L32 Stroker

[Kodie]

Hail my fellow Zedders,

 

It has finally come to pass (Teetering on the edge more so due to the ridiculous prices and availability) that I will switch from my original idea of using a vh41 in the 240 to using a l31/2 stroker with triples strapped to the side.

 

Now I have done some searching and found alot of info but I thought It would be best to ask the people who know, lest I find my self in a situation where I'm paddling a barbed wire canoe up the perverbial creek.

 

So basically I thought I would use something along the lines of this:

 

Block: l28 (not sure what one)

Head: N42

Pistons: KA24 (possible hypereutectic or the classic forged route depending on piston weight)

Rods: L16 or perhaps something else

Crank: LD28 (although I have heard of an after market one but haven't seen neither hide nor hair of any sellers)

Carbs: triple mikus or 48mm deltos

 

Now I have found some vague info on some of the machining and was hoping that you guys might be able to point me in the right directions for a comprehensive set of requirements or enlighten me in this topic.

 

Any input would be greatly appreciated. Please don't write in about the search button because I have tried for the last 3 days across this and other forums only to find tid bits (unless I'm using the wrong search phrases?!?).

 

Regards,

Kodie Graham.

 

[NZeder]

ok.

 

1. For a L32 you need to run a 90mm bore not that stock KA24 sizing of 89mm

 

2. That is a 4mm overbore I have had 2 L6 engines at 90mm and only do this if you really want the extra cc as you will go through a number blocks before you find one that will take that large of an overbore (just use any block ie L24 and sleeve it might be easier and you know what wall thinkness you will have)

 

3. There are many LD28/custom cranks around and a number of places in the states will make just about anything you want comes down to $$.

 

4. KA24 pistons are not light they are designed for a truck engine really and have large rings (good for no ring binding you get with the small stuff if not used from time to time) so this will limit the power

 

5. Invest in a good clutch setup from the start ie twin plate 7.25 it is worth it in the end for high HP strokers

 

6. If you have issues finding L16/L24 or early L20a rods (all the same spec, well some of the early L16 and L24 only have 8mm rod bolts but generally speaking they are all 133mm c to c and have 9mm rod bolts, 21mm pin) get some L24 H-Beams - they will be lighter and already balanced and have a good bush in there - they will only cost a little more that prep'n the L16/L24 rods anyway.

 

7. Depends on the power goals but I would consider a smaller bore 87mm as this will give you more room to move in the future with the same block + with the LD28 stroke you can still make 260HP at the wheels with bore around this size so how much do you want or need - that would be more than twice the RWHP of the factory L24

 

8. Have you been in a well sorted L28 on triples? You might not even need a stroker

[Kodie]

This is the reason why I ask, instead of taking all that is written on the web as gospel

 

Cheers for the advice Nzedder.

 

In regards to power levels, I want as much power as is practically possible to get out of a reasonably reliable engine. So, having said that I have ruled out the idea of an L32 as I am not keen on the idea of going through blocks.

 

Hmm, so the KA24 pistons are heavy buggers. Considering I want a punchy, free revving engine they are probably not the piston of choice then.

 

Also I haven't been in a well sorted L28 with triples, perhaps one might be at the symmonds day of the Tassie trip? Quite prudent to suggest it as 260 at the wheels is roughly what I was looking at from the vh41! Which my keep me satisfied for a while

[dat2kman]

go for a JE or a CP piston made to what you need ( dimensions)

I have for sale a set of 6 x 133mm  Nissan rods, with ARP rod bolts, posted in the for sale section here.

[Kodie]

Is there any difference between the 280zx L28 and the 280z L28?

[dat2kman]

sorry my bad, the 6 133 mm conrods with ARP bolts are $250

( Ithought I posted a for sale, but didn't yet!

There is no difference between 280Z and 280ZX L28 motors, it is in the block casting numbers that there are slight differences, ie: blocks cast as N42 (non turbo use, and earliers) vs. cast as F54( turbo use but not always)

Heads also had different casting no's, for differing applications.

Best to let us know what you have found and what it is/was in.

There are sections here which explain fully the differences, and, as we all have our own views on what is good or not so good, you will get all kinds of reccomendations etc.

Just go ahead and DO IT, you will be happy!

[C.A.R.]

If you wan't to go slower, build a stroker

[Zedman240®]

If you are chasing around 260 Hp at the wheels with a stroker, be prepared to spend mega dollars on it... An NDSOC member with a 3.1 liter, mild headwork, triple Weber 45's and 74' cam is getting approx 230 at the wheels. To get around 260, you may need 50mm Webers (or EFI throttle bodies) and a 76' cam and some serious head work. If it's just for the street, be prepared for it to behave like a pig! My last L28 with EFI and 74' cam managed approx 205hp at the wheels which was plenty. Good enough for the sprints and plenty for the street.

 

If this engine will never see the track, you may be better off spending the money on suspension brakes etc..

[NZeder]

well you don't need a big cam or bore to get 260HP at the wheel just good head work (there is the bulk of the cost of any good strong L6 engine build) and then a bottom end to support the flow you have just got out of the head, JE's or CP but forged units, triples (44 mikuni will do it - trust me they flow better than 45 webers) and a good exhaust.

 

You are correct not cheap - you are looking (at approx numbers) $5000 for the bottom end, new pistons, rods balanced, new turbo oil pump, comp sump, ARP rod bolts, ARP head stud kit, good head gasket aka 1mm metal reusable item, crank work (lucky for us in NZ we get LD28 for a lot less than you blokes but when you check them, radius blah blah balance it all adds to the bottom end cost. Head you are looking $4000-5000 depends hours that need to go into it. That would include new seats, SS oversize valves, new cam and work to match the lifter etc + you should lighten the lifter also the list goes on but get a copy of the Frank Honsowetz book on modifying the L series engines this does have a lot of good info in it.

 

Now you are around $10,000 and now you build the bolt on bits ie carbs $1500 + new jets and chokes they will be wrong for the power you will be changing $800, headers and exhaust + fuel lines and pump upgrades etc

 

So basically 250hp at the wheels does come at a cost - this is why in the US they just chuck a V8 in there for 1/2 the price you get the same power. This is also why in the US turbo is common also - they pick up a 280zx turbo for $500 and just swap that in - then do a little work to the old engine and get big numbers.

[PZG302]

I must be using the wrong engine builders, or dyno operators at least......

 

All of my L series race motors, L28's varying from 0.020" over to .120" over and a stroker to 3.1 have only ever shown around 150-170 hp at the wheels on dynos setting up the fuel for the computer....

 

Admitidly they were never big dollar builds, just done right to make plenty of torque and be reliable for a couple of seasons between freshen ups.

 

To me it seems that a lot of people are optimistic with power figures, or maybe there are a few dyno operators out there that are maybe tweaking things a little. I know choice of wheels I use and tyre pressures can give me 20hp depending on what I'm doing, ie power run for Prod Sports you want as little as possible for the P/W ratio they work on, before they seal the motor and computer.

 

As NZeder said to get 260hp at the wheels is a big ask that costs a bundle of cash.

 

I also look at the dollars spent and work done on other race engines I know and can understand when they are 50 or so more hp than mine, but getting that sort of power for a road motor in an L series, I'm not so sure, especially when you read as to what has been done, or not, to the motors that produce that power.

 

In all honesty, if you want big power, you are much better off going RB with a snail off the side or V8, an L series isn't going to cut it unless you are prepared to spend a big wad of cash, ie around $10K.

 

My 150Hp is good enough to get me around EC in 1:50's and Lakeside in around a 60sec lap.

[NZeder]

The dyno guy we use are known to so lower figures than what you actually have.

 

As stated for a road car and one that might see the track every now and then I would just recommend a much cheaper build with a L28 and for get the stroker just use the $$ on suspension and brakes and the engine bolt on's as these can be used on a stroker later

 

My L32 had 245psi on each cylinder so those that want to work that out can but that should tell you that

 

1 it would not run on pump gas

2 was a bitch under 3000rpm (later fixed with a more street head setup to lower the compression and smaller cam)

3 would drink gas like you would not believe (V8 or also jag V12 results)

 

My first 240z race car had just a L28 stock bottom end (no work at all) a N42 head with on a cam (no port work or valve work) triple 40's and a good header. Suspension was worked some. It made just over 110HP at the wheels after 3 years of racing on the setup. It would get kicked by other zeds on the track and other cars (might have the fact it was an auto when I got it) but on the road it was fast and fast enough to have lots of fun.

 

The point strokers are fun and have good torque but to do right cost big $$. For a road zed I would just stick with a mild L28 with a good set of mikuni or OER (both flow more than webers and are better carbs IMHO) and headers then spend more on brakes and suspension as a good handling zed is worth having in my book.

[PZG302]

I think we are all heading in the same direction when we say to stick with the L28 crank. My L29's, standard crank and 89mm bore were great motors. I run a N42 head tha has been worked to suit injection and an old Haltech F9 fuel only computer with 280ZX electronic Dizzy.

 

I am only running a stroker at the moment because it fell into my lap for the great price of, well it fell into the engine bay as my L29 was tired.....

 

The motor currently needs a bottom end freshen up, happening next month, and if it needs more than rings bearings and a hone then I will be looking at building an L29 with one of my spare motors and the L31 kept for a rebuild over a couple of years as spare cash comes up to spend on it.

 

I think if you went for a ride in a good L28, or talk Scando into taking you for a ride in his turbo L28 you wouldn't be eorrying about the extra expense of the stroker build.

[stevo_gj]

We should make a sticky thread titled:

 

"Thinking about stroking your L6? Think again!"

 

and just stick all these posts in it. the question does come up alot after all

[Kodie]

Hmm yes, seems like alot of effort really. Guess I will have to weigh it all up.

 

As far as a turbo l28, I have no doubt they are great but I have had an fj, sr and also a fairly well spastic rb31 hybrid with a 35r snail hanging off it, they are all fun but I want something different as such was looking to either have a nice atmo high revving straight 6 or a v8.

[NZeder]

I think we are all heading in the same direction when we say to stick with the L28 crank.

Yes we are I did build a L30 with a stock L28 crank (well about 1KG lighter than stock ) and a 90mm bore on a N42/N42 however I never finished the build - this was going to go into my zed - but for some crazy reason I wanted the DOHC look and sold the block and with the $$ for that paid for the RB26/25 hybrid NA engine from Japan. The head build for this bottom end was sold with my L32 powered car and the new owner installed this on the L32 stroker to reduce the compression so it would run on pump gas (the head was designed for 10.5:1 at a 90mm bore so it could run on pump gas the cam was also custom for the head - however I was going to use EFI so the profile was for EFI but it went on to the OER carb'ed stroker as stated but it was not big 230/230 with 0.49 lift not big at all) anyway the stroker dropped only 20 HP at the wheels from race gas, high compression and big cam (but poor port work - not like the new head - different builder) so that was a good result and shows that big cams and ports aren't always the answer. It made 230HP at the wheels on pump gas and the smallish cam

[PZG302]

Hmm yes, seems like alot of effort really. Guess I will have to weigh it all up.

 

As far as a turbo l28, I have no doubt they are great but I have had an fj, sr and also a fairly well spastic rb31 hybrid with a 35r snail hanging off it, they are all fun but I want something different as such was looking to either have a nice atmo high revving straight 6 or a v8.

 

If you want a high revving six, the L series isn't really the motr to have without big dollars spent on the build.

 

I have always used the rule of thumb of $1,000 per cylinder for a reasonable street motor, for a good race motor, triple that at least. I have been in the very fortunate position that when I was racing seriously back in NSW that my motors were built for me by the workshop that sponsored me.

 

In my motors I have them built for the torque they produce to haul me out of corners, typical rev range I use on the track is from 3500-4000 through to 6800-7200, with a very flat torque curve from 3500 to 5200 and maximum power at around 6500 to 6800.

 

The standard bottom ends handle this quite well, and I have yet to do anything to the crank or rods beside go through the all the 2nd rods available on the workshops shelf and find the 6 that were closest in weight. That was the extent of the balance work as the L series motors are built very well from the factory. I also use a good qulaity harmonic balancer, at the moment chasing up getting my Ross harmonic balancer that was on my L29 sent up to put on my L31 for the rebuild, or I will buy another Ross balancer to suit as I have never had a problem.

 

The main thing limiting the revs I use has been the top end, ie the cam profile and where the power is made, and the rockers. I find that if I go over 7200 the motors tend to spit lash pads with my N42 head set up, generally the exhaust on number 5. We retrieved about 6 lash pads from the sump when the L29 was pulled down to put the head onto the L31.

 

I know of a few of the guys revving their motors to much higher but they are spending big dollars to get those revs, and with that comes the problems with breaking cranks. Unless the guy building your bottom end knows what they doing, you will break cranks if they are modified from standard. I have seen plenty of L series cranks let go because the engine builder, though good, wasn't a L series specialist or guru. To build an l series motor is a lot different to building a 202 or 265 motor.

[Cdr Zero]

Some good information here guys.  I appreciate you guys sharing your knowledge, I'm learning something all the time. 

[Kodie]

If you want a high revving six, the L series isn't really the motr to have without big dollars spent on the build.

 

Sorry, I should have been more specific. If I can't get the eight then I want to use one of the L series to power it. A 7200rpm limiter sounds fine, my description was a fanciful one just to give an idea of my goal.