Mazda Rotary Club

Cars by Model Type => 3rd generation RX-7's => Topic started by: jag60dog on December 09, 2007, 11:33:11 AM

Title: RX7 engine query
Post by: jag60dog on December 09, 2007, 11:33:11 AM
hey all

Well I not quite a noob but I haven\'t been here since 06:rollin  Anyway I\'m in milton keynes an seem to be noticing more an more of these gorgeous rex\'s now I own a mr2 turbo which I\'m soon looking at selling an laying my hands finally on my very first rex woohoo but I know alot about how the engine drinks oil and the rebuilds will be regular. But if I do get one I will looking to remove it............:2eek  an fitting an f20(s2000) I dont know if its been done over here as of yet!!

But this all depends how I take to engine maintance anytips would be great guys/girls
Title: RX7 engine query
Post by: shaunwil on December 09, 2007, 12:05:23 PM
TBH if you look after the car and make sure its tuned well then it should last quite a long time. Why is 40-50k miles classed as frequent ??

Why would you want to swap to an engine that only produces just over 200bhp ?

Ok swap it for a V8 for life and power.

If it was me stick with the rotor in the engine bay, make sure you do all the safety mods and look after it. It will repay you with a very good life :D

Shaun
Title: RX7 engine query
Post by: orange_rex on December 09, 2007, 03:09:51 PM
Would be quite interesting to see this done, the F20 is a great engine and at 240bhp its not slow either. keep us posted and good luck with it.
Title: RX7 engine query
Post by: Timmy on December 09, 2007, 03:32:46 PM
Generaly 60k is considered rebuild teritory so if your an average user thats a rebuild once every 5years. I think most people that have one do alot less milage and use a second car. So it becomes more like once every 10years. So if you save £1 a day for those 10 years you\'ll £3650 for rebuild and change. If your still worried about other reliabilty issue go ls1 or ls2. As "v-tech is like waiting for bad sex"
Title: RX7 engine query
Post by: Martiny on December 09, 2007, 04:45:05 PM
Oil consumption stories are a load of hogwash. A half litre for about 1000 miles is normal. I wish I could find the person who started that pack of lies.
Title: RX7 engine query
Post by: jag60dog on December 09, 2007, 07:25:27 PM
Ok so you owners havent had to many major issues with your motors.........thats very comforting to hear. I do like the rotary its just I have been doing alot of research on an f20 conversion , dont really want a v8 quite yet (still the tender age of 21) but im not daft chav kid I\'m very aware of what i do. So do alot of owner work on their own rexs or not?
Title: RX7 engine query
Post by: chrisJDM on December 09, 2007, 07:36:52 PM
why dont you just buy a s2000???? i would say similar sort of styling, rear wheel drive, newer then a rx7, whats the point in buying a rx7 and putting a s2000 engnie in it, just buy a s2000, surely sourcing and buying a s2000 engine would be quite a bit, plus fitting and getting it set up, plus buying a rx7 in the first place
Title: RX7 engine query
Post by: Red and Single on December 09, 2007, 07:56:59 PM
You might as we\'ll just keep your MR2 and save your money, there is no point buying an RX7 just to downgrade the powerplant.

I\'m all for engine transplants but they must be upgrades or what is the point of all that expense !!

Still, it\'s a free country, good luck whatever you decide.
Title: RX7 engine query
Post by: shaunwil on December 09, 2007, 10:17:12 PM
Plus on a serious note could you insure an rx7 that is modded (all be it with less power) at your tender age ?

Shaun
Title: RX7 engine query
Post by: neil_jdmr on December 09, 2007, 10:32:21 PM
Quote from: MartinyOil consumption stories are a load of hogwash. A half litre for about 1000 miles is normal. I wish I could find the person who started that pack of lies.

 
Totally agree:Thumbs-up
 
My previous car, a integra type r used loads more oil than my rx
 
I still really like honda\'s and the sound of vtec at 9k rpm is awesome but i could never swap out the 13b now ive had the taste of it.
 
Each to their own though and will be interested to hear how you get on.
Title: RX7 engine query
Post by: J.j. on December 09, 2007, 10:42:59 PM
QuoteBut if I do get one I will looking to remove it............ an fitting an f20(s2000) I dont know if its been done over here as of yet!!

Please dont get one if above is what you have in mind.
Title: RX7 engine query
Post by: RemarkLima on December 09, 2007, 11:39:22 PM
I know with a SC they [the F20] can see 300bhp, but again is a lot of work and considering the engine alone will be in the region of £2000 for a decent one, you could get the 13B rebuilt for a wee bit more.

I\'d say stick with the rotors too, if you want a V8, get a chavette, removing the rotors from a RX7 is making a MX7, just wrong ;) Like someone said before, like a lady boy!!!!

But seriosuly whatever you do, good luck with it! All I can say is make sure you keep the 50/50 weight as the chassis is just sublime, the suspension great! Having raced MR2\'s the RX7 is a much more precise instrument :D
Title: RX7 engine query
Post by: jag60dog on December 10, 2007, 09:16:01 AM
Just wanna say you guys are amazingly helpful an well to be honest I\'m shocked as you owners all have good things to say about these rotary engines which I was hoping for as i do want to experience true rotary power. As for keeping my mr2 thats just not gonna happen I\'m fed up or the completly off weight distribution if you take them to 300bhp they cant be moved around a bend!!!!!!!! As for insurance it actually works out cheaper than my grp20 mr2 turbo. Im not gonna ask if the engine is easy to work on as all engines have difficult points but i would like to know accessability of the bay.
Title: RX7 engine query
Post by: chrisJDM on December 10, 2007, 10:28:24 AM
well i think and im sure alot of other peps on here agree with me, you should just keep the rotary engine, its designed for the car, more power then the     s2000 standard and more tuning potential at a cheaper price.  Also oil consuption probably isant any worse then the s2000.
Title: RX7 engine query
Post by: SmbFD3S on December 10, 2007, 10:29:43 AM
Depends if the engine is standard or not, there is easy access to most of it unless you neet to get to the turbo pack and then it gets difficult...  Nothing really to mess about with, with the actual engine, and with only 3 moving parts some say it\'s easier to rebuild than a piston engine.  I\'ll be doing my own rebuild project next year on mine so i hope this is true....Can\'t be as bad as a V12 XJS that i\'ve done tho i guess lol...
 
And most of all keep it rotary, this is the sole reason the RX7 lives on. The sound, smoothness and power of the rotary will pursuade you anyway when you drive one  :)
Title: RX7 engine query
Post by: sadgoth on December 10, 2007, 11:26:05 AM
Quote from: jag60dogJust wanna say you guys are amazingly helpful an well to be honest I\'m shocked as you owners all have good things to say about these rotary engines which I was hoping for as i do want to experience true rotary power. As for keeping my mr2 thats just not gonna happen I\'m fed up or the completly off weight distribution if you take them to 300bhp they cant be moved around a bend!!!!!!!! As for insurance it actually works out cheaper than my grp20 mr2 turbo. Im not gonna ask if the engine is easy to work on as all engines have difficult points but i would like to know accessability of the bay.

basic maintenance on a 13b is straightforward, oil and filter changes can be done easily, plugs are a pain because of the rats nest on top of the block, but you can get to them from below easily, like all Japanese cars there isn\'t a lot of space in the bay so be prepared for scraped knuckles, but all in all it is relatively easy to work on the engine yourself.

I love the S2000 and the F20 is a great engine (in the S2000), however it is REALLY difficult (read that as expensive) to get loads more power out of it and at 240bhp, it is already down on the 13bREW so you are starting at a power disadvantage and you\'ll be spending loads to get it up to say 300bhp, which the FD can acheive with a decat and full exhaust, air filter and a ECU change (say £1k)

If you like the F20, buy the car it belongs in, if you like the FD stick with the 13bREW it is a great engine and nowhere near as unreliable as people make out, it just needs to be PROPERLY maintained, as would the F20!
Title: RX7 engine query
Post by: elford_tim on December 10, 2007, 11:34:01 AM
Quote from: jag60dogJust wanna say you guys are amazingly helpful an well to be honest I\'m shocked as you owners all have good things to say about these rotary engines which I was hoping for as i do want to experience true rotary power. As for keeping my mr2 thats just not gonna happen I\'m fed up or the completly off weight distribution if you take them to 300bhp they cant be moved around a bend!!!!!!!!

Hmm. No offense, like, but given that the MR2 is mid-engined and as such has pretty much perfect weight distribution, this statement worries me a little. Especially as an RX-7 has fairly similar weight distribution - I haven\'t got the figures here but I\'m pretty sure that it\'s around 50:50 as well...

Quote from: jag60dogAs for insurance it actually works out cheaper than my grp20 mr2 turbo. Im not gonna ask if the engine is easy to work on as all engines have difficult points but i would like to know accessability of the bay.

Good call regarding the insurance, but make sure that they\'ll cover even mild mods. I think we\'re all a bit surprised that an RX-7 works out cheaper to insure...
Title: RX7 engine query
Post by: 20B_boy on December 10, 2007, 12:01:40 PM
Quote from: elford_timHmm. No offense, like, but given that the MR2 is mid-engined and as such has pretty much perfect weight distribution, this statement worries me a little. Especially as an RX-7 has fairly similar weight distribution - I haven\'t got the figures here but I\'m pretty sure that it\'s around 50:50 as well...
Ever driven an MR2 turbo? I think generally mid-engined cars are a lot more scarey and harder to drive (well) than FR cars.
Title: RX7 engine query
Post by: elford_tim on December 10, 2007, 12:26:10 PM
Quote from: 20B_boyEver driven an MR2 turbo? I think generally mid-engined cars are a lot more scarey and harder to drive (well) than FR cars.

Yes, but only a standard one. And I\'ve driven - and spun - most of the other non-exotic mid-engined cars with the exception of the Honda NSX. OK, that mainly leaves the various Fiat/Lancia mid-engined cars and MR2s... And yes, I know that most of them are a bit hair-trigger when it comes to overcooking things. You could say I found out the hard way, on a public road, back when I was young and stupid. Today I\'m just not young anymore.

My point was more that while an RX-7 may be a little easier to drive fast, it\'s weight distribution is still fairly close to the one on an MR2. That said, I was surprised that the MR2 is supposed to be 46/54 - I had expected it to be closer to the FD\'s 50/50.
Title: RX7 engine query
Post by: prince_of_tokyo on December 10, 2007, 01:02:33 PM
whats the weight difference between a FD and an s2000? as i know the vtec engine does not develope alot of torque...not a huge fan of vtec\'s, i have to say...
Title: RX7 engine query
Post by: orange_rex on December 10, 2007, 03:46:22 PM
Its about 1300kg for a s2000, they dont have much torque. Thet are both great cars and i wouldnt say that my s2000 was that much slower than my type r rex but they both give you a great thrill just in a slightly different way.
There is a e36 bmw with an F20 in it on you tube and personally i think its mint i guess its just a matter of what you like, either way it would certainly be different and get lots of attention.
Title: RX7 engine query
Post by: RemarkLima on December 10, 2007, 07:47:40 PM
Quote from: elford_timMy point was more that while an RX-7 may be a little easier to drive fast, it\'s weight distribution is still fairly close to the one on an MR2. That said, I was surprised that the MR2 is supposed to be 46/54 - I had expected it to be closer to the FD\'s 50/50.

Are you sure about the MR2 being 46 / 54??? I\'d say it\'s more like 60 - 65 / 40 - 35 IMHO, certainly feel like it! And the Gen1 MkII\'s are a complete death trap due to the rear suspension design, them maccy struts are pants ;)

Like 20B, true mid engined stuff is much nastier on the oversteer than 50 / 50 (like RX7\'s, 99% of BMW\'s, cateringvans and 7\'s) and will give you some vicious snap oversteer which you don\'t get as badly in these.

All IME ya know! The chassis one the RX is just so peachy! Up there with the Lotus\' IMHO, just a bit (a lot!) heavier ;)
Title: RX7 engine query
Post by: antnicuk on December 10, 2007, 08:12:51 PM
i am all for engine swaps but not for something with less power and harder to get more power out of.   If you are handy enough to do an engine conversion with any other engine, then you will have no problem building and modifying the rotary which would easily see 350 - 400 bhp and reliable if done properly.  once you strip it and get rid of all the complicated stuff, its easy to work on.
Title: RX7 engine query
Post by: tinker-27 on December 10, 2007, 09:26:29 PM
my fd with a 7.0l v8 is still 50/50 with 25 litres of fuel,so it can be done without screwing up the handeling, how about a s2000 motor with a blower ?
Title: RX7 engine query
Post by: elford_tim on December 10, 2007, 09:35:45 PM
Quote from: RemarkLimaAre you sure about the MR2 being 46 / 54??? I\'d say it\'s more like 60 - 65 / 40 - 35 IMHO, certainly feel like it! And the Gen1 MkII\'s are a complete death trap due to the rear suspension design, them maccy struts are pants ;)

Well, the info regarding the weight distribution was found on the Internet, so it must be true :D. Actually 60/40 wouldn\'t be too bad unless you\'re driving in snow and have to go look for some traction :P. It\'s usually the rear end being slightly heavier that tends to catch people out and has you exiting the road arse first.

Quote from: RemarkLimaLike 20B, true mid engined stuff is much nastier on the oversteer than 50 / 50 (like RX7\'s, 99% of BMW\'s, cateringvans and 7\'s) and will give you some vicious snap oversteer which you don\'t get as badly in these.

Don\'t I know that, that\'s what I meant with their hair-trigger behaviour.

Quote from: RemarkLimaAll IME ya know! The chassis one the RX is just so peachy! Up there with the Lotus\' IMHO, just a bit (a lot!) heavier ;)

Oh, I agree that the FD chassis is a good \'un...
Title: RX7 engine query
Post by: RemarkLima on December 10, 2007, 11:18:57 PM
Maybe I\'m thinking of the Lotus I had which was more like 36% front, 64% rear, surprisingly rear biased! The MR2\'s biggest failing IMHO was the MacPherson struts, if they\'d put double wishbones on it it\'d have been a very sweet bit of kit!

Still, one thing that\'s always puzzled me, why are MR2 doors so light and FD doors and made of depleted uranium???
Title: RX7 engine query
Post by: jag60dog on December 12, 2007, 09:47:18 AM
for those of you who havent driven an mr2 turbo they are potentially very dangerous cars especially the revision1 mk2. its not so much the power that make it dangerous its the weight distribution especially when making sharp direct corners due to being mid-engined you do need to lift the wieght when cornering and if it does start to swing fast correction is a must as these cars are known for there snap back. I had mine for over a year an have only spun out once!!! but when my best mate bought his the 2nd week he was driving around an roundabout in the damn at NO more than 20mph I swear to you all he swung the car out then it snaped to the opposite direction an up the curb.....lucky for him no major damage I repaired it for him an he vows to never own one again. the n/a it great but add boost an they become a handfull with is why im looking into a FR spec car nowadays it makes sense lol
Title: RX7 engine query
Post by: RemarkLima on December 12, 2007, 10:23:58 AM
Yep, 100% agree, the Rev1\'s are a death trap! The rev2\'s are much better mind, but still not the best ;)

The Mk1\'s are just a better handling car all round IMHO.

But I\'d say the RX7 is still midship, the engine is quite a way behind the front axle, so it\'s the best of both worlds! :D
Title: RX7 engine query
Post by: jag60dog on December 12, 2007, 06:45:48 PM
remarklima your totally correct the mark1 are better handlers along with the mark3 it may have girly looks but trust me the thing is a beast at cornering like being on rails but a tad under powered.
Title: RX7 engine query
Post by: jag60dog on December 13, 2007, 09:26:08 AM
one other question I\'ve been looking around at tuning these rotary engine an a few times I have come across people owning 4rotor or 3rotor an I cant seem to understand exactly what they are meaning an any1 help?
Title: RX7 engine query
Post by: RemarkLima on December 13, 2007, 09:35:38 AM
If you think of the engines as plates sandwiched together, the bread being the side / end plates and the filling being the rotor housing and rotor.

The 13b is a club sandwhich, so 2 sets of filling between 3 slices of bread.

The 3 rotor 20b is a mega club sandwich, so 3 fillings in between 4 slcies of bread, with the 4 rotor being a huge sandwich (of just a normal one for our American coursins) with 4 fillings and 5 slices of bread ;)

I guess there\'s no reason you can\'t add more other than the eccentric shaft (same job as a crank shaft) will start to get weaker and more likely to crack the more you add, the same as a crank shaft rarely goes "longer" then 6 cylinders (an inline 6, while a V8 is only 4 cylinders long IYSWIM).

That\'s the best way I can see of visualising it anyway :D
Title: RX7 engine query
Post by: sadgoth on December 13, 2007, 10:01:36 AM
Quote from: jag60dogone other question I\'ve been looking around at tuning these rotary engine an a few times I have come across people owning 4rotor or 3rotor an I cant seem to understand exactly what they are meaning an any1 help?

As RemarkLima said it refers to the number of rotor housings and also therfore the number of rotors. Very few 4 rotors out there, Carl has one.

It is like having more cylinders in a piston engine.

3 Rotor engines are found in some of the Cosmos and these engines are referred to as a 20b as opposed to the 13b in the rx7

advantages are the engines produce more power and a lot more torque
Title: RX7 engine query
Post by: jag60dog on December 13, 2007, 07:02:54 PM
ahhh  ok im starting to understand now lol.