Mazda Rotary Club

Cars by Model Type => 1st generation RX-7's => Topic started by: Don Pamponi on October 22, 2004, 06:26:28 PM

Title: V8 Rx7?
Post by: Don Pamponi on October 22, 2004, 06:26:28 PM
Hmm...  it occurs to me that I could probably drop in a rover V8 for a lot less £ than a £2K rotary lump.

It would make more RELIABLE bhp, & last a shite load longer without blowing up.

I know I\'d be lynched by the rotary community, but ask yourselves - deep down, truthfully, doesnt it make more sense?

Admit it: we are all fighting a losing battle.  Lets all throw away the mazda red herrings and stuff the little RXs with V8s!

You can buy a running rover V8 for £150, a re-built one for £500

Think about it guys.  All that torque & for peanuts.

I worry that we\'re all misguidedly chasing the Holy Grail of rotary power.  
Just like fanatical Norton or Triumph motor bike fans did in the face of overwhelming superiority of japanese 4s.

Is it time to give it up & go for pistons?

I may just do it to prove a point.
Title: V8 Rx7?
Post by: ScuttleRX on October 22, 2004, 06:30:46 PM
what about the weight, handling issues.

Half of the rex\'s appeal is its sublime handling :)  a big ol\' v8 in the front is gonna upset the weight balance a bit :)

Be good for 1/4 i reckon tho :D but still blasphemous!
Title: V8 Rx7?
Post by: Don Pamponi on October 22, 2004, 06:33:39 PM
Rover V8 is an alloy lump & weighs about the same as a pinto.

You cant enjoy the handling that much cos the steerings too heavy & low geared.

Seems more suited to straight line action to me - too much like hard work round the twisties!
Title: V8 Rx7?
Post by: ScuttleRX on October 22, 2004, 06:37:38 PM
QuoteRover V8 is an alloy lump

ah didnt realise that matey, sounds like a plan, could be a 1/4 mile monster.

You have such a nice looking example tho, shame to ruin its rotary heritage :)
Title: V8 Rx7?
Post by: Carl on October 22, 2004, 06:41:05 PM
Hi Don,
If you want to sell your car as it is let me know,I maybe interested.
I think your steering is affected by the wheels you have.

I have owned Rovers before and I can tell you that back to back I could get a stock 1st gen to outperform in every way a 1st gen with a rover V8 in it on a race track.

The Rover engines do not make that much power unless modified,and they do not rev very high either unless serious money is spent.

Kind regards
Carl
Title: V8 Rx7?
Post by: MikeLMR on October 22, 2004, 06:42:13 PM
Its your car do what you like.

 A rover V8 isn\'t going to be cheap to fit in an FB. if you aren\'t building and fitting it yourself I doubt you would get change from your rotary rebuild costs.

As for a rover v8 being lighter than a pinto ... that has more to say about how heavy a pinto is than how light an RV8 is.

Mike
Title: V8 Rx7?
Post by: Don Pamponi on October 22, 2004, 06:42:15 PM
Bollox to its rotaryness - its rotary heritage has ruined me!

SO much time money & frustration, it could be this or throw a match in the troublsome demanding little bugga:reallymad
Title: V8 Rx7?
Post by: Carl on October 22, 2004, 06:44:18 PM
QuoteOriginally posted by Don Pamponi
Bollox to its rotaryness - its rotary heritage has ruined me!

SO much time money & frustration, it could be this or throw a match in the troublsome demanding little bugga:reallymad

Hi Don,
Find something more suited to the Rover engine and sell your car to me!LOL!
Kind regards
Carl
Title: V8 Rx7?
Post by: Don Pamponi on October 22, 2004, 06:48:16 PM
All quite true Gentlemen.

However, its friday I\'m knackered & feeling rebelious.

I may go outside and taunt the car for a bit, then threaten it with pistons & walk away into the night cackling dementedly
Title: V8 Rx7?
Post by: MikeLMR on October 22, 2004, 06:53:23 PM
Don, just remind yourself who rebuilt your engine and what a good job he did on tigthening the bolts on the rest of your car ... could you turn your back on the rotary just yet ? Find someone reliable to rebuild your 12a and make sure its tuned proprely and it should be reliable ... just as other engines are all around the world.
Title: V8 Rx7?
Post by: Don Pamponi on October 22, 2004, 07:00:00 PM
Has anyone super charged a rotary yet?
Title: V8 Rx7?
Post by: MikeLMR on October 22, 2004, 07:05:43 PM
yes, these guys sell kits. (be they good or bad I know not!)

http://www.atkinsrotary.com/

I seem to recall one of members in Ireland has Supercharged Cortina back in NZ.

I also have some nice video of a white 1st Gen rx with a huge blower running on methanol.
Title: V8 Rx7?
Post by: MikeLMR on October 22, 2004, 07:10:02 PM
oooh nearly forgot Antinuk is building a supercharged 20B FD

but dropping a 20B in a 1st gen will spoil the handling just as much as fitting a v8 unless you go mad with the body modifications to get it nice and far back.
Title: V8 Rx7?
Post by: MikeLMR on October 22, 2004, 07:10:49 PM
oooooooooh and a linkie to the mad supercharged 1st gen

http://ausrotary.dntinternet.com/forums/viewtopic.php?t=46457&highlight=supercharger
Title: V8 Rx7?
Post by: Don Pamponi on October 23, 2004, 07:45:51 AM
Well at least an RV8 wouldn\'t make it look that ugly!

I don\'t fancy having half the motor outside the car ;)
Title: V8 Rx7?
Post by: Don Pamponi on October 23, 2004, 08:06:48 AM
What a shame I didn\'t sell the car before it lost a tip.  I doubt id even get the cost of the wheels & tyres back if it sold as is.
Title: Here we go!
Post by: Don Pamponi on October 23, 2004, 08:32:30 AM
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=10414&item=2496164773&rd=1

I can get that fitted for about £750 all in.

Why do we pay such a premium for a rotary engine?

Scarcity value?

They are comparitivly simple, small & light.  Loads less work to remove & rebuild.
Title: V8 Rx7?
Post by: antnicuk on October 23, 2004, 10:08:59 AM
go for it.
putting one in a 3rd Gen FD is one thing but the first Gen isnt as refined and \'sublime\' as the FD.    

As for your steering, all first gens were SH*T, the mk2 was a little better but its the steering box that causes it. After a few miles its a sod to keep straight.  

You might want to have a rack and pinion put in while the engine is being done, it makes a massive difference.  My FB has rack and pinion to miss the turbo, its the best thing about the car.

As for which V8, go Yank, with 5.7 chevy, it will have about 100 more BHP than a stock range rover lump, but for cheapness the rover will do the job.  

Regards
Tony
Title: V8 Rx7?
Post by: clive on October 23, 2004, 10:54:39 AM
Hi Don,

Huge commiserations about the loss of your engine real shame as l remember your initial enthusiasm and had been looking forward to seeing your car at shows etc. :) :) :) :)

Could l ask how you lost a tip ? and it\'s odd to lose Gen 1 engines  throu tips as they tend to wear out from high mileage, even elfords.  

As for the piston route, l have been around Rotary\'s for quite a few years now and have witnessed people go this route before and been disappointed.

One l remember was a Guy called Steve Irons who \'lost\' a couple of pip\'s engines in his Black Gen 2 and after being a Rotary enthusiast for a few years \'dumped\' a 4.5 Rover lump in it, yes he had a lot of power and it made a LOT of noise but soon after he sold it as he quickly realised he now had a car that didn\'t handle but more than that he realised he had tore the heart out of his car and sold it on after just a short time !!!!.

Couple of things, as Mike points out comparisons made to the Pinto really aren\'t good, the damn thing is a boat anchor !

One year when l raced in National Hot Rods l brought a Barry Lee pro-built car that had been built for a \'Kent\' engine but could not afford the £5k needed to keep the original engine so l put a \'Pinto\' due to a rule that would let me have more power cheaply, Grrrrrrrrrrrrrrrrrr, never did dial out the understeer due to the extra weight, and went from winning races to a best result of third for that season,    nuf said !!

As for it\'s all O/K now l have pistons thing, if you put a piston in it you will probably be very disappointed if you fit a Land Rover lump in as these are real low comp engines so you will immediately need to start off down the tuning route again !

Also if you go this route before parting with money as from memory there are lots of different Rover V8 engines and not all are desireable.

And as l have found many times a badly or wrongly tuned piston engine will die just as quick as a Rotary, for instance years ago l raced in a Mini Formula and due to a bad tuner/ engine builder who l made an agreement with to let him supply engines for me on a one  season contract, l went from winning lots of races and being the previous years champion to not even finishing most races and consuming 5 engines along the way, so l do understand engine blow up problems intimately !.

Yes the Rover lump will go in the Gen1 as we have seen one at the Pod running mid to high 13sec 1/4ers
( hardly earth shattering ) but as sadly there are now very few of these cars left all he has archived is \' bastardising\' a good handling sports car!

Sorry for me engine \'sermon drivel\' but it\'s sad to see someone who had so much enthusiasm be down and all l am saying is not all is always Rosy in the world of pistons either.

I\'ll get me coat now! and wish you well in whatever you decide.
Title: V8 Rx7?
Post by: Carl on October 23, 2004, 12:28:58 PM
QuoteOriginally posted by antnicuk
go for it.
putting one in a 3rd Gen FD is one thing but the first Gen isnt as refined and \'sublime\' as the FD.    

As for your steering, all first gens were SH*T, the mk2 was a little better but its the steering box that causes it. After a few miles its a sod to keep straight.  

You might want to have a rack and pinion put in while the engine is being done, it makes a massive difference.  My FB has rack and pinion to miss the turbo, its the best thing about the car.

As for which V8, go Yank, with 5.7 chevy, it will have about 100 more BHP than a stock range rover lump, but for cheapness the rover will do the job.  

Regards
Tony

Not all the 1st gens had bad steering,the Mk1 had excellent steerring.
Kind regards
Carl
Title: V8 Rx7?
Post by: Don Pamponi on October 23, 2004, 06:14:12 PM
Funny - Tim at RX Motors said my car had really good steering for a 1st gen (ie: most are much worse, what was I moaning about?).

I still think it\'s poo compared to every other car I\'ve driven, and most have not been powered.  Rack & pinion is a MUST for a sports car.  What the crap were Mazda thinking?!

Gen 1s need more torque & a rack.

Here\'s one for ya:

I just came accross an 115bhp HDI lump going cheap.  Now they\'re torquey ;)

Oh, a cast iron chevy lump would weigh more than 2 or 3 RX7s!

Yeah, I thought it weird (& very disapointing) that it went bang rather than slowly fading.  Not that its had a chance to, only having done 100 miles since the build.

Mind you, who\'s to say it ever got put new tips in?  Clive said he did but......still shoukdn\'t have gone bang at 60K either way.

Looked at it today: got all the sparks, got fuel, it starts & runs unevenly, will drive but has NO power, as if someone swapped the engine for a 1200 beetle lump.

That & the pinking followed by graunching noise says tips to me.
Title: V8 Rx7?
Post by: Carl on October 23, 2004, 07:10:50 PM
As a more direct comparison you really need to judge like for like...
What I mean by that is have you tried to buy a secondhand 12a just like a Rover V8?
You should be able to get one  for quite a small amount of money.
If you were to get a Rover V8 and reconditon it fully then the price would still be on a par with a rotary in a 1st gen.
Have you priced up a used engine?
Kind regards
Carl
Title: V8 Rx7?
Post by: Don Pamponi on October 23, 2004, 09:44:38 PM
Nope, but I think I might know where to find 1.  Any ideas?

I\'m considering getting the parts & doing it myself.  Don\'t want to risk another big bang tho.
Title: V8 Rx7?
Post by: Carl on October 23, 2004, 10:34:34 PM
QuoteOriginally posted by Don Pamponi
Nope, but I think I might know where to find 1.  Any ideas?

I\'m considering getting the parts & doing it myself.  Don\'t want to risk another big bang tho.

Are you up to taking the engine out and putting it back in?
That would save some money.
I may be able to help on the engine front.
PM me about it.
Kind regards
Carl
Title: V8 Rx7?
Post by: Don Pamponi on October 23, 2004, 10:55:45 PM
Oh yeah, no problem.  Big hammer, crowbar.  Should be fine.

I\'m sure I could take it apart & replace the tips, but I\'m no expert & wouldn\'t perhaps be able to tell what damage if any was done to bearings & such.

Mine I suspect blew up because of 3 factors:

1)No retard solenoids/vacume bleed valve

2)higher than recomended boost for a mile or 2

3) Amature engine build

I can remove the first 2 factors but not the third if I attempt a rebuild myself.

So, watcha got?
Title: V8 Rx7?
Post by: travellinbob on October 24, 2004, 03:44:26 PM
hey Don, and here i was thinking that it was just a nasty rumor going around that you were considering a v8 transplant.
 Dont give up the ghost just yet buddy. Listen to Carl. Why not go down the route of a decent second hand lump (12a) and give yourself some time to think it through.
 If you were dead set on a piston jobbie then how about a twin cam mx5 one? Their smallish, rev quite well and perform not too badly. But only if you must. I reckon that there must be some 12a\'s sitting around out there on peoples garge floors that may only be worth about £150-ish?
 cheer up, and remember that the world goes round and round, not up and down :D
Title: V8 Rx7?
Post by: MikeLMR on October 24, 2004, 08:23:40 PM
I have a spare 12a but I reckon its properly goosed :( Its going be stripped by me so I can have a play but I doubt it\'ll give up any usable housings.

a nice ally twin cam would go quite nicely in an rx ... the K series jobies are very nice and much better than the ford zetecs that people harp on about so much.  The new Duratecs are nice engines ... but then they would be as Mazda had a hand in designing them.
Title: V8 Rx7?
Post by: MikeLMR on October 25, 2004, 06:44:05 PM
having another V8 argument on a rally forum and found some good links to engine weights. appart from the small size the weight isn\'t that low for the rotary.

http://www.bacomatic.org/~dw/engfyi.htm
Title: V8 Rx7?
Post by: Carl on October 25, 2004, 06:52:35 PM
Weight is not everything though,where it is located is pretty important too.
Kind regards
Carl
Title: V8 Rx7?
Post by: MikeLMR on October 25, 2004, 07:04:28 PM
exactly ... thats why I said the size is important ;)
Title: V8 Rx7?
Post by: Don Pamponi on October 25, 2004, 11:22:44 PM
12A 260lbs  vs RV8 318lbs

Not much heavier considering the size & capacity (not to mention the potential for massive power if properly tuned)

I bet its lighter than a 3rd gen lump!  

Ho Ho - rotaryschmotary eh?!
Title: V8 Rx7?
Post by: Carl on October 26, 2004, 09:10:39 AM
QuoteOriginally posted by Don Pamponi
12A 260lbs  vs RV8 318lbs

Not much heavier considering the size & capacity (not to mention the potential for massive power if properly tuned)

I bet its lighter than a 3rd gen lump!  

Ho Ho - rotaryschmotary eh?!


RV8 would not have all of it\'s weight as far back as any two rotor engine and the 3rd gen lump would produce far more power too than the RV8.
The stock RX7 3rd gen can do over 160 mph and is pretty quick on the 0-60mph too. Much better than the stock RV8 MG.
maybe you should buy an MG RV8 car?LOL!
The "Massive power" of the RV8 would cost some serious dosh too.
You know you want a 12a turbo,or a 13b ported engine......
:D ;)

Kind regards
Carl
Title: V8 Rx7?
Post by: MikeLMR on October 26, 2004, 12:17:21 PM
Don, how much is loads of power ? full race 3.5 V8\'s rarely make much more power than a 12a is capable of.

QuoteHow you going to get 290 BHP out of a 3.5? they are an absolute pig on carbs when they run out of tune. I used to race a 4.6 Simmbughinni with 350BHP and that was on throttlebodies. I once had a really revvy 3.5 done by Reel Steel and that was around 220BHP and on the edge of reliability.

quoted from the other v8 discussion on the rally forum

A TVR sourced 5 litre v8 would make about 340bhp out the box ... but just price one up ! Mega bucks !