"Lightweight" V8 Engines

Hi everyone!   I've searched all over the internet for hours to no avail, finding empirical data on fully dressed engines(all accessories needed to run, clutch and flywheel) apparently is next to impossible.  So far from what I can gather I'm looking at the GM aluminum block "LS family", Toyota 1UZ-FE, Rover V8, and Ford Windsor 302(even despite being iron) as popular choices.  If anyone has sources to real "running in the car" weights that'd be fantastic, there's enough hearsay on the internet as it is(and the reason behind this post) so please keep from posting such(that's not meant to be rude, sorry if it sounds like it).  It'd be nice to get a definitive guide here that can be referenced to in the future.  That or if there's a weight with all accessories but missing the flywheel and clutch that could work too, and especially since the 1UZ was auto only.  Also if there's some other longitudinal lightweight V8 I'm missing that's affordable please share it.

For whatever it's worth this is to help with me planning out my long term "dream car" goals with a NB2 Miata; it's the only way I'm going to get a car that's lightweight(well under 3,000 pounds), small, double wishbone front and rear, RWD, and then having a V8 with a manual added will make it perfect(for me anyway).  I'm not as concerned with power as all should meet my modest requirements, heck I find the 142 horsepower Mazda BP-Z3 adequate.   Any help would be greatly appreciated!

Happily I can tell you that a 1UZ-FE can be easily modified to fit a 5-speed- they bolt directly to a W58 trans using a 3S-GTE flywheel that has had some light re-drilling of it's bolt holes.

Before we get to numbers, what are you trying to make that's reliant on a lightweight block?

Weight and power levels would be good information to collate. For example, you'll have a hard time keeping an LS engine down to the power level of a fully built Rover V8. Then you have to consider the transmission that will be required to survive that powerplant - an LS will rapidly disassemble a light T5 while the Rover won't, so you're going to have more weight in the trans and rear end with the LS car. But if you want 400 hp, that's what you're going to have to do. If you just want a bit more than the stock BP, well, turbocharge it 

I'm pretty sure we went though this just recently on this forum, no? I've provided fully dressed LS numbers a couple of times. 

If you're planning on putting this in an NB Miata, consider how much fabrication/engineering you want to do. The Ford and Chevy options are pretty well figured out. Toyota/Lexus has been done but you're still going to be doing a bunch of your own work. Rover has been done a few times but you're basically on your own for fabricating everything.

GIRTHQUAKE said:

Happily I can tell you that a 1UZ-FE can be easily modified to fit a 5-speed- they bolt directly to a W58 trans using a 3S-GTE flywheel that has had some light re-drilling of it's bolt holes.

Before we get to numbers, what are you trying to make that's reliant on a lightweight block?

I knew there were some conversion kits out there to put a W58 or R154 behind the 1UZ, but outside of the expensive Collins kits I can't seem to find them. 

I just want to keep weight gain at a minimum as I don't want to upset the handling and balance of the Miata more than it has to be from putting a V8 into it.  Unless you mean something else?

Pretty sure aluminum LS is the answer for adding a V8 to the answer.

Keith Tanner said:

Weight and power levels would be good information to collate. For example, you'll have a hard time keeping an LS engine down to the power level of a fully built Rover V8. Then you have to consider the transmission that will be required to survive that powerplant - an LS will rapidly disassemble a light T5 while the Rover won't, so you're going to have more weight in the trans and rear end with the LS car. But if you want 400 hp, that's what you're going to have to do. If you just want a bit more than the stock BP, well, turbocharge it 

I'm pretty sure we went though this just recently on this forum, no? I've provided fully dressed LS numbers a couple of times. 

If you're planning on putting this in an NB Miata, consider how much fabrication/engineering you want to do. The Ford and Chevy options are pretty well figured out. Toyota/Lexus has been done but you're still going to be doing a bunch of your own work. Rover has been done a few times but you're basically on your own for fabricating everything.

I'm more than happy with 200-300 horsepower and especially in a Miata, I want the V8 more for the soundtrack than anything.  It's just everything that comes with a V8 stock is too heavy, too big, and/or too unsophisticated in terms of suspension.  As far as weight goes it'd be nice to keep weight gain within 100 pounds over stock if at all possible.  The GM and Ford options were front runners due to cost, parts availability, and easily finding/putting a manual behind them in addition to being well documented as you mentioned.  It's just if for some reason the 1UZ or Rover were substantially lighter(and internet hearsay tells you they would be, but I don't quite buy it) I thought they'd be worth further investigation as I knew both have been put into Miatas before.

I don't want to dilute things since I asked for it not to be done, but from what I've found the aluminum LS fully dressed is around 500 pounds as is a fully dressed all iron small block Ford.  So in theory a 302 with aluminum heads and an aluminum intake would be lighter.  I was thinking a LM4 as far as the LS goes, so figured a third gen F-body T-5 would survive with me driving like an old lady most of the time. 

The 230hp  3.4L Yamaha/Ford SHO V8 is about 375lbs, see https://forum.miata.net/vb/archive/index.php/t-174555.html  

I have one, not easy to find anymore.  The Volvo 4.4L is roughly the same, so it should be about the same weight, they are easier to find.

A Mazda AJ v6 sounds different than most v6, I have one in my mx-3, it does sound  glorious, particularly when at 7500 rpm.. :)

Not sure what it weighs, but certainly less than a V8.      

Correction, this v6 is a KL mazda, and not the ford AJ.  

nimblemotorsports said:

The 230hp  3.4L Yamaha/Ford SHO V8 is about 375lbs, see https://forum.miata.net/vb/archive/index.php/t-174555.html  

I have one, not easy to find anymore.  The Volvo 4.4L is roughly the same, so it should be about the same weight, they are easier to find.

A Mazda AJ v6 sounds different than most v6, I have one in my mx-3, it does sound  glorious, particularly when at 7500 rpm.. :)

Not sure what it weighs, but certainly less than a V8.      

That's the funny thing though, I mostly want to swap for a V8 because of the exhaust note.  Otherwise I'm content with the stock BP-Z3 that's in it as far as power goes.  I already tried a factory car with a V8 and it didn't last because I just couldn't come to terms with the size and weight of it in addition to the SRA, plus it didn't help I couldn't see past the dashboard and just never got comfortable with driving it.  Maybe I'm just a crazy girl, or maybe it's from my music background, but the engine tone is really important to me and to my ears only eight cylinders and up sound good.  That's not to say all V8 engines sound good either, all the f*** bois with straight pipes on their low lift low compression V8 trucks sound just as bad or worse than any I4 ever could.  My brother's N54 335i sounds ok at best to me, and that's one of the best sounding six cylinders I've heard.  I like deep roaring burble(good V8) or high pitched screamers(V10/V12), I know others like the sound of various four and six cylinders and I can admit and distinguish when one sounds good for what it is but they just don't do anything for me.  So please no one take what I said personally, it's just what I find pleasing to the ear.

Find an L33, possibly an LC9 (gen 3 or gen 4 aluminum truck 5.3). Add applicable car intake and cam. Insert into NB. Biggest pipes you can fit. Call it good.

Daylan C said:

Find an L33, possibly an LC9 (gen 3 or gen 4 aluminum truck 5.3). Add applicable car intake and cam. Insert into NB. Biggest pipes you can fit. Call it good.

From what I could gather earlier when searching is that the L33 is really rare, and it was just the heads, pistons, and cam? that made it slightly better than the LM4.  If I found one then great, but I don't think it'd be worth the hassle for 30 horsepower I won't use.  I rarely fully used the 300 or so horsepower I had in a 3,400 pound car, so would probably never fully use it in one about 2,600 pounds or less.  At least on the street anyway, on a track would be another story.  I'm not a speed demon or power freak, I would ask if that is a guy thing but my mom and cousin are almost as bad as my brother.   Anyway, I put priority on handling and feel hence giving up a 305 hp V8 in a 3,400 pound car with SLA front and SRA for an 142 hp I4 in a 2,400 pound car with double wishbone front and rear.  I'm just in love with the sound of a nice V8, cause 'Merican?  Maybe I'm just weird and am just wanting something crazy, wouldn't be the first time. 

If you want cheap lightweight v8 then Ford 302 will probably be the go to.

If your just wanting super cool v8 sounds your going with any v8 with the nastiest roller cam you can get and headers. 

I was going to comment that Ford made plenty of V8s with 200hp and glorious noises. The 80s were great.

After more searching, instead of sleeping , I did finally come across this on a BMW forum somehow: https://www.bimmerforums.com/forum/showthread.php?2290083-Engine-weights-current-figures-351w-302-m20-NEED-ls1-m60-m42-1jz-2jz

So an aluminum LS complete with T-56 came in at 609 pounds, then a 302 with aluminum heads and T-5 came in at 572(on second page someone had a picture of their's at 552 but said to add 20 for p/s and etc...) so in theory a complete LM4 with a T-5 would weigh around 569 pounds so a few pounds less than the 302 with aluminum heads.  Aluminum heads for the 302 alone are more than a LM4, so I guess that decides that then.  From what I can gather the Mazda 1.8 BP weighs in around 320 pounds complete, and the transmission is around 80 pounds so 400 or so total?  So looking at a gain of 170 pounds best case if the differential and CV axles wouldn't need changed for the LM4 and my granny driving.  From what I can gather the Rover 3.5 isn't any lighter than the LS despite what some will tell you, the Buick 215 was allegedly 60 pounds lighter than the Rover variant so maybe that's where all the misinformation stems from?  The only thing I can find on the 1UZ is that it comes in at 450 pounds complete(though everyone is quick to quote a weight of 360 pounds, Rover syndrome again), but that'd be sans clutch and flywheel so probably not any less than the GM aluminum LS.  If anyone can confirm the 1UZ that'd be nice, but for the complication I'm not sure if it'd be worth it just for the sake of keeping the car all Japanese.

Anyway, I guess I just needed another 5 hours of digging and searching and sleep deprivation...  If anyone could confirm what I've found that'd be lovely.   Now for sleep... 

In reply to mazdeuce - Seth :

They made 200hp v8s with good noises in the 90s too. That one weighs a lot and probably won't fit in a Miata though. Hell it barely fits in a Mustang.

In reply to Daylan C :

So the theme is to look to about 1988 for the perfect V8? Or..... and hear me out......build a crazy light aluminum 302 to 1988 specs! Light, gnarly sounding, and barely able to get out of it's own way! Now where did I leave that one mile roll of vacuum line........

In reply to mazdeuce - Seth :

So we get an aluminum Dart Windsor block. Crappiest aluminum heads we can find. Deep dished pistons. Stock replacement 1988 Mustang cam. Stock mustang manifolds and run it with 2.25" dual exhaust. And don't forget the flowmasters.

The L33 isn't that uncommon. It's not as common as the standard iron block 5.3 motor but you can still get them pretty easy. The L33 with the swap headers and a nice cam will be low to mid 300 WHP tuned. It'll make great sounds and look good under the hood too. 

LSx is the answer.  You can find them in almost any junkyard and you won’t need to rebuild or make internal changes to have a great motor.  Ford 302s are getting harder to find in a performance iteration.  No point is buying a 5.0 out of a 90’s F150 because it will have a million miles and need a rebuild before you use it. 

 Sound?  Spend 10% of your swap budget on a stereo, buy the soundtrack to LeMans and play it at 11.  The new “performance” cars are all producing electronically aided engine sounds into the cabin. Except the Mustang which judging from the local crop seem to have straight pipes from the factory.

Since the LS engines are much like LEGO, you could search out any 5.3 aluminum block and use the internals from another iron LS. I just missed an LH6 with a spun rod bearing for $125 and I can find 4.8/5.3 iron engines for $2-400. Had I got the LH6 I was going to create a 4.8 aluminum block motor to use in a Challenge car.

I'm also eager to see how dusterbd's V6 Miata goes and sounds at this year's Challenge.

mazdeuce - Seth said:

I was going to comment that Ford made plenty of V8s with 200hp and glorious noises. The 80s were great.

I wonder what an ls4 weighs? Bolt one up to a 4th gen T5 and you've got a pretty lightweight combo.

For whatever it's worth this is to help with me planning out my long term "dream car" goals with a NB2 Miata; it's the only way I'm going to get a car that's lightweight(well under 3,000 pounds),

Not sure where you are going with this level of granularity? ANY of the V8 swaps will keep you under 3000 lbs unless you go crazy on the bling and amenities. Have you been in a V8 Miata as a passenger or a driver? Forget the thought of losing the"Miata Purity": The freaking thing is transformed into something else altogether. We talking Miley Cyrus caterpillar to Bad-ass butterfly kind of change. You wont care about what you lost because of what you gain.

If you are worried about where the weight ends up, realize that any weight increase will be distributed pretty much as per the stock weight distribution. So 200 lbs extra drivetrain weight will end up 90 lbs on the rear and 110 lbs on the front. That is not going to affect the handling/feeling/response/zen all that much.

I would think that a matrix of weight, cost and hp/lb would be a more useful decision filter. I can pretty much guarantee that the correct answer is going to be some variant of the LSx.

For" best chance of actually completing the project" the well supported and developed 302 and LSX swap kits are the way to go.

Pete

If you're not looking for 400hp, the cost/weight/sound equation = smallblock Ford with aluminum heads and T5 trans.

IMHO Ford 302s sound much better than LSx engines, unless the LS has a ridiculous cam...

In reply to rezisehtnys :

I sent you a PM about an adobe document I have. (about 12 pages, lists lots of engines and their respective weights).  It seems to be "Pre LS" though. 

If anyone else wants it, shoot me a PM and I can send it your way as well.  I have no idea where I got it from, but I've had it for a while.

FWIW, it does say a Chrysler M4 tank engine weighs 5,244lbs (30cyl, 5 banks of 6, flathead ww2).

Cheers!

That Yamaha v8 that Ford put in the Taurus SHO does sound absolutely mad. And Ford's "other" 90's engine - the 4v 4.6 - is one of the best sounding domestic engines ever made, in my opinion. It would never fit into a Miata though.

So yes, as everyone else has said, the answer here is LS.