Jump to content

ANOTHER Datsun Z/LS3/T56 Swap Thread

Recommended Posts

18 hours ago, NewZed said:

Before the fuel rail is called "dead heading".  The fuel rail is a branch off of the pressurized side but the end of the "branch", the rail, is closed.  Pressure is built up and maintained but the fuel can only get out through the injectors (edit - wrong)Fuel pressure in the rail can't be released quickly for varying manifold vacuum.  That's bad.  After the rail is more normal, "bypass" style, where the FPR acts as a pressure relief valve, letting fuel out of the rail after set pressure is reached.


Edit - Correction.  I wasn't thinking right on pressure control.  Rate of response can be affected but the pressure will still be controlled by the FPR just back at a central node instead of right at the end of the rail.


Size and length of fuel line would be a consideration.  Vacuum hose also.  


BRAAP has written about this.  Carry on...




Share this post

Link to post
Share on other sites
On 2/5/2019 at 10:46 AM, Ironhead said:

My fuel pump is a done deal.  The cell has an integral trap door reservoir and the ubiquitous Bosch 044 pump.  I don't know the specs exactly, but I know that pump will handle far more power than I will ever have in this car.  Honestly my intent is to leave the LS3 stock....LOL....I know, I know, famous last words.  But I have done my share of messing with modified engines, and wanting a break from that is one of the main reasons I went LS3 in the first place.  The problem with highly modified engines....yeah they go fast....but they need good gas....and the biggest problem for me is that no matter how much time you put into it, you can never get a perfect tune.  I don't mean at WOT....that's easy....I mean part throttle and idle and all that.


My current plan:  I borrowed the Bosch FPR adapter off my BMW for fit up.  I am going to "Y" the AN8 fuel supply line from the cell into two AN6 lines, one going into each fuel rail.  The FPR adapter will mount to one of the heads and will be plumbed between the two fuel rails.  It will use a Bosch 078133534C 4 Bar (58 PSI) FPR for an Audi S8 (and numerous other Audis).  Then an AN6 return line back to the fuel cell.  This might be a bit of overkill, but at least I know I won't have to re-do it all down the road.


Thanks again to all for the input.  Very helpful.


I think that is going to work out great. Quick google-foo shows me that Radium has an FPR housing built around that same regulator style. Makes for nice way to land AN fittings on that regulator. Is that what you are using? 




I am considering ditching my Aeromotive regulator, seems like lots of people have problems with them. 




Share this post

Link to post
Share on other sites

I'm using the Bosch Motorsport mount that New Zed linked a few posts ago, just because I already had one on my BMW and it was easy to pull off for mock-up.  The Radium one looks better though....just because it comes set up with AN6 ORB threaded ports.  The Bosch one has M14 threads, but adapters to AN6 are easy to find.  Boy though, Radium is sure ripping people off with their price on the Bosch 3 and 4 bar FPRs.  I just bought a 4 bar from Pelican Parts and it was less than half what Radium is charging.


The only possible issue, is the Bosch FPR is really small, so small it is kind of disconcerting compared to most of the aftermarket ones.  I worry that it might not handle the fuel flow of my engine/fuel pump combo.  But this same Bosch FPR was used on the 2001-2003 Audi S6, which was a fairly high HP car, so hopefully it is up to the task.  If not, it will be a simple matter to switch to a higher flow unit, without significantly re-designing my plumbing setup.


I don't think there are specifically problems with Aeromotive FPRs so much as that the aftermarket ones in general are not designed and made to the standards of the OEM ones.  Newzed is right on the money with that as far as I have seen.  Plus all the aftermarket ones are adjustable, which IMHO adds another unneeded variable.  I have read of several high end automotive tuners who won't tune cars with adjustable FPRs, just because there is really no need for adjustable fuel pressure, and they have found that the adjustable FPRs are much less reliable.  Fuel pressure problems can quickly kill a highly tuned engine....from going lean and detonating.


I just did some more reading....these Bosch FPRs are rated to "reflow" up to 220 LPH...and my Bosch 044 pump is rated to deliver 220 LPH at 4 bar.  So, I should be good, considering it won't generally be sending back all the fuel the pump is providing, at least not unless the engine isn't running.


Apparently if the FPR has too little capacity, you will see a rise in fuel pressure beyond what it is rated at.  This wouldn't be catastrophic, like going lean might be.  I will just have to monitor fuel pressure for a bit once it is all up and running, to make sure all is good.

Edited by Ironhead

Share this post

Link to post
Share on other sites

I got the transmission installed in the car.


I am using the Hoke cross-member and tranny mount, but since I have the car stripped I figured it made more sense to weld in the support plates rather than use the bolt in Hoke units.  So I cut new ones out of .25" steel and welded them in.






As posted earlier, my plan was to use the Sikky shifter, since the T56 Magnum tranny I am using apparently moves the shifter further forward that with the standard T56 the Hoke kit was designed for.  The problem that developed with this plan was that I really did not like the feel of the Sikky shifter.  It added a lot of slop and "vagueness" to the shift linkage, and I did not want to build a car that (to my tastes) shifted poorly.  So I decided come hell or high water I was going to use the Tremec shifter.  This involved welding up the OEM shifter cutout, and cutting a new one for the Tremec shifter.  Not a big deal, but I am also going to have to modify my (completed, I thought) dash structure which would now interfere with the shifter.  If I am honest with myself, I think I was just trying to dodge the additional work and that the Sikky shifter would save me from it.



I also found that I had to further lower my steering rack, in order for it to clear the oil pan.  With the tranny installed and bolted up, I found that the engine sat in a more level attitude than I expected, which pivoted the front of the engine back down onto the steering rack.  So I will have to further space down the tie rods as well.





I know the long shift lever evokes a school bus and won't win any style points, but I prefer having the shifter as close as reasonably possible to the steering wheel.  This shift lever accomplishes that, as well as angling backward to make up for the slightly-too-far-forward shifter pivot.






I think I did the right thing not using the Sikky shifter, I cannot believe how nicely the setup shifts with the stock Tremec shifter.  It is silky smooth and very precise.  I am just pissed off that I spent the money on the shifter that I won't be using.  Since I installed it I cannot really in good conscience return it....it no longer looks perfect and new.


Thanks for looking.


Edited by Ironhead

Share this post

Link to post
Share on other sites

So, in this thread: https://forums.hybridz.org/topic/129738-someone-please-refresh-my-memory/ 

I was inquiring as to whether or not I could remove the horn brackets, as I forgot what they were for.  When others confirmed they were for the horns....they were destined to be gone...because they are in the way of my oil cooler plumbing.


So I figured, easy job, good access, just three spotwelds on each bracket....I'll just drill them out then remove the brackets.  That way I can save them if for some lame reason I decide I need them after all.  No sign of trouble ahead.


Well, I dunno, something about spot-welding relatively thick steel or something.  My spot weld drill-out bit got partway through the metal, then hit a patch so hard it might as well have been glass.  Seriously, the bit would just spin without removing any metal whatsoever.  I tried a different bit, same result.  And, there was way too much metal remaining to just pry or otherwise force them off.


So, all that remained was to grind the damn things off.  I hate grinding metal...you know...loud, makes a mess that gets everywhere, that sort of thing.  But what else could I do?  Funny how jobs that appear easy often wind up being a serious PITA.  I know all you fellow car dorks understand....


PSA:  If you find yourself having to do something like this, I found that a 36 grit flapper disc removes metal MUCH faster than a grinding stone.  I would have assumed the reverse.  


Sorry for the rant/tangent.







Share this post

Link to post
Share on other sites

All I have really done the past couple of weeks is work on installing the radiator and plumbing the coolant and oil lines.


The radiator is a Ron Davis unit.  He said he already had a template for a Datsun Z/LS swap radiator.  I told him I wanted the biggest radiator that would fit, just to hopefully prevent any future cooling problems.  I should have been careful what I asked for.  The radiator does fit, but it has to be installed absolutely perfectly or it hits the frame rails, or the fill cap hits the underside of the hood.  And the hose fitting interferes with my passenger side strut tower brace which had to be "clearanced".  I finally got the radiator installed, but it took a lot of fiddling.  It clears the frame rails by less than 1/8" on each side.


If I was doing this all over again, I would have passed on using AN hose and fittings for the radiator hoses.  The AN20 fittings are just too bulky and expensive.  They eat up too much of the available room between the front of the engine and the radiator fans.  I got everything to go in, for the time being at least, but I am rapidly running out of space in the engine compartment.


The oil lines were a similar drill, trying to route them so they use up as little space as possible and allow as much clearance as possible for the exhaust.


Thanks for looking.

















Share this post

Link to post
Share on other sites
19 hours ago, Ironhead said:

But what else could I do?  Funny how jobs that appear easy often wind up being a serious PITA.  I know all you fellow car dorks understand....

Like every friggin' job I do on the car and otherwise!  Oh this will only take an hour or two...6 hours later I'm still plugging away.  No wonder I don't have any hair left! 🤣

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...