lightest 3.0+ liter 4 stroke engine

Pete. (l33t FS) said:

In reply to NickD :

Spending time working on and driving a '62 Tempest has admittedly been part of this idea.

 

It's a shame there are no good cams or rods and pistons for the 2.2 pushrod engine.  The head in that looks really, really nice.

Rods can be custom made for not a big number. ( Carillo) And the same with camshafts. (Crower) 

Pete. (l33t FS) said:

In reply to white_fly :

Rotaries are remarkably heavy.  They are metal-dense, with very little airspace inside, and a lot of the metal used in that density is thick iron.  Consider that people do V8 swaps without really changing the weight of the car.

Wikipedia suggests the renesis was 247lbs, mostly dressed, dry weight. It's a bit lighter than a 4-cyl. I suspect if Mazda had more resources allocated to the renesis they would have gone with aluminum side housings. Racingbeat aluminum side housings save 42lbs.

Pete. (l33t FS) said: How heavy is a VQ35?  It has all sorts of things going against it: it is a DOHC engine (heavy) and it is a V engine (more weight) and has timing chains (the covers add mass and bulk in addition to the weight of the drive itself) and it has variable cam timing (more weight) and it has a giant intake manifold (weight, weight, weight).

irish44j said ~300#.  Google search said the same:

https://www.google.com/url?sa=t&source=web&rct=j&url=https://grassrootsmotorsports.com/forum/grm/engine-weight/9145/page1/%23:~:text%3DAccording%2520to%2520the%2520geeks%2520at,at%2520just%2520over%2520300%2520pounds.&ved=2ahUKEwjq_Nf0y_3uAhUCG80KHepdDZEQFjACegQIAhAF&usg=AOvVaw04NTdKTMOo3-Hr0fECSC9g

here are a couple other aluminum pushrod engines that aren't the lightest but are pretty light.

the LV3 4.3L V6.  $2.2k including shipping.  I haven't seen a verified weight.  I'd guess 340 lbs.

https://en.m.wikipedia.org/wiki/General_Motors_90%C2%B0_V6_engine

TAPerformance Buick V6 is around 320lbs.  If I remember correctly, the maximum displacement is ~4.1L.

http://www.taperformance.com/proddetail.asp?prod=TA_V3800

another thing to consider is that high torque engines typically require heavier transmissions and axles

Run_Away [FS] said:

I don't have a weight for just the engine, but here's my own picture of a VQ35

 

 

 

 

You're the hero the internet needs, but not the one it deserves

maschinenbau (I live here) said:

Run_Away [FS] said:

I don't have a weight for just the engine, but here's my own picture of a VQ35

 

 

 

 

'

is that an automatic or manual transmission?  I wonder how much weight that adds.

The Ford 3.7L DOHC Ti-VCT weighs in at 275lbs with alternator...about 300lbs with starter, flywheel and clutch(assuming you use the 5.0L flywheel and not the DM unit it comes with). Of course the matching MT82 trans is fairly hefty at 150+lbs, and the engine is as tall as a 351w but still not a bad power to weight ratio

Not 3.0+ Stock  but 2.7 stock is the Suzuki H27. They're used in aircraft according to google and weigh 315lbs or less. 

Or...you could go with the Ford Polimotor, a whopping 138lbs...but they were 2.3L DOHC 4 cylinders....the turbo versions did make 450HP though....a great race engine if every ounce matters.

Snrub said:

Pete. (l33t FS) said:

In reply to white_fly :

Rotaries are remarkably heavy.  They are metal-dense, with very little airspace inside, and a lot of the metal used in that density is thick iron.  Consider that people do V8 swaps without really changing the weight of the car.

Wikipedia suggests the renesis was 247lbs, mostly dressed, dry weight. It's a bit lighter than a 4-cyl. I suspect if Mazda had more resources allocated to the renesis they would have gone with aluminum side housings. Racingbeat aluminum side housings save 42lbs.

Practical experience suggests that if they are ~250lb then they are not US pounds, given that 4cyl swaps would raise the nose, and V8 swaps barely change ride height or chassis balance.

Aluminum side housings do save a lot of weight, but they are, what, $1600-2000 each?  And IIRC they need special parts to work like 12 bolt stationary gears.

maschinenbau (I live here) said:

Run_Away [FS] said:

I don't have a weight for just the engine, but here's my own picture of a VQ35

 

 

 

 

You're the hero the internet needs, but not the one it deserves

This site claims 313 lbs dry weight for a VQ35DE

Bizon said:

 

TAPerformance Buick V6 is around 320lbs.  If I remember correctly, the maximum displacement is ~4.1L.

http://www.taperformance.com/proddetail.asp?prod=TA_V3800

Bigger than that.  I personally handled a 4.5l one.

Even with the Champion heads, Buicks are not power monsters until you apply forced induction.

Bizon said

is that an automatic or manual transmission?  I wonder how much weight that adds.

It's a manual.

I plan on weighing it again without trans, mounts, stock exhaust and AC compressor next time it's out.

I also have an 08 fwd VQ with the plastic intake I'll be weighing.

In reply to Pete. (l33t FS) :

I've looked into this quite a bit. I'd like to eventually V8 swap my Genesis Coupe. I'll most likely go LS, but if someone decides to pay me silly money a big bore, 3.2 stroke, aluminum Windsor would be a hell of a power and response improvement while SAVING weight and improving weight distribution.

Here's where someone gave a weight for a Honda J series:

Honda J35 Weight

He shows 377 lbs with alternator and A/C compressor, so figure ~350 for just the engine.  I guess that puts it roughly in the range of the VQ's?

In reply to BA5 :

I researched engine weights endlessly for my Datsun; most of the V6 engines come in around 350-425.  Twin cam 4 cylinder turbos were really close to that as well. The 5.0 ford V8 could be whittled down to right on 400lbs, given the availability of parts from Jegs and Summit it seemed like the way to go to me. The other factor no one seems to take into account is the transmission, I found many cases where the tranny added back in another 25-40lbs so any weight savings over a V8 was negated. 

Pete. (l33t FS) said:

Snrub said:

Wikipedia suggests the renesis was 247lbs, mostly dressed, dry weight. It's a bit lighter than a 4-cyl. I suspect if Mazda had more resources allocated to the renesis they would have gone with aluminum side housings. Racingbeat aluminum side housings save 42lbs.

Practical experience suggests that if they are ~250lb then they are not US pounds, given that 4cyl swaps would raise the nose, and V8 swaps barely change ride height or chassis balance.

We don't need to argue about it and we're off topic, but there's no reason to suspect the figure is off by hundreds of pounds. Is it possible the quoted figure is off a little? Perhaps. I have trouble understanding how a 4-cyl could "raise the nose". Let's say the Renesis is 50lbs heavier than quoted. It's not going to amount a noticeable change vs. a 4-cyl in the 300lbs range. As a sanity check, I've carried long block/assembled/short block 13B/13BTs with friends as well as Miata engine. I work on computers, I'm simply not strong enough for the figure to be off a hundred pounds.

Regarding V8 swaps, in a RX-8, let's say the weight of the car goes from 3000lbs to 3300lbs. That's 4.5% extra weight in the front, not the end of the world. I suspect many swaps do not retain stuff like AC, they're moving from a OEM exhaust manifold to a header, etc.

In reply to Snrub :

For the sake of discussion;

The 1200cc engine in my Datsun is 173lbs complete with starter, clutch, and fluids. The 1500cc engine is 185lbs. The gearbox is 54lbs with the total engine/gearbox combo being 239lbs with the 1500.  The car itself is 1652lbs.  The front suspension uses 225lb springs the rears use 160lb springs

When looked at engine swaps a complete SR20DET with gearbox came in at 476lbs and a Ford 5.0 w/aluminum heads and gearbox came in at 480lbs.

Using over simplified math (it's the only kind I know) and pretending all of the 200lbs of extra engine weight went on the front suspension the front suspension would drop 7/8ths of an inch. Pretending all of the gear box weight went on the rear would result in a 5/8th inch drop.

So with all that said one could really argue either way on the ride height change; whereas on a street car a 7/8ths drop isn't huge on a race car it is.