Lil' Blue performance upgrades, turbo?

[livemeyer]

Been a while since I've posted on here guys.  I own a 1985 720 standard cab I call Lil' Blue.  I'm her second owner, have had her since 1989.  So basically, since before the wife, the home, the kids.  Other cars and trucks have come and gone, but she's a keeper.  I've taken really good care of her and these days I just get her out mostly for summer cruising and occasionally to haul something.  Classic car insurance on her now and she lives under a carport to stay dry.  But hey, she's a truck, and I don't baby her.  Clean but not a trailer queen.  Got her cleaned up a few weeks ago for the Old School Reunion at the Kelley Farm in Sumner, WA.  Fun show.  

 

Before I get involved in discussing what options I'm considering, first you have to know the history.  She came to me in 1989 with 126,000 miles on the odo.  Being only four years old, these were all freeway miles.  At $3k in 1989 for essentially a brand new truck with high miles, I couldn't pass her up.  She got me through college and many years of driving into Seattle.  Heck, her first replacement clutch came at 180,000 miles!  In 2003 she finally let her head gasket go at 240,000 miles.  At that time, with a young family I didn't have much money to spend getting her fixed up, but a retro union renegotiation check came through and was a good chunk of cash to get her going again.  I had bought a performance cam from eBay (sorry, I don't know the grind, too much time has passed) and had the engine completely rebuilt (she was super clean inside the cylinder walls, but a failed attempt at head gasket repair and a cold winter allowed water into #4, necessitating the rebuild).  Around this time I also upgraded to a Weber 32/36 and a pacesetter header.  The truck ran great, but had very poor idle, which I attribute to the cam.  Speaking of the cam, I don't know it's grind but it's characteristics are poor low rpm torque but incredibly strong mid-range pull.  Basically, won't spin the tires in the dry but will get all squirrely in the wet in second gear with too much throttle.  To cure the poor idle I swapped out the 32/36 for a 38 Outlaw.  I think it's DGAS.  Now, during the build, the shop had difficulty getting the engine timed.  The timing gear has three options and generally you use the middle hole, but I sometimes wonder, since it is a racing cam, if hole #1 or 3 should have been used.  The timing is extremely far advanced.  Right now I would guess it's pushing 130 at the wheels but that's just a guess.  It's a hyperactive blast on the freeway but slow off the line.  I raced an MR2 on the way to Old School Reunion on SR167.  I lost, but not by much considering he had a turbo and I was carrying spare parts in the back (bumper, starters, front lower fascias) and a 180lb passenger. 

 

Yet, during the show, my truck doesn't get much attention.  I want it to look unassuming.  A sleeper, basically.  But it should garner some interest at the show when I pop the hood.  So, I again have gone down the rabbit hole of how to increase performance.  Eventually I plan to electrify it, placing two Leaf battery packs in the bed or under the bed, but I'm not ready yet for that big step.  So I looked at engine swap options, and I've read a number of posts regarding RB engines, KA engines and the like, and the smart guys like DatsunMike keeps everyone's pipe dreams tampered with a reality check on how hard these swaps are.  I don't have the tools to cut up an oil pan.  I don't want to start cutting into the firewall or do anything to take away from the looks or enjoyment of the truck.  What I want is for it to look unassuming, but launch hard and keep pulling strong to redline.  I think I have settled on the possibility of doing a turbo setup.

 

From what i've read in posts, some 9-10 years old or older, is that the Z24 is an especially good engine to turbo.  I think the cam was intended for flat-track racing, which would explain its strong mid-range power but weak torque off the line.  The Weber 38 has a flat spot in it at about 2000 rpm, maybe smaller jets could reduce the richness and it may perform better there, but I worry I'd be sacrificing quality idle.  I will experiment.  Back to the turbo idea: I figure a blow-through turbo is the way to go, but I expect it will only amplify the engine's mid-range characteristics and not improve the low-end torque, which is my main goal.  Still, a rising tide floats all boats, so I figure adding a turbo would likely give me at least a small amount of low-end gain, possibly enough to satisfy.  My target is 175hp, and considering where the engine is at now, I think that's possible.

 

Now, again from reading - a lot - I have seen the KA24e exhaust manifold will bolt to the Z24, but some grinding needs to be done to make the ports match a little better.  What I haven't seen in the older posts is that there seems to be kits now listed on eBay that can accomodate this build, even though they are advertised as a turbo kit for the KA24 in a 240sx.  I've also found that a complete kit can be bought from an Aussie or New Zealand company (http://www.turbodatsun.com/Blow Through Carby Kit.htm) (http://www.turbodatsun.com/Z24 T3 Turbo Kit.htm) as well.  Looks like they will also sell my the B&M Blow-through plenum kit on Ebay (https://www.ebay.com/itm/Blow-Through-Turbo-Plenum-WEBER-32-36DGV-38DGMS-Bonnet-Hat-Gemini-Escort-Datsun/273902269965).  So I do wonder, has anyone tried their kits?  And would it be cheaper to source the parts individually instead of buying their kit?  I've seen some T3/T4 turbos on eBay for just a bit over $100 (https://www.ebay.com/itm/Turbo-T3-T4-T04E-V-BAND-Turbocharger-63-A-R-5A-R-Internal-Wastegate-Universal/333240037387) (https://www.ebay.com/itm/T3-T4-T04E-V-BAND-Turbocharger-Turbo-63-A-R-5A-R-Internal-Wastegate-Universal/201748429871) but unfortunately I don't know enough about turbocharging to know if I'd be getting the best part for the job.  I've also seen these complete kits for the 240SX and wondered if they could apply (https://www.ebay.com/itm/Turbo-Kit-For-89-90-Nissan-S13-240SX-with-Stock-KA24E-Single-Cam-Engine/141172093466).  I've also seen some very appealing partial kits and other specific parts such as this KA header (https://www.ebay.com/itm/Equal-Length-Turbo-Top-Mount-Stainless-T3-Manifold-S13-Single-Cam-SS-KA24-KA24e/183560486802) and this partial kit (https://www.ebay.com/itm/OBX-Turbo-Manifold-For-1989-to-1990-Nissan-240SX-KA24E-SOHC/152830000532).

 

Basically, I think I now know the direction I want to go, but I want to make sure I have found the right parts to get there.  This is not my daily so I can afford to have it down for a time.  I just don't want to buy parts only to discover they don't fit or are intended to work with a different system.  Love to get some input here.

 

BEYOND engine improvements, I've been considering other upgrades.  What front brake upgrade is most common?  My brakes work pretty well and have great brake feel, but with added power I'd want to be considering added stopping power.  Also, some of my low-end torque issues might be attributed to a weak or tired clutch.  What's the best or strongest clutch upgrade out there?  Is it Exedy?  

 

For all you fans of the Nissan brand and the 720 trucks, know this: Lil' Blue is still on the original radiator, 5-speed transmission and fuel pump, among other things.  These trucks are insanely reliable if taken care of.

[livemeyer]

In 1990:  https://s112.photobucket.com/user/livemeyer/media/scan0019b.jpg.html?sort=3&o=0

 

[livemeyer]

Today:  https://s112.photobucket.com/user/livemeyer/media/IMG_5961.jpg.html?sort=3&o=11

 

 

 

[Charlie69]

You might want to find anew picture host Or start paying PB a monthly Payment and then still have all your pictures with a big PhotoBucket water mark on all your pictures.

[datzenmike]

Going from a 32/36 to a 38/38 is not the way to fix an idle issue. Carb size has little to do with the idle, they both pretty much adjust the same way. Perhaps the 32/36 needs to be cleaned out. Increased cam overlap extends the time both the intake and exhaust are open at the same time and this lowers the intake vacuum and a poor idle and low speed is the result. Too much carb and too much cam is usually hard to live with.

 

 

You mention the timing. Would this be ignition or cam timing as they are completely separate things on this engine.

 

The cam timing is usually set on the number 2 hole on the cam sprocket. The other hole is only for adjusting out chain stretch or if your head was milled down. Stretch or milling will cause the cam events to happen later than they normally would. Moving to the #3 hole advances the cam timing about 4 degrees.

 

Ignition timing is set by adjusting the distributor and should be around 5 degrees.

 

[Charlie69]

My 86 720 the under the hood sticker recommends 3 degrees.

[livemeyer]

On 6/25/2019 at 4:57 PM, Charlie69 said:

You might want to find anew picture host Or start paying PB a monthly Payment and then still have all your pictures with a big PhotoBucket water mark on all your pictures.

Was there a problem?  I haven’t used photobucket much.  

[Stoffregen Motorsports]

My Photobucket pics don't have the watermark.

[Charlie69]

You have been a paying contributor for long time.  I believe this is the difference and who knows maybe if you pay PhotoBucket enough money and for a long enough time all the watermarks go away. 

 

In the beginning if PhotoBucket would have gone about charging for there free service in a different way I would have stayed with them, but when they held my pictures for ransom I felt I was being black mailed and left Photobucket and have not looked back.  I recieved emails from them wanting monies for their services but I throw the email in the junk mail. 

 

 

[livemeyer]

On 6/25/2019 at 4:57 PM, Charlie69 said:

You might want to find anew picture host Or start paying PB a monthly Payment and then still have all your pictures with a big PhotoBucket water mark on all your pictures.

I moved the photos so here's a better link:  

 

In 1990: https://s112.photobucket.com/user/livemeyer/media/My 85 Nissan/scan0019b.jpg.html?sort=3&o=0

In 2019: https://s112.photobucket.com/user/livemeyer/media/My 85 Nissan/IMG_5961.jpg.html?sort=3&o=11

 

I'll do a video, post on youtube, share it here.  If a picture is worth a thousand words, a video must be ten thousand.

[livemeyer]

On 6/25/2019 at 5:41 PM, datzenmike said:

Going from a 32/36 to a 38/38 is not the way to fix an idle issue. Carb size has little to do with the idle, they both pretty much adjust the same way. Perhaps the 32/36 needs to be cleaned out. Increased cam overlap extends the time both the intake and exhaust are open at the same time and this lowers the intake vacuum and a poor idle and low speed is the result. Too much carb and too much cam is usually hard to live with.

 

 

You mention the timing. Would this be ignition or cam timing as they are completely separate things on this engine.

 

The cam timing is usually set on the number 2 hole on the cam sprocket. The other hole is only for adjusting out chain stretch or if your head was milled down. Stretch or milling will cause the cam events to happen later than they normally would. Moving to the #3 hole advances the cam timing about 4 degrees.

 

Ignition timing is set by adjusting the distributor and should be around 5 degrees.

 

Any time I start a discussion about what I've done and what I want to do, I get more critique about what I've done (wrong or right) than helpful comments about what I can do going forward.  The discussion about the 32/36 versus the 38 is pointless.  I did this years ago, the 32/36 is long gone, and the 38 gave the truck a good idle and great performance.  I'm not going back.  A secondary question would be can I continue to use the 38 if I go to a blow-thru system?  

 

Regarding timing: the info about the number two hole on the timing gear is great info.  I was thinking if this cam makes the distributor need more advance, why not move it in the timing gear, take that 4-degree advance, then pull it back at the distributor?

 

To be clear:  I like the way my truck is set up.  It's powerful, runs great, is a blast to drive.  I'm in a good place I just crave more power.  

 

Story about the timing: when I had the engine rebuilt I took it to a reputable shop.  They pulled the motor and took it to a machine shop that did the overbore, planed the head, everything.  It came back to the shop, they put it back in, and set the timing to stock.  They called me, said it was done, but it wasn't running very well.  True that, at stock advance it runs shitty.  This race cam needs much more advance to run properly.  That's it, end of story.  Nobody needs to stand up and say "well, the correct way..." you'd have to be here and see what it does.  The only small issue I have with advance timing is run-on after shutting it down.

 

I kinda think running a turbo might be ideal, that it might give me the opportunity to retard the timing a little bit.  There's probably a thousand little things to do to get it tuned right, but a little more torque and power might make this quite the performer.