Cpt.Zanzibar

hey guys, me and a friend were wondering if you know how much the racing beat 3 rotor racing engine weighs? we're trying to do some calculations between divfferent engine types.

alexdimen

iTrader: (13)

define "racing engine"

try the weight of a 20b + whatever bolt ons it has... duy

mightymite

iTrader: (1)

if your talkn about the engine im thinking of with that killer price tag who cares its a 1000+hp engine

Sideways7

iTrader: (7)

Oh, your talking about that monster 13g on the RB website. Now I unerstand. Honestly, what does it matter? You will never be able to afford it. But just for kicks, I would assume that it weighs in the neighborhood of a TII block, maybe a bit more. Plus the weight of the beefy driveline that thing would need, you're looking at probably 1-200 pounds more than the stock turbo stuff. Again, this is just a wild guess, but probably relatively acurate.

Twofer

Well you know, shipping and such. When you're looking at buying an engine like that, the shipping cost is the deal breaker.

Sideways7

iTrader: (7)

Lol, so true.
Thats like people complaining because its costs several thousand dollars to change the brakes on an Enzo. You just paid 3/4 million for a car, and have the nerve to complain about spending a few thousand on brake pads.....

GodSquadMandrake

I have HEARD that the 20B is more than twice the weight of a 13B because of the way the last rotor was added on and how large the manifolds are. I don't remember the exact number but it was more than twice a 13B.

classicauto

iTrader: (3)

IIRC, a bare block 20B is approx. 300lbs...

alexdimen

iTrader: (13)

i didn't realize he was talking about that engine... that thing is ridiculous

mikaz

Just think of how much a V8 weighs!! I love rotaries.

Sideways7

iTrader: (7)

This isn't a 20b, though. It is a mosnter race-prepped PP 13G that runs on methanol and puts down 1000HP. Go to the 2nd gen section of racing beat's website and look for the "complete race engines" section, or something like that. I believe I had read that it was custom built for someone, then he had a heart attack or something.
Also, an aluminum block LS1 only weights slightly more than a 13BT engine. Once you do the full swap, the car weights about the same and still has the 50/50 (or maybe even 49/51) dist. once you relocate the battery.

BLUE TII

iTrader: (9)

Stock weights

LS1- 490 LBS
13BREW- 425 LBS
13BT- 370 LBS
13B- 340 LBS

Anyone have stock 20B weight? I know it is REW weight plus rotor, rotor housing, front side housing, and heavier e-shaft and int. sidehousing. Ouch!

Zero R

iTrader: (1)

Bare blocked 13BREW's are roughly 170ish at least all the ones I get here are.

-S-

mightymite

iTrader: (1)

yeah i woulda had a heart attack to after lookn at the price tag on that beast
and if that didnt do it the first pass down the strip would have

Attila the Fun

iTrader: (1)

According to Peter Farrell, the 20B is approximately 100 lb. heavier than the 13B-rew.

riceburner1r2001

iTrader: (4)

i agree with zero

BASTARD

iTrader: (4)

300+, maybe with a flywheel + transmission attached+ wire harness+++++

slo

iTrader: (1)

I had a complete 13b-rew shipped to me recently. It weighed 424 pounds inlcluding a very heavy pallet. I would guess 380-390 pounds for the engine minus the pallet. Only parts that doesn't include are the intercooler a couple peice of rubber intake ducting and the air box.

BLUE TII

iTrader: (9)

Published engine weights

Sport Compact Car Feb 2002

"According to mazda, the Renisis weighs 332lbs, which is significantly less than the RX-7 engine, which weighs 450 lbs."

These weights are with full engine attached accessories, flywheel, etc to maximize the weight savings of the Renisis from lack of PS pump and AC comp bracket as well as plastic UIM, lightened flywheel.

I had a complete 13b-rew shipped to me recently. It weighed 424 pounds inlcluding a very heavy pallet. I would guess 380-390 pounds for the engine minus the pallet. Only parts that doesn't include are the intercooler a couple peice of rubber intake ducting and the air box.

Sounds like that is close to the right weight. 2 weeks ago I weighed a heavy pallet made from oak (as opposed to the lighter Pine ones we get) that was 36" x 60". I was thinking 30+ lbs, but it weighed in at 17lbs!
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More published engine weights from 279 page book "RX-7, the New Mazda RX-7 and Mazda Rotary Engine Sports Cars" By Jack Yamaguchi 1985


1965 production Cosmo L10A (alum. sidehousings)--- 225 lbs (pg 261)

1968 production Cosmo 10A (alum. sidehousings)--- 224 lbs (pg 262)

1968 production R100 10A (cast iron side housings)--- 268 lbs (pg 262)

1971 production JDM RX-3 10A--- 282 lbs (pg 264)

1967 production R130 13A--- 301 lbs (pg 264)

1977 production USA 12A --- 321 lbs (pg 244)

1977 12A sports kit (over the counter P-Port)--- 242 lbs (pg 244)

1977 12A MFR (factory P-port)--- 224 lbs (pg 244)

1977 production 13B--- 330 lbs (pg 244)

1977 13B MFR (factory p-port)--- 233 lbs (pg 244)

1978 production RX-7 12A--- 348 lbs (pg 267)

1983 production RX7 12AT (turbo)--- 356 lbs (pg 270)

1986 production RX-7 13B DEI--- 337 lbs (pg 47)

1987 production RX-7 13BT--- 377 lbs (pg 52)

speedturn

iTrader: (1)

"1977 13B MFR (factory P-port)--- 233 lbs"
that weight seems close to what my complete (with flywheel, carb, intake & header) home style P-port motors weigh. That light engine weight is why my complete car is light, and has a 6 lb/hp ratio.

BLUE TII

iTrader: (9)

Well- I didn't note it, but Mazda retained the aluminum sidehousings for their factory race efforts as well as lighter lost wax cast rotors, etc.

Your engine is likely more like the "sports kit" 13B or somewhere between the 233 lbs MFR 13B and the 330 lbs production 4 barrel carb 13B.

example-

12A MFR--- 224 lbs
12A sports kit--- 242 lbs
12A USA prod.--- 321 lbs

j9fd3s

iTrader: (3)

my fc gained 40lbs going from 13bt to 20b... same exhaust, radiator, 13b does add the swaybar...

BLUE TII

iTrader: (9)

Did you delete any engine peripherals on the 20B like AC or PS in addition to the lightweight flyweel you had to add?

The difference of 13BT to 13BREW is over 40 lbs...

I would love to see some published weight #s on a stock 20B, I know it is over 500lbs- but how much over?

the_glass_man

iTrader: (2)

Throw in some Racing Beat aluminum housings, a lightened e-shaft and rotors into the mix.

j9fd3s

iTrader: (3)

same flywheel and clutch for both engines, same radiator, same exhaust except for the dp. neither had a/c or ps.

13b did have an air pump and all the emissions, but its top mount ic
20b had a front mount but no air pump or emissions.

it was weighed with a full tank of gas (its repeatable that way)

ive posted the info before, in the 20b section, w 3 rotor it was 2860lbs, with 13bt it was 2820lbs....