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Turbo Swap Questions


dat240zg

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OK Turbo Gurus...I'm in need of help. Finally got my turbo motor(s) and all needed for the swap. My questions are

 

1. Is there a performance difference between the P-90 and the P-90A head? I have motors with both, is one better than the other?

 

2. I've collected several pics from turbo swaps and the majority of them have a lot less clutter on the intake manifold than my motor. Which of the plugs, vacuum hook ups, wires and things like that do I need to leave on?

 

3. Right now, I have the stock fuel pump setup on my '70. Do I need to go to a higher output pump than what I have as well as one of the '75/'76 gas tanks?

 

BTW, I already read the Z Club website article on the swap, but was still uncertain. If any of you who have already done the swap are available to answer any questions, it'd mean alot.

 

Thanks hail.gif

 

Bryan

Dat240ZG

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Guest Aaron

Ok, I have never done the swap, but here is $0.02. Search the forum for info about the p-90. I have seen it before, and I think think the P-90 is the one to use. Plan to upgrade the Fuel system. The carbs use like 7PSI, while a FI engine uses like 40PSI. The FI also uses a return line that a '70 Z may not have.

 

Someone much more experienced should chime in.

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OK here goes. You have to have the electric fuel pump for turbocharged and fuel injected applications.

 

Use the P90 head. P90a has hydraulic lifters, and they suck.

 

You can order a bolt that goes in the intake manifold off a single turbo 300ZX from the Nissan deal that will plug the hole for the pop off valve in the intake, cause it needs to go. A popular modification is to use a 75 non egr equiped manifold, and you can certainly do that if you would like. If you are not going to have AC, just about everything on top of the manifold can go, although I like the IAC and leave that on if you live where the temp gets cold.

 

You don't need water running to the throttle body so chunk that too.

 

I think the only bolt in fuel injected tank for the 240 is the 75 model 280. Your 240 should have a return line, but it is to small if you use a higher capacity pump than stock.

 

Probably the easiest thing to do is drop the engine in with all the stuff on the manifold, get it running, and then start removing stuff. That is what I did.

 

I would also make sure I had an R200 diff in the back, and a good clutch behind the turbo engine. The stock will hold up fine for a while.

 

Oh you will probably need to find a turbo exhasut system and get the part than bolts to the downpipe. I never could find a substitute, except for running a down pipe from the back of the turbo, and I am not sure if the stock one will allow that. It was many many moons ago that I have a stock turbo.

 

Good luck.

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The E88 head is probably because he wanted to end up with 40cc combustion chambers (P90 is 53.6cc), plus with the throttle bodies he doesn't need either the notch in the intake ports, nor the 10mm hole between/above the intake ports. BTW, there are two E88 heads, the most common one has 44.7cc chambers but there is a rare early one that has 42.5cc chambers and looks more like an E31 chamber. DAW

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Guest mongrel

The P90a is excellent for what it´s designed for, running silent whith no valve clatter.

On the other hand it can´t handle big cams.

The hydralics will suffer from "pumpup", they will go static which allso happends at higer rpm than oem redline.

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1. I know of a stroker motor with the P90A that runs to 7300 rpm, so it can do highish rpm. I still think I'd go with the non-hydraulic head.

 

2. I've seen some REALLY clean FI manifolds, some with the extraneous bosses/holes filled with weld and worked to match the casting. Lotta work, good luck!

 

3. FI fuel pumpage/management *required*

 

DAW, my info says there are FOUR E88 heads:

'71, which has the E31 combustion chambers, and supposedly the best-flowing L6 runners

'72, 44.7cc chambers, still good for decent compression (9.8:1 on a flat-top L28)

'73, bigger chambers (47.8?), avoided

'74, same as '73 but with bigger L28-sized exhaust valves, also avoided

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You're right Dan, I forgot about the changes to the E88 related to emissions regs and the use on L26s (larger exhaust valve used with bore-notched block). The first Zcar I owned (still own) was an early '72 (8mm rod bolts). It was reportedly completely stock but it was always quicker than other stock 240Zs and tended to ping a bit more. When I replaced the engine I pulled the E88 head off and was surprised to find a smaller chamber that looked more like an E31 than any other E88 I'd seen. DAW

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Well I guess the E-88 head that I have should go to scrap since it`s a 73 twak.gif I wasn`t going to use it myself, but I`ve been storing it hoping someone could use it someday.

If anyone wants it let me know soon, or it will end up as a few hundred pop cans. :D

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  • 4 weeks later...

Ok, now you guys got me thinking...

 

Our Mitsubishi's have hydraulic lash adjusters very similiar to the ones in the P90A (not all P90A's have hydraulic lash adjusters, though) and I've seen no problems with them up to 8000+ rpm.

 

We first need to examine what an HLA does and now it works. It is basically a spring assisted hydraulic plunger that removes valve lash by taking up the extra play. The oil pump supplies the hydraulic pressure needed for the plunger to keep up with the rocker arm ass'ys.

 

If you are installing a 1000 watt amp in your car you will need a large power cable to feed it. This is because the amperage requirements of the amp exceeds the amperage carrying capabilities of the smaller cable.

 

The same thing goes for the lifters. If your oil supply is not up to par (for any reason) or if there is sludge buildup in the lifter ass'y then oil pressure will drop in the lifter ass'y due to lack of oil volume.

 

So, by ensuring we have a good oil feed system and good oil pressures we can keep our HLA plunger operating at it's peak capacity. This may include soaking the HLA in diesel to clean it thoroughly and/or drilling the HLA oil supply hole to a slightly larger diameter so that, just like our 1000 watt amp, we have enough oil flow into the lifter to ensure that it does not experience low oil pressure internally.

 

I'm also willing to bet that by examining the oil feed through the block and the oil pump itself there may be other solutions to any high speed rpm operation problems.

 

Just something to think about....

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