Engine Choice for MK5 Roadster

[FlyingTiger]

Please help, I'm new to the FFR community. I ordered a 30th Anniversary Roadster kit. I want the car to be the lightest and best handling car possible. What is the "lightest" engine available (and any weight specs of different engines for comparison would be helpful). I am more concerned about light weight vs HP. Thanks everyone!

[GoDadGo]

The all aluminum LS-3 is about the lightest V8 you can get.
It is also supported by Factory Five Racing.
You can get them from mild to wild.
They even have a warranty.
See link below:

https://www.summitracing.com/parts/nal-19435104

[Jeff Kleiner]

I did some research on this a while back and found that fully dressed an aluminum block LS and Coyote are pretty much dead even at 460-470 pounds. A dressed 5.0 Windsor or derivative like a 347 with aluminum heads will run around 420. If you want to take the weight savings farther a T5 will save around 50 pounds vs a TKX but you’ll have to be conservative about how much power you put into it.

Jeff

[Mike.Bray]

I did some research on this a while back and found that fully dressed an aluminum block LS and Coyote are pretty much dead even at 460-470 pounds.

I can't believe that BUFF of an engine the Coyote weighs the same as an LS3. The Coyote must have twice as many parts as an LS.

Learn something new everyday.

[Blitzboy54]

I can't believe that BUFF of an engine the Coyote weighs the same as an LS3. The Coyote must have twice as many parts as an LS.

Learn something new everyday.

Twice as much aluminum too

[Jim1855]

My aluminum 427W is about 420#. Air cleaner to oil pan with starter and alternator. Don't think the flywheel (13#) and clutch (20#) is included in the total.
The final configuration of what's included changes the actual weight.
Jim

[OB6]

I've also heard that the LS3 and Coyote are roughly the same weight (unbelievable really), but I've got to believe the LS3 has a lower center of gravity. Probably not a factor for most, but the OP said he wants the best handling...

213539

[JimStone]

The all aluminum LS-3 is about the lightest V8 you can get.
It is also supported by Factory Five Racing.
You can get them from mild to wild.
They even have a warranty.
See link below:

https://www.summitracing.com/parts/nal-19435104




It's annoying Chevy sells the 525 HP version for $1100 more than the 495 HP version. Only difference is a different grind on the camshaft.

:rolleyes:


Also makes it $1200 more than Blueprints equivalent version

[Justin]

Aluminum 8.2 deck Windsor. Spend the money, you'll make more.

[gbranham]

Do you plan to track the car, since you're concerned about weight? Or is it just a weekend cruiser?

[GoDadGo]

If you want to take the weight savings farther a T5 will save around 50 pounds vs a TKX but you’ll have to be conservative about how much power you put into it.

Jeff

Wow, I never realized the T5 weighed so little.
By comparison my ZF tips the scales 95 pounds heavier.

ZF S6-40 General Specifications:
Gear ratios - 1st-2.68, 2nd-1.80, 3rd-1.29, 4th-1.0, 5th-0.75, 6th-0.50, Reverse-2.50
Description - 6 Speed 95 mm Fully Synchronized
Weight (w/shifter) 145 lbs

[CraigS]

The weight thing makes one of the upgraded T5s look pretty good doesn't it?

[GoDadGo]

The weight thing makes one of the upgraded T5s look pretty good doesn't it?

I recently scaled REDBONE and fully fueled with a trunk load of crap my Iron Eagle Headed Dart SHP/SBC Engine, spinning 28-lbs. billet steel flywheel tipped the scales at 2,534. With that being said an aluminum headed iron blocked 302, 306, 331 or 347 SBF with an Upgraded T-5 could easily keep that weight down by roughly 200-lbs.

We all know that every 100 pounds usually equates to 1/10th of a second in the quarter mile because HP to Weight Ratio is Truly King.

[edwardb]

Do you plan to track the car, since you're concerned about weight? Or is it just a weekend cruiser?

This is the most important question. On the street, IMO 50-100 lbs one way or the other isn't going to make a big difference. At least within a "reasonable" driving envelope and to some extent on your driving skill/experience. The story changes when guys put iron big blocks under the hood, but with your emphasis on weight, doubt you'll go that way. An aluminum big block is pretty cool. But be prepared to spend a lot. The Godzilla that Factory Five put in their prototype weighs in at a chubby 580 lbs. As I recall, they used different springs to help it out. The transmission is right around the center of gravity. So while it may help with overall weight, not sure how much the difference between a T-5 and a TKX is going to make. The advantages of the TKX are pretty significant. I have a T-56 in my Coupe and like it a lot. But it's another 30 pounds over the TKX. (99 lbs vs 130). But I don't notice it. But then I also don't notice any difference between before and after Thanksgiving dinner. So consider the source. :rolleyes:

IMO an aluminum head small block (347 or 363 are great matches) or a Coyote will give you the best bang for weight. I'm not a huge LS fan in the Roadster or Coupe. But that's just my opinion and let's not have that discussion here (again). Since this is your first post, I'll just repeat what is often said: Ask for input and we're not shy to give you our opinions. But in the end, it's your build. Do what you want and what makes you happy.

[Blitzboy54]

I recently scaled REDBONE and fully fueled with a trunk load of crap my Iron Eagle Headed Dart SHP/SBC Engine, spinning 28-lbs. billet steel flywheel tipped the scales at 2,534. With that being said an aluminum headed iron blocked 302, 306, 331 or 347 SBF with an Upgraded T-5 could easily keep that weight down by roughly 200-lbs.

We all know that every 100 pounds usually equates to 1/10th of a second in the quarter mile because HP to Weight Ratio is Truly King.

That tracks. I had a aluminum head 306 with a T5. My car weighed 2250lbs without me in it.

[Jeff Kleiner]

That tracks. I had a aluminum head 306 with a T5. My car weighed 2250lbs without me in it.

Mine was 2,180 with a full tank of gas.

Jeff

[FlyingTiger]

Do you plan to track the car, since you're concerned about weight? Or is it just a weekend cruiser?

This is just going to be a pure "TOY". Just driving around the hills and countryside of NW Arkansas. I finally bit the bullet and ordered a Roadster, but I'm a real novice with these cars... Any input about a build is GREATLY appreciated!

[JMD]

I would advise going to the weekend build school, if you can swing it. It's a great overview to the project, will answer a lot of questions and bring up even more you would never know to ask. Apart from that, this forum is by far the best resource you can use during the build. Hardly a day went by that I didn't search the forum for some applicable piece of info. Just type in 'factory five forum _________' filling in the blank with your question or topic and you will certainly find a thread that addresses your issue. It's an amazing resource and the only people I know of who struggle to build one of these are those who don't know how to use it.

[Entropy]

These are my "notes to self" when researching this question (and casting a wide net on engine possibilities) along with sources for some of the info:

214170

Notes:

302 and 351 DART SHP blocks are about 65 lbs heavier than the above factory weights
So a Dart block 351W based stroker weighs about the same as the Godzilla!

LS and 351 Windsor are baically the same size, including width with stock exhaust manifolds at about 24"

Coyote is a LOT wider because the OHC heads are a lot taller, so the "valve cover to valve cover" is more.
It's really not clear how much wider the Coyote vs Windsor are at the EXHAUST PORTS.

Sources:
https://www.onallcylinders.com/2013/01/10/engine-dimensions-for-popular-swaps/
https://stangnet.com/mustang-forums/threads/question-302-weight.466801/
http://www.tmeyerinc.com/tech/engine-weights/
https://www.supraforums.com/threads/2jz-gte-single-turbo-engine-weight.677361/
https://www.supraforums.com/threads/need-physical-dimensions-of-2jz.403696/
https://www.reddit.com/r/projectcar/comments/11v77vm/351w_ls_size_comparison_i_hope_this_helps_someone/?rdt=60087

[rich grsc]

These are my "notes to self" when researching this question (and casting a wide net on engine possibilities) along with sources for some of the info:

214170

Notes:

302 and 351 DART SHP blocks are about 65 lbs heavier than the above factory weights
So a Dart block 351W based stroker weighs about the same as the Godzilla!

LS and 351 Windsor are baically the same size, including width with stock exhaust manifolds at about 24"

Coyote is a LOT wider because the OHC heads are a lot taller, so the "valve cover to valve cover" is more.
It's really not clear how much wider the Coyote vs Windsor are at the EXHAUST PORTS.

Sources:
https://www.onallcylinders.com/2013/01/10/engine-dimensions-for-popular-swaps/
https://stangnet.com/mustang-forums/threads/question-302-weight.466801/
http://www.tmeyerinc.com/tech/engine-weights/
https://www.supraforums.com/threads/2jz-gte-single-turbo-engine-weight.677361/
https://www.supraforums.com/threads/need-physical-dimensions-of-2jz.403696/
https://www.reddit.com/r/projectcar/comments/11v77vm/351w_ls_size_comparison_i_hope_this_helps_someone/?rdt=60087
The godzilla is at least 60+# heavier than a 351 block, not even close to "about the same". That 60+# is quite a bit extra on the front of a 2200# car, and will have a serious reduction in the handling department

[BEAR-AvHistory]

These are my "notes to self" when researching this question (and casting a wide net on engine possibilities) along with sources for some of the info:

214170

Notes:

302 and 351 DART SHP blocks are about 65 lbs heavier than the above factory weights
So a Dart block 351W based stroker weighs about the same as the Godzilla!

LS and 351 Windsor are baically the same size, including width with stock exhaust manifolds at about 24"

Coyote is a LOT wider because the OHC heads are a lot taller, so the "valve cover to valve cover" is more.
It's really not clear how much wider the Coyote vs Windsor are at the EXHAUST PORTS.

Sources:
https://www.onallcylinders.com/2013/01/10/engine-dimensions-for-popular-swaps/
https://stangnet.com/mustang-forums/threads/question-302-weight.466801/
http://www.tmeyerinc.com/tech/engine-weights/
https://www.supraforums.com/threads/2jz-gte-single-turbo-engine-weight.677361/
https://www.supraforums.com/threads/need-physical-dimensions-of-2jz.403696/
https://www.reddit.com/r/projectcar/comments/11v77vm/351w_ls_size_comparison_i_hope_this_helps_someone/?rdt=60087

https://thefactoryfiveforum.com/attachment.php?attachmentid=214196&d=1747962167

[edwardb]

Coyote is a LOT wider because the OHC heads are a lot taller, so the "valve cover to valve cover" is more.
It's really not clear how much wider the Coyote vs Windsor are at the EXHAUST PORTS.

The Coyote heads are certainly massive. Double overhead cams will do that. But the bare block is relatively normal in size. I borrowed one for mockup when I was building my Gen3 Coupe. The block looks pretty innocent sitting in the engine compartment. The headers aren't compatible to other blocks, but similar height and width as other engine choices.

https://thefactoryfiveforum.com/attachment.php?attachmentid=80949&d=1518656839

[rich grsc]

This is just going to be a pure "TOY". Just driving around the hills and countryside of NW Arkansas. I finally bit the bullet and ordered a Roadster, but I'm a real novice with these cars... Any input about a build is GREATLY appreciated!
Then why are you worrying about weight?

[rthomas98]

if you are just driving around and want good handling just about every option is good. I guess the question is what does your wallet tell you? Mine told me solid rear axle and base 302 with a T5. I can assure you handles great for drives. But I never intend to autcross or race it. Put too many hours of labor into it for me to run out of talent and bounce it off a wall.

[Blitzboy54]

if you are just driving around and want good handling just about every option is good. I guess the question is what does your wallet tell you? Mine told me solid rear axle and base 302 with a T5. I can assure you handles great for drives. But I never intend to autcross or race it. Put too many hours of labor into it for me to run out of talent and bounce it off a wall.

My first build was the same for the same reasons. Entirely budget related. For what it's worth I ended up with about 350HP at the crank and there was not a single moment in the cockpit it felt under powered. Also one of the best handling cars I have ever driven even with a solid rear axle.