Engine blown in my RX7, rebuild or V8?

[Kash_]

I would agree with you up to a point, as mentioned look at craigs time attack car, is winning nearly every n/a race.. It\'s combination that works on the track, whifbitz with a rotary didnt do quite so well..

Craig\'s car is in a completely different class in terms of performance... The Pro class is where all the 800hp + Evo\'s, Scoobys, Skylines etc are so it\'s a heck of a lot more difficult to win, especially when racing against professional race drivers. Then you look at lap times and top speeds of the Whifbitz FD and Craig\'s... Whifbitz has had lap times 3-4 secs quicker and top speed readouts upto 10 mph quicker and both cars are pushing out similar power except the V8 which is putting out more torque... seems to me the Rotary can handle itself good enough!

[Papercup]

Most of these conversions are in the US and from what I’ve read the owners of these cars, many of whom have raced them both before and after the conversion state that they are unable to feel a difference in handling. Maybe we should listen to those with experience of racing the FD before and after the conversion as I would have thought that they are the only people whose opinions really count?
 
As for the weight issue, how many of our cars have not been modified in any way affecting the weight?
There are many of these conversions where the car comes out lighter than the original.
To get a true comparison would be almost impossible.  

1. Bear in mind human nature. The website is \'V8RX7\' or whatever. I wouldn\'t expect for a moment for most of them to even admit they drive differently, even if they did. Its why i said to Mr Wiltshire above, \'the grass is always greener\'. When we find the website \'V8s are rubbish.com\' we\'ll find a bunch of people who say the opposite thing. Of course they drive differently, they must, because there is more weight. They must drive differently and the fact that people in the States say they drive the same is the best indicator of human nature; they are being economical with the truth because they are happy with their car. Understandable, but not all that helpful to me and Mr Wiltshire because i genuinely want to know the differences. I know there must be differences and when people say there aren\'t i just raise my eyes and go ask someone else.
 
2. We know they weigh more. Tinker says so. I\'m surprised you didn\'t weigh your car before and after. You certainly swapped the engine and must have realised that the engine crane looked a little more strained with a great big V8 block and gearbox on it, rather than the ickle rotary. With the same car, before and after, the weight goes up. It must. You\'d have to be daft to look at the rotary engine next to the LS-series and think they weight the same, alloy block or not.
 
I am interested in how much it goes up, and what it affects. I would still consider a V8 conversion, but would need to drive one first. As i\'ve said, i would expect it to make a different car, that doesn\'t really feel quite like an RX-7 any more, but more like a hybrid of two cars. The power delivery, all that torque and no need to rev high, it must feel very different. These are the experiences i want to hear about.
 
I\'ve stood with Tinker and discussed the conversion in detail at the last two Fighting Torque events, so I have some idea. I\'d go to him in a second to have it done. But i\'d be scared to lose the character of my car.
 
I\'d genuinely like to hear what you think. You\'ve driven both. I expect you are happy with the car, but....really....whats it really like? Don\'t say \'its the same\'!
 
We can all talk about this without getting narky, it turning into \'rotary vs V8\' thing, and getting locked. Its a pity, the mods here tend to stamp on the V8 discussions, or certainly used to.
 
Andy

[Hi RX7]

Can I just make one thing quite clear as I have stated I am not pro or anti rotary. I have made a decision regarding what will happen next if my rotary fails I will cut my losses and go for the V8 conversion. I have no interest in whether the rotary can trounce the V8, what I want is a conversion that will replicate the type of thrill the rotary gives me without that nagging feeling that it may blow, quite obvously the V8 is unstressed and when put in such a light car the low end grunt I am sure will make for some interesting driving.
I am all for constructive debate thats how we all learn things, so please if we can avoid extreme pro and anti thrusting getting in the way of what I hope is an open considered debate about the pro and cons of this type of conversion.
I also wonder if it might be better to transfer this topic to a different heading as my original thread heading is a bit Sun newspaper like thinking about it

[Papercup]

Can I just make one thing quite clear as I have stated I am not pro or anti rotary. I have made a decision regarding what will happen next if my rotary fails I will cut my losses and go for the V8 conversion. I have no interest in whether the rotary can trounce the V8, what I want is a conversion that will replicate the type of thrill the rotary gives me without that nagging feeling that it may blow, quite obvously the V8 is unstressed and when put in such a light car the low end grunt I am sure will make for some interesting driving.
I am all for constructive debate thats how we all learn things, so please if we can avoid extreme pro and anti thrusting getting in the way of what I hope is an open considered debate about the pro and cons of this type of conversion.

I agree
 
I am also trying to \'keep it clean\' and ask others to do the same !
 
We can have a V8 discussion without arguments!
 
I am concentrating more on the performance/track/race aspect as it is more relevant to me. But the whole thing interests me.
 
My race car is a rotary powered RX-7
 
But day to day i drive a 4.4 V8 BMW (540i) and LOVE the engine in it
 
(I use the BMW to pull the trailer with the Rex on it!)
 
Andy

[Brett]

I can split the thread if you want?

:wave

Got a title in mind for the new thread?

[Spartacus]

1. Bear in mind human nature. The website is \'V8RX7\' or whatever. I wouldn\'t expect for a moment for most of them to even admit they drive differently, even if they did. Its why i said to Mr Wiltshire above, \'the grass is always greener\'. When we find the website \'V8s are rubbish.com\' we\'ll find a bunch of people who say the opposite thing. Of course they drive differently, they must, because there is more weight. They must drive differently and the fact that people in the States say they drive the same is the best indicator of human nature; they are being economical with the truth because they are happy with their car. Understandable, but not all that helpful to me and Mr Wiltshire because i genuinely want to know the differences. I know there must be differences and when people say there aren\'t i just raise my eyes and go ask someone else.
 
2. We know they weigh more. Tinker says so. I\'m surprised you didn\'t weigh your car before and after. You certainly swapped the engine and must have realised that the engine crane looked a little more strained with a great big V8 block and gearbox on it, rather than the ickle rotary. With the same car, before and after, the weight goes up. It must. You\'d have to be daft to look at the rotary engine next to the LS-series and think they weight the same, alloy block or not.
 
I am interested in how much it goes up, and what it affects. I would still consider a V8 conversion, but would need to drive one first. As i\'ve said, i would expect it to make a different car, that doesn\'t really feel quite like an RX-7 any more, but more like a hybrid of two cars. The power delivery, all that torque and no need to rev high, it must feel very different. These are the experiences i want to hear about.
 
I\'ve stood with Tinker and discussed the conversion in detail at the last two Fighting Torque events, so I have some idea. I\'d go to him in a second to have it done. But i\'d be scared to lose the character of my car.
 
I\'d genuinely like to hear what you think. You\'ve driven both. I expect you are happy with the car, but....really....whats it really like? Don\'t say \'its the same\'!
 
We can all talk about this without getting narky, it turning into \'rotary vs V8\' thing, and getting locked. Its a pity, the mods here tend to stamp on the V8 discussions, or certainly used to.
 
Andy

The reason I have quoted the US site is that they are in a position of having experienced both non converted and converted from a racing point of view. I don’t see why they would be lying and I’ve never heard of any of them swapping back to rotary. My point is if you want to find out what the differences are they are the people to tell you, not just people with opinions but with no experience. Maybe the lack of the site V8s are rubbish.com should tell you something?

"I know there must be differences and when people say there aren\'t I just raise my eyes and go ask someone else."

How many people are you going to ask before you believe? them or are you waiting for some one to say the handling is ruined and then say I told you so?


From what I have read there is meant to be around a 40lb difference "IF" all things were equal. But that is a big if as they are never equal. And those 40lbs isn’t on the nose of the car its spread.
There is a school of thought that the LS1 actually has a better centre of gravity than the rotary as most of the weight is low down compared to the rotary. How true this is I don’t know but it is worth thinking about.

I\'m sorry I didn’t manage to weigh mine before and after but I\'m quite happy to weigh it now if you can find a car the same spec as mine to compare it with. Oh and no the crane didn’t seem to be straining any more lol. Yes the LS engines are great big things but they are alloy and plastic with at least 5.7 litres of air in them.

Oh I have got the weights of the rotary and gearbox which I can find if you want?

Yes I’ve driven them before and after but I\'m sorry to say that my driving skills were not up to a F1 driver so yes/no I cant tell any difference.

In the end of the day if you want to do it you will find good enough reason s to do so and if you don’t you will also find reasons not to.

[Hi RX7]

In reply to Brett
 
Its just that my initial thread title is a bit inflammatory and may invite extremist views or am i being a bit limp wristed about it?

[Hi RX7]

The reason I have quoted the US site is that they are in a position of having experienced both non converted and converted from a racing point of view. I don’t see why they would be lying and I’ve never heard of any of them swapping back to rotary. My point is if you want to find out what the differences are they are the people to tell you, not just people with opinions but with no experience. Maybe the lack of the site V8s are rubbish.com should tell you something?
 
"I know there must be differences and when people say there aren\'t I just raise my eyes and go ask someone else."
 
How many people are you going to ask before you believe? them or are you waiting for some one to say the handling is ruined and then say I told you so?
 
 
From what I have read there is meant to be around a 40lb difference "IF" all things were equal. But that is a big if as they are never equal. And those 40lbs isn’t on the nose of the car its spread.
There is a school of thought that the LS1 actually has a better centre of gravity than the rotary as most of the weight is low down compared to the rotary. How true this is I don’t know but it is worth thinking about.
 
I\'m sorry I didn’t manage to weigh mine before and after but I\'m quite happy to weigh it now if you can find a car the same spec as mine to compare it with. Oh and no the crane didn’t seem to be straining any more lol. Yes the LS engines are great big things but they are alloy and plastic with at least 5.7 litres of air in them.
 
Oh I have got the weights of the rotary and gearbox which I can find if you want?
 
Yes I’ve driven them before and after but I\'m sorry to say that my driving skills were not up to a F1 driver so yes/no I cant tell any difference.
 
In the end of the day if you want to do it you will find good enough reason s to do so and if you don’t you will also find reasons not to.

I did extract those weights I posted from the american site after doing a search there are loads of different posting there regarding corner weighting etc in fact there is about an hours worth of reading there and the weights I posted seemed to be in my opinion about average.

[Brett]

No probs - what do you want the title to be then? :wave

[Hi RX7]

Re-build or V8 transplant for the RX7 ?

[Hi RX7]

Thanks, as I mentioned in one of my earlier posts if a new member considering buying an RX7 read the heading it could scar them for life.

[Brett]

No problem - it beats working

[connor66]

David, you\'re being limp wristed. Your thread title is not inflammatory (although I can understand exactly why you might feel that way), it\'s just a statement of a true event which has happened to you. Unfortunately, these threads always end up as V8 versus rotary, even if they didn\'t start out that way, they always end up there (just look back at the history). I\'ve owned both rotary and V8 FD\'s (my current FD is V8). I loved my rotary and ended up rebuilding it twice myself (water seal failure on both occasions) before reliability issues eventually sickened me. After a brief spell back with a supra, I went for the V8 conversion (done by tinker). In terms of handling, both rotary and V8 still "feel" like RX7\'s, both handle equally well as far as my driving skills go. Of course the engine characteristics are totally different and that preference is down to personal choice. The key word for ME (read: my view only) was reliability. After my experiences with the rebuilds (and the constant worry about it letting go again afterwards) I wanted an RX7 with a decent amount of power (350~450hp) that would be reliable, and that\'s exactly what I have (owned for 1 year now). I fully understand your concerns regarding rotary reliability (even when they\'re built by the experts with all the right bits) and I know what it feels like when your pride and joy takes a sh1t on you. I really hope your rebuild works out and if you do consider V8 in the future, then it\'s because you WANT to, rather than feel you HAVE to. For all the V8 bashers out there (and just for the record, I do not mean all rotary owners), when\'s the last time you spoke to someone who had just been for a ride in a V8 RX7 and didn\'t love it???

Gary

[Hi RX7]

There is no doubt my mind is made up and I have started the ball rolling with regards to which engine etc I will eventually settle on, the guys who did my re-build will be happy to do the conversion and I know they will do it right. The re-built rotary is running nicely at the moment and I am enjoying wasting petrol in the car. As I have said checking out the various threads on the U.S. site satisfies and confirms my decision about going down the V8 route and no points raised so far once investigated has put me off.
I can acknowledge that as a very new owner to the RX7 my descision could be taken as an over reaction but like decisions I have to make running my business ultimately the can stops with me so if it goes tits up its nobodies fault but mine.

[Spartacus]

This might be a good thread to read as this is about as close as a direct comparison that could have been. Unfortunately it now looks like it won’t happen, but makes interesting reading.
http://www.v8rx7forum.com/v8-rx7-technical/49714-gunfight-ok-corral.html

Oh, also it looks like the LS FD came out lighter than the rotary.