Howdy, here's my new to me '72 521

[datzenmike]

I've has 2, Z24, 2, Z20E and 2, Z22S heads. I cc'd them and they are the same volume. This does not include the Z20S W04 head which with a little reverse engineering would have a combustion chamber of about 45cc combined with flattop pistons for an 8.5 to 1 compression. We didn't get these engines in Canada. The valve train including cams are... the same. Other than the round intake ports on the Z20E&S and Z22E&S they are the same as the Z24.

 

I've port matched several L20B head/intakes and they are close but never perfect. Intake ports are often slightly off center and are smaller than the head ports. For the most part a small lip does no harm.

[RetroRocket]

i'm going to look at designing a simple adapter plate to mount twin-scroll cooper mini turbo to the ignition interval-paired cast iron naps-z exhaust manifold. low pressure turbo set up, intercooler. the turbo will orient in at an angle with respect to the axis of the vehicle............so what? it makes no difference; just not what we're accustomed to.

I'm building a twin-scroll turbo motor for my '75 toyota chinook around the same concept.

[RetroRocket]

Hey Mike, when i'm talking about doing this or that e.g., twin-scroll turbo onto cast iron oem-style naps-z manifold through an adapter, using a mini cooper off-axis turbocharger i don't mean trying to do such modifications all at once to an engine. these myriad ideas that have to introduced and tested in a staged, scientifically assessed manner.   but that doesn't mean that they won't become proven/manifest and actually work. look at turbo tom hx. an Eerily quiet PL510 rocket before its time. function over form.

 

The aftermarket naps-z Dorman cast iron exhaust manifold is an inferior material and casting as compared to a nissan oem factory part. but the dorman has a plugs placement in each and every runner. this means a wide-band O2 sensor or an EGT sensor can be temporarily placed in each exhaust runner to monitor the tune of each cylinder and each runner can be assessed and tuned throughout the combustion cycle of individual cylinder. that is a lot of tuning info available but was not intended in any way by design; it is incidental, serendipity, or as i'd like to believe: providence. opportunity writ large.

 

I appreciate your objective analysis about the 720 steering column collapse capability. i saw my son today the one who drove recklessly and caused an accident that should never have occurred but for his abusive mis-application of throttle. his decade-ago quartering head-on, 720 vs modern sedan was brutal. but without the nissan engineered design features that you cited, he wouldn't even be here. those collapsible features all got collapsed, but the when the referenced point of origin (the steering gearbox) itself has been displaced 6" rearward right from the start (impact ground zero) and the collapsible features absorb 5" of the 7" needed to miss striking the face and chest of the driver....bam! the human tissue yields to the reluctance of the steering wheel to bend/yield. steering wheel 'one'; face/chest: 'zero'. you would think that it would have knocked some sense into him...jury is still out on that one...

 

anyway, cheers. we all have to drive responsibly in slow, average, and fast cars.

 

same son today said that a z20s intake manifold gasket image (round port) and a z24i intake manifold gasket image (round port) could probably be plugged in to a CAD program and a smooth-flow transition interface/adapter about 1/4" thickness could be easily spit-out. aluminum is probably the material to go with for CAD.  but glass-reinforced nylon using e3-D printing clearly has potential merit.

[RetroRocket]

oops: i meant to say z24i intake manifold (square port) above.

 

actually the plate could just be a round port template straight through and 1/4" thick, and then the intake manifold side gasket matched to the square-port side with hand grinder.

 

it could be possible to take a round-port head and cut with horizontal band saw a 1/4" aluminum section from the intake manifold aspect, drill the bolt hole threads out so 8mm bolt/studs pass through it, and gasket match both sides: one side round match to round port-match; the other side square-port match. and that is the adapter needed.

 

[one would need to obtain 8 mm bolts and studs that are 1/4" longer length than originals] i included this sentence for those readers who would say: 1) but if you did that the bolts would be 1/4" too short therefore it wouldn't work, and  2) pics!! we need picks!! of such an adapter plate and 3) this can't be done!! if it were possible it would have already been done and we would know about it.

 

cheers

[datzenmike]

I would JB weld around the intake holes perhaps 3/4" in then use the round gasket for a guide and port match to head with a Dremel. KISS... keep it stupid simple.

[Stoffregen Motorsports]

Yes, the epoxy method has been used for decades on many different engines. Instead of JB Weld, there are other epoxies that are made for that task. They are more firm and easier to control where it's going.

[RetroRocket]

Thanks both of you. I have been considering that approach and it would be the easiest way. my concern is that if some of the material let loose it goes directly into the cylinder/chamber. i'll start searching for what binds best to aluminum.

maybe i could use a correctly-sized tube that has a release agent on it or some material that i could just melt or burn out of the way after the filler material has set (like a wax candle or a zuccini or something).

 

[RetroRocket]

i mean for the bore, a mandrel,  and the material gets packed around it at the intake port of the manifold to form a round opening shape

[RetroRocket]

or, i could work smarter not harder and shape the material into the square corners of the manifold ports so that they slope to a generally round shape, then wall it off with material; let it cure, and center drill the material to match the round gasket. step-drills work well for this and then finish/polish with a dremel 

so, forget the zucchini ...

[Stoffregen Motorsports]

Engine builders use products like this - https://goodson.com/products/prk-99-intake-port-reshaping-kit

 

If applied correctly, it will not come loose.

[datzenmike]

Also the it necks down from larger intake to smaller head port so it's not going to fall into the smaller hole.

[iceman510]

I have some Z22 parts including a head and likely in intake from an '81 720 if interested and need more raw material for your Frankenstein experiments.  Carbureted  vehicle though.  Cheap except for the shipping.

[RetroRocket]

thanks. good to know. shipping is prohibitively expensive to me though at least for the non-aluminum parts. a bare head might be inexpensive to ship UPS though.

 

I do have a core Z22S short-block to work with to replace the Z24. Since my D21 4wd is not going to be a work truck and it is not going off-road, and since i don't like driving long stroke inline engines past about 90 stroke, i will probably use Z22 block and an 86 mm stroke L20B crank, and the W04 head. i will probably do a low-pressure turbo with a relatively high static c.r.  just a modest approach but hoping to gain efficiency through effective tuning and engine mgmt through reverse-engineering and retro-fitting mechanisms and methods from the more recent technological advances. the more efficient emission controls of today's cars can be retro-fit at the same time the power and efficiency is upgraded. for example, i'll pull off a heavy rusted air-injection pump, use a three-way catalytic convertor and light it off using an electric air pump jy sourced from a mercedes or whatever through a relay/toggle switch activation to use for the first start of the day, etc. i hate the smell of untreated car exhaust, and the poison.

 

my approach is: to typically leave my piston/rod pick/selection to follow my geometry parameters of bore/stroke/r-s ratio without initial regard to what make, displacement, #cyl, etc; strictly dimensions/crunching numbers. i sometimes come up with an unusual combination of parts (like alfa romeo rods + northstar pistons, etc) because i select individual components by dimensions. i consider, early on, what rod/stroke ratio i am seeking for my intended application, then i identify a rod with the c-c length and b.e. dia and b.e. width dimensions that fit directly (or minimally machined to fit)  to find commonality to the specific dimensions i need. then i select a piston of the dia. i need; and pin ht of piston; together with pin dia of the piston and the rod; and then float/non-float pin style must match (or if the rod s.e. were bushed down a bit, etc). next is to filter for dish volume [ already known]  the range of dish-flat-dome that would or would not work for your chosen c.r. and compatible combustion chamber/piston top configuration] 

 

Then material choice of piston (hypereutectic vs plain, cast vs forged), and price new and used, and the availability. i often pick the piston based on what diameter i need from an oversize selection that would apply to the engine make/series that the piston originally came in but now it fits the bore diameter of the one i'm putting together just right, even though my block might be at std bore.   that is really a key variable to include as a range of what would fit the bore size you are working with. increased variability of diameter choices by including the possible oversizes (the actual diameter spec)from a catalog of new pistons is a real luxury that expands selection. sometimes there will be a donor piston whose std size is 0.5mm is larger than the block i'm working with. if the piston is really a nice match otherwise then a 0.5mm block overbore is the answer to make a match-up.

 

oh, and a federal-mogul or trw, mahle, etc main catalog for bearings by specs can help to find a rod bearing of the width needed but just a bit off in journal size needed can help find the needle-in-the-haystack match by including bearing undersize dimensions available. the dimensions are what one needs to match up for shell dimensions (shell thickness, i.d., width, and locating tang configuration.

 

and don't forget to pay attention to pin offset difference between L and R banks of a V engine if that is the piston source. sometimes you can find a set of 5 out of 6 used or new, etc., but you may only be able to use from a V6 or V8, exclusively R bank or L bank pistons in your inline due to valve-pocket mismatch if the piston needed to be oriented to comply with the direction of pin-offset required for the new application. it could come down to having to buy an individual R piston [often not easy to find] to constitute the set of four needed for an inline four.

 

one piston i recently sourced was the right dimensions of bore dia, compression ht, pin dia,...but a mismatch in valve reliefs between intake side and exhaust side placement from the donor engine compared to my engine configuration......but low and behold i could reverse the normal front-rear piston alignment of the donor configuration to have the valve reliefs correctly located with/to my valves and yet not have a piston pin-offset nightmare...how?...because the pistons sourced were from a Honda engine that turns in the opposite direction from the one i am configuring. the offset became what i needed when those pistons were flipped around and installed front edge to back.

 

in general it has become easier to fix the messed-up rotating geometries which resulted when mfg's increased stroke of an engine to gain some displacement needed when emissions standards reduced hp and torque/driveability. mfg's typically accommodated the increase in crank throw length by a reduction of c-c length of the rods (which meant the rod/stroke ratio was doubly impacted [lowered]). that stop-gap approach made some engines less fun to drive. but with more modern engines and lower and lower compression ht pistons widely available it has become easier to use longer rods with shorter piston hts to restore geometry. 

 

i know, a book right? maybe tips useful to someone. it has become a combination of sport and art for me. maybe a mod could transplant this blurb to somewhere else on site if need be.

cheers.

 

 

 

 

 

[RetroRocket]

 

6 hours ago, Stoffregen Motorsports said:

Engine builders use products like this - https://goodson.com/products/prk-99-intake-port-reshaping-kit

 

If applied correctly, it will not come loose.

thanks for the tip. i started searching and hadn't seen that one yet. i hate to spend the money on this product but i'm probably go with this product because it is temp rated to 1400* and suited to aluminum specifically: https://www.amazon.com/Pyro-Putty-1000/dp/B00AKJJMD2

 

but while searching i stumbled upon these interesting products:

https://caswellplating.com/cerakote-piston-coat-ceramic-thermal-barrier.html

 

https://caswellplating.com/paints-and-coatings/high-temp-ceramic-coatings.html

 

i wasn't looking for these products but any experience with these or similar?

 

 

 

[RetroRocket]

where at in MI?

6 hours ago, Stoffregen Motorsports said:

Engine builders use products like this - https://goodson.com/products/prk-99-intake-port-reshaping-kit

 

If applied correctly, it will not come loose.

 

5 hours ago, datzenmike said:

Also the it necks down from larger intake to smaller head port so it's not going to fall into the smaller hole.

i lived in MI for a few years and more than a few road trips...i moved there from illinois just before my last yr of high school 1969.  i didn't do team sports but a friend and i represented our hs  by competing in the national plymouth troubleshooting contest instead of team sports    lots of street racing around detroit      looking back i feel very irresponsible and i don't tell stories in front of my kids......big car culture, detroit back then   my first car was when i lived in chicago,  a'55 chevy 2dr post that i talked my parents into letting me buy at age 15 so that i could work on it and have it ready to go by the time i got my drivers license........they put it in our garage (because it looked like a POS).....and i was not allowed to work on it unless i maintained a 'B' average............so there it sat the block cracked over the winter as it had weak anti-freeze and detroit gets mighty cold.

the block might not have been all that strong though as it was a 265 c.i. that had been bored to 283 displ which iirc was a .120" overbore. it had 283/283hp fuel injection pistons (domed) so i just put everything in a std bore 283 block. once i got the car (towbar) behind family car..........my buddy was going along and we had assumed that we'd be in my car, playing guitar...stuff like that.we're getting set to leave our old house and my parents break some bad news to Danny and me: it's against the law...we're looking at each other thinking 'just how dumb are we anyhow?'  so we had to ride in the family car all the way from chicago to detroit. we would have preferred hitch-hiking to that.

 

blah,blah...within a year of getting to MI i had a 327/350hp engine assy in it and was out on telegraph road every weekend. i always have had one of the rattiest, but fastest, cars. i think i might have gotten that car to all one color (red primer that is, and on the whole car not just 1/3 of it) over the course of my ownership. but i did manage to go through a lot of transmissions and diffs and have to get hd ones, LSD's, put on a 1-pc fiberglass tilt front end, radiused the rear wheel openings, 10" slicks ye-haw!

 

still true with me about the raggedy cars and all (i have ordinary presentable ones too) but the art to me is in function not form. my pursuit is maybe more of a sport than it is art. who knows.

now "fastest" now for me is still a key competitive but i've changed my definition empirically. is taking an old style vehicle and making it faster by substituting in newer under-the-hood technology (and trying to use Junkyard-sourced parts to do this)   i guess i'm limiting my objective now to optimizing 0-60 time while optimizing mpg at the same time; like a ratio of change function. another requirement i insist on to myself is to greatly reduce what can be measured with an emission-result tailpipe test as compared to the EPA period-correct spec limits for myself that

 

 

 

[RetroRocket]

i did not mean to send that stupid biographic blurb. i thought i deleted all of that before sending.

 

oh well, since iceman replied: did you ever ice-race on lakes in MI?

i never have done any but i've seen it in Wisconsin with motorcycles and cars.

 

an ice-boat is a thrill at least until you get chucked out of it onto the ice but then laughing so hard you didn't care. i used to live in CO and did that up on a reservoir in the rockies. the acceleration is scary, and there was a dam at one end which would have been a long drop down. the one i rode could be carried on top of a car because it was high strength lightweight alloy tubing that folded up and pinned together the sail was only about the size of a 'sunfish' little sailboat sail but there were some crazy home-builts that were ridiculously fast.

[datzenmike]

The last air injection pump was on the 1980 L20B 720. After that a tube was run from the exhaust manifold to a one way reed valve on the air filter. Each exhaust pressure wave is followed by a vacuum pulse the one way reed valve allows through. The free exhaust energy pulls air into the exhaust pipe the catalytic converter uses to burn any hydrocarbons.

 

As for the Z22 block and L20B crankshaft... no matter what rod you go with you'll need a custom piston. There is another possible choice...

 

Z22 block bored to 89mm. Use 89mm KA24E flattop pistons on the Z22 or L20B rods. The piston is 1.55mm below the deck but the added displacement with a Z series head produces 8.4 compression. Want lower? substitute 15cc dish Z24 pistons for 7.4 compression. Bonus this produces a 2,288cc engine

[RetroRocket]

Thanks Mike for the input. i know the standard combos. i've taken to putting recipes together by using oem parts from other brand vehicles to configure what i want to end up with. i strive to spend as little money as possible, including machine shop expenses, yet get the most bang for the buck in my results. the objective is usually to satisfy my own curiosity to see if what i calculated to work out does actually work out as viable.

 

i love the generation of L-series nissan engines especially in the historical context of Bob Sharp, Paul Newman, BRE etc., i.e., the giant killers of that era. i've owned so many PL510's, 240Z's and 280ZX's over the years that i've lost count. i still have at least one of each of those cars and spares. i also have other cool cars, swedish, german, italian, other japanese brands, three usa brands, and a korean brand vehicle. i have an extensive project list for each of these vehicles but it is just a hobby. i don't work on other peoples' vehicles at all except to help my three boys or a friend out with theirs if, and only if, they actually need my help/time.

 

I have come to appreciate those like you who have a wealth of knowledge and are selflessly willing to share it. i hadn't been working on any of my datsuns for a while but i recently resumed it. i know you have encyclopedic knowledge so rather than flounder around i just asked you first and i truly appreciate your input.

Best.

 

 

[Stoffregen Motorsports]

When I was younger, and building race engines for a living, nobody could tell me that the L series Datsun engine wasn't the pinnacle of engineering. They were strong and capable, yet simple and easy enough to work on yourself, and obtain parts for. Over the years since, I have come to understand that while all of what I thought was true then, it certainly isn't true now. The L motor is a great engine in stock form, and even with a few gentle mods, but to make big horsepower with any L series, every single part inside the engine needs to be either massaged or replaced with a Hi-Po parts. Some of these parts are not easily obtainable anymore and the people who know how to build L motors are moving on to other things, or are returning to the mothership for their final voyage.

 

To get to my point - there are far better engines to choose from these days. If you're hellbent on keeping the L (or Z) motor, understand that you can perform many of the small mods in your garage, but these mods won't give you the HP, MPG or reliability of a modern engine.

 

Cool story about the '55.

[RetroRocket]

I agree about the L engine being timeless and an elegant design. It is a great motor to teach a kid about engines with. I like your return to the mothership analogy. Although I draw the line at small block chevy. i abandoned american marques and pushrods in the '70's. Too crude. I've only come back to some american brands because that is what is popular and nostalgic around the west puget sound.

 

Of course it is way outdated in technology but i'm more interested in historic racing even as time-only Solo I and Solo II and benchmarks that applied earlier that can be retro-fitted by technical tuning like hemholtz principles, etc. DIS, and modern accoutrements  within the framework of limitations of the large cast pieces: block, crank, head.

One of my cars, a 72 240Z i bought in southern california in '86 when i lived there and i've moved it around with me from there to st louis then to wa state but limiting my mods to  daily driver street legal changes. i won SCCA NW Region 'B/Street-Prepared' here in Seattle with it in '95. have had an H-Prepared 72 510 and a 280Z with L28ET that i have run as Solo I. but i can't afford the expense of racing wheel-to-wheel so i kept it simple. I've had other 2 dr 510's, 240Z's and still have several. But i also have concurrent projects with my seven mercedes cars, two italian cars, toyota, amc eagle 4wd wagon (a high-altitude spec car from CO with a lower gearing than the flatlander cars got) with stroker inline six, KB pistons, etc., 73 maverick 5.0L, hotrod dodge motorhomes (x3), and lots more vehicles that i design exhaust systems for, refit with more modern transmissions with overdrive and TC lock-ups that didn't even exist at mfg date, gear vendors units, etc

 

It's is strictly a hobby at my chosen pace. which it always has been. turning my attention back to my datsun stuff has been comforting somehow. like running into an old chum that you haven't seen in 30 yeares.

 

Gotta go: OR road trip through mountains today.

Best

 

 

 

 

 

[datzenmike]

The head is what makes power, the block only needs to be strong enough to stay together. The Z head is not at all the best for flow and even worse for performance increases. This is due to the exhaust but mostly the intake ports being close to and horizontal to the block with a bend at the valves. One only has to look at the great flowing L series intakes and how high they are on the head. Air falls straight down and into the combustion chamber. The Z series was never designed with performance in mind, however it does have a few things that are very good. Hemi combustion chambers... the most efficient. Dual spark plugs to shorten the burn time and reduce ignition timing. (shorter burn for less time to form NO but also less time for heat to be absorbed by the combustion chamber increasing efficiency. The Z head is quite detonation resistant) Cross flow heads to get the hot exhaust ports away from the intakes and keep them cooler. Cross flow also makes running a turbo much easier and allows an inter cooler too. A turbo can somewhat mitigate the poor breathing by simply pushing harder.

 

The L series heads will also fit onto the Z series blocks. This will solve the breathing problem but add others.

[Stoffregen Motorsports]

Yeah, instead of wasting spending time on the Z head, consider an L head on the Z bottom end.

[iceman510]

On 10/24/2022 at 8:29 PM, RetroRocket said:

oh well, since iceman replied: did you ever ice-race on lakes in MI?

i never have done any but i've seen it in Wisconsin with motorcycles and cars.

 

 

I have not personally ice raced, but knew many that did,  I lived in Wisconsin for 22 years into my mid-20's, so knew guys with Rabbits and Bugs and sometimes 510s that did it.  Been to Illinois in between, and now in Michigan for 8+.  Now just looking to stay warm in winter.  Worked in the garage last night and it was 46 in there. 🌡️

[Stoffregen Motorsports]

I grew up in Duluth MN. and we used to go watch them race in the bay. The Archer brothers were always there racing, I think, Honda Civics.

[datzenmike]

Ahhh then you would know who Dick Bong was.