how do you feel your engine swap changes the character of your Z?

[dreco]

I've driven my Datsun with a 3.0L stroker and now an LS6.  I did like the sound of that L6 stroker motor, but I sure dont miss SU Carbs.   The LS6 makes more tq at idle i think haha.  I also love the driveability of my modern fuel injected V8.  Add headers, 3 inch exhaust and a straight through muffler and it  sounds amazing! 

 

https://www.youtube.com/watch?v=vwaXXpC9MK4

 

A Datsun is a blank canvas to me.

[rnye]

Absolutely.  The engine defines the car.. I'm an L6/RB/2JZ guy.  I like the NA stroked cars (like mine with triple weber 48s), the whoosh and blowoff valve noises (my old L28ET) and the smooth, balanced, surge of power that comes with the newer inline 6s under boost.

I do not like V8s.  Any of them in this car.  My M5 has a wonderful V8 and it's a great fit for the car.  I personally would never do the swap on an S30. 

Edited June 5, 2015 by rnye

[MM569457]

On 6/4/2015 at 2:44 PM, dreco said:

I've driven my Datsun with a 3.0L stroker and now an LS6.  I did like the sound of that L6 stroker motor, but I sure dont miss SU Carbs.   The LS6 makes more tq at idle i think haha.  I also love the driveability of my modern fuel injected V8.  Add headers, 3 inch exhaust and a straight through muffler and it  sounds amazing! 

 

https://www.youtube.com/watch?v=vwaXXpC9MK4

 

A Datsun is a blank canvas to me.

Dreco,

 

I bought the stroker off of you back in 2007/2008. What exhaust set up did you use? I’m looking into getting a similar setup and really liked the sound your 240z had!

On 6/4/2015 at 2:44 PM, dreco said:

I've driven my Datsun with a 3.0L stroker and now an LS6.  I did like the sound of that L6 stroker motor, but I sure dont miss SU Carbs.   The LS6 makes more tq at idle i think haha.  I also love the driveability of my modern fuel injected V8.  Add headers, 3 inch exhaust and a straight through muffler and it  sounds amazing! 

 

https://www.youtube.com/watch?v=vwaXXpC9MK4

 

A Datsun is a blank canvas to me.

 

[Ironhead]

There's no doubt an engine swap completely changes the character of the car.  Mine has a 525 HP LS3, and it is more like a lighter, less refined Corvette than a Z car, honestly.

 

Some might say I should have just bought a Corvette, but I have a method to my plan and I am happy with the outcome.

[JMortensen]

Mark Haag and I have driven each other's cars many times. Here's a cool shot of his, with mine going around the autox course (I'm driving Mark is passenger) in the background.

He has a high strung 12:1 stroker that pushes a little over 300bhp. I have an L33 which is an aluminum 5.3, makes about 370 whp. I've got more tire, obviously. Both cars are built to autocross, mine more seriously.

You can make arguments for both, and they're both fun to drive. I have to say if you were looking for the best noise, his wins hands down. But mine is faster at autox and I think if we went to a big track I'd just drive away. I know he wouldn't trade me, and I wouldn't trade him either. We both are big fans of each other's car. Different strokes...

[AydinZ71]

@JMortensen Curious from that experience Jon, do you feel it was your low-end torque that gave you much more confidence on the autoX course? The fundamental character difference I experienced from the L6 and a V8 (not a swap, just another car with an LS) is that immediate, ass-moving torque. I am building a modest 3.0 stroker block right now (CP rods and pistons) that will be for vintage racing, but wanted something more reliable and less expensive operationally. Staying at 10:1 CR, don't think I will break 250 HP without going to a 300+ duration cam, but who knows! A part of the fun is just trying things out. As I get older, I seem to appreciate so many more aspects of an engine package than just max power. I would like to get the "feel" of a 300bhp L series one day, just to get a sense for what the trade-offs were to make that power. 

[JMortensen]

Mark has the strongest L6 I've ever driven by a long shot, it's hard to say it's lacking power. But yeah, the "area under the curve" is WAAAY bigger with the V8, and it's most noticeable when I don't shift in slow corners and he does. I also have a lot more tire than he does. My springs are about twice as stiff too. They're just different. He always raves about how my car turns in a lot harder than his. His is easier to drive, just does everything a bit slower and more calmly.

I would suggest you get that 300+ duration cam. I had an 11:1 L28/E31 .490/280 cam with the chambers polished and valves unshrouded and all the stuff done and it pinged really badly until octane got to about 95 or 96 (had to mix race gas). It both pinged and could have used more top end. I was planning for a bigger cam and all that and then finally succumbed to the V8 temptation.

[AydinZ71]

@JMortensen thanks Jon!

 

yeah I have been nervous about the head on the 3.0. Have a solid lifter P90 for her, and still fiddling with the specs.

 

the EP head I had made is 0.500/320deg, but there isn’t much guess work when you can read rules and naturally max out what you can. Again, same as the button clutch just sitting and waiting for that damn car… 

any reason you picked 11:1 CR? Were you shooting for pump gas with the E31? I have read some folks going for it, but not sure if anyone had success. 

 

in your opinion, how difficult do you find it to drive at lower speeds with a 300+degree cam? I wanted this stroker to be more of a “muiti purpose” motor I could use for shorter tracks and maybe even autoX. Hence looking at something “tamer”. Maybe I should get the EP motor up and running First before I settle on a head design. Greg gave me a great reference for an L6 magician, so I might get started on the porting and chamber work. I can get the cam ground and reassembled locally. 
 

it feels like so many of my questions could just be answered by getting the darn thing on the road. 

[JMortensen]

I wanted something around 10.5:1. I cc'd the chambers and did all of that and was going to hit my numbers. On the first build of this motor I used the wrong machinist. He installed the previous, smaller cam and there was coil bind. Rather than replace the springs he cut the crap out of the valves to lower them in the head, so the "margin" on the valves was zero. from the cut part of the valve to the top was pretty  sharp, and the valves got hot and tuliped because of this. Set them on a table and they rolled funky, but the engine still made pretty good power when the harmonic damper failed and keyway on the crank broke. After the crank took a crap I went for a rebuild with flap tops. 

Anyway I had everything just where I wanted it as far as chamber size, then replaced the valves. the new valves had no dish in them and sat much further into the chamber so it jacked the compression up, and then the head needed to be surfaced just a hair, and between the two that bumped it into race gas territory.

Mark's car is easy to drive around the grid. I don't think the cam will be your problem. It will be the clutch. Mine is much harder to move around at low speeds. You can do it, but you just don't even try to be smooth, because those tiny clutches wear quickly, so just be rough and don't slip the clutch.

I don't know if you were here when Monzter was an admin, but he had I think a triple disk 5.5 on his street car. He made a crazy intake manifold and actually seemed to get decent numbers out of the MSA Stage 3 cam (only person I've ever seen make that POS cam work). Might be worth looking up his old threads.

[AydinZ71]

@JMortensen Thanks Jon!

 

Gotcha! Yeah I suspected you may have been trying to thread the needle with the CR. I thought about pushing it too, but even my EP head is only 10:1 for now. I don't have convenient race gas nearby and I am a total novice to road racing, so burning cash on extra octane did not seem like a priority. Il bump to 12:1 if I see myself becoming even remotely competitive. 

 

Good to hear the feedback on the cam! Il have to brace myself for getting used to the button clutch sounds like. 

 

The EP cam was a custom grind. I think I posted a shot a year ago of the timing sheet, but happy to again if anyone has interest. I suppose interest might wait until I can get it dyno'd. Limiting factor will be the SU's naturally. My machine shop made custom bee-hive valve springs for the head too, but I am a little anxious about them TBH. They claim to have a ton of experience on them and were confident they will work, but without any head-specific engineering taking place...we shall see! 

 

I will look up Monzter's posts for some insight on the 5.5". 

[Ironhead]

It is amazing, on track, how massive amounts of torque seem to minimize the effects of sloppy driving.  I also have a BMW E30M3 track car, with an N/A four cylinder engine that has very little torque, and really only develops HP above 5000 RPM.  It's a classic momentum car, in which you have to take turns at the absolute limit, keeping momentum up, particularly before the long straights.  If you fail to do this your lap times plummet.

 

The LS swapped Z is completely different.  Any momentum lost is immediately regained with a stomp on the throttle, almost regardless of RPM.

 

Obviously both cars take a great deal of concentration to drive at their individual limits, but just "going fast" is so much easier in the Z.  I can just mosey through turns, nowhere near the limit, and still lap significantly faster than the BMW.

[Michael]

Two data points…

 

A local friend (also a member here) graciously let me drive his basically-stock 260Z.  The engine has a more aggressive cam.  Wider wheels/tires and maybe upgraded shocks… otherwise stock.  The car is beautifully restored, but compared to my daily driver – a 1991 Miata – it feels sluggish and ponderous.  Again, I mean this with no offense towards the builder; he did a marvelous job.  The “offense”, if there is one, is against the stock S30.

 

Second data point is test-driving a Tesla Model 3 Performance.  This thing is nothing short of phenomenal.  Yes, it’s heavy and vague at times, but so is a modern M3 or Camaro.  The Tesla delivered precisely the sort of punch that I’d love to have from my big-block Z.

 

Speaking of the latter, I finally drove it the other day.  It had *nearly* the on-demand acceleration of the Tesla.  It was lighter than the stock 260Z, or at least felt lighter.  Steering effort was less, and driver position was more comfortable.  The extra torque made it feel more “connected”, although the high noise was ghastly uncomfortable.

 

At the risk of getting banned here, my next car will be electric!

[AydinZ71]

@Michael I will touch on my main complaint... weight vs. energy. The Tesla model 3 in its lightest form is 3850lbs. Strip that car down to bare-bones, and you still aren't breaking 3000lbs. The 272 mile range drops dramatically if you drive it in its highest performance mode. Pretty soon you will realize the car is not well-suited for road racing since driving at break-neck pace simply robs from your range, and you cant just "refuel" it. The show "Silicon Valley" even had an episode joking about this exact dilemma. 

 

we were just discussing last week how @tube80z got his Z down to 1700-1800lbs range. As you experienced, you can throw-in a high-torque V8, trans, heck even a ford 8.8 rear end, and it can still be done for less than 2100lbs. That includes a 50-80lb roll-cage, and everything else you need to meet road racing requirements.

 

As a street car it still works, but the tradeoffs I am describing in a road racing scenario still bleed-over into a street application. I would read-up on the Tesla fine-print for their Insane and Ludicris driving modes:

 

https://www.tesla.com/ownersmanual/2012_2020_models/en_kr/GUID-E692415D-F83C-4F07-B30A-9E50499CFC30.html

 

In conclusion, you end up in a situation where you MUST add weight to achieve/sustain large amounts of torque when electric. As some have mentioned on this forum before, an LS motor paired with a 6-speed is only a little heavier than an L-series w/ a Nissan 5spd (mostly thanks to an AL block). You will not see that same type of relationship when comparing electric powertrains, since we still have not cracked a weight-efficient means of storing electric power. 

Edited April 19, 2022 by AydinZ71

[AydinZ71]

OH, and I just looked-up Tesla's fastest model available, the S Plaid version... 1,000hp! ...aaaaand 4800lbs. batteries, batteries, batteries. 

[JMortensen]

I've got 14" wide slicks, V8 swap and I'm at 2352 lbs. Could turbo the 5.3 and be at 2425 lbs or so and have 1000 hp if I wanted. I don't want, but it's well within the realm of possibility.

The 3's are doing pretty well at the local autox. I appreciate what they are and the advantages that electric cars have. I just want that battery weight to come down. 

[Michael]

My 1978 is down to around 2600 lbs... that's aggressively stripped, including cutting off bits from the tub, partially gutted doors, no dash, etc.  Granted, that's with a big-block (aluminum heads), beefy mild-steel "roll cage" and very heavy steel bellhousing.  An LS would be lighter, but not 500 pounds lighter, right?

 

Yes, batteries still have horrible energy density, but they do have excellent power density.  If I were attempting any organized form of racing, other than drag racing, I'd use my 1991 Miata - and not a Z, or a Tesla, or a Corvette or anything like that.  Instead, on the street, essentially ALL that matters for me personally, is grin-inducing sharp but brief bursts of acceleration.  The big block Z is starting to do that acceptably.  In stock form it never had a chance.  Electric cars have potential to do it very well.

 

The Tesla that I test drive - the Model 3 Performance - on paper has about the same hp as my big block.  And it's 1400 lbs heavier.  But at least subjectively, it felt faster.  Because I'm not racing in any organized environment, the subjectivity is all that matters! And if we do an apples-to-apples comparison, what does a GT Mustang weigh these days?  Or an M3 BMW?  Pretty close to that Tesla!

 

The Model S is 1000 pounds heavier.  Never had a chance to drive it, but it's reputed to have a 0-60 a full second faster than the Model-3 Performance. 1000 hp in a 5000 lb car.  Would my Datsun ever achieve 500 hp in a 2500 lb car?