes on the factory cam all look good. So I am going to swap the towers, spray bar, rockers and the "A" cam to my P90.

 

I am installing an E31 "A" Cam, rockers, and matching external oil towers with spray bar into my L28ET/P90A solid "lifter" (rocker post) engine. The full engine rebuild will start today and proceed for the next couple of weeks. Based on the info here, I should have a nice gain in top end with some possible mid range torque gains. Will report my butt dyno results, of course. Any word from the OP and the "C" cam?

 

I've done quite a bit of searching and reading up on these cam swaps, but I still have a couple questions, and of course any comments on this swap are welcome.

 

The lash pads are of course worn, and I have kept them with the associated (and numbered) rocker arm. Assuming the wipe pattern is centered on the rocker arm, is it ok to reuse the lash pad or do I need a new one? If I can re-use the lash pad, does it matter if it is installed 180 degrees around (I didn't document orientation)? I suppose I can mark the lash pad surface like the rocker surface and ensure the pattern stays within the wear area...

 

Tell me if this is false economy. I am just trying to get a valve train up and running with a new fuel computer, and then I intend to re-do the valve train properly, perhaps with another set of externally oiled cam towers once I have a reasonable tune. I don't want to worry about a cam break-in without a reliable tune.

 

And I am also interested in feedback from the OP on any aspect of this swap, or anyone else regarding used cam swaps and/or results of the 240 cam in a turbo engine.

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