Engine choice

Simply put, im stuck between two engines that would work well in the rx7, that aren't rotary. Reasons be told, after a decade of playing with them, im not messing around with rebuilding. Anyway, to keep within the rules and appease any chance of mazda contingency, i plan to use one of two mazda availible engines, the Duratec 23 from the 2001 up Ranger/ B series, Or the FE-Dohc (sometimes called the FE3). I would love some insight into what might be worthwhile direction to go. Im leaning towards one over the other at the moment, but id like some advice.

The Duratec 23: good for 145hp stock from Ranger
1. 2.3L Aluminum block, 16v head
2. 87.5mm x 94mm bore stroke
3. Adapter exisits to mount T5
4. 10.8:1 compression ratio
5. Varibable Valve timing can be hand from the FWD models.

FE3: Good for 123hp stock from kia sportage
1. 2.0L Iron block, aluminum 16v head
2. 86mm x 86mm bore stroke
3. Could use smooth case (M type) mazda transmission via breaking down B2000,2200 cases to change the bellhousing. At this point, im not sure if the R type (the strong ones) could be used.
4, Stock compression ratio is 9.2:1 but could be addressed.



Edited 1 time(s). Last edit at 07/11/2011 09:05AM by Gravity Fed.

Duratec without a doubt.
It is positioned to be around as a performance motor for a long time.
people who are rally peeps are developing BETTER junk for them like steel lighter flywheel for good pressure plates (If either William of I ever have enough brains to remember to pick up and place into my car the one we bought), accessory drive, and since I already have rods made for Volvo, I can also start bringing in rods for both the 2,0 and 2,3 motors, and if there's demand, steel cranks...

And Alex look at the gear ratios in the Rrrrrrr-anger (thats rrrrr like a growl and anger like pissed off, all trucks neeed ral macho-man names and anger or Rampage, maybe Toyota TANTRUM sound mean and aggressive, OK?)
pick up--prolly ain't any worser-er that whatcher gots now, might save a pile of dough while we invent a better T5 bellhousing with actual finished mounting for annular slave, external slave and Ford or GM pattern..


Then you can plop the motor into a nice car, like an Xratty

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

I have no clue about the FE3 - but sound like a dud to me.
Duratec has a bunch of things going for it in my oppinion:

- T5 adapter
- Widely available go-fast parts as John mentions
- More cubes
- More power/compression/everything out of the box - IIRC from another thread, rebuilding the Wankel(r) was too expensive... well, then I would go with the motor requiring the least trickery to get into decent shape.

I'm no expurt in either of those engines - but I've always chosen to go with "simpler" - it's more fun to drive (fast) than building forever and inventing something "unique" (aka "something weird that costs a fortune and takes forever to get right".
When I started with my Golf, I bought a Golf due to availability (parts AND knowledge) and simplicity.
Started out as an 8 valve... when I wanted to go faster, I pondered 8V vs 16V forever... until I came to the realisation that at the horsepower point where I had poured a ton of money into the 8V, the 16V would have cost me basically a rebuild and some headwork... and after that I could STILL pour the same amount of money into the 16V, and get an additional 50-60 horses....
So it came down to: build a fragile and expensive 8V? Or get a 16V, refresh and do some slight tuning that wont affect durability for less than half that money, and have the same horsepower AND more potential?

Kind of a no-brainer...

and no crap about you being able to get a FE3 for half of what a Duratec would cost you... at the end of the day (or rather at the end of the project), the Duratec will most likely be cheaper and more power.

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Brgrds
Brian

I remember miata guys drooling over the FE3 - but I thought there was a 2.3 variant available. I sold my miata around the time guys were looking into making it fit, but IIRC, they were looking at it as a candidate for forced induction, since the BP motors when using expensive billet stroker cranks and an overbore were just getting close to 2.0L.

In a light car like an RX7, I'd say go for the lighter engine - and the fact that the Duratec makes more power out of the box is a big bonus.

Dave

FE3 hasn't much support. They can be homebrewed to put out ridiculous hp/tq, but may not be worth the effort. If duratec weighs less, then stick that one in there. I bet with appropriate doses of money that it can be made to scare the crap outta you on a regular basis...

Do the MZR engine. If possible, get it from a B2300 and not a Ranger. (Seriously, that engine looks like ten tons of badass) 48mm throttles, header, and more compression will really wake that engine up.

The FE3 might not be contingency legal unless you get a J-spec unit, since the Kia unit is from a Kia. Mazda Motorsports seems to be weenies about things like that. I tried signing up and they want to know everything about your car right down to what CD is in the stereo.

A question: Do any of the MZR engines share bellhousing pattern with the B6/BP? If they do then a swap will be super easy, just use an early Miata trans. I hope.

well the duratec was the one i was leaning towards. hell i already have some T5s in the garage. And the weight factor. the rx7 is a portly 2450lbs as it sits now. The duratec 23 seems to be in the junkyard just as often as the FE3 so they are essentially the same cost. (gotta love a pull apart).

any particular reason for the B2300 pulling than a ranger, Pete?

Quote
Pete
Do the MZR engine. If possible, get it from a B2300 and not a Ranger. (Seriously, that engine looks like ten tons of badass) 48mm throttles, header, and more compression will really wake that engine up.

The FE3 might not be contingency legal unless you get a J-spec unit, since the Kia unit is from a Kia. Mazda Motorsports seems to be weenies about things like that. I tried signing up and they want to know everything about your car right down to what CD is in the stereo.

A question: Do any of the MZR engines share bellhousing pattern with the B6/BP? If they do then a swap will be super easy, just use an early Miata trans. I hope.

Bellhousing seems to me Duratec unique. We're already working on making a better one for T5 than the Quad-rods thing.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

whats your estimated pricing. also whats exactly wrong with the quad rods

Quote
Gravity Fed
whats your estimated pricing. also whats exactly wrong with the quad rods

We'll see on pricing,
The existing one I had had no provision for any kind of slave cylinder, no hole for hydraulic hoses, no hole for a clutch arm, no boss for a pivot ball and I was loathe to start chiseling up something that cost 475 bucks.

We want to have provision for annular slave and option for an arm and external slave becuase personally despite like the annular type surrounding the clutch shaft, I think it would be nice to be able to swap/blled a external slave in case of problems rather than pull trans for one stinking leaky O ring.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Cuz some of us have had our goddam FILL of pulling trans for one stinking leaky O ring...

well hopefully it arrives on the market before april 2012! Its going to be everything i can muster to get the car done with a 6mo deployment added in

Where you going?

And I say the B2300 because if they did like they did on the MX6/Probe then one will have Ford valve cover and the other will have Mazda.

And it's an RX-7, it's like a half hour to pull the trans out if you're slow and can't find the bottle opener, I've only ever seen one internal slave leak anyway.

Quote
Pete
Where you going?

And I say the B2300 because if they did like they did on the MX6/Probe then one will have Ford valve cover and the other will have Mazda.

And it's an RX-7, it's like a half hour to pull the trans out if you're slow and can't find the bottle opener, I've only ever seen one internal slave leak anyway.

Pete, are you drunk or did you have a stroke?
B2300? Whatchooo stinkin' ?
Get a alloy 16v Dura-da (or Maz'd) that will flow air for 220 Beee Haitch Peas
with just 10mm valve lift ---in the 2.0 so more in the 2300 since they share heads...

Don't know if there's anything on the valve cover....so stick a fawkin Maz-dawg sticker on a Rrrr-anger motor you get for $200 and presto-insta-maz-dawg.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

i have no idea how i would get 220hp out of the duratec, im guessing $$. At this point, it just needs to run (and seemingly that would be same output the 12a streetport had). Id love to know the difference between the "NS" and "EW" engines. The VVT equipped models would be nice, but i dont know if there are oddities in where coolant passages are located or anything. And thus far i haven't found any cheap Duratec 23s. All around the 900-1200 range from junkyards. Ill keep an eye on craigslist.