LD28(T) swap into a 1978 280Z.

#16

Savage, the oil filter thing was more about the possibility of using an oil cooler setup b/w the filter and it's current location.

(like this: http://www.summitracing.com/search/Prod ... toview=SKU)

#17

Savage, the oil filter thing was more about the possibility of using an oil cooler setup b/w the filter and it's current location.

(like this)

#18

The LD28 (in automotive, North American trim) already has a oil-to-water heat exhanger (just like the 280ZX Turbo). You're not going to do better than that with an external cooler. And you'll lose the bypass filtration of the '83 setup, by using a sandwich adapter, unless you buy an external bypass filter, and now you're adding a lot of cost and a lot of plumbing that isn't necessary or even desirable -- IMO, of course

#19

asavage wrote:The LD28 (in automotive, North American trim) already has a oil-to-water heat exhanger (just like the 280ZX Turbo). You're not going to do better than that with an external cooler. And you'll lose the bypass filtration of the '83 setup, by using a sandwich adapter, unless you buy an external bypass filter, and now you're adding a lot of cost and a lot of plumbing that isn't necessary or even desirable -- IMO, of course

huh, didn't know it already had an exhanger, good to know. I might down the road go with an external AMSOil filter setup, but for now, stock location is fine by me.

#20

Hi ya PanzerAce, from the land of OZ, Perth. I'd avoid using the oil feed from the feed to the vac pump on the alternator as I've already been there & my turbo soon started making these odd howling moaning noises on a fresh recon! I then found that the oil feed is restricted by restrictors in the block top to purposely keep (I'd Presume) crank pressures high & restrict excessive oil feed to cam as nowhere near as much load as crank. This reduced oil feed is from the head to the vac pump naturally reduced too. The bloke at the turbo shop I sourced mine from had a LD28T, that he'd done, in a Australian Holden Commodore. He said I should be able to take the feed for my Turbo from this as he had done pressure & flow checks, & found that the pressure was low, (we now know why) but the flow seemed good & he'd used it with no problems, (he had only recently done the conversion, may not have been enough time to possibly give the same prob's I'd had) So I done as advised, after about 1-2 weeks of running, the noises started, I re directed the feed from the oil pressure sender with a tee junction & hose & had no further problems for about the last 10 years running, using the same turbo & a few times round the clock, (miles) too!
The oil pressure dropped 10-15 Psi when I diverted to the main oil gallery, it had suffered no noticeable drop when taking it from the vac pump supply line. I then fitted a brass fitting in the outlet of the tee junction oil feed to the turbo, that had about a 2 mm hole to slightly restrict the feed to the turbo, but nowhere near as much as it was before as I now have a 5-10 Psi loss in normal oil pressure. Hope this helps?
Would like to add some input to the various other Q's you asked in this thread, but late at night & must go to bed. Will add when I get the chance over the next few days.
Richard Teale.

#21

Hi again, you asked how much boost can you go, Ive pushed up to 15-16 Psi & had trouble with exhaust valve seats dropping out & making funny popping, burbling noises when idling as the engine cooled off and allowed them to start jumping up & down with the valves

I was getting 180 horse power at this stage & am now back to round 150 Hp. It also cracked the head (with no great problem) between most of the inlet to exhaust valve seats, which may have later developed to the cooling system a few years later, as it started to blow the coolant out. I had a replacement engine available, so replaced it & decided to set the boost at a max of 12 Psi for reliability & a lack in interest in repairing it! The fuel delivery was set to the same as it is now- black smoke when flooring it, up to about 10 Psi Boost & above that, clear.
The oil cooler that's standard on the upper filter housing, when I turboed it, I fed the coolant that comes from the head into the cooler, first through a radiator cooler up front (its a Mazda 323 heater core), then back into the heat exchanger/oil cooler. I dit some temp checks after I did this, it comes out of the head at naturally about 85 deg C. The 323 core then drops it 10 deg C to 75, then the oil cooler raises it to 85 deg C again. So it works as a more effective oil cooler by having more temp difference between the fluids. I'd recommend an even bigger radiator to cool the coolant down first, of what ever sort that suits your application for that hot climate you are in!
Options for the Tach are the odd model have a pulse generator in the timing cover to the Inj pump pulley, with 2 wires that can be amplified with a electronics box/project, & run a standard 6 Cyld rev counter. I don't know where you would find one in USA but I got one from a company called Genesis Electronics in New Zealand before I moved to Perth, AU. You may be able to Google it & find out about it? The other option is ones especially designed for Diesels that tap into one of the phases of the alternator & with a hand held light sensitive rev counter reading off a shiny strip sticker put tempoarily on the crank pulley, one can twiddle the adjustment on these alt type rev counters to calibrate it to suit.
The Q of how much compression these have, I have a copy of the genuine manual & it says that it's 22/1. I haven't needed to use a special head gasket/copper shim, as a standard "Permaseal" brand h-gasket has done fine.
I have married a LD20T IP top housing including the anaroid fuel control diaphram to a standard LD28 IP. It hasn't been calibrated properly yet but should work well to stop the black smoke when it is not boosting, when I finally get this done. I have a photo but I need to know how to post it. can some1 tell me how?
Richard

#22

Richard

First, thanks for the turbo info - great stuff and I know several folks will be interested.

I'll get back and edit this with a link to the picture posting instructions.

Edit: Here's a link about posting pics on this forum.

http://nissandiesel.dyndns.org/viewtopi ... g+pictures

Cheers, Rufus

#23

Here we go again, useless computers & all the other crap that's involved with them.
I've just wasted another 2 & 1/2 hours trying to upload the LD28 Turbo IP pic, to photobucket, imageshack & others with nothing but blocks, holdups & whatever it can throw at me to prevent me from doing what should be a simple task!

Looks like I should hire a computer guru to do it for me one day. So until then, no picture.

#24

cracked b/w the valve seats? Damn, never heard of that happening before. Is it possible that it was a byproduct of the seats dropping onto the valves?

I'd ask about more stuff, but I've got to drop my other Z off at the auto shop jail tomorrow in......7 hours, so I need to sleep first.

As for pictures, if you can email them to me at panzerace@gmail.com, I'll host and post them.

#25

Maybe it was a result of the valve seats not coming up squarely with the valve & then "when push comes to shove" the piston would ram it home & the mis-aligned seats cracked the head as they were forced into place? I'd presume that's your thought trail? I don't think that was the cause, as the fault only happened at idle after 15-20 seconds to allow the exhaust seats to cool off & contract to start dropping out. I never noticed a crunch, tick, click or bang to show this possibly happening, & I was all over it, listening intently, trying to figure out what was going on! I do think that it was excessive heat from the power I was getting from it & cast iron not being the best heat conductor (or as good as aluminum) to transfer this heat away to the cooling system. It is also likely that the super heated exhaust seats expanded enough to cause the cracks! It is also possible that the exh seats became hot enough to become moldable/plyable to squash them into a smaller diameter to help them drop out when cooled off at idle?
I had the head off my original engine a couple of times to fix the valve seats & never noticed any gashes or marks in the head to also possibly indicate this. It also did it again a third time & I couldn't be bothered fixing it again & left it until the combustion leak to coolant happened & sold the motor for repair or parts, so never fount the cause for that.
The picture of the LD28T, IP I will e-mail to you (& possibly any others of interest) to post, thanks very much!

#26

Yup, that's kinda what I was thinking.

Though I just got some new info that might explain it. Do you happen to remember what year the motor was made (I don't know if you guys down under got the LD when we didn't, but I suspect you did, since I think the patrol? had it as well). Apparently there was a 2-3 year stretch where diesel and some gasser heads (though not the ones that went into Z cars) didn't have an alloy mix that really allowed long term heavy duty use. Under normal driving conditions, they would likely never have a problem, but under heavy use (lots o' boost, etc), they would start splitting between valves, and sometimes even b/w valves and the coolant passages.

#27

LD28T IP courtesy of RT. For those that didn't see it:

I have married a LD20T IP top housing including the anaroid fuel control diaphram to a standard LD28 IP. It hasn't been calibrated properly yet but should work well to stop the black smoke when it is not boosting, when I finally get this done.

#28

Update on my own swap though: Still haven't gotten the engine. My buddy that was going to get it for me has been in and out of the hospital for the past two months because of some health problems, but it's looking like the doc figured out the problem, so he should be good for a trip to get the LD in a few more weeks.

Turbo wise, I'm going to be going with a HE351VE. For those not up on current DI diesel stuff, it's a variable geometry turbo (VGT) developed by holset for the Cummins 6.7 (or 6.9? don't remember) straight six diesel engines. It can have the A/R continuously varied to provide the specified amount of boost over a greater RPM range than a conventional (even twin scroll) turbo. The best part about them is that they can be had for ~150 + shipping almost new. The bad though is that they are electronically controlled, so I'll have to either change to a mechanical WG actuator setup controlling the VGT components, or jury rig a computer. I'm also going to have to get a custom manifold(since placement isn't good on the stock 280ZXT manifolds, and I would have to get a flange adapter anyways), along with a custom bent exhaust.

#29

No doubt revealing a bit of ignorance here, but... Wouldn't a turbo for a 6.7+ be a big large for the LD28???

Rufus

#30

Well, normally yes. But there are a few things going for it in this case that allow it to be used.

1) The Cummins TDs turn *really* slow, even relative to other Diesels. IIRC, the redline is something like half that of an LD even.
2) the VGT tech allows a stupid low boost threshold. I found a thread where someone ran a HE351VE on a 2.4 liter TSI, and he was hitting 20+lbs before 4krpm (and that was with the VGT plane fully open by 11psi). Realistically, the limiting factor for the boost I can push is going to be fuel (which is fine by me. Lean is cold is good). The opening for the exhaust varies from the 3-4cm^2 range all the way up to 25cm^2.
3) The HE351 isn't really that big of a turbo. It's the limiting factor on the power of the cummins engines, and people in the Z world have been using the HE351 series (and the very similar HY/HX35) for years with good results.

If I had to use a "normal" turbo, I'd almost certainly go with a smaller one, but the VGT removes all the problems that the larger one has (other than fitting into the engine bay), so I see no real reason to go with a smaller one (especially at the price of a VGT

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LD28(T) swap into a 1978 280Z.

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